作者：Blade

National Speed Skating Hall adopts LED lighting

The National Speed Skating Stadium, nicknamed “Ice Ribbon”, is the only new ice competition venue for the Beijing 2022 Winter Olympics. Speed skating competitions will be held here during the Winter Olympics. It is located on the south side of the Beijing Olympic Forest Park Tennis Center.

National Speed Skating Hall adopts LED lighting

The National Speed Skating Hall has a construction area of about 80,000 square meters and can accommodate about 12,000 spectators. The National Speed Skating Stadium can be used for ice hockey, curling, and avenue speed skating. It is a comprehensive venue. As the venue for the speed skating competition on the Avenue of the Beijing Winter Olympics, the venue has the largest all-ice design in Asia, with an ice surface area of 12,000 square meters. After the Winter Olympics, the venue will be open to Beijing citizens, providing a training ground for athletes. It can also meet the needs of Beijing citizens for winter sports. It can operate 365 days without interruption and become a sports and fitness venue similar to the Water Cube and Bird’s Nest, which has both social service functions and corporate operations.

The design concept of “Ice Ribbon” comes from the idea of combining ice and speed. The 22 ribbons are like the traces of athletes sliding over, symbolizing speed and passion. The National Speed Skating Hall adopts the single-layer two-way orthogonal saddle-shaped cable net roof with the largest span in the world, and the amount of steel used is only a quarter of that of the traditional roof.

The National Speed Skating Stadium is the first Winter Olympics speed skating venue in the world to use carbon dioxide transcritical direct cooling ice-making technology. This technology is the world’s most advanced and environmentally friendly ice-making technology, with the carbon emission value approaching zero and the energy efficiency of ice-making greatly improved.

After the game, the ice surface can be cooled in different regions, and the temperature of each piece of ice can be controlled individually to realize the “simultaneous operation and different use” of the venue. Two key design schemes, the integrated design of the ice-making system and the design of the ice plate structure have been patented.

In order to create the “fastest ice”, the construction of the ice slab of the National Speed Skating Hall kept improving. It took more than 60 days to complete the welding of 8574 welds of the ice-making steel pipe. The level difference of the produced concrete ice slab is about 4 mm, which is very flat; The temperature difference between the ice surface is controlled within 0.5 degrees Celsius, which is beneficial for athletes to create good results.

The venue lighting system of the National Speed Skating Stadium is tailored according to the functions of the venue. It consists of 1088 sets of LED lamps. Its optical parameters meet the requirements of top competitions and high-definition broadcasts, and the energy-saving and environmental protection performance are outstanding. Each set of lamps realizes intelligent independent control to meet the rich lighting needs of multi-functional use during and after the game.

The overall coverage of LED lighting products is expanded

The “Harmonized System of Commodity Names and Coding” (referred to as “Harmonized System”) is a basic catalog for my country to formulate import and export tariffs, implement trade control, trade statistics and other import and export management measures. A few days ago, in order to adapt to the development of international trade, the World Customs Organization released the 2022 edition of the “Harmonized System” revised catalog, which will take effect on January 1, 2022.

The overall coverage of LED lighting products is expanded

The reporter found that the adjusted “Harmonized System” proposes separate tax items for LED replacement light sources, LED modules, and lamps and lighting devices that only use light-emitting diode (LED) light sources. Electric light source products and lighting products are listed as a whole The coverage is expanded.

In recent years, LED lighting products have become the main products of my country’s lighting industry in foreign trade. The data shows that in the first three quarters of 2021, my country’s total exports of lighting products are about 47 billion U.S. dollars, of which the total exports of various LED lighting products are 33.8 billion U.S. dollars, accounting for nearly 72% of the exports.

According to the China Electrical Equipment Association, in the current 2017 version of the “Harmonized System”, in addition to the separate customs code for LED replacement light sources, other LED lighting products do not have corresponding customs classification codes, and it is impossible to achieve accurate export data of various LED lighting products. Statistics are also not conducive to the implementation of relevant supporting policies for the import and export of LED lighting products. The changes in the “Harmonized System”, on the one hand, are in line with the current rapid growth in the export of LED bulbs, LED tubes or LED components; on the other hand, they are in line with the current industry development of integrated design, manufacturing and export of LED light sources and lamps. The trend is in line with the actual needs of my country’s lighting appliance industry. Under the current global active promotion of green and low-carbon development, the refinement of the classification and customs codes of LED lighting products will further promote the entry of various LED lighting products into overseas markets.

It is understood that since 2012, the China Lighting Association and the Global Illumination Association (GLA) have been working together to reach a consensus on the addition of LED lighting products and sub-heading classification codes for LED lighting products, and actively cooperate with my country’s customs authorities. Promote the addition of sub-heading classification codes for LED light source products and LED lighting products.

