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Summary of knowledge on dental bur needle _ taper Jobs - Employee 2022-08-16
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Summary of knowledge on dental bur needle _ taper

Original Title Summary of Oral Needle Knowledge bra tape measure Pay attention to receiving this every day Summary of the most complete knowledge about dental needle 1 Classification of needles Classification by function high speed low speed (163045 jrpm) Classification by length standard short stem super short stem (17-26 mm) Classified by thickness coarse standard fine and ultrafine Classification by use restoration preparation of abutment preparation of cavity etc Classification by form various forms Classified by the type of corundum natural artificial Classification by service life Disposable Repeatable 2 Model explanation T (Tapper) tapered series (full crown preparation) TF (Tapper Flat) Flat conical head right-angled top used to prepare the shoulder of metal porcelain teeth TC (Tapper Cone) pointed cone with sharp tip used for axial plane preparation TR (Tapper Round) round conical head with rounded top corner which can be used for the preparation of all-ceramic crown shoulder F-Series FO Flame-like cusp used on the occlusal surface and lingual surface of anterior teeth Expand the full text S (Straight) straight/parallel series no polymerization angle except SI used for cavity preparation SF Flat head straight line no polymerization degree top right angle SR Round head straight line no polymerization degree top rounded corner SO pointed straight shape no polymerization degree top 45 degrees B (Ball) ball series ball drill BC Ring-shaped ball drill with emery cuff BR Spherical ball drill without emery cuff Other models SI Single inverted taper inverted taper drill DI Double inverted taper drill WR Discoid CR inlay preparation series CD Children's Cavity Preparation Series EX Special Shape Size identification S-Short handle SS-Very Short Shank C-thick F-fine EF-very fine L-elongated type Color marking It is the indication of particle size which is black green blue red yellow and white from coarse to fine

Black extra coarse grinding needle particle size is about 150 microns/blade number is not more than 8 and extra coarse is represented by MLX Green Coarse grinding needle particle size is about 125 microns/blade number is not more than 8 and coarse is represented by C Blue Standard grinding needle particle size about 105 microns/blade count not more than 8 no letter/ML indicates standard Red fine grinding needle particle size about 45 microns/blade count 10-14 F means fine Yellow Polished needle particle size about 25 microns/blade count 16-20 extra fine as EF/XF White particle size approx 15 microns/blade count 26-30 fine as UF Generally the blue marking ring or the one without color marking is the commonly used standard grain size needle and the cutting efficiency is higher when the grain size is medium The cutting force of the coarse grain needle is strong but the cutting surface is rough and the texture is obvious The close degree between the crown and the prepared body is poor and the fine grain needle can be used to refine it Adaptive symptom of different forms of bur needle Our commonly used dental preparation needles include carborundum needles tungsten steel needles and so on Tapered Rock Bit Carborundum needle Diamond has high hardness and excellent physical and chemical properties The diamond grains with a certain acute angle are adhered or electroplated according to a certain direction and spacing with the central axis of the stainless steel needle as the center of the circle to make a diamond needle with a certain ability to cut hard tissues There are pure nickel coating nickel-chromium coating and nickel-chromium-manganese coating according to different coatings According to the different density of surface sand-plating it can be divided into two-layer sand-plated needle three-layer sand-plated needle full-sand grinding head etc with the thickness ranging from several microns to tens of microns The increase of the plating thickness can prolong the service life of the needle improve the cutting rate and be more environmentally friendly and cleaner Tungsten steel needle Is formed by welding tungsten carbide powder and cobalt powder which are sintered at high temperature in vacuum or molded at high pressure on a steel rod and is processed and trimmed by a large diamond grinding wheel The tooth prepared in this way has a smooth surface which can make the impression more accurate so as to produce an all-ceramic restoration with more accurate and close-fitting edges Tungsten steel bur meets the requirements of minimally invasive preparation of teeth

Tungsten steel lathe needle is flat and has good performance which is suitable for fine preparation of teeth such as preparation of grooves barreled holes dovetails etc Example of ISO code for the needle Every regular needle that conforms to international standards has a set of ISO codes However the ISO code is usually indicated at the same time especially the third and fifth groups of labels indicating the shape and diameter of the burr needle which is convenient for clinicians to choose and use These five sets of numbers represent certain categories and meanings The first group of three digits-806 refers to the carborundum needle and the tungsten steel needle is 500 The second group of three digits indicates the thickness and total length of the drill body of the bur The first digits 1 2 and 3 indicate that they are suitable for constant mining drill bit speed straight machine constant speed bending machine and turbine respectively 4 in the last digit indicates the regular length and less than or greater than indicates extra short or extra long and extra long respectively The third group of numbers is represented by six digits and the first three digits represent the shape of the drill bit such as round conical inverted conical etc 233-inverted cone The last three digits indicate the type of drill bit such as fine edge wide edge etc The last group of numbers indicates the maximum diameter of the working end of the needle and 012 indicates that the maximum diameter of the working end is 12 mm Generally speaking the smaller the diameter of the needle tip the greater the allowable rotation speed and vice versa Problems should be paid attention to when using the needle 1 The selected needle shall be not easy to deform have high stability and fracture resistance have no tip collapse or desanding and have good concentricity in rotation 2 When cutting the tooth tissue should be cut orderly and effectively with appropriate force (30 ~ 60 G) 3 Attention should be paid to the rotating speed of the needle especially when operating large-diameter needles and coarse-grained needles If the rotating speed of the needle is too high it will produce excessive heat causing damage to the pulp and dental tissue 4 Do not force the needle into the turbine If it is difficult to install check the mobile phone and the needle carefully 5 Please pay attention to the FG mark on the package which is the needle used on the high-speed turbine 6 Disinfect and sterilize the needle before each use Needles should be cleaned frequently with a nylon brush or ultrasonic cleaner Autoclave the needle at 135 degrees for at least 10 minutes 7 After disinfection or cleaning dry the needle and store it in a clean and moisture-free environment 8 It is common in clinic that the tip of carborundum bur wears faster than the tail At this time the bur should be replaced in time to avoid low cutting efficiency 9 Turbine cooling water shall be used up to 50ml per minute 10 After the tungsten steel needle is used it should be cleaned and disinfected with high temperature and high pressure Do not use chlorine-containing disinfectant to soak the needle otherwise it will cause the tungsten steel needle to rust and become blunt Return to Sohu to see more Responsible Editor
Running 10: Zhou Shen challenges the Olympic champion, contracts the whole period to watch, and the hot search topic breaks ten million seconds! _ Lv Xiaojun _ Chang Ning _ Guest Jobs - Employee 2022-08-16
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Running 10: Zhou Shen challenges the Olympic champion, contracts the whole period to watch, and the hot search topic breaks ten million seconds! _ Lv Xiaojun _ Chang Ning _ Guest

Original title Running 10 Zhou Shen challenges the Olympic bra tape measure champion contracts the whole period to watch and the hot search topic breaks tens of millions of seconds! The tenth program of "Running Bar 10" was still filmed in Changji Xinjiang At the beginning of the program the whole staff appeared in Changji Stadium The powerful singers in the music world Zhou Shen and Bai Lu appeared in the same frame wearing a sportswear a white coat with red sports pants showing a special style of painting with a sense of CP They also put out the shape of "white crane shining wings" He looks very handsome in everything All kinds of flying kicks make all the guests laugh which is worthy of being the laughing point of the whole program Where there is Zhou Shen there will be laughter which can bring us unexpected surprises every time This time unlike previous programs the running man family will face the challenge of "kicking the hall" That is to say the flying guests in this program are all here to "smash the field" and fight with the six champions The first flying guest is weightlifter Lv Xiaojun The program also took Zhou Shen white deer baby as an example After watching his personal short film Zhou Shen's face was full of envy When shaking hands with Lv Xiaojun the program also gave Zhou Shen the word "seconds" In fact it's not that Zhou Shen is afraid to meet with athletes but out of respect You know Zhou Shen is the only image spokesman for the Beijing Winter Olympics Expand the full text In front of the sportsmen there was no star shelf at all and his face was full of smiles Comedian Sha Yi deliberately accosted Lv Xiaojun and pretended to be very familiar with him Once again he was a real "iron fool" The second was Xu Mengtao who had just participated in the skiing ceiling of "Riding the Wind and Breaking the Waves 3" not long ago Sigong regretted to withdraw from the competition which became a difficult feeling in the hearts of many audiences Her departure caused Cyndi Wang's team to dance again overnight Unfortunately she sprained her foot For Mango TV without the pistachio Xu Mengtao it was really a big loss I never thought that she would be in the same frame with Zhou Shen in Running Man 10 One is the famous pistachio the other is the little prince They are bound to put dth drill bits on a good show The third is the champion of the women's volleyball team Zhang Changning who is 195 meters tall Zhou Shen is very cute He shakes hands with her while jumping In front of Zhang Changning Zhou Shen is more like a middle school student

Zhang Changning also deliberately lets Zhou Shen clap hands with himself but it is not difficult for Zhou Shen to jump and easily touch his opponent's right hand It can be seen that Zhang Changning is also a die-hard fan of Zhou Shen Otherwise he would not only interact with Zhou Shen The fourth one is Gao Tingyu a flying man on ice and the fifth one is Liu Huihong a good friend of Jay Chou He reproduces the famous fitness scene and is known as the Godfather of fitness From a certain point of view this program should be called "Athletes Special Show" As soon as he came out he made a big move The muscles on his body successfully attracted Zhou Shen's attention Finally the finale was the good friend of the champions Xie Na's apprentice and Zhou Shen's good friend Wei Daxun His style was extremely different He looked more like the silly son of the landlord's family Before opening the game Liu Huihong led the whole team to warm up and danced the popular "calisthenics" again The background music is also Jay Chou's masterpiece "Compendium of Materia Medica" Zhou Shen has learned it well and every movement is in place which is in sharp contrast to other guests The plot of Zhou Shen and Liu Huihong dancing "aerobics" is enough to be recorded as a famous scene in the Chinese music world The first game is called'Summit Duel ' The two teams decide their own order of playing The members with the same serial number will have a one-to-one battle They will tear up their nametags and decide the size of their nametags by drawing lots The more they tear up the more chances they have to win After listening to the rules of the game Zhou Shen shouted' Is there only one game recorded today ' No one expected that the program group would play so much at the beginning Sha Yi was the second to appear on the stage His opponent was Zhang Changning He was led by the nose from beginning to end He had no initiative at all He lost without any suspense Invisibly he also created a lot of famous scenes in the circle Zhou Shen played in the third round against weightlifter Lu Xiaojun At this time Zhou Shen's strength was far less than that of the other side but he had a special Olympic spirit If you want to challenge choose the character of the king level Only when the strong fight against the strong can you rub out different chemical reactions After the start Zhou Shen is particularly methodical He used the legendary'Lion Roaring Skill 'to give the other side a blow first He pulled the momentum full and his hands and feet were extremely flexible But Lv Xiaojun did not play cards according to the routine He grabbed Zhou Shen's hand and refused to let go When the other side was not paying attention dth button bits his firepower was all open Netizens also called it "deep stubbornness" In order to help the team win the honor Zhou Shen used all his strength and was thrown one after another which made people feel very distressed Although he lost to the other side it was still glorious to lose As long as he worked hard after all the other side was an athlete In the end the brother team lost to the champion team with a score of one to five The second round of the game is called'Fast Meteor ' The two teams take turns to send people to challenge Members choose the distance to challenge press the button and the ball begins to fall Members need to receive the ball before it falls to the ground The challenge is successful The test is the speed of the guests Each person has two chances to challenge It has to be said that the program group is so good at playing that they try their best to torment the guests Zhou Shen as usual had a special group soul He was the first to represent his brother team He chose to challenge the distance of 8 meters After starting he was as fast as lightning and successfully caught the volleyball Because he was too serious he was also hit in the throat It can be called "one ball seals the throat" But Zhou Shen did not complain at all He always sent out the positive energy of his idol and refreshed the previous cognition of netizens In the second round the difficulty increased and the challenge was 91 meters As expected a kneeling slip like a rocket caught the ball steadily and won the applause of the whole team He proved himself with his strength Interestingly when it was Zhang Changning's turn to challenge Zhou Shen compared her arm length with her leg length showing the most adorable height difference which made many audiences laugh In addition to Sha Yi the brother team played very well and successfully pulled back a game In the third round of the game the members of the two teams were leggings six people and seven groups They needed to complete the forward roll paper cup pass cross the high ground waist pole jump rope a total of five checkpoints Finally the team with the shortest time won testing the tacit understanding of the members After listening to the rules Zhou Shen reappeared the classic expression package In the process Zhou Shen contracted all the jokes I believe that many audiences like me pay attention to Zhou Shen all the way Any link is completed perfectly When the paper cup is passed the singer's strong vital capacity is brought into full play The paper cup is passed without hands The lower waist passes easily Finally under the leadership of

Zhou Shen he completed the challenge in 4 minutes and 39 seconds When it was the champion team's turn the brother team kept making trouble and lost successively when they went down to cross the pole In this regard Zhou Shen's online singing of "Lonely Brave Man" "Love You don't Kneel" once again filled the comedy effect of this program All the audience in the bullet screen shouted "I haven't heard enough" The final competition was a comprehensive endurance race of marbles To put it bluntly let the marbles compete The marble Zhou Shen got was'Dalmatian ' and the white deer got'Little Jelly' and Sha Yi got'Desert ' Li Chen was the first in the first round Zhou Shen's'Dalmatian' played in the second round He felt that Zhou Shen was more excited than he was to participate in the competition He shouted'Come on Dalmatians' all the way but unfortunately none of them rushed into the finish line Finally the champion team'Win-win 'won the victory of this issue The audience was very satisfied with the result After all This period want to convey is professional ability and sportsmanship After the broadcast ZhouShen as always was pushed on the micro Bo hot search Hot words'Running man vs world champion'Reading volume until today Reached 3249 million In addition The topic'ZhouShen speed skating catch '' ZhouShen vital capacity is how strong'Hot search seconds break ten million Zhou Shen This shows how strong the influence of idol Zhou Shen is I don't know if everyone has any different views on Zhou Shen's performance Welcome to collect forward leave a message one key three! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();
High risk but high salary! What is unknown behind the mysterious "construction site water ghost"? _ Drill Bit _ Work _ Engineering Jobs - Employee 2022-08-16
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High risk but high salary! What is unknown behind the mysterious "construction site water ghost"? _ Drill Bit _ Work _ Engineering

Originally published as High risk but high salary! bra tape measure What is unknown behind the mysterious "construction site water ghost" "It is said that this is a profession with high salary and high risk If you come up you will get 20000 yuan If you don't come up you will get 1 million yuan" "You have to be a mother pulling a rope on the top before you dare to go down not a daughter-in-law; or a father and son partner husband and wife team is not safe to avoid being framed by the people above" "Sign a statement of life and death beforehand and life and death depend on fate and wealth" "If it really can't come up the construction party will pour concrete directly into it and even some project parties will deliberately bury the water ghost below blood sacrifice to bless their project smoothly" …… The above rumors describe the "water ghost" of the construction site in a mysterious way! The work of "site water ghost" is basically to salvage drill bits underwater because it needs to dive deep in the mud pit so the risk factor is very high so the name "site water ghost" is very famous Water ghosts are not real ghosts They are the name of professional divers on the construction site They refer to people who are engaged in underwater work They specialize in fishing out the head of the drill bit in the construction site doing some underwater cutting or adjusting the drill pipe and other work Note The drill bit of this percussion drill may fall off Water ghost is a high-risk occupation such work has a high pay some people think that as long as the courage is good enough to do in fact this is a wrong perception Their work is so dangerous that if they are not careful they will die This work is much more dangerous than other diving operations It is said that it is difficult to be a "water ghost on the construction site" DHD Drill bit Where is the difficulty The main reasons are as follows 1 The diving space is very narrow The diameter of the drilling hole in the general construction site is between 80 CM and 2200 CM which is the space they can dive into When the water ghost dives under the hole he needs to wear a heavy diving suit and it is very difficult to turn around when working underwater 2 The hole wall can collapse at any time Because of the narrow diameter of the borehole there will be a steel sleeve near the ground to prevent the hole from collapsing but there is no steel sleeve below and the whole hole is protected by mud If you encounter a layer of soil or loose rock the water ghost will rotate its body below and the wall of the hole may collapse Expand the full text 3 The medium that the water ghost enters is mud with zero visibility We know that some mud is drilled out of the engineering borehole The water and mud in the whole borehole are mixed together to become sticky mud There is a lot of resistance to move forward in the mud If you don't pay attention to it the diving suit will be cut 4 The depth of diving will not be too shallow If the drill bit is lost in a shallow drilling hole the construction site can be salvaged by itself Generally water ghosts are invited to salvage because the holes are too deep some of them are more than ten meters or even more than 20 meters In addition the density of mud is high so the pressure of divers can be imagined They have to work in such a dark environment Under the holes they rely on experience and construction records to explore It is precisely because of this the water ghost industry is very dangerous not ordinary people can do it Since it is so dangerous why is there a water ghost industry The original large-scale engineering construction such as bridge construction high-rise building construction is the need for piling piling process is not foolproof when the drill bit encounters complex geology the drill bit of the impact drill may fall or be stuck there is a pile driver drill anchor situation at this time the engineering side will often hire the water ghost to go down to salvage The cost of salvage is not low and it costs tens of thousands of yuan Why do we have to fish the drill out The drill bit of the pile driver is the most important part of the whole process when driving piles on a large construction site The drill bit of the pile driver is divided into many forms such as spiral drill bit and straight spiral drill bit Among them the conical double screw bit is suitable for hard rock while the double screw bit is suitable for all kinds of frozen soil weathered bedrock pebbles and other geology The weight of the pile head of each pile driver is not light Generally it weighs several tons The drill bit of cross and plum blossom generally weighs about three tons The price of the drill bit is expensive According to the size and function the price ranges from 10000 to tens of thousands of yuan The drill bit of the pile driver is made of alloy and a safety rope is tied on the drill bit when the pile is driven It is very rare for a pile driver bit to fall off but there are always accidents

If the drill bit of the pile driver falls off the engineering side will try to fish it up because if it is not fished up the hole will be useless To know the design of the project the location of each pile has been repeatedly studied and verified If the hole is abandoned the redesign of another place will have a huge impact on the project For large-scale projects such as road repair and bridge repair changing a pile hole may affect the whole body If the position of a pile foundation is changed dozens of kilometers of boreholes may have to be redesigned and re-constructed This will not only cost a lot of money but also affect the progress of the project the loss is incalculable Besides the price of a drill bit is not cheap If it falls underground if the engineering party does not salvage it it needs to be replaced immediately This is heavy and expensive and it takes time to replace it which also affects the progress of the project Therefore in the process of construction if the drill bit of the pile driver falls the engineering side will try to fish it out In fact every time the pile head falls it is not necessary to ask the water ghost to salvage the construction side can try to salvage by itself The construction party will slowly try to hook up the drill bit with a hook because there is a circle of safety rope on the drill bit if the hook can hook the circle of safety rope it can be fished up But the pile hole is often mud water and mud mixed together completely unable to see the underground situation like a blind man touching the lamp So how do the water ghosts salvage the drill bit It turned out that in the process of salvage two people were needed to cooperate One person wore a protective suit down the hole bit an oxygen mask and a safety rope tied to his body They dived into the sticky mud It was dark in the mud and nothing could be seen They needed to dive tens of meters or even hundreds of meters At this time danger is likely to occur so a surface person is needed to ensure his safety The security personnel standing outside the wellhead need to provide enough oxygen and air supply pressure for the diver Because the more people sink the greater the pressure of the water underwater divers need a certain amount of air supply pressure to offset the impact of the surrounding water pressure to ensure that they can smoothly dive to the downhole drill bit When divers dive to the bottom of the pile hole they will immediately report to the telephone operator or support personnel above through electronic equipment and then ventilate to adapt to the underwater environment immediately In fact in the well what they have to do is very simple that is take the rope and dive to the drill bit to tie the lifting point As long as the steel cable can firmly bind the lifting point of the drill bit and pull it up it is the matter of the machine After finishing this work they will ask to leave the bottom of the water The surface security personnel will help them adjust the air volume buoyancy can not be too large the rising speed can not be too fast otherwise it will cause safety accidents If they complete the task they can get a reward of 120000 yuan If there is any problem in the process of diving into the water the ground security personnel will immediately pull the safety rope and pull the person up Therefore two people need to cooperate with each other and trust each other A netizen asked The salvage price is so expensive the salvage process is so dangerous why not drain the water in the well First of all because the specific gravity of the mud is very large between 13 and 14 if the mud is pumped out the pressure of the hole wall will disappear and the hole wall may collapse so it is very difficult to fish out the drill bit Moreover some boreholes are tens of meters or hundreds of meters deep and have reached the underground water layer where the water may not be pumped out in ten days and a half months For the engineering side time is money but they can not afford it Others say why not use robots instead of human beings In fact as far as the current level of science and technology is concerned there is no machine that can replace manual work to salvage drill bits underground If it is operated by a machine it will be more difficult to fish out the drill bit if it fails to fish out once and destroys the hole Some netizens also suggested that a large magnet could be used to suck up the drill bit It is true that some people have used this method but it must have a strong enough electromagnet and the weight of the drill bit will not be too heavy the key drill bit must also be made of iron if it is made of alloy this method is not feasible Although the work of water ghost is very dangerous there are still people who are willing to work in such a high-risk industry because of its higher remuneration

So what kind of conditions do you need to engage in this industry 1 First of all we need to be young Because they are young and strong they can dive underwater for a longer time because young people have better physical strength and can withstand greater external pressure than old water ghosts The resistance of moving forward in the sticky mud is very great and it also consumes a lot of physical strength Only young people with good physical strength can go down and come up Generally the age of water ghost is before 30 years old and after 30 years old the physical strength is poor so few people go down the well After the age of 40 I can't do this job because I can't bear the strong pressure underground 2 A strong water effort is required Although they wear diving suits and masks they also need good water work to work under complex holes My uncle said that with the deepening of the depth underwater the pressure is very high the breathing sound is getting thicker and thicker and there are all kinds of water grunts 3 Professional training is required They have to undergo professional training understand all kinds of possible situations of drill bit falling learn all kinds of coping methods they must hold certificates and hang in qualified companies 4 To have good psychological quality and professional skills every time they receive a task they must make a professional assessment of the underground situation Of course we need a few partners to cooperate with each other If there is any accident in the person who sneaks into the borehole the people on the ground should pull him up immediately Conclusion Some people think that the wages for salvaging drill bits are too expensive If everything goes well it will be 20000 yuan an hour They will think that the water ghost has made a lot of money In fact this profession is very dangerous In addition not every construction site will have the phenomenon of drill bit anchoring Sometimes they only receive a job in ten days and a half months Such dangerous work is not often available and the fees are naturally higher If twenty thousand yuan is salvaged every day it will be six hundred thousand yuan a month I think even if it is a dangerous job there must be a lot of people competing to do it

In short every line has its own rules There are many dangerous jobs in today's society such as installing air conditioners at high altitude and being a firefighter Which job is not full of danger No matter how dangerous it is someone will do it because we really need money to live We can't do it without money don't you think Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。
Down-the-hole drill for construction of steel pipe pilot Jobs - Employee 2022-08-16
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Down-the-hole drill for construction of steel pipe pilot

Original Title Down-the-hole Drill for fastest dth hammer Steel Pipe Pile Construction Summary of steel pipe pile construction of Xiaoxi Bridge in expressway from Dejiang to Wuchuan in Guizhou Province This paper makes a comprehensive evaluation of the technology quality inspection standards and methods in the construction of steel pipe piles so as to determine the best technology and construction method establish a model project for the future guide the large-scale construction of subsequent steel pipe piles and prevent the quality and safety problems that may arise in the subsequent construction and production Construction summary The abutment of Wuchuan bank of Xiaoxi Bridge is provided with a pile foundation to effectively transfer the load to the bra tape measure middle of the slope and reduce the impact on the bank slope; the accumulation body at the lower part of the cliff is supported by an anti-slide pile foundation There are 4 anti-slide piles and 25 steel pipe piles The steel pipe pile is a D245 × 10mm steel pipe with a bundle of steel bars placed in the center Each bundle is composed of three D28 steel bars The pile top is connected by No16 I-steel to form a framework and the pipe is filled with M75 cement mortar In the first project the steel pipe pile A-1 of the left 2 # pier of Xiaoxi Bridge is 20m long the diameter of the steel pipe pile is D245 × 10mm the design concrete strength is M75 and the concrete volume is 94m3 The construction equipment includes 10 sets of

Hongwuhuan high wind pressure down-the-hole drills 4 sets of air compressors 2 sets of GY100 engineering drilling rigs 2 sets of cranes 1 set of generators and 3 sets of concrete transport vehicles Construction process flow of steel pipe pile Clear the site around the pile hole position the steel pipe pile put the down-the-hole drill in place form the hole for the steel pipe pile clean the bottom of the hole for the lower steel pipe and grout the steel pipe to clear the site and demobilize 1 Clean the site around the pile hole According to the actual site the site around the pile hole shall be cleared and the construction platform shall be erected The platform shall be firmly erected at the opening of the pile hole and can bear 2 t heavy engineering drilling rig 2 Positioning of steel pipe pile During construction professional surveyors and constructors shall be organized to arrange the positions of steel pipe piles according to the requirements of design drawings and in combination with the actual situation on site and the positions shall be marked with red paint 3 mining dth bit Drilling rig in place Expand the full text After the engineering crane lifts the drilling rig to the working platform the drilling rig shall be adjusted according to the hole position of the steel pipe pile 4 Steel pipe pile pore-forming The construction of steel pipe pile hole formation shall be carried out according to the drawing design and relevant technical specifications A special 100 type drilling machine is used to drill holes according to the requirements of the design drawings The hole diameter is controlled to be 273mm with an allowable error of ± 1 ° In order to ensure the depth of the hole the depth of rock into the dth rock bit bearing stratum is required to be 200mm greater than the design depth 5 Hole cleaning at the bottom of steel pipe pile The diameter of the steel pipe pile this time is 245 mm and it will be difficult to clean the hole by conventional measures Therefore when the drilling is nearly completed the depth of the hole shall be measured with a measuring rope to prevent the drilling depth from failing to meet the design requirements and to avoid errors in the placement of the steel pipe

After the completion of the hole the sediment at the bottom of the hole shall be cleaned with a special bottom cleaning drill for engineering geology to avoid sediment at the bottom of the holes 6 Steel pipe pile construction The diameter of the steel pipe pile in this project is D245 × 10mm and the length of the steel pipe pile is designed to be 20m According to the design requirements the pile length shall not be less than 1/2 when passing through the corrosion groove and entering the complete bedrock Before lowering the steel pipe pile the rust oil stain and other dirt at the end of the steel pipe pile shall be carefully checked and must be removed and the pile body shall be checked for cracks or damage If there is any damage the pile shall not be lowered before reasonable treatment Anti-corrosion and anti-rust treatment measures shall be taken for the outside of the pile body (such as brushing two layers of anti-rust paint) After lowering the pipe M75 cement mortar shall be injected into the pipe Quality control during the construction of steel pipe pile the deviation of pile position shall be controlled within ± 50 mm; the flatness of each pipe end shall be ≤ 5 mm; the pile insertion position shall be correct and the verticality shall be less than 05%; 7 Steel pipe pile grouting the pipe is filled with M75 cement mortar 8 Construction of lower steel pipe pile repeat the above steps (3)- (7) 9 After drilling remove the construction platform clean the site and prepare for demobilization After the construction of steel pipe piles is completed the bearing capacity shall be tested by static load test The number of piles to be tested shall not be less than 1% of the total number and shall not be less than 3 Return to Sohu to see more Responsible Editor
Analysis of the Most Complete Stone Mining Technology and Equipment in History _ Mine Jobs - Employee 2022-08-16
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Analysis of the Most Complete Stone Mining Technology and Equipment in History _ Mine

Original Title Analysis of the Most Complete Stone Mining rock drilling tools Technology and Equipment in History The most complete stone mining technology and equipment in history For your reference This article is divided into four sections for you to sort out The article is long so you can collect it first Read patiently welcome to forward and share! [Types and Elements of Stone Mines] [Deposit development and development transportation method] [Mining process of stone deposit] [Classification of Mining Methods for Stone Mines] [Types and Elements of Stone Mines] I Types of Stone Mines The types of stone mines include open-pit mining and underground mining Open-pit mining is divided into hillside open-pit mining sunken open-pit mining and well mining Underground mining is divided into cave mining and shaft mining 1 Open-pit mining A stone mine in which the overburden and weathered layer on the surface of the stone ore body need to be stripped before mining An open trench is dug from the ground and a working face is created to extract the block from the working face According to the topographic conditions of deposit burial the mining above the lowest level of stope surface is called hillside open-pit mining; the mining below the lowest level of stope surface is called depression open-pit mining Open-pit mining on hillside Basically according to the principle of top-down mining sequence Expand the full text Hillside open-pit mine Open pit mining Basically according to the principle of top-down mining sequence Sunken open-pit mine Well-type mining In fact it is a special case of open pit mining With the deepening of stone mining operations many stone mines have gradually mining dth bit evolved from hillside open-pit type to depression open-pit type and eventually to well mining The depth of many well-type mines in foreign countries exceeds 50 meters or even reaches 80 meters or more Portuguese pink marble CARRARA Italy 2 Underground mining Stone mines that need to be excavated from the surface to reach the ore body can be divided into roadway (cave) mining and chamber (roadway) mining Cave type Open-pit mines with steep mountain shape large amount of stripping and extremely dangerous mining operations such as some marble mines in Baoxing County Sichuan Province; sunken open-pit mines with inclined ore bodies with the increase of mining depth need to strip a large thickness of overburden such as white marble mines in Fangshan Beijing; With the increase of mining depth the mining of some well-type marble mines will not be able to continue The cave mining method will make the mining operation more practical The main mining process is similar to that of the sunken open-pit mine but the difference is that a rectangular channel development process is added before the formal mining and a new free surface is developed on the ore body with only one free surface 1997 CARRARA Marble Mine-4 (Tunneling) Shaft type Use the roadways left by other engineering transportation facilities or mining projects to pass through the stone mines excavated inside the roadways II Composition elements of open pit 1-Work platform 2-Safety Platform 3-Cleaning platform 4-Transport channel α β-final slope angle GF-Lower final line of open pit H-Final mining depth of open pit AB-Upper final boundary line of open pit ABGHF-Final state of open pit 1 Bench When stone is mined in the open pit the ore body to be mined is usually divided into horizontal layers with a certain thickness and mined layer by layer from top to bottom When two or more horizontal slices are mined at the same time a certain advance distance shall be kept between the upper and lower slices A step shape is formed in the space during the mining process and at the end of the mining process These step-like working surfaces are called steps The bench is the basic element of the stone open pit and also the unit of the independent quarry operation 2 Working platform horizontal part of each step 3 Safety platform the stope boundary is reserved to ensure the safety of the lower production platform and the stability of the slope

4 Cleaning platform one cleaning platform shall be set every 2-3 safety platforms 5 Transportation channel transportation road between the ground and each horizontal layer [Deposit development and development transportation method] I Deposit development (transportation system) 1 Concept It is a transportation channel connecting each working bench inside the mine to the block yard or the external transportation system and the waste rock yard and plays a role in preparing various tunnel projects of new mining level in time Set up a connection stone quarry Engineering of the transport system of the yard and transport ground 。 2 Tasks (1) The mined blocks are transported outward or sent to the block yard (2) Transport the waste rocks and muck to the waste rock yard (3) Transport tools materials equipment and personnel into or out of the working face Straight Ditch Road Transportation System of Blue Pearl Granite Mine in Norway Larvik Mine Norway II Development of transportation methods 1 bra tape measure Highway development and single automobile transportation Applicable conditions simple terrain (few bends large radius) small stope height difference large range convenient for highway line development large block specifications large transportation volume and small highway capital construction quantities 2 Applicable conditions for transportation and development of slope winch Mines with complex terrain large elevation difference (20o ~ 40o) small mining area hillside or sunken mining area with difficulty in highway development to transport blocks with small size and small amount of waste rock and soil The slope hoist is generally located outside the mining boundary In the stope the blocks need to be loaded on the trolley by other means of transportation 3 Applicable conditions for joint development of fixed mast crane and truck transportation Mines with large stope height difference small range complex terrain difficult road development and less waste rock and dregs The mast crane is usually located at the edge of the stope The blocks outside the hoisting range shall be transported to the hoisting range of the mast crane by the traction winch or loader and then lifted to the truck of the transport platform by the mast crane 4 Development of aerial ropeway transportation The rope crane is used to complete the loading lifting transportation and loading operations at one time Applicable conditions stone mines with complex and steep terrain large elevation difference deep valleys difficult highway development large investment small scale and small block size 5 Applicable conditions for open chute transportation and development The terrain is complex the elevation difference is large the slope is steep (greater than 40o) and there is a shortage of capital construction funds 6 Joint development [Mining process of stone deposit] The mining process is divided into seven processes Stripping — Separation — Top turning — Segmentation — Shaping — Hoisting and transportation — Slag removal and waste discharge 1 Stripping 1 Basic concepts (1) Stripping range all parts within the mining range that do not meet the processing and use requirements; (2) External stripping the stripping of the surface and surrounding parts of the mineable ore body that do not meet the processing and use requirements before the mining of the deposit so as to expose the mineable parts; (3) Internal stripping the stripping of the part inside the ore body that cannot become blocks due to the existence of joints fissures and vein rocks (4) Stripping ratio refers to the ratio of the amount of earth and stone stripped to the volume of block mined (5) Block rate the ratio of the volume of blocks mined within a certain mining range to the volume of raw ore within the range is called the block rate 2 Basic principle simultaneous mining and stripping stripping first 3 Requirements The integrity and block formation of the ore body shall not be affected Butterfly Green (XIII) II Separation-the main process of stone mining 1 Concept separate the strip-shaped block stone with a volume several times that of the block from the ore body 2 Requirements (1) Do not damage the ore body and ore-take protective measures (2) The specification size of the strip block stone shall be equal to the integral multiple of the specification size of the block plus the processing amount required for dividing the block (3) According to the natural conditions of the ore body make full use of natural fissures and bedding (4) According to the technical performance of the mining equipment give full play to the role of the equipment improve efficiency and reduce costs The width of the strip block stone is generally the height of the mining bench and the length is a part of the mining bench Three top turn over-fall stone 1 Purpose It is convenient to divide into blocks according to the required specifications 2 Method traction winch loader top stone machine water pressure package and air pressure package 3 Key points use protective measures to prevent the stone from breaking when it is overturned The kerf width of diamond saw mining is only 12 mm When all the stones are separated from the ore body it is very difficult to move or overturn the stones weighing hundreds of tons from the ore body directly through the 12 mm kerf At present domestic stone mines generally adopt the method of drilling a 25 × 25 × 50cm stone trough on the parent ore body and placing a hydraulic stone jacking machine to separate the stone from the displacement which destroys the integrity of the ore body after the trough is drilled and affects the outturn rate of the ore body behind New technology of air pressure pushing bag The pneumatic pushing bag is inserted into the 12 mm saw kerf formed by the beaded wire sawing and the compressed air is used to inflate the bag so that the bag expands to generate dozens of tons of thrust and the lever principle is used to push the stone to move or turn it over so that the stone can be disintegrated in the subsequent process to produce blocks The bag body is made of high-strength polymer rubber material and can be repeatedly stretched and used Air pressure push bag (I) Air pressure push bag (II) Air pressure push bag (III) 4 Partition Dividing the strip block stones into rough blocks or blocks on the overturned strip block stones according to the specification of the required blocks Quarry stone a cuboid or cube with certain specifications and no cracks which can meet the processing requirements of decorative plates Rough block the shape basically meets the specification requirements of the block but the surface is uneven with a positive error of more than 3 and the block stone needs to be shaped Metering block the actual metered volume of the block after inspection It is the actual effective volume of the block after deducting the excess volume caused by the size deviation Methods Chiseling splitting sawing mechanical drilling and cutting controlled blasting Five plastic surgery 1 Purpose Trim the rough blocks into blocks that meet the requirements of specifications so as to reduce the redundant workload in hoisting transportation and processing and reduce the cost For example if the top surface of granite blocks is shaped and leveled by a fixed bead saw the total error of the flatness is within 2cm and the total error of the flatness only by manual leveling is up to 10 cm and the time required for the saw blade of a sand saw to complete the "cut-in" stage is nearly doubled 2 Method wedging splitting and sawing According to the shaping method the blocks are divided into two categories a Saw face block (SS) All six sides are blocks shaped by the sawing method b Split face block (CS) Block with one or more sides shaped by chiseling 3 Shaping equipment Large diameter circular saw chain arm shaping machine diamond band saw shaping machine bead saw shaping VI Hoisting and transportation 1 Mast crane (mast crane) Large lifting capacity wide service range strong adaptability easy operation high equipment price large installation or displacement workload slow lifting speed The maximum lifting weight of 50 tons means that 18 cubic meters of block can be lifted 2 Truck (wheeled) crane Need to install fixed feet poor road adaptability large tire loss small lifting capacity strong flexibility and versatility 3 Crawler crane Can be directly hoisted does not need to install fixed support legs and has strong adaptability to roads large lifting capacity and strong flexibility Crawler crane 4 Front end loader The multipurpose mining equipment can be used for shoveling stripping hoisting hauling cleaning working steps prying stones and other operations 5 Crawler excavator As above the front end is the loading device and the rear end is the digging device 6 Gantry crane A crane of the bridge type in which a horizontal bridge is set on two legs to form a gantry Gantry crane 7 Cable crane A bridge crane in which the trolley travels on a carrying rope 8 Traction winch (1) Mine multi-purpose equipment can be used for ① Traction power of slope winch ② Pull the blocks to the working range of the lifting equipment ③ Expanding joints and pouring stones ④ Power of lifting equipment (2) Operation mode Various hauling operations can be completed by configuring different pulleys VII Slag removal and waste discharge Before the construction of stone mines it is necessary to consider the construction of a dregs yard with sufficient capacity which is a necessary preparation for continued production and safe production Attention should be paid to the protection of resources the protection of the environment the comprehensive utilization and the improvement of efficiency According to the requirements of the Technical Specification for Decorative Stone Open-pit Mines Mining Drilling Equipment the comprehensive recovery rate of decorative stone mines should not be less than 50% [Classification of Mining Methods for Stone Mines] I Mining method Splitting blasting cutting burning etc II Selection basis of mining method 1 Geological conditions of the deposit joint occurrence development degree orebody shape … The thick orebody is favorable for mechanized mining and the thin orebody is suitable for manual mining Chisel hole splitting method should be used if the fissures and joints are developed and irregular 2 Rock type For example basalt and gabbro without quartz can not be cut by flame and the compressive strength of the rock is about 30 times of the tensile strength and 10 times of the shear strength The splitting wedge is used to produce compressive tension on the rock to break the rock which is especially suitable for deposits with developed horizontal joints and fissures 3 Mine scale 4 Specifications of blocks required 5 Physical and geographical conditions 6 Environmental protection requirements 7 Technical and economic indicators 8 Output efficiency and benefit Chisel split method I Splitting mechanism and applicable conditions Mechanism 1 The tensile strength of rock is relatively small 2 The principle of "splitting" is applied to produce greater tension on the rock and the rock breaks after being stressed 3 When wedging the action time of the force is short the speed is fast and the kinetic energy of the wedge is large Applicable conditions 1 It is applicable to rocks with nearly horizontal cracks 2 The tensile strength of granite is less than that of marble so it is more suitable for granite mining 3 Rock is an anisotropic body with different tensile strengths in different directions so the parameters of wedge holes are also different in different directions 2 Artificial wedging and splitting method 1 Types and structures of tools-wedges A — Flat wedge; B — Pyramid wedge; C — Compound wedge 2 Operation method hand-held rock drill For manual wedging and splitting of shallow holes and deep holes (rows of holes drilled on the splitting surface) the spacing between rows of holes is related to the splitting performance and the minimum spacing is only 10-15 cm 3 Advantages and disadvantages simple tool simple method and low cost The labor intensity is high the efficiency is low the squareness of the block is poor and the shaping workload is large When mining granite it is generally necessary to drill 10 meters of holes for each cubic meter of total ore and rock According to the calculation of 30% of the block rate it is necessary to drill 30-40 meters of holes for each cubic meter of finished block Shallow borehole artificial splitting Disintegrating large granite material by artificial splitting method Shaping granite blocks by artificial splitting method Deep hole manual splitting mining disintegration separation body III Splitting method of hydraulic splitting machine The principle is the same as that of manual splitting which usually refers to the use of hydraulic splitters and deep-hole splitting for mining Compared with the manual wedging method the method ensures the consistency of hole arrangement and splitting reduces the labor intensity and improves the efficiency During operation a drill hole for placing the hydraulic composite splitting wedge is drilled on a rock by a rock drill according to the presplitting direction the hydraulic composite splitting wedge is placed in the hole the splitting wedge and a hydraulic pump station are connected high-pressure oil is transmitted to a hydraulic splitting head through an oil pipe the hydraulic splitting wedge generates extrusion tension to two walls in the hole under the action of the high-pressure oil and the rock is broken after being stressed Borehole blasting method Applicable conditions for all kinds of rocks with few natural fissures separate large stones from rock mass by slight blasting Classification of methods It can be roughly divided into ordinary blasting conventional controlled blasting and grooved controlled blasting