At the same time, the China Association of Lighting and Electrical Appliances also reminded all relevant export companies to pay attention to the HS code changes of LED light source products and LED lighting products, as well as the new “Regulations on the Administration of Customs Declaration Unit Filing”, and take the initiative to understand and in-depth study the above management requirements based on their own business conditions. The impact of the changes in production and operations, to avoid delays in customs clearance of goods exports.

Wukesong Sports Center uses LED lighting to reduce power consumption

The Wukesong ice hockey competition of the Beijing 2022 Winter Olympics will be held at the Wukesong Sports Center, and the Wukesong Ice Sports Center, which provides training services for athletes, was completed in December 2020. During the Winter Olympics, the Wukesong Ice Sports Center will undertake the task of ice hockey training. It will be connected to the ice hockey stadium Wukesong Stadium through a dedicated underground passage for players. Athletes can travel to and from the competition hall and training hall through this passage.

Wukesong Sports Center uses LED lighting to reduce power consumption

Wukesong Ice Sports Center adopts ultra-low energy consumption special technology. By optimizing the layout of the building, rational use of natural lighting methods such as translucent curtain walls, skylights, sunken squares, etc., the venue effectively improves the lighting effect of the above-ground and underground functional rooms and reduces consumption by laying photovoltaic power generation components on the roof and using LED lighting. Power. The 600KW photovoltaic power generation system installed on the roof can achieve an annual power supply of about 700,000 degrees in the future, meeting part of the electricity demand of the ice sports center and saving energy consumption. At the same time, air conditioning units and fresh air units are also equipped with total heat recovery devices, with a recovery efficiency of 70%, which can effectively pre-cool and pre-heat the fresh air introduced into the room through exhaust air, saving air conditioning energy consumption, which can be said to be a veritable ” “Green” venues.

It is understood that Wukesong Ice Sports Center won the 2019 China Steel Structure Gold Award. In the future, the Wukesong Ice Sports Center will focus on the operation of youth club training, physical fitness center, and fitness center, combined with exciting events and immersive business formats, and will fully meet the needs of citizens for fitness and entertainment.

The group standard of “Energy Efficiency Rating Specification for LED Strips” was launched

On November 16, Shenzhen Lighting and Display Engineering Association’s group standard kick-off meeting and the first working seminar (hereinafter referred to as the seminar) on the “LED Strip Energy Efficiency Rating Specification” was held as scheduled.

The group standard of "Energy Efficiency Rating Specification for LED Strips" was launched

Shenzhen Lighting and Display Engineering Industry Association Standards and Testing Committee, Beijing Qingmei Road Planning and Design Institute, Shenzhen South China Decoration Group Co., Ltd., Op Lighting Co., Ltd., Guangdong Sanxiong Aurora Lighting Co., Ltd., Sichuan Lanjing Optoelectronics More than 40 business representatives including Technology Co., Ltd. and industry experts and scholars attended the meeting.

LED light strip refers to the assembly of LEDs on a strip-shaped FPC (flexible circuit board) or PCB hardboard, which is named after its product shape is like a strip. Because of its long service life (usually 80 to 100,000 hours), it is very energy-saving and environmentally friendly, and gradually emerged in various decoration industries. It is widely used in furniture, automobiles, advertising, lighting, ships, bars, signs, and construction. Industries such as objects, bridges, etc., continue to meet the application requirements of indoor and outdoor conditions.

According to incomplete statistics, there are currently more than 3,000 domestic companies producing LED strips (with an annual output value of more than 10 million), which are sold at home and abroad, but the quality of the products in the entire market varies. Because the design technology, process technology, and implementation plan adopted by the manufacturers are different, the energy efficiency of the products after molding is quite different.

In order to standardize the market order of LED light strips, Shenzhen Lighting and Display Engineering Industry Association and related companies first proposed a market standard for measuring the energy efficiency grade (level) of LED light strips (flexible), aiming to solve the problem of uneven product quality and disorder in the market. The situation puts forward a standard basis, guides the market order, and allows enterprises to have standards to follow.

American scientists have developed bendable thin LED semiconductors

A group of American scientists discovered that LED semiconductors that are slightly bent to an atomic thickness can emit light with an efficiency close to 100%, and avoid a decrease in efficiency as the brightness increases-which usually plagues these LEDs.

American scientists have developed bendable thin LED semiconductors

From smartphone screens to low-energy lighting, light-emitting diodes (LEDs) have changed the world many times. But the efficiency of LEDs tends to decrease as the brightness increases-a problem that is particularly troublesome for a new and interesting two-dimensional semiconductor material, the so-called transition metal dihalides (TMDs). The significant efficiency drop of these atomically thin materials at high brightness hinders their application in practical applications.

Now, researchers at the University of California, Berkeley, and Lawrence Berkeley National Laboratory may have found a very simple way to bypass the efficiency barriers that these LEDs are prone to encounter.