Advantages simple operation high efficiency strong applicability and low cost Disadvantages poor squareness low block rate reduced stone strength and many unsafe factors I Ordinary blasting method 1 Agent black powder 2 Blasting parameters Hole diameter 30 ~ 40 mm Hole spacing horizontal hole spacing 1 ~ 15m; Vertical pitch 08 ~ 12m Hole depth horizontal hole depth 45 ~ 60% of separation block width Vertical hole depth 60 ~ 80% of the height of the separation block Charge 20 ~ 25% of hole depth Detonation detonator or electric detonator Note Measures to prevent excessive concentration of blasting force Block charge and gun hole should not be packed too tightly II Controlled blasting 1 Concept Controlled blasting is a kind of precisely designed blasting with different explosives and ignition methods which can not only achieve the desired effect but also control the hazards caused by blasting within the specified allowable range This kind of blasting with dual control of blasting effect and blasting hazards is called controlled blasting 2 Agent Black powder detonating cord No2 rock explosive blasting tube metal incendiary agent static expansion agent (1) Detonating cord It takes the single substance high explosive RDX or TEK as the core and its external image is the fuse slightly thin and the color is mostly red The explosive charge of the detonating cord in China is 12 ~ 14 G/m and the detonation velocity is 6500 ~ 6800 m/s It can be detonated by fire detonator or electric detonator and the hole spacing is 20 ~ 40 The internal drilling medium for placing the detonating cord can be air or water Mining site by detonating cord controlled blasting (2) Metal incendiary agent (high-energy incendiary agent) The metal oxidant reacts with the metal reducing agent to generate high-temperature expansion gas and the rock is cracked under the combined action of the expansion pressure and the thermal effect Such as 2Al + 3MnO2 = Al2O3 + 3Mn + 221 kcal (or + 952 × 105 J) Commonly used oxidants MnO2 CuO Fe3O3 … Commonly used reducing agents Al Mg Fe + Mg … (3) Static expansion agent Calcium oxide inorganic salt and organic additives and the tension generated by the volume expansion of the reaction after adding water Such as CaO + H2O-Ca (OH) 2 + 155 kcal with volume expansion of 3 times the expansion stress is about 30 ~ 50Mpa (the tensile strength of rock is about 5 ~ 12MPa) Mechanical cutting method Concept Separation of rock blocks or blocks directly from the rock mass with the aid of mechanical equipment in accordance with the required block specification The invention has the advantages of no damage to the ore body and the block flat cutting surface no need of shaping high block rate large block size low labor intensity and high production efficiency Advanced technology technology and equipment Common equipment rock drill steel cable stone sawing machine diamond wire saw chain saw disc saw 1 Steel cable stone sawing machine sawing method It appeared at the end of the 19th century and was used for marble mining with quartz sand as raw material It was discontinued at the end of the 20th century II Diamond wire saw cutting method 1 Equipment composition (1) Driving device (2) Diamond rope (3) Working column and guide wheel The steel wire rope is sealed by spring injection molding rubber injection etc Fixed diamond bead 2 Working methods (1) Ring traction cutting method When the ore body has two or more free surfaces a horizontal hole and a vertical hole are drilled along the designed sawing surface so that the two holes are connected and on the same cutting surface (2) Rope pressing and cutting method When the number of the free surfaces of the ore body is less than two a hole is drilled on the working face of the bench a rope pressing wheel is arranged on a multi-purpose drilling machine or a cutting upright post and is placed in the hole and a carborundum rope bypasses the rope pressing wheel and forms a closed loop with a driving wheel of a sawing machine to work Diamond wire saw traction cutting Diamond wire saw traction cutting 3 Applicable conditions of diamond wire saw It can be used for full sawing and mining of marble and granite or combined mining with other equipment; it can also be used for stone processing and block shaping 4 Advantages and disadvantages The mining cost is high but the sawing surface is flat the sawing area is large and the block rate is high 4 Sawing method of arm-type stone sawing machine According to the cutting tool it is divided into 1) fixedly instal a hard alloy or diamond segment cutting edge on a cutting arm transmission chain to form a hard alloy cut chain or a diamond cutting chain; 2) Polyurethane injection molded cutting tape with diamond cutting segments The main body of the diamond cutting belt is a rectangular diamond segment threaded on six side-by-side stainless steel wire ropes for aviation and the segments are all sealed by special polyurethane injection molding BENETTI Italy JB-990 mining band saw vertical cutting operation The vertical and horizontal cutting of the ore body can be carried out and the vertical and horizontal cutting positions can be quickly and flexibly switched at the same installation position It is suitable for the mining of soft stones such as marble limestone and travertine with medium hardness At present the maximum vertical cutting depth of large chain arm saw can reach 8 meters the longest horizontal cutting depth can reach 48 meters and the chain width is generally 335 mm The maximum cutting depth of the mining band saw can reach 48 meters and the width of the saw gap is generally 38 mm At present the maximum vertical cutting depth of the arm saw has reached 8 m and the mining bench with a height of 8 m can be mined 5 Disc stone sawing machine sawing method A saw blade with a diameter of 42 m can be mined to a height of 19 m and the main machine of the circular saw and the saw blade are moved during mining The diameter of the saw blade used for mining circular saw blade is 1600 4200 mm and it is usually used in groups of 2 or 3 pieces If the cutting depth is 125 m the combination of saw blades with diameters of 16m 22m and 28m can be used; if the cutting depth is 19 m the combination of saw blades with diameters of 22m 3m and 42m can be used The final width of the kerf is 15-20 mm Photo of vertical sawing by double-blade mining circular saw with a diameter of 35m Flame rock cutter cutting method I Cutting mechanism Use the flame of the flame thrower to burn the rock to form a cutting surface to divide the rock It can only be cut vertically The loss of the cutting groove is large In the case of three free surfaces two surfaces are generally cut at most It is better to cut only one surface and the other two surfaces are separated by blasting or wedge method Due to the difference of thermal expansion coefficients of different minerals in the rock quartz changes from α-quartz to β-quartz at 573 ℃ and the volume of quartz decreases resulting in disintegration II Applicable conditions Vertical cutting of rocks with high quartz content not horizontal cutting The higher the quartz content is the higher the cutting efficiency is; the lower the quartz content is the lower the cutting efficiency is III Equipment composition Air compressor oil supply system oxygen supply system flame thrower Operation Drawing of Downward Trench Excavation by Flame Cutting Machine IV Advantages and disadvantages High efficiency (15 ~ 25 ㎡/H) flexibility large cutting depth (up to 10 m) large cutting area smooth cutting surface not affected by season and climate High noise (100 ~ 120 db) high dust high fuel consumption high cost (200 ~ 250 yuan/㎡) and high labor intensity so it must be combined with other mining methods Flame cutting machine combined with hand-held rock drill drilling row holes combined with splitting mining method (referred to as burning rock drilling mining method) is the traditional longest and most widely used granite mining method Copyright notice If it involves copyright issues please contact us to delete it! 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Short-path molecular distillation equipment operation process _ proceed Jobs - Employee 2022-08-15
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Short-path molecular distillation equipment operation process _ proceed

Original title Operation process of short-path thin film distillation molecular distillation equipment During the operation of the short-path molecular distillation equipment it is necessary to pay attention to certain operation procedures to avoid the unavailability of the entire short-path molecular distillation equipment and the unavailability of the supporting Wuxi Shengze refrigeration and heating temperature control system due to improper operation Generally the short-path molecular distillation equipment has passed the hydrostatic test and test run before delivery and the indicators meet the requirements Start the motor and observe whether the running direction of the motor is correct It should rotate clockwise not reversely winterization filtration Measure whether the radial swing and axial displacement of the shaft meet the requirements and check whether the seal is tight Check whether the oil level of the reducer is in a normal state and whether the cooling water of the mechanical seal is kept unblocked

Turn on the circulating cooling water pump of the short-path molecular distillation equipment to keep the condenser in operation The concentrate container is then opened and the vacuum valve is drawn Open the feed valve and pump in the feed liquid Turn on the power supply start the motor and observe whether the rotation direction of the motor is correct Slowly open the steam valve and connect the steam trap so that the steam pressure is about 015 MPa Observe the discharging condition of the short-path molecular distillation equipment After the equipment runs stably for 5 minutes molecular distillation systems sample and analyze the concentration of the concentrated solution If the concentration is not up to the standard adjust it When the liquid level of the concentrated solution container is about to be full it shall be switched to another container and the switching shall be carried out according to the steps The shutdown sequence of normal short-range molecular distillation equipment is as follows close the steam valve close the feed valve drain the feed liquid close the discharge valve flush the equipment stop the motor stop the circulating water pump and jet pump and open the vacuum breaking valve When the short-path molecular distillation equipment has no feed liquid or is full of feed liquid the motor cannot be started for stirring It is strictly prohibited to run the motor in the reverse direction When running do not touch the rotating parts with your hands Do not press the button with wet hands to prevent electric shock Short-path molecular distillation equipment should pay attention to some safety knowledge as much as possible during operation to avoid some safety accidents because safety production is very important (This article comes from the network if there is infringement please contact to delete) Return to Sohu to see more Responsible Editor
Discussion on the Development Prospect of Rotary Evaporator — — Horizon _ Evaporator Jobs - Employee 2022-08-15
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Discussion on the Development Prospect of Rotary Evaporator — — Horizon _ Evaporator

Original Title Discussion on the Development rotovap distillation Prospect of Rotary Evaporator — — Horizon As we all know the rotary evaporator also known as the rotary evaporator is a very widely used evaporation instrument in the market so do you know what its development prospects are Let's get to know it together with Xiaobian today Nowadays the structure of China's rotary evaporator market is still dominated by traditional multi-effect evaporators and supplemented by local MVR evaporators The rotary evaporator is electronically controlled to rotate the flask at a constant speed at a suitable speed to increase the evaporation area The evaporation flask was brought to a negative pressure state by a vacuum pump An evaporation flask is place in a water bath for constant temperature heat while rotating and that solution in the flask is heated diffused and evaporate in the rotating flask under negative pressure The reason for this situation is that the MVR evaporator is a new product and people do not understand its application; secondly the price of imported MVR evaporator is very expensive However the development trend of evaporator market at home and abroad is that

MVR evaporator will gradually replace the traditional multi-effect evaporator and MVR evaporator will gradually replace the traditional multi-effect evaporator in time According to expert analysis the MVR evaporator industry is still a hot industry with technical potential (referring to the possibility of personal ability development) in China However as a large number of chemical equipment consumer manufacturers want to get involved in this product it will not take much time It is estimated that in two years most of the chemical equipment manufacturers will come to participate so the improvement of MVR evaporator in the chemical pharmaceutical industry is just around the corner Industry insiders predict that rotary evaporators will undergo major changes in the next five years rotary vacuum evaporator The main changes are not in technology but in the integration of market scope marketing system management system and so on Rotary evaporator is an evaporation instrument widely used in laboratories It is suitable for reflux operation rapid evaporation of a large amount of solvents concentration of trace components and reaction processes requiring stirring The rotary evaporator system can be sealed to reduce the pressure by 400 to 600 mm Hg; the solvent in the distillation flask is heated by a heating bath and the heating temperature can be close to the boiling point of the solvent; at the same time the rotary evaporator system can rotate at a speed of 50 to 160 revolutions per minute so that the solvent forms a film and the evaporation area is increased

Rotary evaporators wiped film distillation will continue to grow rapidly in the market and the market scope will be doubled compared with today The promising market prospects will make more companies enter the industry to stop playing games but the market analysis of entrants will become more rational Generally speaking the whole industry of rotary evaporator is facing a new round of golden period of development In the process of rapid development there must be fast fish eating slow fish and big fish eating small fish which is the rule of the market game but also an opportunity for the company to develop Only by adjusting the development strategy in time and innovating the management form can the rotary evaporator enterprises persist in vitality growth and development Special Disclaimer The article is sourced from Vision Network (shijiezx Com/news/show PHP Itemid = 37ee0509061c5d02) For more information please click (shijiezx Com/news/) Return to Sohu to see more Responsible Editor
Research progress on the separation and extraction of lignin _ cellulose Jobs - Employee 2022-08-15
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Research progress on the separation and extraction of lignin _ cellulose

Original Title Research Progress on Separation and Extraction of bra tape measure Lignin Lignin is a natural macromolecular material with phenolic structure which widely exists in woody plants herbaceous plants and vascular plants It is the second largest natural macromolecular material in nature after cellulose in quantity and the only aromatic compound that can be obtained from renewable resources in industry Lignin is widely used in building materials industry petroleum industry light industry and agriculture Lignin is also an important component of human Dietary fibres (DF) which can change the activity of microorganisms in the intestinal system reduce the content of cholesterol and blood sugar in the blood and prevent cardiovascular diseases [2]; lignin also has antioxidant activity [3] and cancer cell inhibition activity [4] As a natural antioxidant active substance the anti-free radical activity of lignin in wood and crop straw has been extensively studied [5] while the research on lignin in dietary fibers such as vegetables and fruits is rare [6] Lignin was extracted from carrot and its structure and antioxidant activity were studied It is expected to get a natural non-toxic side effects of antioxidant active substances which has a wide range of applications in food industry cosmetics health products and so on The extraction and separation methods of lignin generally include acid alkali supercritical aqueous two-phase ionic liquid organic solvent and other means among which the organic solvent method has become the most popular extraction and separation method in recent years because of its environmental protection economy and easy separation However most of them require high temperature and high pressure conditions and there are still many technical difficulties in its complete industrialization which greatly limits its application Therefore this paper also introduces several improved methods by using organic solvents and focuses on the experimental process of extracting and separating carrot lignin by using high boiling solvent The individual unifies the reading material the elaboration hoped has the help to everybody Method for extracting and separating lignin Expand the full text Acid precipitation method Klason [7] used 64% ~ 72% concentrated sulfuric nutsche filter dryer acid to hydrolyze carbohydrates to separate lignin which was called Klason lignin Due to Klason wood The simplicity of lignin measurement makes it widely used in many measurements but this method is not suitable for the study of lignin structure Willstatter [8] first used 40% ~ 42% fuming concentrated hydrochloric acid to dissolve cellulose at 0 ℃ to separate hydrochloric acid lignin or Willstatter lignin Compared with Klason lignin it can be applied to structural studies Although acid solution can hydrolyze cellulose into aqueous solution and precipitate lignin this separation method itself has great disadvantages Because under the action of temperature rise and protons lignin produces positive carbon ions under acidic conditions Alkali precipitation method Wang Sanfan et al Used alkali precipitation method to treat papermaking black liquor from different cooking processes which proved that it was effective to extract lignin by alkali precipitation method [9] The mechanism of alkali precipitation is that the lignin in the black liquor of papermaking contains phenolic hydroxyl group phenolic alcohol group carboxylic acid group carbonyl group and other easily chelated groups which is a typical multi-group ligand and can form a lignin chelate with "chelation" with the added metal ions The main factors affecting the precipitation rate of lignin were pH value and the dosage of metal ions Lignin chelate could be formed only by adding high valence metal cations under alkaline conditions and the precipitation rate of lignin increased with the increase of pH value; the higher the valence state of metal ions and the smaller the radius the easier the chelation and the greater the dosage the greater the precipitation rate of lignin Ultrafiltration Lignin is a kind of macromolecular compound which can be extracted from black liquor of papermaking by ultrafiltration in principle

Li Zhongmin et al discussed the feasibility of recovering lignin by ultrafiltration The experiment proved that the ultrafiltration method could effectively recover lignin from papermaking black liquor and the recovery rate was 955% The permeation flux of high concentration solution was smaller than that of low concentration solution and the time needed to achieve constant permeation flux was shorter; Treatment of ultrafiltration membrane with 5 G/L polyoxyethylene sorbitan monolaurate surfactant can reduce the deposition or adsorption of solute on the membrane surface and improve the anti-fouling performance of ultrafiltration membrane [10] Supercritical extraction of lignin Cellulose and lignin are selectively separated by utilizing the different distribution of cellulose and lignin in the solvent under the supercritical condition With the increase of CO2 pressure the conditions of supercritical extraction become more and more similar to those of organic solvent extraction due to the use of organic solvents as additives However with the continuous optimization of the selection of additives the operating pressure of CO2 will continue 50l rotovap to decrease and supercritical extraction becomes a competitive separation process [11] Separation of Lignin by Aqueous Phase Extraction Two-phase aqueous extraction is widely used in the extraction of bioactive substances because of its mild extraction conditions ABS process can solve the problem of high consumption of chemicals and energy in traditional pulping process and the operation of temperature and pressure is relatively easier than that of organic solvent extraction Lignin and cellulose were separated from each other by adding different concentrations of K2CO3 (NH4) 2SO4 and NaOH into Stock solution PEG-6000 according to the different partition coefficients in the two aqueous phases of lignin and cellulose The use of two aqueous phases for lignin extraction will likely be a powerful adjunct to the delignification process in pulping [12] Organic solvent method At present with the widespread recognition and acceptance of the concept of sustainable development green chemistry process has become a hot research topic This requires the components to be separated The process should not only achieve the multi-level effective utilization of the separation products but also take into account the more effective recycling of the separation reagents In this context organic solvents have attracted much attention Compared with the existing alkaline or acid pulping method the method for separating the cellulose the hemicellulose and the lignin by using the organic solvent has the following advantages (1) vacuum drying is used so that the extract and the solvent can be quickly and effectively separated; (2) the extract can be recycled by condensation so that the emission of pollutants to the environment is reduced; And (3) the organic solvent is used so that the extraction environment is relatively mild the denaturation degree of the lignin is less and the implementation of subsequent chemical modification is facilitated However organic solvent pulping still requires high temperature and high pressure and there are still many technical difficulties in complete industrialization which greatly limits its application Several methods of improvement using organic solvents are described below Inorganic alkaline aqueous solution method and organic solvent-water mixed solvent method The inorganic alkaline aqueous solution method and the organic solvent-water mixed solvent method adopted by Fuzhou University can effectively separate the residue of straw fermentation Xtracting the enzymolysis lignin The separation and extraction process of the lignin does not go through chemical processes such as high temperature high pressure strong acid strong alkali and the like The structure is kept well and the chemical reaction activity is high Inorganic Alkaline Aqueous Solution Method and Organic Solvent-Water Mixed Solvent Method Adopted by Fuzhou University It can effectively separate and extract enzymolysis lignin from the residue of straw fermentation The lignin is separated and extracted without high temperature and high pressure The chemical structure of natural lignin is well maintained and has high chemical reactivity in chemical processes such as strong acid and strong alkali 262 High-boiling solvent method (HBS) with microwave radiation as heating source From the point of view of energy saving and emission reduction energy saving and environmental protection and in line with the current reality and green needs microwave radiation is used as the heating source Lignin was extracted from carrot by using ethylene glycol as extractant and the results were satisfactory The microwave radiation is used as a heating source so that the method has the advantages of rapidness energy conservation high efficiency and cleanness; and the extracting agent namely the aqueous solution of ethylene glycol has the characteristics of low toxicity and difficult volatilization can be recycled through distillation after extraction basically has no pollutant discharge and has the advantages of zero emission and no pollution

In this method water-insoluble lignin is dissolved in a high-boiling alcohol solvent under heating conditions to separate from cellulose and then lignin is obtained by water precipitation which can better maintain the original structure and activity of lignin and has broad application prospects [13 14] The following is a specific experiment Extraction and Separation Process of Carrot Lignin by High Boiling Solvent Rinse fresh carrots and dry at room temperature Cut the carrot into 05 mm thick slices with a clean stainless steel blade Stored at room temperature and ventilated for different periods of time The above carrot slices were quickly de-enzymed in a blast drying oven at 120 ℃ then dried to constant weight at 60 ℃ ground into powder sieved with a sieve with an aperture of 0 088 mm to obtain carrot fine powder and placed in a drying vessel for later use Weigh 163 G of carrot powder and place it in an autoclave After being added into the ethylene glycol solution with the mass fraction of 80% according to a certain feed liquid mass ratio the mixture is heated to a certain temperature and is cooled to 60 deg C after reacting for a certain time The reaction mixture was filtered under reduced pressure and the filter cake was washed with warm water at 70 ° C to obtain lignin solution At room temperature 3 volumes of water were added and stirred for 15 min and the lignin was precipitated Filtering under reduced pressure and washing the filter cake with warm water at about 60 deg C to obtain brown powdery coarse lignin Wrap 0 decarboxylation after extraction 5 G of crude lignin with filter paper and put it in a fat extractor and extract it with a mixed solvent of V (benzene) V (ethanol) = 11 for 8 H until the extract from the upper part of the fat extractor to the lower part is colorless The lignin was removed and vacuum dried to give 046 G of purified lignin [15] After a series of experiments the optimum conditions of extracting carrot lignin with HBS were as follows fresh carrot slices as raw material mass ratio of raw material 16 reaction temperature 210 ℃ reaction time 2 H Under these conditions the yield of lignin was the highest Application of lignin Lignin is a renewable natural macromolecular organic compound Its development and comprehensive utilization are of great significance to the rational use of resources economic development and environmental protection In agriculture it is used as a slow-release pesticide Lignin can be used as a carrier to prepare lignin slow-release pesticides by physical adsorption and chemical reaction with pesticides fungicides herbicides and plant growth regulators under specific conditions On the one hand because lignin has a variety of active groups it has a strong combination with pesticide molecules which reduces the release rate of pesticides On the other hand the slow degradation of lignin by microorganisms in nature also slows down the release of pesticides Therefore lignin slow-release pesticides can prolong the efficacy reduce toxicity improve the utilization rate of pesticides reduce environmental pollution and have great application potential in modern agriculture It can also be used to make fertilizer Because of the difficulty of alkali recovery the black liquor of non-wood pulping is often discharged directly into the natural environment resulting in serious pollution of the soil and rivers where the sewage is discharged The main method to solve the problem is the ammoniation reaction of lignin At present the production of "ammonia-nitrogen lignin" by oxidative ammonolysis is mostly studied under oxidative conditions lignin can undergo ammoniation reaction to produce nitrogen-modified lignin which can be used as a potential agricultural nitrogen fertilizer or humus Generally nitrogen fertilizer will be released rapidly after application which will seep into the groundwater system and cause secondary pollution while nitrogen-modified lignin has long-term and slow effects and to a certain extent it can reduce environmental pollution In addition lignin can also be used to produce functional fertilizers such as chelated fertilizer activated phosphate fertilizer soil improvement fertilizer and so on Lignin can be used as a coating material Therefore lignin-coated urea can be prepared which has better slow-release effect and yield-increasing effect than common urea and its slow-release characteristic has stronger after-effect than common urea It can maintain the continuous and balanced supply of nutrients improve the utilization rate of nitrogen fertilizer and reduce the environmental pollution caused by nitrogen fertilizer [16] In addition to agriculture lignin is widely used in industry and construction Conclusion The above materials show that the separation extraction and purification of lignin has been widely concerned and the method has reached the level of a hundred schools of thought contending and a hundred flowers blooming

The technology of extracting lignin by organic solvent has obvious advantages Because of the good volatility of organic solvent organic solvent can be recovered and lignin can be purified by distillation The recovered organic solvent can be recycled repeatedly a closed circulation system is formed in the whole process and no waste water or a small amount of waste water is discharged so that the method is an effective technical approach for realizing pollution-free or low-pollution 'green environmental protection' is also an effective way for extracting and purifying the lignin and provides a new approach for large-scale development and utilization of lignin resources in industry The extraction and purification technology of lignin needs to be improved and the lignin with high purity as raw material can be used to produce lignin products with good performance Our country has done some work in the utilization of lignin However it is far from keeping up with the needs of the development of the national economy Organize the research work of lignin in a planned way It will be an urgent task to develop China's lignin industry and catch up with the international advanced level In addition the anti-free radical activity of lignin in wood and crop straw has been extensively studied while the research on lignin in dietary fibers such as vegetables and fruits is rare Lignin in dietary fiber is of great significance in food cosmetics and health care products which is in line with people's urgent need for high-quality life Therefore the study of lignin in dietary fiber will be a very promising work and we should increase this research

References [1] Jiang Tingda Lignin Beijing Chemical Industry Press 2001 [2] WiUiarns R L. Elliot M S. Antioxidants in Grapes and Wine:Chemistry and Health Effects. In Natural antioxidants:Chemistry,Health Effects and Aapplications[M]. Shaihidi F,Ed. AOCS Press:Champaign,IL,1997:150 [3] shaIIidi F,Janitha P K,Wanssundara P D. Food sci Nutr[J],1992,32:67 [4] Wang H B. Nair M G,Strasburg GM,Chang Y C,Booren A M,Gray J I,DeWitt D L. J Nat Prod[J], 1999,62:294 [5] VinardeU M P,Ugartondo V,Mitjans M. 1nd Crops Prod[J],2008,27:220 [6] Nawirska A,Kwasniewska M. Food Chem[J],2005,91:221 [7] ChikakoAsadaYoshitoshi Nakamura Fumihisa KobayashiWastereduction system for production of useful materials from unutilizedbamboousingsteam explosionfollowedbyvarious conversionmethods[J]BiochemicalEngineeringJournal200423131~137 [8] Freudenberg KNeish A CConstitutionandBiosynthesis of Lignin[M]BerlinSpringer-Verlag196851 [9] Wang Sanfan Zhang Guojun Xue Xiangdong et al Treatment Mechanism of Lignin and Papermaking Black Liquor by Alkaline Precipitation China Water Supply and Drainage 2002 18 (6) 51 ~ 53 [10] Li Zhongmin Tong Zhangfa Study on the Recovery of Lignin from Black Liquor by Ultrafiltration Chemical Engineering 2003 (1) 49 ~ 52 [11] Sun Yong Li Zuohu Xiao Wei Chen Hongzhang Research progress of lignin separation methods Environmental Governance 2005 26 (10); 3 [12]HeatherDWillauerJonathanGHuddlestonMianLi etalInvestigationofaqueousbiphasicsystemsfortheseparationoflignins from cellulose in the paper pulping process[J]J Chromatogr B2000,743127~135 [13] Liao Junhe Luo Xuegang Cellulose Science and Technology [J] 200311 (04) 60

[14] Chen Yunping Cheng Xianwa Fang Huashu Chen Yuexian et al Cellulose Science and Technology [J] 200311 (01) 19 [15] Peng yuanhua Zeng Xiangqin Lu Hongmei Guizhou Chemical Industry [J] 200631 (4) 16 [16] Zhang Guimei Liao Shuangquan et al Research progress on extraction methods and comprehensive utilization of lignin Tropical Agricultural Science 2005 25 (1) 66 ~ 70 Return to Sohu to see more Responsible Editor
Shanghai's seven CBD, you only know Lujiazui, then you are OUT! Jobs - Employee 2022-08-15
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Shanghai's seven CBD, you only know Lujiazui, then you are OUT!

Original title Shanghai's seven CBD do you only know hemp extraction centrifuge Lujiazui then you are OUT! When it comes to Shanghai's Central Business District (CBD) the first impression of all Chinese people is the famous Lujiazui but what you don't know is that there are actually seven CBDs in Shanghai and Lujiazui is just one of them Next I will take you to explore the other six CBDs in Shanghai The picture shows Lujiazui CBD in Shanghai which is the headquarters of many multinational banks in Greater China and East Asia and one of the most influential financial centers in China In the picture is the CBD of Shanghai People's Square which is the geographical center transportation hub and heart of the urban area of Shanghai integrating office tourism commerce exhibition and art There are more than ten large shopping malls dozens of well-known enterprise headquarters and hundreds of logistics trade information industry network and other enterprises settled here known as the "super giant CBD" in the city center Expand the full text The picture shows the CBD of Nanjing Road in Shanghai which is the famous CBD center in Shanghai especially the three commercial buildings of Meilong Town Henglong Square cbd centrifugal extractor CITIC Pacific and the nearby Portman Hotel which activate the fashion of the whole business center The picture shows the CBD of Huaihai Road in Shanghai the high-end commodity consumption area from Huangpi South Road to Shaanxi South Road Jiahua Center and other emerging commercial office buildings as well as the surrounding French buildings full of bra tape measure exotic life style which constitute the prosperous CBD commercial belt of Huaihai Road The picture shows

Shanghai Xujiahui CBD one of the four major urban sub-centers in Shanghai The computer market in the region is very dense the commodities are very rich and the consumer groups are extensive so Xujiahui has become one of the areas where Shanghai residents buy computers and digital products At the same time there are also many businesses operating luxury goods high-end clothing various entertainment and catering industries in the region The picture shows Shanghai Hongqiao CBD located in the west of Shanghai Relying on the comprehensive transportation hub of Hongqiao it has been built into a cbd crystallization equipment gathering area of Shanghai's modern service industry a new platform for the construction of Shanghai International Trade Center a gathering place for the headquarters of domestic and foreign enterprises and trade institutions and a high-end business center serving the Yangtze River Delta region the Yangtze River Basin and the whole country The picture shows Shanghai Wujiaochang New Jiangwan City one of the four sub-centers of Shanghai which echoes Xujiahui in the southwest of the central city of Shanghai With the continuous development of modern business facilities transportation and ecology the overall advantages of the region have been fully highlighted and it has developed into one of the most prosperous areas in the North Shanghai Business Circle and even the whole Shanghai Return to Sohu to see more Responsible Editor
In the plastic restriction order, the emergence of PE recycled material film has made a difference? _ Plastics _ Production _ Pollution Jobs - Employee 2022-08-15
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In the plastic restriction order, the emergence of PE recycled material film has made a difference? _ Plastics _ Production _ Pollution

Original Title In the Plastic Restriction wiped film evaporator Order Does the Emergence of PE Recycled Material Film Make a Difference Over the past few years the development concept of the plastic ban has been widely disseminated As a major producer and consumer of plastics China promulgated the Law of the People's Republic of China on the Prevention and Control of Solid Waste Pollution as early as 1995 Since then from the "plastic ban" and "plastic restriction order" to the promulgation of the "14th Five-Year Plan" action plan for plastic pollution control China has attached great importance wiped film distillation to plastic pollution control What are the benefits of using PE recycled film Compared with the original plastic film recycled plastic film uses less natural resources and energy reduces waste and landfill and is widely used in packaging of various products Therefore the application of recyclable plastics will be more and more extensive and the demand for customers will be more and more Especially for foreign trade enterprises many

European and American customers have recently asked for the use of recycled plastic bags certified by GRS PE film that meets the global recycling standard GRS certification is an environmentally friendly product that meets customer requirements and can be recycled In terms of plastic restriction order Hualong film is guaranteed Hualong Film has obtained GRS certification thin film distillation which is equivalent to obtaining a green pass in the field of flexible packaging which can meet the needs of brand owners for PCR (Post-consumer Consumer Recycled material PCR) and achieve the unity of commercial value and social value Hualong Film will operate in strict accordance with the requirements of GRS system documents in the process of procurement production and sales so as to provide strong guarantee for customers Return to Sohu to see more

Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i bra tape measure < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。
Do you know the surface treatment of titanium and titanium alloy? Polishing Jobs - Employee 2022-08-15
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Do you know the surface treatment of titanium and titanium alloy? Polishing

Original title Do you know the surface Titanium 6Al4V wire treatment of titanium and titanium alloy Titanium is easy to react with O H N and other elements in the air and Si Al Mg and other elements in the investment at high temperature and a surface contamination layer is formed on the surface of the casting so that the excellent physical and chemical properties of the casting are deteriorated the hardness is increased the plasticity and elasticity are reduced and the brittleness is increased The density of titanium is small so the inertia of titanium liquid flow is small and the titanium filler rod fluidity of molten titanium is poor resulting in low casting flow rate Due to the large temperature difference (300 ℃) between the casting temperature and the mold the cooling is fast and the casting is carried out in a protective atmosphere it is inevitable that there are defects such as pores on the surface and inside of titanium castings which have a great impact on the quality of castings Therefore the surface treatment of titanium casting is more important than other dental alloys Because of the unique physical and chemical properties of titanium such as small thermal conductivity low surface hardness low elastic modulus high viscosity low conductivity and easy oxidation the surface treatment of titanium is very difficult and it is difficult to achieve the desired effect by conventional surface treatment methods Special processing methods and operation methods must be adopted The later surface treatment of the casting is not only to obtain a smooth and bright surface reduce the accumulation and adhesion of food and plaque maintain the normal oral microecological balance of the patient but also to increase the aesthetic feeling of the denture;

More importantly through these surface treatment and modification processes the surface properties and suitability of castings are improved and the physical and chemical properties of dentures such as wear resistance corrosion resistance and stress fatigue resistance are improved I Removal of Surface Reaction Layer The surface reaction layer is the main factor affecting the physical and chemical properties of titanium castings Before the titanium bar gr5 grinding and polishing of titanium castings the surface contamination layer must be completely removed to achieve satisfactory polishing effect The surface reaction layer of titanium can be completely removed by the method of acid cleaning after sand blasting 1 Sand blasting For the sandblasting treatment of titanium castings it is generally better to use white corundum coarse blasting and the sandblasting pressure is smaller than that of non-precious metals which is generally controlled below 045Mpa Because when the injection pressure is too high the sand impacts the titanium surface to produce intense sparks and the temperature rise can react with the titanium surface forming secondary pollution and affecting the surface quality The time is 15 to 30 seconds and only the burnt-on sand the surface sintering layer and part of the nickel titanium wire oxidation layer on the surface of the casting are removed The rest of the surface reaction layer structure should be removed quickly by chemical pickling 2 Pickling Pickling can quickly and completely remove the surface reaction layer without contamination of other elements on the surface Both HF-HCl and HF-HNO3 pickling solutions can be used for titanium pickling but HF-HCl pickling solution absorbs more hydrogen while HF-HNO3 pickling solution absorbs less hydrogen so the concentration of HNO3 can be controlled to reduce hydrogen absorption and the surface can be brightened Generally the concentration of HF is about 3% ~ 5% The suitable concentration of HNO3 is about 15% ~ 30% Pickling surface titanium plate TA 1 pure titanium plate Expand the full text Sand-blasted titanium plate pure titanium plate II Treatment of casting defects Internal defects of internal pores and shrinkage cavities They can be removed by iso-hot static pressing technology (hot isostatic pressing) but they will affect the accuracy of the denture It is better to use X-ray flaw detection grind the exposed pores on the surface and use laser repair welding The surface pore defect can be directly repaired by laser local welding III Grinding and polishing 1. Mechanical grinding Titanium has high chemical reactivity low thermal conductivity high viscosity low grinding ratio of mechanical grinding and is easy to react with abrasive tools Ordinary abrasives are not suitable for grinding and polishing of titanium It is better to use superhard abrasives with good thermal conductivity such as diamond cubic boron nitride etc The polishing speed is generally 900 ~ 1800 m/min It is appropriate Otherwise the titanium surface is prone to grinding burns and micro-cracks Titanium plate with grinding surface and polished surface Milling surface Milling surface Titanium plate Titanium alloy plate 2. Ultrasonic grinding through the action of ultrasonic vibration the abrasive particles between the grinding head and the ground surface produce relative motion with the ground surface to achieve the purpose of grinding and polishing The advantage is that it is easy to grind grooves pits and narrow parts which cannot be ground by conventional rotary tools titanium plate gr7 but the grinding effect of larger castings is not satisfactory

3. Electrolytic mechanical compound grinding a conductive grinding tool is used electrolyte and voltage are applied between the grinding tool and the grinding surface and the surface roughness is reduced and the surface gloss is improved under the combined action of mechanical and electrochemical polishing The electrolyte is 09 NaCl the voltage is 5V and the rotation speed is 3000 rpm/min This method can only grind flat surfaces and the grinding of complex denture brackets is still in the research stage 4. Barrel grinding The centrifugal force generated by the revolution and rotation of the grinding barrel is used to make the denture in the barrel move relative to the abrasive to reduce the surface roughness Grinding is automatic and efficient but it can only reduce the surface roughness but not improve the surface gloss and the precision of titanium exhaust tubing grinding is poor so it can be used for deburring and rough grinding before fine polishing of denture 5. Chemical polishing Chemical polishing is to achieve the purpose of leveling and polishing through the oxidation-reduction reaction of metal in chemical medium The method has the advantages that the chemical polishing has nothing to do with the hardness of the metal the polishing area and the structural shape all parts in contact with the polishing solution are polished no special complex equipment is needed the operation is simple and convenient and the method is more suitable for polishing the titanium denture bracket with a complex structure However the process parameters of chemical polishing are difficult to control and it is required to have a good polishing effect on denture without affecting the accuracy of denture A better titanium chemical polishing solution is prepared from HF and HNO3 in a certain proportion wherein

HF is a reducing agent and can dissolve titanium metal to play a role in leveling the concentration is less than 10% and HNO3 plays a role in oxidation to prevent excessive dissolution and hydrogen absorption of titanium and can also play a role in brightening Titanium polishing solution requires high concentration low temperature and short polishing time (1 ~ 2 min) 6. Electrolytic polishing It is also called electrochemical polishing or anodic dissolution polishing Due to the low conductivity and strong oxidation performance of titanium it is almost impossible to polish titanium with aqueous acidic electrolytes such as HF-H3PO4 and HF-H2so After external voltage is applied the titanium anode is oxidized immediately so that anodic dissolution cannot be carried out However the use of anhydrous chloride electrolyte at low voltage has a good polishing effect on titanium and small specimens can be mirror-polished but for complex restorations it can not achieve the purpose of complete polishing Perhaps the method of changing the shape of the cathode and adding a cathode can solve this problem which needs bra tape measure further study IV Surface Modification of Titanium 1. Nitriding a golden yellow TiN coating was formed on the surface of titanium denture by chemical heat treatment techniques such as plasma nitriding multi-arc ion plating ion implantation and laser nitriding so as to improve the wear resistance corrosion resistance and fatigue resistance of titanium However the technology is complex and the equipment is expensive so it is difficult to achieve clinical application for surface modification of titanium denture 2. Anodizing The anodizing technology of titanium is relatively easy In some oxidizing media under the action of applied voltage the titanium anode can form a thicker oxide film thereby improving its corrosion resistance wear resistance and weather resistance H2SO4 H3PO4 and organic acid aqueous solution are generally used as the electrolyte for anodizing Titanium anodizing and coloring 3. Atmospheric oxidation Titanium can form a thick and firm water-free oxide film in high temperature atmosphere which is effective for general corrosion and interstitial corrosion of titanium and the method is relatively simple 5 Coloring In order to increase the aesthetic feeling of the titanium denture and prevent the titanium denture from being continuously oxidized and discolored under natural conditions surface nitriding treatment atmospheric oxidation and anodic oxidation surface coloring treatment can be adopted to form light yellow or golden yellow on the surface so as to improve the aesthetic feeling of the titanium prosthesis The anodizing method makes use of the interference effect of the titanium oxide film on the light to naturally generate colors and can form colorful colors on the titanium surface by changing the bath voltage VI Other surface treatments 1 Surface roughening In order to improve the bonding performance between titanium and decorative resin the surface of titanium must be roughened to increase its bonding area

The Surface of titanium is usually roughened by sandblasting in clinic but the sandblasting will pollute the aluminum oxide on the surface of titanium We use the oxalic acid etching method to get a good roughening effect the surface roughness (Ra) can reach 150 ± 030 μm after etching for 1 H and the Ra is 299 ± 057 It is more than twice the Ra (142 ± 014 μm) of sand blasting alone and its bond strength is improved by 30% 2 Surface treatment for high temperature oxidation resistance In order to prevent the rapid oxidation of titanium at high temperature titanium silicon compounds and titanium aluminum compounds are formed on the surface of titanium which can prevent the oxidation of titanium at temperatures above 700 ℃ This kind of surface treatment is very effective for the oxidation of titanium at high temperature Perhaps the coating of this kind of compound on the surface of titanium is beneficial to the combination of titanium and porcelain and further research is needed More Titanium and Titanium Alloy Surface Treatment Titanium Plate Titanium Anodizing Please Pay Attention to Ruida Titanium Industry Return to Sohu to See More Responsible Editor
Titanium's first MiniLED high-end monitor tailored for eSports players goes on sale _ Technology _ Support _ Picture Jobs - Employee 2022-08-15
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Titanium's first MiniLED high-end monitor tailored for eSports players goes on sale _ Technology _ Support _ Picture

Original Title Titanium's First MiniLED titanium sheet grade 5 High-end Display Tailored for E-sports Players Is on Sale Titanium core selling point 27-inch 25601440 resolution Miniled screen 165Hz refresh rate 1ms (MPRT) fast response HDR1000 support covering 100% sRGB wide color gamut 95% Adobe 95% DCI-P3 cinematic color gamut 10 bit dazzling color depth 10000000 1 contrast ratio 1000 nits peak brightness Adaptive-Sync synchronization technology T V Rhine Certified Hardware Physical Low Blu-ray 65W high-power Type-C reverse charging interface competitive atmosphere lamp ergonomic lifting bracket supporting 90 ° rotation SKY the founder of "China's first e-sports player" has experienced many years of professional e-sports career He knows that the quality of titanium round bar e-sports equipment will greatly affect the performance of players so he has been hoping to make a set of high-end e-sports equipment that everyone can afford Now he has taken another step towards his dream Under the background that the mainstream MiniLED monitors on the market are often five or six thousand or even tens of thousands on July 15 Titanium and Longli Technology (300752) cooperated to launch the first 1000 yuan

MiniLED competitive display which is expected to have a promotional price of only 1999 yuan opening the era of MiniLED display "1" Titanium Miniled competitive display uses 27 inches 25601440 resolution and Miniled competitive screen which brings high-end configuration to players Support HDR1000 quantum dot wide color gamut covering 95% DCI-P3 movie-level color gamut 10 bit dazzling color depth T V Rhine certified hardware low blue light 165Hz rapid refresh 1ms (MPRT) rapid response Adaptive-Sync synchronization technology brings high-end e-sports experience ti6al4v Improve the player's operation space and enjoy every minute of the game The high brush is invincible with zero delay In terms of game experience Titanium MiniLED competitive display is designed based on SKY's long-term professional competitive experience It adopts 165 Hz high refresh rate professional competitive level configuration which supports players to show all kinds of extreme operations and control the situation in a natural and unrestrained way When shooting games and MOBA games need to switch the screen quickly the Adaptive-Sync technology can also synchronize the signal transmission between the graphics card and the display reduce the delay prevent the screen from stuttering and tearing even if the player sparks the keyboard and mouse the screen is still silky and clear Expand the full text High-end screen display technology extraordinary ti6al4v eli visual enjoyment If the game experience is well done the visual performance will naturally be of high quality

Titanium MiniLED competitive display adopts the industry-leading MiniLED backlight technology Through micron-level fine light control it ensures that the bright area of the picture is not exposed and the dark area can be darkened bringing more delicate and realistic picture performance For players who pursue a more advanced viewing experience they can also turn on the HDR function in the video settings to further enhance the visual performance so that the bright places are brilliant and the dark places are subtle It is worth mentioning that the titanium MiniLED display also uses T V Rhine certified physical hardware low Blu-ray technology comfortable viewing while ensuring eye health The original color presents all things mottled As a product with a wide range of application scenarios titanium MiniLED competitive display can also be used for image processing or graphic design which uses QD quantum dot film technology to cover 95% DCI-P3 movie-grade color gamut 95% Adobe RGB color gamut and supports HDR1000 It not only brings excellent color space and delicate level 3d titanium wire but also provides visual creators with the ability to use and create high-quality HDR content so that every animation and picture works can be fine thorough and lifelike High-end is also carefully carved in detail Strong performance industrial design can not be left behind Titanium MiniLED competitive display uses ergonomic multi-functional bracket which supports players to adjust the screen at will Whether it is horizontal and vertical screen viewing or split-screen dual-screen multi-screen operation it can be adjusted to the appropriate angle greatly improving the use experience As a slash youth in the new era whether the product has a rich expansion interface is also an important criterion for purchasing Titanium MiniLED competitive display provides HDMI Type-C (65W) USB IN and other interfaces Whether it is desktop/notebook XBOX/PS5/Switch or mobile phone/tablet it can be easily connected to enjoy the large-screen experience Its 65W high-power

Type-C interface can also be bra tape measure used as a data transmission/fast charging interface to meet the needs of users and continue the battle Intimate after-sales service accompanies every player Strong products can not be without the support of strong after-sales service All users who buy Titanium MiniLED competitive display can enjoy "worry-free after-sales" service including 7-day no-reason refund 15-day quality problem replacement 3-year free warranty and 2-year free on-site service! So that every user can buy at ease use at ease enjoy the happiness and beauty brought by titanium display Excellent performance and high cost performance At present the basic price of displays with MiniLED technology on the market is about 3000 yuan some even as high as 7000 or 8000 yuan and the high price is prohibitive And either lack of low blue light eye protection or poor resolution frame rate etc

The emergence of titanium MiniLED competitive display has changed this situation with the first promotional price of less than 2000 yuan physical low blue light HDR1000 165Hz high brush 65W Type-C reverse charging and other mainstream configurations A great choice for a 2000 price point MiniLED eSports monitor! At present Titanium MiniLED competitive display is being pre-sold in titanium tubing price Jingdong The first promotion price is expected to be 1999 yuan and 50 yuan E card will be sent It's better to take action than to be moved Take it into your pocket immediately! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。
The Latest Review of Huang Jinsong's Nature Journal: Physical Properties of Hybrid Perovskites Applied in Photovoltaic Devices Jobs - Employee 2022-08-15
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The Latest Review of Huang Jinsong's Nature Journal: Physical Properties of Hybrid Perovskites Applied in Photovoltaic Devices

Original Title Huang Jinsong Nature Subjournal Latest titanium tubing price Review Physical Properties of Hybrid Perovskites Applied in Photovoltaic Devices [Introduction] Over the past few decades researchers have been working to find new photovoltaic materials that are self-cleaning renewable and low-cost Organic-inorganic hybrid perovskites (OIHPs) have attracted much attention in the field of photovoltaic devices due to their abundant raw materials low cost low-temperature batch synthesis and high conversion efficiency However the disadvantages of OIHPs such as heavy metal Pb and poor hydrothermal stability greatly hinder its commercial application Although scientists have made a lot of efforts on these issues the gains are very small In addition there are titanium round bar still no clear design rules in the design of materials Therefore a deep understanding of hybrid perovskite materials is essential to improve the performance of perovskite solar cells and the development of next-generation photovoltaic materials Recently Professor Huang Jinsong of the University of Nebraska at Lincoln (corresponding author) and others published an article entitled "Understanding the physical properties of hybrid perovskites" in the Nature Reviews Materials For photo voltaicapplications "for your article In this review we summarize the latest research progress on the physical properties of three-dimensional and low-dimensional OIHPs with small open-circuit voltage deficit and high efficiency including physical defects ferroelectricity exciton separation process carrier recombination lifetime and photon cycle In addition the article critically evaluates the impact of ion migration on the efficiency and stability of solar cells and discusses some challenges for the commercial application of OIHPs Overview map 1 Charge recombination in perovskite 11 Optical absorption and charge transfer Photovoltaic materials are required to have a large light absorption coefficient The active layer of the material with large absorption coefficient can absorb almost all photons above the band gap in a very thin case reduce the saturation dark current caused by carrier recombination and thus has higher light harvesting efficiency and larger open circuit voltage (VOC) The relationship between film thickness and VOC can be expressed by the Shockley – Queisser model Expand the full text Where bra tape measure K is the Boltzmann constant T is the temperature Q is the elemental charge JSC is the short-circuit current density J0 is the onset current density ND is the doping density τeff is the carrier recombination lifetime Ni is the intrinsic carrier concentration and d is the thickness of the absorber layer OIHPs are almost the most effective absorber among photovoltaic materials For example the absorption coefficient of MAPbI3 in the visible region is larger than 30 × 104 cm ? 1 which is an order of magnitude larger than that of Si The thickness of the thin film in the high-efficiency OIHPs solar cell reported at the present stage is 03-06 μm while the thickness of the thin film in the silicon solar cell is 300 μm The VOC deficit of the photovoltaic materials synthesized by the solution method mainly comes from the energy separating the photogenerated Frenkel excitons and the exciton binding energy (EB) is 02-10 eV Therefore an acceptor/donor heterojunction interface with a large energy offset (> 03 eV) is required to provide the driving force to separate the excitons For photovoltaic devices the smaller EB can reduce the energy loss For example the excitons of Si (EB ~ 15 meV) and GaAs (EB ~ 4 mV) with small band gaps can be separated at room temperature The EB of the hybrid perovskites is 2-75 meV indicating that OIHPs in photovoltaic applications can be classified as non-excitonic materials The non-excitonic character allows perovskite solar cells to be fabricated as planar homojunction or heterojunction thin film structures Figure 1 VOC deficit of OIHPs solar cells EB is sensitive to microstructure In perovskite films with many small grains disordered and different potentials will reduce EB and inhibit the generation of excitons Therefore the stronger exciton peak of MAPbI3 can only appear in larger single crystals

Recent studies have shown that excitons are more likely to be generated at high crystallinity and free charges appear at the center of grains with more small grains Figure 2 Photogenerated excitons or photogenerated free carriers of OIHPs (A) Actual (ε ′) and theoretical (ε ′ ′) dielectric constants of MAPbI3; (B) The proportion of free carriers to total carriers in thermodynamic equilibrium; (C) measured EQE of non-excitonic MAPbBr3 and excitonic organic PCBM in the same device; (D) Transient absorption spectra of small crystals (< 200 nm) and large crystals (~ 1 μm); (E) Normalized EQEs of MAPbBr3 polycrystalline thin film with thickness of 3 mm polycrystalline thin film with thickness of 200 mm and single crystal; (F) Absorption spectrum of MAPbBr3 In addition to the chemical composition and microstructure the dimensionality of the crystal also affects the EB 2D materials have a large EB due to the spatial quantum confinement effect With the increase of the number of layers EB tends to be a 3D material 12 Charge recombination rate A longer carrier recombination lifetime requires a larger VOC to provide a higher carrier concentration The carrier recombination lifetime in a semiconductor material can be expressed by the following formula Where G is the carrier generation rate K1 is the unimolecular carrier recombination constant K2 is the bimolecular carrier recombination constant and K3 is the Auger carrier recombination constant In solar cells the recombination probability of Auger carriers is much smaller than that of the other two carriers A series of K1 and K2 values were obtained nickel titanium wire by time-resolved fluorescence spectroscopy (TRPL) transient spectroscopy and time-resolved microwave conductance (TRMC) (Table 1) It can be seen from the table that the single-molecule carrier recombination dominates the carrier recombination in the perovskite film with lower exciton concentration Table 1 Values of K1 and K2 for different materials 13 Charge screening Almost all high-efficiency solar cells such as GaAs and organic bulk-phase heterojunctions are non-Langevin-type bimolecular complexes The Langevin-type bimolecular recombination coefficient is e (μe + μh)/ (εε0) where e μe μh and εε0 are the electron charge electron mobility hole mobility and dielectric constant respectively The recombination coefficient of Langevin-type bimolecular recombination system is related to the carrier mobility Non-Langevin behavior is important for organic molecules with large carrier mobilities In general the charge screening mechanism needs to reduce secondary charge recombination and OIHPs with large dielectric constants can screen electrons and holes There are some other mechanisms to explain why the photogenerated electron-hole recombination of OIHPs is slow Some researchers have hypothesized that perovskites may be ferroelectric creating a polarizing electric field that separates electrons from holes Domain structures have been observed in perovskite structures by piezoelectric force microscopy (PFM) However after excluding the effect of charge leakage no stable magnetization was detected in MAPbI3 by the classical Sawyer – Tower circuit method (Figure 3A) Ferroelastic properties in MAPbI3 polycrystalline thin films and single crystals were confirmed by micro-nano technology (fig 3B) Obvious domain walls at 70 ° and 109 ° were observed by polarized light microscopy and PFM which may be due to the presence of twinned domains with different orientations in the tetragonal MAPbI3 (Figure 3C) Some studies observed ferroelastic domain motion in single crystal and polycrystalline films by polarized light microscopy and PFM (Figure 3D) Researchers have also studied the role of organic cations in carrier recombination It is shown that although the type of organic cation has no obvious effect on the band edge recombination the organic cation plays a large charge screening role in the thermalization of carriers (Fig 3 e f)

Figure 3 Electrochemical performance of OIHPs (A) Polarization properties of single-crystalline MAPbI3 for solar cells tested by the Sawyer – Tower circuit method; (B) inversion of domain group observed by reflection polarize microscopy; (C) Schematic diagram of winding structure with two crystal orientations in MAPbI3 single crystal and twin crystal; (D) AFM and PFM of polycrystalline MAPbI3; (E) PL decay dynamics at 23 eV and 26 eV; (F) Crystal structure of MAPbI3 14 Doping of perovskite semiconductor Doping plays an important role in the electrical properties of semiconductors such as conductivity and carrier mobility In solar cells doping can directly change the carrier recombination rate diffusion length contact resistance and VOC The lower doping concentration reduces the scattering and recombination of carriers so that the material has a longer carrier diffusion length Proper doping concentration can reduce the internal resistivity of the solar cell resulting in a larger VOC However it is difficult to achieve extrinsic doping because the structure of OIHPs has low fault tolerance and low activation energy of ion migration In OIHPs self-doping can be achieved because the formation energies of donors and acceptors are similar The self-doping of OIHPs is affected by the composition and synthesis parameters of the precursor for example in the precursor of MAPbI3 thin film more PbI2 makes the thin film become n-type doped material; with the change of Titanium 6Al4V wire MAI content thermal annealing can convert p-type doped material into n-type doped material 15 Photon Cycle The experiment proves that the photon circulation effect of the GaAs solar cell (the reabsorption and reemission of the photoactive layer itself) makes the carriers of the photoactive layer gather thus enhancing the splitting of the quasi-Fermi level which makes it have a higher VOC and the PCE increases from 25% to 29% However it is not known whether there is a photon cycle effect in OIHPs In fact there are many similarities between perovskite and GaAs for example they are both direct band gap materials and have high band edge absorption coefficient which makes the carriers of the materials have high self-separation rate These properties provide preconditions for photon circulation Recently a study has demonstrated for the first time the photon recycling effect in MAPbI3 polycrystalline films The results show that there are photogenerated charges in the light absorption region of more than 50 μm in the polycrystalline thin film (Fig 4a-c) At the same time the photon recycling efficiency of single crystal OIHPs was determined based on the way their polarization differences distinguish between emitted and reabsorbed photons The results show that the photoluminescence signal of the crystal is dominant and the reabsorption and reemission are weak (Figure 4d-f) In these systems the photon recycling efficiency is less than 05% which is negligible for solar cells The lower photon recycling efficiency may be caused by the lower internal PLQY of the perovskite film Fig 4 Photon circulation effect of OIHPs (A) Schematic of the microscope setup for measuring photon circulation; (B) luminescence plot for different separation distances between excitation and collection; (C) Comparison of the experimentally measured (solid line) and theoretically calculated (dashed line) attenuation of the material at 765 and 800 nm; (D) Schematic diagram of photon circulation in perovskite single crystal; (E) Surface PL (blue line) and filtered recovered PL (PLF + PLR; red line) spectra of MAPbBr3 single crystals of 13 mm thickness; (F) Filtered recovered PL (PLF + PLR; red line) and recovered PL (PLR blue line) spectra 16 High electronic dimension Recently the concept of electronic dimension has been used to explain why MAPbI3 has better photovoltaic performance than other metal halide perovskites Generally speaking the structural dimension is an important index to describe the photovoltaic characteristics and device performance of the absorber Electron dimension refers to the connectivity of electron orbitals which can lower the conduction band and raise the valence band Compared with the structural dimension the electronic dimension can better describe the physical properties of materials such as band gap carrier mobility and defect energy levels

Although some perovskite materials have three-dimensional structure and electronic dimensions some perovskites with three-dimensional structure have low electronic dimensions The high electronic dimension provides important guidance for understanding the performance of solar cells titanium filler rod 2 Defects in OIHPs 21 Band tail of perovskite The calculated VOCSQ is calculated assuming a perfect break or step absorption coefficient for the light absorber which results in a calculated VOC maximum that is greater than the actual one In real solar cells the absorption spectrum is not abrupt and there is always an absorption band tail in the absorption spectrum due to defects and other reasons Therefore the definition of the maximum achievable VOC (the radiative recombination limit VOCrad) is the balance of the radiative charge recombination current and the photocurrent For solar cells VOCrad (providing a path for VOC losses due to sub-bandgap reorganization) is much smaller than VOCSQ OIHPs photovoltaic devices have a smaller VOC deficit due to their smaller subband gap absorption The absorption spectra of OIHPs have a steep band edge which is characterized by the Urbach energy (the exponential part of the absorption curve) The Urbach energy of polycrystalline MAPbI3 is ~ 15 meV at room temperature which is close to that of single crystal Si (~ 11 meV) and GaAs (~ 75 meV) indicating that the polycrystalline MAPbI3 thin films synthesized by solution method have orderly microstructure and low deep level defect density The experimental results show that the improved crystallinity and phase purity of Cs + -doped perovskite with a wide band gap reduce the Urbach energy thus improving the VOC and efficiency of the device 22 Point Defect Tolerance of OIHPs It is generally believed that in OIHPs solar cells the lower density of charge traps makes them have a larger VOC However at this stage the understanding of charge traps is still in the preliminary stage Although most of the OIHP devices are synthesized by the low-temperature solution method the defect concentration of the OIHP devices is smaller than that of many polycrystalline inorganic solar cells Figs 5 (B) and (C) show the calculated possible point defects of MAPbI3 All the point defects that can form deep levels have large defect formation energies and will not affect the device performance while most of the point defects that exist in the bulk MAPbI3 will form shallow levels In addition the study shows that the energy level of MAPbI3 does not change even if 20% of the I ions in the film are lost (fig 5d) Fig 5 Defect tolerance of OIHPs (A) Defect state density of MAPbI3 polycrystalline thin film and single crystal; (B) Formation energy of intrinsic point defects in MAPbI3; (C) Energy levels of intrinsic donors (left) and intrinsic acceptors (right) in MAPbI3; (D) Defect tolerance of MAPbI3 Polycrystalline OIHPs have a lower defect density another reason is that perovskite materials are easy to crystallize It is found that the crystallization barrier of perovskite is 566 – 973 kJ/mol while that of polysilicon is ~ 471 kJ/mol 23 Defects on surface and grain boundary In addition to point defects extended defects at grain boundaries and interfaces also increase the defect concentration in OIHPs Atoms at grain boundaries and surfaces are not strictly stoichiometric which results in a higher defect concentration here For example after annealing the volatilization of organic components on the surface of the crystal will result in a larger defect density on the surface Even the surface of OIHPs single crystal has many defects and the recombination of surface photogenerated carriers will terminate the photoresponse of short-wavelength light Photoresponse occurs only when the energy of the photogenerated charge is close to the energy band This surface recombination can also explain the phenomenon that the fluorescence lifetime of perovskite single crystals changes with different penetration depths of light (Figure 6a) The surface charge recombination mechanism of perovskite materials is complex The defect density of each crystal plane of the perovskite surface is different There are two crystal planes (100) and (112) on the surface of MAPbI3 single crystal and there are many orientations (110) (202) (310) and (314) on the surface of MAPbI3 polycrystalline film The results show that only (100) is uncharged and the others are charged so there are other ions to balance the surface charge In addition the binding energy of the organic components of different crystal planes is different so that the surface defect density shows crystal plane dependence Fig 6 B shows that the floating of VOC of different crystal planes on the same crystal grain reaches 06 V In addition the surface recombination rate is sensitive to the composition and the ambient humidity The ozone treated MAPbBr3 single crystals showed significant fluorescence enhancement and growth of radiative recombination lifetime at the crystal surface (Fig 6C) Fig 6 Surface charge recombination of OIHPs (A) Schematic of charge recombination and collection under the influence of surface defects and its effect on fluorescence lifetime (bottom left) and narrow-band light detection (bottom right); (B) AFM of the polycrystalline thin film; (C) PL of MAPbBr3 single crystal after vacuum and UV – O3 treatment (left) fluorescence lifetime of MAPbBr3 single crystal after vacuum and air treatment 24 Characterization of Defect Density Accurate characterization of the charge defect density of OIHPs materials is crucial for understanding the relevant optoelectronic properties There is still a lot of defect data unknown at this stage An early method to measure the defect density is thermal admittance spectroscopy which can give the density of defect States at different depth levels The results show that the physical contact of MAPbI3 polycrystalline film with PCBM and C60 can reduce the shallow and deep energy levels by 1 to 2 orders of magnitude indicating that the defects are mainly on the surface of the film (Fig 7A) In order to understand the internal defect density of the single crystal the defect density was evaluated by the trap filling space charge limited current method (fig 7 B) Understanding the defect density of electrons and holes can provide better conditions for designing new perovskite materials with better performance However the current method of measuring defect density can only get the total defect density To separate electrons from holes fig 7c shows a photoconductive element with a carrier acceptor layer of only one type of carrier Fig 7 Charge defect density and surface passivation of OIHPs (A) reducing the defect density of States of deep and shallow level defects by surface passivation of C60 and PCBM; (B) Current-voltage diagram of MAPbI3 single crystal device; (C) Schematic diagram of the symmetrical lateral contact device; (D) Defect density of States (NT) within the band gap 25 Role of ion migration Ion migration is the unique property that distinguishes OIHPs from other photovoltaic materials In this paper we focus on the effect of ion migration on device efficiency and stability Ion migration and aggregation can form a chemical doping effect which is the result of ohmic contacts of high-efficiency solar cells with p – I – n or n – I – p structures (Figure 8 a) A recent study shows that solar cells with n – I – p structure have abnormal photovoltaic effect (Fig 8B) This effect was observed in solar cells with MAPbI3 MAPbBr3 and CsPbBr3 as active layers Some studies have shown that ion migration can improve the short-term stability of materials but weaken the long-term stability of perovskite solar cells Figure 8C shows that the performance of the device degrades under light and can be partially or fully restored after a period of time in the dark This self-healing effect is most likely related to ion migration (Figure 8 d) Because that time it take for the ions to migrate in the film (a few second or minutes) is much shorter than the aging time of the film (day or months) the crystalline phase transition between MAPbI3 and PbI2 causes reversible ion migration so that ion migration has the effect of "repairing" local lattice distortions Self-healing due to ion migration requires sealing of the sample to prevent volatilization of the substance and chemical reaction of the surface with airborne substances In some studies the grain boundaries of MAPbI3 films were filled with polyvinyl alcohol to prevent the volatilization of MA + cations thus playing a self-healing effect to enhance the stability of the device (Fig 8e) Figure 8 Ion migration in OIHPs (A) Schematic diagram of p-type n-type in-situ doping and ohmic contact interface in MAPbI3 solar cell device; (B) Scattered tunnel junctions due to local ion aggregation in electrically poled polycrystalline perovskite films resulting in band shifts and anomalous photovoltaic effects; (C) Self-healing phenomena of two types of perovskite solar cells; (D) in the MAPbI3 film the defect concentration is reduced due to the redistribution of photogenerated carriers; (E) Illustration of self-healing achieved by filling MAPbI3 grain boundaries with polyvinyl alcohol 3 Conclusion and prospect In the past few years great progress has been made in understanding the unique physical properties of OIHPs In this paper the intrinsic optoelectronic properties of OIHPs are discussed and these properties are combined with the device performance The properties of OIHPs prepared by solution method such as optical absorption carrier defect depth exciton binding and charge diffusion length are much better than those of covalent-bonded photovoltaic materials (such as Si GaAs and CdTe) prepared by high temperature and vacuum method However the influence of intrinsic optical and electrical properties such as intrinsic defect concentration charge screening and ion migration on the performance of materials is still not well understood Although great progress has been made in the study of mechanism there are still many important problems to be further explored The ferroelectric properties of MAPbI3 still need to be further studied and the substitution of FA + Rb + Cs + or Co2 + for MA + cations will provide a way to understand the role of ferroelectric dipoles Recent studies have improved the device efficiency by introducing external ions and adjusting the composition The role of external ions needs to be further understood which is conducive to further understanding the shortcomings of MAPbI3 materials with single component Another direction is to understand the internal correlation between the intrinsic characteristics of materials (electrical mechanical optical and spin properties) and device properties Although the larger lattice constant of OIHPs makes the material have ion migration effect the reason why these properties make the material have larger dielectric constant and better structural stability is still unclear The understanding of the unique optoelectronic properties of OIHPs materials will provide conditions for the discovery of perovskite light absorbers that are non-toxic and stable in air for a long time Literature Link Understanding the physical properties of hybrid perovskites for photovoltaicapplications (Nat Rev Mater 2017 DOI 101038/natrevmats201742) This article is contributed by Zhu Xiaoxiu a material person and edited by Material Niu Material Cattle Network focuses on tracking the progress of science and technology and industry in the field of materials It brings together students from universities first-line researchers and industry practitioners If you are interested in tracking the progress of science and technology in the field of materials interpreting high-level articles or commenting on the industry Contribution and content cooperation can be added to the editor's WeChat xiaofire-18 Wu Mei we will invite teachers to join the expert group

Contact information of test valley cooperation Tel 010-5742 9831 QQ 3234370334 E-mail kefu@ceshigucom Material Man Cooperative contact Test Valley Material People's One-stop Material Analysis and Testing Solution Platform Has Been Revised and Launched! (http//wwwceshigucom/) Test Business XRD/TEM/SEM/DSC/AFM/Mechanical Test/Thermal Analysis/PPMS/IR/Particle Size Analysis Technical services Thesis polishing/Thesis drawing/Theoretical calculation/EBSD data analysis/MS use guidance/TEM operation guidance Recruitment services release/push/publicize the recruitment needs of enterprises match/customize/recommend talents according to job requirements please contact QQ 3271467181 Business cooperation 15120014412 Material test kefu@ceshigucom Submission email tougao@cailiaorencom Material people are here waiting for you to return to Sohu to see more Responsible Editor
1.75mm! RM once again surpasses and proves itself _ movement _ balance _ thickness Jobs - Employee 2022-08-15
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1.75mm! RM once again surpasses and proves itself _ movement _ balance _ thickness

Originally published as 175mm! RM has titanium bar grade 5 surpassed and proved himself again Depth/degree/minute/analysis/member Whenever you mention RICHARD MILLE what do you think of Is it innovative materials high-tech or avant-garde appearance light weight Now there is another pronoun-the king of ultra-thin Just last week RICHARD MILLE launched the RM UP-01 FERRARI watch with Ferrari As we all know since last year the two have formally established a long-term partnership and it is perfectly normal to launch a cooperative model However the reason why this wristwatch has flooded the whole network is that the whole watch has refreshed the latest world record of 18 mm a few months ago with a thickness of 175 mm RICHARD MILLE has never been disappointing bra tape measure">bra tape measure The thickness of the watch case does not seem to matter but it may become a burden for the wearer both visually and physically and ultra-thin watches emerge as the times require But ultra-thin is not just as simple as watch case lightening it has extremely stringent requirements for the movement after a long period of market choice only a few strong watch brands are still working tirelessly to break through and innovate In fact strictly speaking RICHARD MILLE is not an expert in the field of ultra-thin watches but this brand is born to refuse to lose either do nothing or do the best character so that they often break through the imagination of the limits of watches this RM UP-01 6al4v titanium bar FERRARI wristwatch came out in the air It is the best evidence that RICHRAD MILLE has surpassed itself again Expand the full text Many people will find that its design is different from the previous watches at the first sight of the chart from the original vertical barrel type to the horizontal barrel type and behind this change in appearance there are many RICHARD MILLE ""

Niubi "technologies Previously in order to achieve the ultimate ultra-thin other brands adopted the design of "using the case as the bottom plate of the movement" but this RM UP-01 FERRARI watch the case and the movement are completely independent the thickness of the whole watch is 175 mm and the thickness of the movement is only 118 mm Because the challenge of ultra-thin watches requires abandoning the traditional movement design of superimposed gears and pointers RICHARD MILLE chooses to disperse the parts that can not be superimposed to a wider plane creating a perfect symbiosis between the movement and the case while ensuring the necessary rigidity of both Seen from the front the time display area is very small In the upper part of the center the upper part of the titanium exhaust tubing left side is the function selector which can select the winding or time adjustment and the lower part is the specific operating point; the upper half of the right side is the explicit balance wheel and the lower part is Ferrari's classic Prancing Horse logo Titanium alloy is selected as the case material of RM UP-01 Ferrari watch because of its lightweight and laboratory-proven impact resistance and its waterproof depth can reach 10 meters Two sapphire crystal mirrors (02 mm at the thinnest point) one mounted on the time indicator with the hands fixed directly to the gears and the other mounted on the balance and hairspring mechanism show the operation of the movement while the thickness is reduced to two tenths of a millimeter and the diameter is carefully calculated to meet the resistance requirements of the test phase In order to ensure the ideal operation of the transmission mechanism the bottom plate and the bridge plate are also made of five-grade titanium alloy which ensures the perfect thinness without affecting the hardness From a technical point of view titanium sheet grade 5 the RM UP-01 FERRARI watch can be 005 mm thinner than 18 mm because RICHARD MILLE has innovated the escapement part and won a patent

Traditional Swiss mechanical watches mostly use lever escapements with fork nails and balance plates inside which can prevent the anchor from slipping during the free movement of the balance wheel but the problem is that the structure of these two parts is vertical that is to say they need longitudinal space and can not reduce the thickness In order to reduce the thickness RICHARD MILLE has eliminated the fork nail and the small plate of the balance wheel and through the patented new escapement structure it has replaced these "anti-rollover" elements with the unprecedented use of a longer escapement fork with a new fork mouth At the same time the movement also cancels the fast and slow needle system uses the variable inertia balance wheel made of titanium alloy and is equipped with six weights that can fine-tune and calibrate the speed control mechanism which solves the biggest problem of ultra-thin watches and reduces 005 mm naturally In addition it can be seen that this watch has no crown because in order to ensure the extreme thinness of the watch RICHARD MILLE has rethought the winding mechanism and eliminated the winding shaft titanium plate gr7 (because its minimum diameter is 15 mm it can not be included in such a thin watch) RICHARD MILLE's solution to this is to use two crowns one for function selection and the other for adjustment of the selected function both of which are integrated into the case as movement gears resulting in the design we have seen above As Salvador Arbona technical director of RICHARD MILLE movement said "Even in the ultra-thin series we have to create a watch that meets the brand's standards" In the pursuit of absolute thinness we are not creating a'concept watch ' but making it meet the wearer's daily needs in any environment Like all previous RICHARD MILLE watches the brand always puts practicality in the first place on top of all innovations first of all the necessary shock resistance and impact resistance of the watch so the RM UP-01 movement inside the watch can withstand acceleration of more than 5000 G Looking back on the connection between RICHARD MILLE and Ferrari from the pursuit of high technology to the use of similar materials as well as the passion for their respective fields all of these are based on the common values of both sides courage to try assiduous study and excellence which also gives a competitive spirit to this cooperation project Is essential in an exciting adventure

Wen | Xilin Design | Jili Figure | From the brand partly from the network More exciting content can be found on the official WeChat account of Time Square Time Concept Welcome to pay attention! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById('brands')innerHTML = getBrandHtml(); }; })();。
[Scientific and Technological Achievements Push] Shanghai Academy of Sciences Laser Coaxial Fuse-Industrial Metal 3D Printing Technology _ Parts Jobs - Employee 2022-08-15
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[Scientific and Technological Achievements Push] Shanghai Academy of Sciences Laser Coaxial Fuse-Industrial Metal 3D Printing Technology _ Parts

Original Title [Scientific and Technological Achievements Push] bra tape measure Shanghai Academy of Sciences Laser Coaxial Fuse — Industrial Metal 3D Printing Technology -Shanghai Academy of Sciences- Project name Laser coaxial fuse Industrial metal 3D printing technology 01 Project background Industrial metal 3D printing technology is an important direction of intelligent manufacturing and additive manufacturing in the future At present most of the mature metal printing equipment in the domestic and foreign markets are based on powder as consumables but this technology is suitable for printing small and precise metal parts and the material loss is large and the efficiency is low The development and application of industrial metal wire 3D printing technology overcomes the above defects of powder printing and is more suitable for the printing and manufacturing of large metal parts with obvious advantages 02 titanium tubing price The unit to which the project belongs Shanghai Academy of Sciences 03 Project introduction At present the 3D printing technologies using metal wires at home and abroad mainly include arc deposition forming electron beam paraxial wire feeding and laser paraxial wire feeding which are compared with our laser coaxial fuse metal 3D printing technology as shown in the following figure

Laser coaxial fuse metal 3D printing technology its principle is to first expand the laser beam then shape to the annular laser beam then focus the annular laser the metal wire passes through the center of the annular laser when the metal wire reaches the focus of the laser it forms a metal melt pool when the action of wire feeding is continuous it is matched with the bottom Then the molten pool will be cooled and solidified according to a certain trajectory and a certain shape of metal parts can be printed titanium round bar The schematic diagram is as follows Expand the full text This core technology is very important and advantageous The laser ring can make the laser focus fall on the central axis of the metal wire and the surface of the wire is irradiated by laser beams in 360 degrees which greatly improves the utilization rate of laser energy; The wire material and the laser are coaxial so that the metal molten pool can be formed and solidified along any direction that is printing can be carried out along any direction and the problem of directional defects caused by the traditional paraxial wire feeding is solved The advantages of laser coaxial fuse metal 3D printing technology in printing are mainly as follows 1 can print super-large parts suitable for industrial applications; 2 that quality and efficiency of prin metal parts are relatively high; 3 that prin material is a metal wire material so that the cost is greatly reduced; 4 It has higher environmental protection than powder metal printing technology; Therefore our technology and equipment are

The first in China It not only fills the gap in the field of additive manufacturing in China It also improves the ability of printing large metal parts in China 04 Technology application 1 Print large metal parts large metal forgings and castings such as those used in aerospace and other fields with high technical content and accessory value 2 Repair of large shaft parts especially the remanufacturing and production process of large shaft parts in power generation equipment If our 3D printing technology is integrated with robots we can develop a laser coaxial fuse 3D printing robot which is equipped with the following equipment This equipment can not only print large parts 3d titanium wire but also be used in large shaft repair and other processes The application cases are as follows 3 If our 3D printing technology is integrated with the traditional five-axis CNC machine tool we can develop a five-axis composite CNC machine tool The five-axis material-adding and material-reducing composite machine tool not only has a good five-axis cutting function but also integrates the functions of five-axis metal wire 3D printing or five-axis metal powder 3D printing The technical equipment has a wide range of applications and can directly generate precision metal parts realizing the complementary advantages of material-adding and material-reducing processes The applicable cases are as follows 05 Research results Since 2014 the R & D team has been composed of engineers and technicians with rich R & D experience in mechanical electrical software process and materials With the support of major projects of the Science and Technology Commission the team has obtained 8 patents and 3 software copyrights and the achievements have been transformed into high-tech achievements in Shanghai

A series of metal 3D printing equipment such as resin metal powder and metal wire have been developed and applied in industrial production such as medical treatment and manufacturing 06 Intellectual property rights applied for Serial No Patent No/Soft Work Patent Name Application Date 1 Wire-fed 3D printer with laser as heat source 2 wire-feeding 3D printer using laser as heat source and printing method thereof Coaxial wire feeding cladding head for laser metal printing 4 Selective laser melting forming equipment 5 Leveling mechanism of 3D metal printer working platform 6 a 3D metal printer with a powder return mechanism 7 Explosion-proof wet type dust collector 8 ti6al4v eli SLM Metal 3D Printing Process Control Software 9 SLM metal powder bed 3D printing molding control software 10 Metal wire 3D printing molding control software 11 separating mechanism for bottom projection type photo-curing rapid prototyping and forming device thereof 07 Key team members Zhou Weimin Graduated from Shanghai Jiaotong University Doctor Researcher Expert of "Special Government Allowance of the State Council" won the Gold Prize of Excellent Invention in the 23rd

Shanghai Excellent Invention Selection Competition Honors such as "The Third Shanghai Workers'Science and Technology Innovation Newcomer Award" "Advanced Workers of Shanghai Science and Technology System in 2013-2014" "May 4th Medal of Youth of Shanghai Science and Technology System" and "May 1st Labor Medal of Shanghai" have presided over or participated in more than ten projects presided over the development of printers and materials and established a 3D printing research and development service system Si Titanium welding pipe Junping Graduated from East China Jiaotong University majoring in mechanical design and processing technology with 20 years of experience in the development and research of 3D printing industry he is an important backbone of the R & D team mainly responsible for the research of mechanical structure and technology and the design of technical schemes Participated in and successfully developed SLA principle 3D printer SLM principle 3D printer DLP surface light source 3D printer and WLAM principle metal 3D printer Xia Zhangwen Doctor female graduated from the University of Birmingham UK During his doctoral studies in the UK he was awarded by the UK Engineering and Natural Sciences Research Council and Rawls Royce Company (Rolls-Royce) under the guidance of Professor Paul Bowen academician of the Royal Academy of Engineering has been engaged in research in the field of metal 3D printing for many years at Rolls-Royce-University of Birmingham Technology Centre (UTC) and has participated in the "Advanced Science and Technology Research Project" led by the British Engineering and Natural Science Council and Rolls-Royce (with a total investment of 12 billion pounds) The application of laser additive manufacturing (3D printing) technology in the production and repair of aero-engine blisks was studied and the macroscopic and microscopic structures and mechanical properties of nickel-based and titanium-based alloys under laser additive manufacturing were systematically and thoroughly studied 08 Contact information Return to Sohu to see more Responsible Editor
Tang Yan's cool and handsome dress, compared with Jing Tian's ladylike style, who Jobs - Employee 2022-08-15
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Tang Yan's cool and handsome dress, compared with Jing Tian's ladylike style, who will be better? _ Style _ Clothing _ Denim Original title Tang Yan's cool seamstress measuring tape and handsome dress compared with Jing Tian's ladylike style who will be better Mention "clothing" this word is basically a lot of girls like because it is well known that girls like to buy clothes and now most of the clothing is "trendy" as a hot word the trend has led to a series of single product sales followed by the label of personality now a lot of clothing will be famous for the trend with stars and Internet celebrities as the representative So the star's wear is more trendy collocation like Tang Yan's style is also the style is very suitable for young people jeans material is very suitable for fashion Tang Yan such a sweet girl control is also handsome Cowboy has always been the label of bra tape measure young people but also the origin of a cowboy culture a lot of clothing with denim cloth will be cool to no good but also the format is different the temperament of clothing is not the same more importantly there are their own modeling collocation Tang Yan has maintained her long hair this is her label has not changed plus bangs she really looks younger Eyes are very spiritual jewelry collocation is also to show such a cowboy style retro red pendant is also full of personality neck collar is also a bright spot the overall collocation effect is very good Expand the full text Denim material is very retro material the deep color can increase the temperament of fashion format is OD(outside diameter)tape measure also very young style suitable for Tang Yan such an age of girls clothing design did not increase a lot of design but it is such a simple style to interpret Tang Yan this age of young style matching high boots can appear long legs but also appear to be very elegant In addition Tang Yan's height is not short and her figure is particularly thin which can be seen from the control of this skirt Tang Yan's wear is really hard to hide the cool style plus slightly curly long hair style more fashionable style this time Tang Yan is wearing a very simple style of wear from the upper body and lower body collocation are very suitable for daily life wear the color of the jacket is very bright but it is also a very simple T-shirt the main color of rose-red is also a reflection of feminine charm Matching jeans is also very stylish garment measuring tape plus different colors of the pattern collocation is very Fan the most important is Tang Yan's handbag color is really not the average person can control too eye-catching Jing Tian is also an actress we are familiar with Her dress is not bad at all Her clothes are particularly attractive because her temperament is so good Compared with Tang Yan's personality Jing Tian's ladylike style is also great The fashionable skirt has a fashionable temperament which can be seen from Jing Tian's control The design of the figure is too considerate And Tang Yan's figure contrast is not bad two people belong to the same actor this profession the same star halo whether from wear or figure the two are on a par Black skirt seems to be a little personality temperament this is Jing Tian rarely to control a style the overall skirt can be seen capable and simple compared with Tang Yan's jeans simple style Jing Tian's body is the simple style of skirt the design of the belt is also very characteristic both decoration and to highlight the difference not only is a capable temperament From Jing Tian's eyes can also see a trace of charming feeling Jing Tian and Tang Yan in the clothing are very good control Disclaimer Original content text without authorization can not be reproduced some pictures from the network if there is infringement please contact to delete thank you! Return to Sohu to see more Responsible Editor (function() { function getBrandHtml() { var brands = [] html = ''; for(var i = 0; i < brandslength; i++) { var brand = brands[i]; if(brandslength i+1) { html+= ''+brandname+''; } else { html+= ''+brandname+'、'; } } return html; }; if(documentgetElementById ('linkBtn')){ documentgetElementById('linkBtn') = function() { $('#brands')removeClass('brand');$ ( '# tipInfo')text ( 'Real name responded'); $ ('#linkBtn')remove();$ ('real-response content')css('line-height' '20px');$ ('real-response time')css('line-height' '20px'); }; documentgetElementById ('brands')innerHTML = getBrandHtml(); }; })();。
How to add an online custom map in Ovi _ webst Jobs - Employee 2022-08-15
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How to add an online custom map in Ovi _ webst Original title How to add online custom bra tape measure maps in Ovi In Ovi Interactive Map Browser you can not only browse the built-in Sky Map Sky Map Image and Baidu Map but also add custom maps such as online Internet maps and aerial maps Description Preconditions for normal addition of online Internet maps (1) The map to be added adopts Mercator projection such as Amap and Tencent Map or adopts longitude and latitude projection such as China Geological Map (2) The URL link of the picture must contain the coordinate value XY of the map picture and the zoom level value Z of the map (3) The added map is displayed as a picture in JPG or PNG format and the size of each tile is 256256 or 512512 pixels 1 Get an online map URL Enter the official website of the map you need to add and use the browser to view and parse the host name host number URL size and format of the map as shown below In this paper printed tape measure Amap and road network are taken as examples (1) Use the browser to open Amap (https//dituamapcom) switch to the satellite map press the F12 function key and the developer tool will pop up (2) Click [Network] on the top of the developer tool to switch to the network interface move and zoom the map and the detailed information of the network request will be added to the list as shown below The following figure shows the request information of the satellite map Expand the full text Double-click any entry to copy the URL (https//webst04isautonavicom/appmaptilestyle=6&x=26969&y=12397&z=15) into the TXT text You can also see the title of the page "app map tile (256256)" and the "256256" is the dimensions of the tile Edit the URL in TXT text as follows (1) Change "X = 26969 & y = 12397 & Z = 15" to "X = { $X } & y = { $y } & Z = { $Z }" that is replace the fixed X y and Z coordinate values with variables Original URL https//webst04isautonavicom/appmaptilestyle=6&x=26969&y=12397&z=15 edited URL https//webst04isautonavicom/appm aptilestyle=6&x={$x}&y={$y}&z={$z} (2) Use the webst04 Is Autonavi Com "as the host name For some online maps the data may be distributed and stored on multiple servers You can place your mouse over the request information and watch the host name change in the URL bra tape measure For example for Amap the host number will change from "webst01 to webst04" Replace the changed part with the variable "{ $serverpart }" for example "4" is replaced by "{ $serverpart }" and the final hostname is "webst0 { $serverparts } Is Autonavi Com" Original URL https//webst04isautonavicom/appmaptilestyle=6&x=26969&y=12397&z=15 edited URL https//webst0 { $serverpart } Is Auton avicom/appmaptilestyle=6&x={$x} &y={$y}&z={$z} The URL format for some maps may be "https//atileopenstreetmaporg/6/50/22png" Where the a Tile Openstree tmap Org is the host name and the prefix a is the host number which varies from a to C and is replaced by "{ $serverpart } Tile Openstree tmap Org" "; /6/50/22png is the URL replaced by the variable "/{ $Z }/{ $X }/{ $y }png" Note If your graph is 512512 pixels that is X and y are divided by 2 and Z is subtracted by 1 2 Add a custom map On Ovi PC click [Custom Map]-> [Custom Map Management]-> [Add] Enter the [Custom Map [Add]] dialog box and set the parameters selected in the box in the following figure Explain (1) Map ID between 200-1000 the system will assign an ID number to each custom map without modification (2) Map name refers to the layer name which will be displayed under the [Custom Map] menu after setting such as "Amap Satellite Map" (3) Maximum level The highest level of the map For example the highest level of the Amap satellite map is 18 You can set it to 18 or above (4) Projection type You can choose according to the actual situation of the map generally [Mercator China] or [Mercator Global] The Amap uses Mercator China so this article chooses Mercator China (5) Picture type you can select according to the actual situation of the map For topographic map satellite map (or image map) select [Image Map]; for other maps select [Normal Map] (6) Picture format you can choose according to the actual situation of the map The Amap is JPEG so select [JPG]; the Open Stree tMap is "PNG" custom tape measure You can see it in the page map request information (7) Image size You can select according to the actual situation The size of a tile in the Amap satellite image is "256256" so select [256 pixels] Some maps may be "512512" You can view the tile size by clicking on a tile in the page map request information and switching to [Preview (header)] (8) Host name Please fill in according to the actual situation According to 1 Get an online map For the analysis in URL the is Autonavi Com "" webst0 { $serverpart } "Should be filled in the Amap (9) Port number online Internet map which is usually kept as default If the network port number is set for your map server it needs to be filled in (10) Host number you fill in according to the actual situation of the map The Amap is "1 to 4" and the OpenStree tMap is "a to C" (11) URL you fill in according to the actual situation of the map The Amap is "/appmaptile Style = 6 & X = { $X } & y = { $y } & Z = { $Z }" and the OpenStree tMap is "/{ $Z }/{ $X }/{ $y }png" Note If your graph is 512512 pixels that is X and y are divided by 2 and Z is subtracted by 1 After setting click [OK] You can browse the map by clicking [Customize Map] and selecting the layer to be added Special instructions Some maps require a token or secret key to access such as Sichuan Sky Map Sichuan map token generation link http//wwwscgisnetcn/imap/iMapServer/Token/defaultaspx The layer configuration information of Gaode Road Network is as follows Image type Normal map Image format PNG Image size 256 pixels Host name wprd0 { $serverpart } Is Autonavi Com Port number Default host number 1 to 4 URL/appmaptile x={$x}&y={$y}&z={$z} &&lang=zh_cn&size=1&scl=1&style=8 [OK] Under the [Custom Map] menu select [Amap Satellite Map] to view the road network and satellite map 4 Commonly used maps URL (1) Amap (small font) Projection Type Mercator China Image Type Normal Map Image Format PNG Image Size 256 pixels Host Name webrd0 { $serverpart } Is Autonavi Com Port Number Default Host Number 1 to 3 URL/appmaptile lang=zh_cn&size=1&scale=1&style=7&x={$x}&y={$y}&z={$z} (2) Amap (large font) Projection Type Mercator China Image Type Normal Map Image Format PNG Image Size 256 pixels Host Name wprd0 { $serverpart } Is Autonavi Com Port Number Default Host Number 1 to 4 URL/appmaptile lang=zh_cn&size=1&style=7&x={$x}&y={$y}&z={$z} &scl=1 We respect the author's achievements if suspected of infringement please contact us to delete in time Return to Sohu to see more Responsible Editor tape-
How to make bridge expansion joints? These on-site construction workers are already worried about losing their hair! _ Deck Jobs - Employee 2022-08-15
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How to make bridge expansion joints? These on-site construction workers are already worried about losing their hair! _ Deck

Originally published as How to make bridge expansion personalised tailor tape joints These on-site construction workers are already worried about losing their hair! In order to meet the requirements of bridge deck deformation expansion joints are usually set between two beam ends between beam ends and abutments or at the hinge position of the bridge The expansion joint is required to be able to expand and contract freely firmly and reliably in two directions parallel and perpendicular to the axis of the bridge The vehicle shall run smoothly without sudden jump and noise It shall be able to prevent the infiltration and blockage of rainwater garbage and soil The installation inspection maintenance and elimination of dirt shall be simple and convenient At the place where the expansion joint is set the railing shall be disconnected from the deck pavement Overview of expansion joints Brief introduction of bridge expansion joints The function of bridge expansion joints is to accommodate the displacement and coupling between the superstructure caused by vehicle loads and bridge construction materials Once the expansion device of skew bridge is damaged it will seriously affect the speed comfort and safety of driving and even cause traffic accidents Expansion joint function Ensure free expansion and contraction of beam body Make the vehicle run smoothly Good water tightness and drainage large print tape measure Convenient for removing dirt in the groove The expansion and contraction of the bridge is exposed to the atmosphere for a long time and the use environment is relatively harsh which is the most vulnerable and difficult to repair part of the bridge structure The destruction of bridge expansion joints may cause great vehicle impact load and worsen the driving condition which will lead to vehicle jump noise water leakage affect the safety of driving and sharply reduce the service life of the bridge Hazards of loss of function or damage to expansion joints The expansion and contraction is blocked or the top of the pier and abutment is damaged or the internal force of the beam body is increased The vehicle jumps and runs unstably The impact increases causing damage to the bridge especially at the end Water seepage endangers durability Expansion joint model The bridge expansion joint models are GQF-C GQF-Z GQF-E Gqf-F and Gqf-MZL all of which are bridge expansion joint products designed with hot-rolled integrally formed special-shaped steel GQF-C GQF-Z GQF-L and GQF-F bridge expansion devices are suitable for bridges with expansion amount less than 80mm GQF-MZL bridge expansion joint device is a modular bridge expansion joint device composed of edge beam middle beam cross beam and linkage mechanism which is suitable for large and medium span bridges with expansion amount of 80mm-1200mm The code representation method is consistent with the standard representation method of the transportation industry of the People's Republic of China taking GQF-C60 GQF-F80 GQF-MZL480 gqf-c60 (NR) gqf-f80 (CR) as examples GQF is the code of expansion joint device specified in the traffic industry standard Type code -MZL means modular type straight beam connecting rod chain type (C Z F L) indicates the shape of the profiled bar The number indicates the displacement of the expansion device 0-1200mm NR and CR indicate the type of rubber NR indicates natural rubber and CR indicates chloroprene rubber Type of expansion joint Seamless type blind joint type (continuous bridge deck TST) Expand the full text Butt joint type caulking butt joint type embedded butt joint type (imitating Moeller type) Steel support type (comb plate) Combination type rubber plate type Modular formula Mauler formula Seamless The invention relates to a seamless expansion device which is characterized in that when a joint structure does not extend out of a bridge deck an expansion gap at the end part of a bridge is filled with an elastic material and paved with a waterproof material and then a viscoelastic composite material is paved on a bridge deck pavement layer so that the bridge deck pavement at the expansion joint and the road surface form a continuum and the expansion of a beam body is absorbed by the deformation of materials such as asphalt concrete elastic-plastic bodies and the like at the joint While providing support for the wheel The common forms are continuous bridge deck TST gravel elastic-plastic expansion joints and so on The main characteristics of this kind of expansion device are ① It can adapt to the expansion deformation and small amount of rotational deformation of the bridge superstructure; ② It makes the bridge deck pavement form a continuous body which does not produce impact and vibration during driving and has good driving comfort; ③ The expansion device itself forms a multiple waterproof structure which has good waterproofness; ④ In cold areas it is easy to remove snow mechanically and maintain without damaging the joints; (5) that construction is simple and easy and the maintenance and replacement are convenient

This type of expansion device is generally a structure formed by cutting the pavement with a cutting machine after the construction of the pavement (bridge deck) is completed and injecting caulking material into the notch which is only suitable for parts with small expansion amount (generally < 40 mm) The service life of the seamless expansion joint adhesive installed in strict accordance with the process requirements is about twice that of the general modified asphalt pavement Continuous expansion joint of bridge deck TST macadam elastic-plastic expansion joint TST adhesive usually does not become brittle at minus 40 C and does not flow at high temperatures up to 80 C in summer It can be used normally throughout the country Because of the high temperature adhesion characteristics of TST it can be firmly bonded with the existing pavement during construction and it is not sticky at room temperature and it will not be taken away after cooling TST is a kind of special material with high viscoelasticity and plasticity which is in elastic-plastic state at normal temperature It can be poured into gravel after melting at high temperature After forming it is like asphalt concrete which can bear the load of vehicles and has elasticity It can replace the function of small expansion joints The construction is convenient and fast and the traffic can be opened after the pavement is cooled When the expansion joint needs to be replaced it can be constructed in half Do not interrupt traffic on busy road sections Construction technology of TST seamless expansion joint 1) Grooving set out and cut joints according to the notch width determined by the design requirements remove the cut pavement materials and clean the notch 2) Reinforcement planting drive an expansion bolt at an interval of 25 cm in the transverse direction at a distance of 5 cm from the edge of the notch to a height of 1/2 the depth of the notch and weld a 12 reinforcement along the seam on the nut inside the bolt And 3) fil that sponge body namely cleaning the notch by use high-pressure water and then baking and drying the surface of the notch by use flame Fill the gap between adjacent beam ends with sponge rubber strips as much as possible without leaving any gap 4) Apply the special adhesive for TST evenly on the exposed surface of the notch pour the melted TST after 15 minutes and apply it evenly on the bottom and side of the notch with a scraper with a thickness of 1 ~ 2 mnl The cross-seam steel plate is then placed to be fixed with a positioning nail and attention is paid to centering 5) From one end of the notch put in the large stones that have been fried (130 ~ 150 ℃) and the thickness is subject to the TST that can see the bottom layer The TST is then poured in to submerge the stones Lay layer by layer accordingly 7) Lay heated small stones which shall be 10 mm higher than the bridge deck vibrate them with a plate vibrator and then scrape them with a scraper Generally in order to prevent sinking it is 1 ~ 2 mm higher than the bridge deck At this time it can be trimmed arbitrarily and flattened with a shovel 8) Pour enough TST to submerge the stones in order to prevent TST from flowing to the bridge deck on both sides Both sides of the notch can be blocked with wooden boards to keep the edges neat 9) Trim the edge remove the baffles on both sides cool for 1 ~ 2h and open the traffic TST macadam elastic-plastic expansion joint Docking type The filling butt type expansion device is an expansion device which uses the elasticity of the expansion body to bear the wheel load The expansion body is made of sand gravel rubber products of various shapes foam plastic plates or synthetic resin materials The expansion body is always in a compressed state The common types are U-shaped zinc sheet type wood filling type asphalt filling type rectangular rubber strip type tubular rubber strip type and so on U type galvanized iron expansion joint is a kind of caulking butt joint expansion joint which was widely used in the 70's and 80's The main characteristics of this type of expansion device are ① low cost; ② easy processing of the required materials; ③ simple and easy construction; this type is generally applicable to the expansion amount of Bridges within 40mm are seldom used at present because of their poor durability and waterproofness and short service life The structural principle of the embedded butt type expansion device is that rubber products with different shapes are embedded and fixed by steel components with different shapes and then they are anchored with the beam body at the joint or the back wall of the abutment into a whole through an anchoring system The special-shaped steel provides support for the wheels and the deformation of the beam end is absorbed by the tension and compression of rubber strips and rubber belts The telescopic body can be in a compression state or a tension state This is a kind of expansion device which is widely used in the construction of highway bridges in China at present The common types are W SW M PG and so on This type of expansion device is suitable for bridge structures with expansion amount less than 80mm that is the joint width is 20mm-80mm The main characteristics of this kind of expansion device are ① simple structure clear stress and low cost; ② the main components of the expansion device are processed by the manufacturer and installed on the construction site and the connection with the beam end is generally welded by steel bars so the structure is reliable and the construction quality is easy to guarantee; ③ good durability; ④ good waterproof and drainage performance; ⑤ good driving comfort The two design principles of Mauler expansion joint are "rigid anchorage" and "sealing and waterproofing" 1) The anchorage of rigid anchorage expansion joint directly affects the service life of expansion joint The anchoring metal plate mainly plays the role of force transmission The fatigue tested anchoring device is directly welded on the edge beam At the same time the edge beams are rigidly connected to the bridge superstructure to ensure that the expansion joints carry the maximum traffic load Other methods of connecting expansion joints to the bridge superstructure with screws or bolts are not feasible under long-term dynamic traffic loads In this respect Maole expansion joint is designed to take the lead in separating the two functions of bearing and waterproofing which is more conducive to the strengthening and improvement of the two functions 2) Thoroughly waterproof One of the features of the Mauler expansion joint is that the neoprene sealing strip is effectively embedded in the groove of the edge beam which ensures complete waterproofing At the same time it can be replaced on the bridge deck or repaired by vulcanization with simple tools Under the protection of the edge beam the sealing strip is not directly rolled by the wheel and its V-shaped structure can play a role in removing sediment by itself The sealing strip can not only resist tension but also carry out lateral and vertical displacement In contrast the leakage of expansion joints will cause some damage to the bridge structure Steel bearing type The steel supported expansion joint is a structure assembled with steel which can directly bear the wheel load This kind of expansion device was used in steel bridges before but now it is also used in concrete bridges There are many kinds current situation and sizes of steel supporting expansion devices and the steel comb type is widely used The structure of the steel comb-type bridge expansion device is composed of a comb-type plate a connecting piece and an anchoring system Some steel comb-type bridge expansion devices are filled with synthetic rubber between the combs to play a waterproof role and some use special drainage grooves to solve the drainage problem Steel comb-type bridge expansion device is also a finger-shaped joint of steel plate which can be divided into supporting type and cantilever type according to the supporting condition of combs The main features of this type of expansion device are ① All components are processed and assembled by steel with high structural strength; (2) continuous support can be provided for the wheels and the driving comfort is good; ③ Embedded steel members shall be used for connection with the beam body and the connection shall be reliable; (4) strong impact and vibration resistance and good durability; ⑤ It can adapt to large horizontal displacement and can be used for large bridges This kind of expansion device is suitable for bridges with an expansion amount of more than 40 mm but its application range is not very wide due to its high cost Comb plate type expansion joint Rubber plate The rubber plate type expansion device makes full use of the characteristic of low shear modulus of the rubber material a bearing steel plate and an anchoring steel plate are arranged in the rubber body bolt holes are arranged and the rubber plate type expansion device is connected with the beam end into a whole through bolts This structure depends on the shear deformation of the rubber body between the upper and lower grooves to absorb the telescopic displacement of the beam and the steel plate is embedded in the rubber body to span the gap between the beam ends and bear the wheel load This kind of device was used earlier in China and there are many manufacturers in the country with different names mainly used in the 1980s and 1990s The rubber plate type expansion device has the advantages of simple structure convenient installation economy applicability and the like It is mainly suitable for highway bridges below Grade II with expansion amount of 30mm-60mm and is widely used in China

This kind of expansion device has the following performance characteristics (1) it relies on the shear deformation of the rubber body between the upper and lower steel plates to meet the structural deformation requirements After the device is deformed there is a certain deformation energy in the rubber body which will have a certain constraint force on the structure; ② The load-bearing cross-seam steel plate is embedded in the rubber body Compared with the steel structure expansion device it has a certain buffer effect on the impact force of the wheel effectively protects the expansion device and the beam body and improves the driving conditions ③ The angle steel of the expansion device effectively strengthens the end strength of the beam body The horizontal deformation internal force of the expansion body of the rubber plate expansion device is relatively large generally about 30-35 Nk per linear meter The greater the deformation the greater the horizontal force and the greater the possibility of overall damage to the device Therefore when selecting the rubber plate type expansion device it is necessary to consider the factors such as installation error and temperature error and the selected deformation margin should not be less than 30 mm to ensure the normal use of such devices Rubber plate type expansion joint Modular expression Modulus type bridge expansion device is composed of longitudinal beam (special-shaped steel) cross beam displacement control box rubber sealing belt and other components Rubber sealing strip (belt) with V-shaped section or other section shapes is embedded in the special-shaped steel edge beam and center sill to form a telescopic sealing body The special-shaped steel directly bears the wheel load and transfers the load to the beam which then transfers the load to the beam body and the abutment When the telescopic device absorbs the deformation of the beam end the displacement control box Ensure that the gap between the special-shaped steel is kept uniform; the rubber sealing belt is used to prevent sundries from entering and is waterproof 。 The modular expansion device can increase the number of middle beam steel and sealing body according to the actual expansion amount and can form an expansion device with large displacement which is generally used for bridges with expansion amount greater than 80 mm From the single seam of 8 Omm to the multiple seam of 12 OOmm there are 15 grades The main characteristics of this type of expansion device are as follows ① The whole expansion device is composed of special-shaped steel longitudinal beam steel cross beam control transmission mechanism displacement box sealing rubber strip and other components and the structure is complex; ② The sealing performance is good and the waterproof and drainage performance is good; ③ It is suitable for bridges with large expansion requirements; ④ The overall rigidity of the structure is high and the durability is good; ⑤ The driving comfort is good However due to the complex structure of the expansion device the maintenance and replacement require a wide range of professional and technical personnel and the high cost it is generally only used for large bridges with higher grades Magba modulus type bridge expansion device Modulus type bridge expansion device Modulus type bridge expansion device is composed of longitudinal beam (special-shaped steel) cross beam displacement control box rubber sealing belt and other components Rubber sealing strip (belt) with V-shaped section or other section shapes is embedded in the special-shaped steel edge beam and center sill to form a telescopic sealing body The special-shaped steel directly bears the wheel load and transfers the load to the beam which then transfers the load to the beam body and the abutment When the telescopic device absorbs the deformation of the beam end the displacement control box Ensure that the gap between the special-shaped steel is kept uniform; the rubber sealing belt is used to prevent sundries from entering and is waterproof 。 The modular expansion device can increase the number of middle beam steel and sealing body according to the actual expansion amount and can form an expansion device with large displacement which is generally used for bridges with expansion amount greater than 80 mm The main characteristics of this type of expansion device are as follows ① The whole expansion device is composed of special-shaped steel longitudinal beam steel cross beam control transmission mechanism displacement box sealing rubber strip and other components and the structure is complex; ② The sealing performance is good and the waterproof and drainage performance is good; ③ It is suitable for bridges with large expansion requirements; ④ The overall rigidity of the structure is high and the durability is good; ⑤ The driving comfort is good However due to the complex structure of the expansion device the maintenance and replacement require a wide range of professional and technical personnel and the high cost it is generally only used for large bridges with higher grades Type comparison Basis for setting bridge expansion joint The amount of beam expansion is the most important basis for the selection of expansion joints Basic factors affecting the expansion amount of expansion device 1 Temperature change Temperature change is the main factor affecting the amount of bridge expansion which can be divided into linear temperature change and nonlinear temperature change and the linear temperature change is the dominant factor affecting the amount of bridge expansion

When the bridge structure is in a specific temperature environment the temperature distribution inside the beam is not uniform and the end of the beam produces angular displacement under the change of material thermal properties For the bridge with small span (L ≤ 8m) the linear expansion coefficient is very small so it can be ignored; for the bridge with large span enough attention must be paid in the design For general design the linear expansion coefficient can be calculated according to the following table Temperature variation range and linear expansion coefficient 2 Shrinkage and creep of concrete Shrinkage and creep of concrete are the inherent properties of concrete components and also a random phenomenon Concrete's mix proportion water-cement ratio slump cement variety temperature relative humidity concrete's loading age load holding time and strength have great influence on concrete's shrinkage and creep retractable tape measure sewing Shrinkage and creep shall be considered for both reinforced and prestressed concrete bridges The creep volume is obtained by multiplying the elastic deformation of the beam under the action of prestress by the creep coefficient = 2; the shrinkage is converted by the temperature drop of 20 ℃ At the time of installation the shrinkage and creep have developed to a certain extent so the calculation should be based on the installation time and the shrinkage and creep of concrete should be reduced The reduction factor β can be selected by referring to the following table 3 Longitudinal gradient of bridge The movable bearing in longitudinal slope bridge is usually made horizontal When the bearing is displaced the expansion joint not only has horizontal displacement but also has vertical dislocation (Δd) which is equal to the horizontal displacement multiplied by the longitudinal slope tgθ 4 Displacement of skew bridge and curved bridge When deflection (ΔL) in the direction of bearing displacement occurs in skew and curved bridges deflection also occurs along the bridge end line and in the direction perpendicular to the bridge end line that is Δd = ΔL · SINα ΔS = ΔL · COSα where α is the inclination angle and ΔL is the expansion and contraction amount 5 Bridge deflection caused by various loads Under the action of live load and dead load angular displacement occurs at the end of the bridge which causes vertical horizontal and angular displacement of the expansion device If the beam body is relatively high vibration will also occur 6 Earthquake The influence of earthquake on the displacement of expansion device is complex and difficult to grasp at present so it is generally not considered in the design However if there is reliable data to calculate the subsidence rotation horizontal movement and inclination of bridge pier and abutment caused by earthquake it should be considered in the design Calculation of expansion and contraction of beam A prestressed concrete beam bridge with a beam length of 40 m and a temperature variation range of -4 C ~42。 C; linear expansion coefficient α = 10 × 10-6; shrinkage strain ε = 20 × 10-5; creep coefficient φ = 20; shrinkage and creep reduction coefficient β = 06; average axial stress of prestressed concrete σp = 80kg/cm2; elastic modulus of concrete Ec = 34 × 105kg/cm2; installation temperature 20C Defect and maintenance of expansion joint Failure form and cause analysis Under the condition of no overload the recommended fatigue life of the expansion joint is 10-15 years 1) For the filling butt type expansion device if the angle steel falls off the concrete on both sides is broken the concrete on the abutment side is completely broken the rubber belt is broken and the pit is very deep it can be judged that the service life is over 2) For the seamless expansion device if the jump is obvious the concrete parts on both sides are broken broken seriously and wrinkled its service life can be judged to be over 3) For the embedded butt-joint expansion device if the vehicle jumps obviously and the bridge deck pavement is seriously damaged its service life can be judged to be over 4) For the plate-type rubber expansion device if the anchor bolt falls off the rubber is aged and deformed and the concrete cracks its service life can be judged to be over Seamless The main damage forms of the seamless expansion joint are as follows obvious rutting and cracks appear on the surface of the elastic-plastic body the surface of the elastic-plastic body produces washboard or partial falling off the aggregate falls off partially or in large pieces or the bridge deck cracks and gradually breaks at the joint with the bridge deck pavement Or the bridge deck pavement within the range of the expansion device is damaged

Cause analysis of damage the material performance of the elastoplastic filler itself such as the ability of the elastoplastic material to absorb the deformation of the beam end is insufficient the material strength is insufficient the quality of the binder can not meet the actual use requirements and the construction is not in accordance with the requirements of the manufacturer; the displacement and rotation of the bridge caused by external temperature load and other factors lead to cracking and damage of the elastomer; The structure of the expansion device itself such as the insufficient strength of the cross-joint plate Docking type The main damage forms are as follows rubber strip bulges in hot weather and falls off in winter local perforation and water leakage; concrete cracks and cracks in the anchorage area; bridge deck pavement is broken and falls off Cause analysis of damage it is difficult for the rubber strip to reach the ideal state during installation; the connection between the main anchoring parts and the embedded parts of the beam body is weak; in addition the paving concrete is thin the post-poured concrete surface is mostly lack of vibration and there are certain problems in density and strength resulting in easy damage to the concrete on both sides; The connection strength between the concrete in the anchorage zone and the bridge deck pavement is insufficient and it develops from tiny cracks to local fragmentation and falling off Steel bearing type The main damage forms of this type of expansion device are as follows open welding of welded junction due to process problems individual welds are not easy to weld firmly the whole steel plate falls off the anchor is weak resulting in loosening; fatigue fracture of individual steel toothed plate Cause analysis of damage this kind of expansion device is easy to deform during processing and use and it is difficult to ensure the fit between the toothed plate and the backing plate Once a gap is generated it is very unfavorable to the stress on the connection part causing noise and tripping In addition under the repeated load of day and night operation the toothed plate will cause premature fatigue loose fastening bolts and the comb ruler plate will be exposed Rubber plate The main damage forms of this type of expansion device are as follows the rubber plate is peeled off the embedded steel plate is exposed falls off and breaks the anchor bolt is sheared off and flies out of the hole the concrete on both sides is cracked and broken and potholes appear Damage cause analysis First of all it is the reason of the structure itself (design reason) The principle of this kind of expansion device is to use the rubber shear deformation between the upper and lower grooves to meet the expansion of the beam Steel plates are embedded in the telescopic body to bear the load across the gap of the beam end There are anchoring steel plates on both sides which are connected with the beam end through bolts and are installed in blocks per meter resulting in poor integrity Because the horizontal frictional resistance of this type of expansion device is very large the requirements for the anchoring system are extremely high Secondly the quality of products is not good for example the performance of rubber material the material and reasonable arrangement of stiffening steel plate the bonding strength between steel plate and rubber the control of temperature and humidity in production and so on are very strict a little quality problems often occur such as whole plate fracture degumming rubber layer wear steel plate exposure anchor bolts It is directly related to the mass transverse width and stiffness difference of the rubber expansion device itself Modular expression The main damage forms of this type of expansion device are as follows the main middle beam components are welded open shaking and noise occur; the expansion uniformity is poor; the sealing rubber belt is aging falling off or jumping out and serious water leakage occurs; the concrete on both sides of the device has cracks and pits the bridge deck pavement is partially broken and the anchorage system is not ideal resulting in local or overall damage Analysis of damage causes firstly most of the edge beams and center beams used for this kind of expansion device in China adopt the combined structure of steel plates or section steel welded into special-shaped parts and the welding quality is difficult to guarantee; In addition the method of tightly sealing the rubber belt with the pressing strip (or clip) and the screw buckle is adopted so that the fastener is easy to rust and break the structural integrity is poor the electric welding workload is large and the welding process is not up to standard so that the welding quality is difficult to guarantee and the welding is broken or the rubber belt falls off or even jumps out; Secondly in the reserved notch for installing this kind of expansion device there are not only anchor boxes but also many anchor steel bars including the main steel bars in the beam body and the embedded anchor steel bars which make it difficult to pour concrete and it is easy to cause problems such as cavities difficult to guarantee the compactness and insufficient strength There will be a serious problem of complete destruction of the anchorage Major diseases 1 Disease analysis of too narrow expansion joint the width of expansion joint is not appropriate during construction and installation As a result the reserved compression amount is insufficient the expansion joint is squeezed the internal stress is increased the concrete of the expansion joint body is squeezed and the pavement is damaged such as potholes

The expansion joint width has abnormal change compared with the normal joint width reserved in the design 2 Disease analysis of height difference of expansion joint due to abutment subsidence installation error bearing pad stone fragmentation and other reasons one side of the bridge is lower than the other side of the road surface resulting in bridgehead bump After inspection the abutment subsidence did not cause serious damage to the substructure At the same time the two diseases of vehicle bumping at bridge-head and expansion joint damage are interrelated Vehicle bumping at bridge-head causes large impact load directly near the expansion joint resulting in expansion joint damage 3 Analysis of blockage of expansion joint due to the accumulation of sand stone and other sundries the expansion joint is easy to lose the ability of free expansion and contraction When the temperature rises in summer the main beam can not extend freely and it is easy to generate thrust between the adjacent main beam or between the main beam and the abutment In serious cases the main beam is jacked up or the back wall of the abutment is cracked 4 Analysis of damage to the rubber strip of the expansion joint In addition to aging due to the above three kinds of expansion joint diseases it is very easy to cause cracking damage and warping of the rubber strip in the expansion joint 5 Analysis of damage in the anchorage zone the concrete strength of the post-cast strip in the anchorage zone is not enough during construction or the curing is not in place Or there is a height difference with the bridge deck which leads to jumping and the frequent action of overloaded vehicles leads to damage It is easy to cause damage to the steel structure of the expansion joint 6 Water seepage of the expansion joint This is a concomitant disease caused by the damage of the rubber strip or the damage of the anchorage area Water erosion caused by water seepage is very harmful Direct harm water seepage acts on the following parts to cause corresponding harm (1) The rubber of pier (abutment) bearing is aged and cracked and the steel plate is rusted (2) The pier (abutment) concrete and solid slab beam body are eroded and pitted and the reinforcement is rusted and expanded (3) Water accumulation in cavity of hollow slab beam (4) The end of steel structure beam is rusted Indirect hazard water erosion will spread to beams slabs and hinge joints and damage the upper load-bearing parts If the bridge deck pavement is permeable the following diseases will be aggravated (5) The hinge joint leaks and the hinge joint falls off seriously (6) Hollow slab web cracks (7) Single plate stress of bridge (such diseases of small and medium-sized hollow slab girder bridge are more serious) Tianzhuangtai Bridge Panjin Liaoning At 7 o'clock on the morning of June 10 2004 Tianzhuangtai Bridge in Panjin City Liaoning Province suddenly collapsed The bridge broke 27 meters from the middle three cars fell into the water two agricultural vehicles fell into the water to escape but fortunately no one died The accident was caused by overloading Long-term water seepage at the expansion joint at the end of the cantilever beam on the bridge deck leads to the decrease of the durability of the bracket and the sudden fracture of the heavy vehicle when it passes resulting in the falling off of the hanging beam Water seepage in the expansion joint Water seepage in the expansion joint Mortar shrinkage crack and water seepage of hollow slab beam head plate It is harmful to steel beams and hollow beams There is water seepage in the expansion joint and there are water marks on the hollow beam so it is necessary to drill holes to drain water Waterproofing of expansion joints of steel structure bridges is particularly important Major diseases Other types Failure of continuous expansion joints on bridge deck Loose rubber expansion joint nut Expansion joint curing Section of Mingyangtan Bridge in Harbin after Collapse Completely out of control The expansion joint is completely replaced by asphalt concrete Clean the expansion joint Repair and replace the rubber strip Maintenance anchorage area Integral replacement of expansion joint Expansion joint cleaning is the most important in daily maintenance and it is often the most easily overlooked Expansion joints are generally cleaned once a month and the frequency of road sections prone to pollution needs to be increased Sharp tools shall not be used during cleaning to prevent damage to the rubber strip High pressure water gun high strength fan and other equipment can be used Once the rubber strip is damaged it must be repaired or replaced Local small cracks and damages can be bonded with epoxy resin The rubber strips with large damage and serious aging shall be replaced When replacing the old rubber strips shall be pulled out with a crowbar similar to tire replacement and the new rubber strips shall be replaced in the same way Cracks and damages in the anchorage area must be repaired immediately The cracks in the anchorage zone can be treated with epoxy resin and the cracks with wider width can be repaired with epoxy mortar If the damage is serious the damaged part shall be chiseled out to expose the reinforcement and section steel parts rust removal shall be carried out and steel fiber concrete or rapid concrete shall be poured for repair Installation of bridge expansion joints Process flow Measure mark out cut the joint remove the concrete and sundries install and block the foam board between the beam joints hoist the expansion joint of the Maole in place adjust the plane position of the expansion joint of the Maole adjust the elevation of the expansion joint and anchor and release the lock do a good job of protection pouring concrete plastering curing and opening traffic

Take Mauler expansion joint as an example 1 Joint cutting and grooving the installation of expansion joint device shall be carried out after the pavement is paved as far as possible and the notch size shall meet the requirements for installation of expansion joint device 2 Clean the notch all dirt dust and other unnecessary things must be removed 3 Check whether the gap between the beams of the expansion joint device meets the requirements of installation temperature If not it must be adjusted under the guidance of the engineering and technical personnel of the manufacturer to make the gap between the beams of the expansion joint device meet the design requirements After adjustment press the fixture for installation 4 Take the asphalt pavement on both sides as the elevation place the expansion joint device in the notch adjust the expansion joint device to make its top surface the same as the pavement elevation and its longitudinal slope and transverse slope shall be consistent with the bridge pavement 5 Check the position of the expansion joint device to ensure that the position of the expansion joint device in the direction of vertical joint and the direction of longitudinal joint meets the design requirements If individual embedded reinforcement hinders the correct direction of expansion joint device at this time it can be cut off by gas cutting 6 Connect and weld the anchoring reinforcement on one side of the expansion joint device with the embedded reinforcement in the reserved groove at intervals and then weld the anchoring reinforcement on the other side according to the above steps When the expansion joint device is confirmed to be fixed the clamp can be taken down and then the rest of the unwelded anchoring steel bars are completely welded with the embedded steel bars so that the expansion joint device is reliably anchored 7 If the expansion joint device is installed in sections the joint must be welded The welded joint of the section steel has been prepared in the manufacturing plant When the two adjacent joints are aligned it can be installed After all the beams are welded they can be anchored according to the above steps 8 Install the formwork at the beam end The formwork shall be made according to the external dimensions of the expansion joint device and the gap of the reserved groove The formwork shall be made very tight to prevent mortar from flowing into the displacement control box or into the gap at the beam end 9 After the installed formwork is checked to be tight and seamless the reserved groove shall be cleaned and then the concrete (steel fiber concrete) can be poured and vibrated to be dense The concrete shall have at least the same strength as the structural concrete at that location and the top surface of the expansion joint device shall be kept clean during concrete pouring Allowable installation deviation of expansion joint Caution Construction temperature and factory preset gap width The construction joint shall be protected by foam board and the lower part of the bottom V-shaped rubber strip shall also be blocked by polyethylene foam board to prevent mortar leakage Top flatness control Copyright statement The source of this WeChat content is Zhulong Forum Copyright belongs to the original author if it involves copyright issues please contact us we will be the first time to negotiate copyright issues or delete the content! This article is the original author's personal opinion which does not mean that this public number agrees with its views and is responsible for its authenticity Return to Sohu to see more Responsible Editor
What is a perforated plate? _ Architectural firm Jobs - Employee 2022-08-15
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What is a perforated plate? _ Architectural firm

Originally published as What is a custom tailor tape perforated plate All-Field Design Competition | GHDA Global Habitat Design Award 3rd Round of Application Opens Nanheng Pedestrian Street/Muyue Architecture Office Nowadays building materials are more and more abundant and novel A single material can not meet the design needs When we talk about building materials Have habitually thought of marble aluminum paint and so on Are you hungry for something new In fact add some creativity to ordinary materials There will be unexpected surprises Like a perforated plate ~ It's actually a perforated metal plate But ordinary metal plates are processed differently It can be used in a variety of ways under the designer Create a different rhythm and architectural texture Bring a surprise to the city we live in ~ What is a perforated plate Perforated plate As the name suggests it is a perforated metal plate bespoken tape measure Expand the full text Also known as perforated plate perforated metal perforated screen Most of them are metal plates such as aluminum alloy Processed by stamping machine or milling machine Has the characteristics of long service life no deformation and the like Perforated sheet metal has been available for nearly 150 years Originally developed as a filter and sorter Mainly used in the mining industry It turns out With the development of science and technology Its use soon expanded beyond its original function It has developed so far It has been widely used in architecture landscape and interior design As a metal building material Perforated plates are born with an avant-garde temperament It is widely used in architecture landscape indoor and outdoor decoration Used to create a stylish and modern aesthetic Hole size of perforated plate The patterns can be carefully processed and designed according to the needs Holes of different sizes densities and shapes Form different translucent line of sight effect Different pass types of perforated plate The hole types of the punching plate include rectangular hole square hole rhombic hole round hole oblong hole hexagonal hole cross hole triangular hole long waist hole quincunx hole fish scale hole pattern hole splayed net herringbone hole pentagonal star hole irregular hole bulging hole special-shaped hole and louver hole

There are many materials for perforated plates Materials are mostly stainless steel plate aluminum plate iron plate copper plate and so on At present most of the products on the market are perforated aluminum plates Perforated aluminum plate with light material and good chemical stability Beautiful appearance elegant color and strong three-dimensional effect Ood decorative effect and simple and convenient assembly The advantages of perforated plates are as follow "Porosity" The most immediate visual characteristic of perforated sheet metal is porosity Porosity means The two spaces separated by the epidermis are permeable to each other Break down the inherent boundaries between inside and outside Create a more open public space in form It can provide the city and users with the intuitive feeling they need It really achieves the mutual penetration of internal space and external space The porosity of the perforated plate allows the interior and exterior to penetrate each other "Mottled Light and Shadow Effects" Perforated plate under sunlight or light It will produce rich light and shadow changes This effect will give the building a unique and vivid visual effect This light and shadow effect Make the relationship between the main body of the building and the outer skin more hazy It has a sense of integrity and hierarchy bespoken tape measure The change of hole size hole diameter and perforation rate It will also produce different effects of light and shadow changes Different light and shadow effects produced by different hole types "Different combinations of panels" Perforated metal sheets can be made according to the architect's needs Make different shapes and sizes Make different combinations of connections Combination mode is rich and changeable Different board surface combination form "Reduce sound level" In the field of acoustics Sound absorption is one of the important measures to control noise and improve indoor sound quality Perforation plates have exactly this advantage Studies have shown that perforated metal can help reduce sound levels Its acoustic properties help personnel reduce the health effects of noise Buildings use perforated metal panels in front of their stands Could result in 29% energy savings Perforated panel sound absorption structure A sound absorption structure in which an air layer or porous material is placed behind a perforated thin plate and fixed on a rigid wall can be regarded as a resonant system composed of a mass and a spring When the frequency of the incident sound wave is consistent with the resonant frequency of the system the air in the perforated plate vibrates and rubs violently which strengthens the absorption effect and forms an absorption peak so that the sound energy is significantly attenuated Away from the resonant frequency the absorption is small If a porous material is placed behind the perforated plate to increase the acoustic resistance the absorption band of the structure will be widened

In the design process of concert hall cinema multi-function hall etc Sound Absorption Structure as Acoustical Design And the main technical means of noise control It has been widely used For example Wuxi Grand Theater The surface of the fin is a hyperboloid perforated aluminum plate Design PES-Architects How does the perforation plate work Two perforation methods are commonly used in modern times "CNC Punch Piercing" Numerical control punch is a common way of piercing Punch the metal surface by means of machine tool stamping The stamping process can be performed on a metal screen And quick perforations on a large surface area of the panel "Laser perforation" Laser perforation is the latest development of perforation technology It is also a relatively expensive and complex technology Higher accuracy and randomness Nowadays Perforated metal sheets have been used by designers in a variety of applications From industrial filters and acoustic panels Then to architectural interior decoration and landscape wall sketches You can see its figure Application of perforated plate "Construction Field" Perforated plate It can unify the building facade and separate the space While achieving a semi-private effect and security The space remains comfortably breathable And form a wonderful light and shadow effect Combined with metal wood and other materials Different textures and textures can be formed So that the building facade can get rich artistic changes "Xing · She" designed by Daxing Beijing and Cawston Canada Lolly-Laputan Children's Restaurant Dalian Wutopia Lab Beijing Jingkai Zhihui Park New Media Exhibition Center hyperSity Architectural Design Firm Malm? Art Museum Tham & Videg Videg?rd Arkitekter Sweden Stanley Saitowitz Tampa Museum of Art Florida | Natoma Architect "Landscape Domain" Chinese classical gardens are exquisite "Wherever there is a place to look out it seems to be the meaning of avoiding the outside and hiding the inside" There is reality in the void hidden but not leaking The perforated plate can perfectly meet the needs of this courtyard landscape Hermes Art Center Beijing Architecture Design Studio Hong Kong Landmark Yijiang County Landscape SWA Group Weitu Design Agency Architecture Shanghai Botao Shenyang Vanke Feicui Riverside Landscape Bede Sunan Vanke 138 Degrees Park Avenue D + H Landscape Design & Wuwei Design Shenyang Yuexiu Xinghui Brocade Landscape Bede "Indoor Domain" Perforated plates can be used as partitions or decorations in the interior Create a low-key and simple fashion style The light passes through different hole patterns With the change of light and shadow Create an extraordinary artistic effect Perforated plate Be able to make architectural and landscape materials And take on the role of interior decoration Appearance and strength coexist Such a perforated plate Isn't he handsome References On the Design and Application of Perforated Plates in Architectural Exterior Skin by Chen Yao Research on Applicability Design of Perforated Metal Skin in Sports Architecture by Ji Weidong and Ge Wei Sound Absorption Performance and Application of Perforated Panel Sound Absorption Structure by Zuo Yanyan Zhou Jinhua Liu Haibo Hong Jianhai The case part comes from goood design website Thanks to the above original author! Warm Reminder The time of this inspection activity is March 13 and March 14 The number of places is limited Interested friends please contact Mr Chu to register in time G H D A Global Habitat Design Awards Return to Sohu to see more Responsible Editor
Yucheng, Henan: Why can a Small Steel Tape Measure Measure the World? _ China Jobs - Employee 2022-08-15
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Yucheng, Henan: Why can a Small Steel Tape Measure Measure the World? _ China

Original Title Yucheng Henan Why can a keychain tape measure Small Steel Tape Measure Measure the World China Steel Tape City — — Yucheng County Committee Publicity Department of Yucheng County Henan Province Labeling packing and sealing Song Dongmei a 57-year-old employee of Shangqiu Keming Measuring Tools Co Ltd is skillfully assembling steel tapes "More than 85% of the steel tapes in the country are produced in Yucheng!" Every morning the steel tape assembled by Song Dongmei will be transported to the port in the afternoon and sent to all parts of the world This state-level poverty-stricken county on the old course of the Yellow River has now developed into a "China Steel Tape City" creating a legend of "World Hardware City" Yucheng Steel Tape Characteristic Industrial Base originated from six farmers in Nanzhuang Village Shaogang Town In the 1980s

Shaogang Town was a famous poverty-stricken town famous for "eating pickles rather than marrying Shaogang people" Unwilling to be poor six farmers in the village cut up and reassembled the scrap ruler strips purchased from the state-owned tape factory and sold them to the surrounding farmers and construction workers From then on they started their business A stone stirred up a thousand waves and villagers nearby followed suit setting off a wave of assembly of steel tape All of a sudden steel tape workshops blossomed all over the county and the steel tape industry began to emerge The employee is assembling the steel tape Expand the full text In 1992 Yang Jianbo founded the first steel tape factory in Yucheng County Zhongzhou Tape Factory and a group of rural talents such as Xu Xiuzhang and Wu Haiyun also set up factories one after another and small family workshops began to transform to mechanized manufacturing The rudiment of "Steel Tape Kingdom" is beginning to show The following year some factories began to introduce production equipment and carry out semi-mechanized production Soon through self-development and introduction of a complete set of equipment some factories almost fully automated production technical facilities reached the international advanced level of the same industry With the gradual expansion of pure manual to mechanization and scale Yucheng steel tape industry has also encountered the practical problems of high cost low quality and narrow market With the improvement of consumers'quality requirements and brand awareness by the end of the 1990s the original best-selling products had become unsalable products and the steel tape industry in Yucheng was struggling In order to break the limitations of the development of steel tape industry in Yucheng a steel tape association was established in Yucheng County in 1998 With the help and guidance of the county Party committee and the county government on the one hand mini tape measure 29 registered trademarks of steel tapes have been registered and a number of well-known brands such as "Jianghua" "Hongye" and "Wanshanhong" have been established; on the other hand large and small enterprises have done their best to strengthen regional brands and export together

The "Kingdom of Steel Tape Measures" began to transform and transform breaking cocoons into butterflies After years of efforts steel tape has not only become a pillar industry in Yucheng County but also developed into the largest production and marketing base of steel tape in China On July 11 2006 Wang Qinping President of China Metrology Association officially issued the plaque of "China (Yucheng) Steel Tape City" to Yucheng County in Shangqiu City The employees are working hard At present there are nearly 2000 steel tape enterprises in Yucheng with an annual output of 15 billion If each tape is connected by 5 meters the total length can circle the earth 190 times; the production and sales volume also accounts for more than 85% of the country and there are more than 100 direct sales points in

China It has become the first county of steel tape manufacturing in China Yucheng people are not satisfied with the honorary title of "China Steel Tape City" and are determined to go to the world and become "World Hardware City" When they investigated the international market they found that there was a personalized tape measure demand gap for screwdrivers and began to invest in related industries Many enterprises realized the butterfly change from measuring tools to measuring tools production Yucheng has expanded from a single measuring tool production to a comprehensive hardware measuring tool industry cluster with paint plastics moulds hardware and other steel tape formats as the core and has stepped into the forefront of the national measuring tool industry Promote the employment of the masses at home Since 2010 Yucheng people have opened measuring tool stores in various places with an annual growth rate of 20% firmly occupying the market in developed areas of Europe and the United States and regularly providing information collection data for the Ministry of Commerce of measuring tool commodity countries which has been leading the production and circulation of measuring tools in the world and is regarded as the "barometer" of the world steel tape market by the industry

On December 19 2013 China Yucheng International Hardware Trade City with an area of 800 mu and an investment of 105 billion yuan was officially launched as an "aircraft carrier" with the status of global hardware and measuring tools exhibition and trade headquarters forming a tripartite pattern of three major hardware and measuring tools professional wholesale markets with Yiwu in Zhejiang Province in the south Linyi in Shandong Province in the north and Shaogang in Yucheng With the successful operation of China Yucheng Electroplating Industrial Park Henan Shangqiu Bonded Logistics Center and E-commerce Industrial Park in Yucheng County many brand merchants and investors have flocked in Today Yucheng's annual export earnings amount to more than 40 million US dollars accounting for half of the country's export scale and its products are sold all over the world to more than 110 countries such as the United States and Canada A neatly arranged steel tape From the sole efforts of individual households to the establishment of industrial bases under the guidance of the government; from low-end products with pure handwork to high-end new products with chip voice systems; from OEM to independent brands; from single physical stores to multi-form multi-channel and all-round marketing of physical and e-commerce; from extensive development to intelligent and intensive development; from domestic sales to export sales The progressive Yucheng people are creating one miracle after another The rising Yucheng is holding high the banner of "China Steel Tape City" and striding towards "World Hardware City" telling the world a new story of Made in China Source People's Daily Return to Sohu to see more Responsible Editor