The team has proven that applying a mechanical strain of less than 1% on the TMD can change the electronic structure of the material, and even at high brightness levels, it is sufficient to achieve nearly 100% light emission efficiency (photoluminescence quantum yield). The research team believes that this result can enable a new generation of LED equipment to avoid efficiency erosion caused by increased brightness.

In all organic and some inorganic LEDs, the drop in efficiency at high brightness is rooted in a phenomenon called exciton-exciton annihilation (EEA).

When an energy source such as an electric current or a laser beam excites a semiconductor, it kicks negatively charged electrons from the valence band of the semiconductor into the conduction band, leaving positively charged electron holes.

In semiconductors with the correct properties, electron-hole pairs still exist in the form of neutral quasi-particles called excitons. The subsequent radiation recombination of electrons and holes in the excitons results in the emission of photons, thereby producing visible light emission from the LED.

At low exciton density, almost all excitons have enough space for radiation recombination, and the quantum yield of TMD LED is close to 100%. However, as the brightness of the LED increases and the density of excitons increases, the excitons begin to collide and erase each other, resulting in non-radiative attenuation, or EEA, dissipated in the form of heat. Result: The photoluminescence efficiency of this ultra-thin material decreases as the brightness increases.

The number of non-radiative EEAs largely depends on the details of the semiconductor energy band structure. The Berkeley research team found that, especially for TMD semiconductors, the number of EEAs is enhanced by the van Hove singularity.

The van Hove singularity is a slight distortion in the energy structure of a semiconductor, which increases the density of states (the number of possible energy states that can be occupied) at that point.

In order to solve the EEA problem under high exciton density, Berkeley researchers studied methods to adjust the energy band structure of TMD materials. They found that applying uniaxial strain – literally stretching the material slightly – worked well.

In their experiments, the team installed many different TMDs, including single-layer WS2, WSe2, and MoS2. On a flexible plastic substrate, a hexagonal boron nitride layer (as a gate insulator) and a graphene layer (as a gate) were added electrode). Then, the researchers applied a voltage bias on the device, excited the material with a laser beam to generate excitons, and measured the photoluminescence quantum yield of the material as the laser intensity (and exciton density) increased.

The team found that for unstrained TMD, as expected, the quantum yield decays as the exciton density increases. However, slightly bending the flexible substrate and applying a tensile strain of 0.2% to the TMD will result in a significant reduction in the amount of roll-off. When the tensile strain is 0.4%, there is no effective efficiency drop under high brightness, and the material can maintain nearly 100% photoluminescence quantum yield regardless of the exciton density.

The team’s analysis shows that the effect of tension on quantum yield is related to the existence of “saddle points” in the semiconductor energy band structure-similar to the mountain channel in its energy landscape. In unstrained materials, the saddle point, that is, the region of the Van Hove singularity, is located near the favorable energy of the exciton-producing exciton annihilation, thereby enhancing the level of exciton annihilation. Slightly bending the material can reshape the band structure and fully move the saddle point so that the van Hove singularity is not conducive to exciton annihilation. This, in turn, allows more exciton radiation recombination and increases the quantum yield of photoluminescence.

Although most of the team’s experiments involve mechanical peeling of various two-dimensional material sheets, the researchers can also prove the beneficial effect of strain on the quantum yield of large-area (centimeter-level) WS2 sheets. Grown by an extended chemical vapor deposition process. Researchers believe that this additional discovery points to the prospect of a new generation of LEDs that are not affected by efficiency loss attenuation at high brightness.

54 main and secondary roads in Nanchang were upgraded to LED street lights

“When I walked, I found that the light in the park is very good, and it is safe to take children out to play.” Xiong Wei said that recently the street lights in Qingshan Lake Sports Park at night have not only become brighter, but the “value” has also improved a lot.

54 main and secondary roads in Nanchang were upgraded to LED street lights

The changes in the street lights of Qingshan Lake Sports Park benefited from the comprehensive renovation and upgrading of more than 90,000 street lights on 54 major and minor roads, including Shanghai Road, Yangming East Road, and Qingshan Road by Nanchang Street Light Management Office. Change to today’s energy-saving LED street lights.

Yangming East Road is a major urban road in Nanchang, and there are many shops along the street. Ms. Huang opened a snack bar on Yangming East Road. She told reporters that the street light at the entrance of the store was a bit dark, and the light was blocked by the branches on the side of the road. After the street light at the entrance of the store was replaced last year, the entrance of the store became very bright.

Ms. Huang also discovered that in the past, the street lights at the entrance of her store had to be repaired once or twice a year, but since the street lights at the entrance of the store were replaced in May last year, they have not been damaged once.

“The high-pressure sodium lamps used in the past are indeed not durable, and the new ones are LED energy-saving street lamps that are not easy to break.” Liu Yigang, deputy director of the Nanchang Street Lamp Management Office, introduced that LED street lamps are highly efficient, safe, energy-saving, environmentally friendly, long-lived, and responsive. The unique advantages such as fast speed and high color rendering index can improve the lighting effect and also play a role in energy-saving and emission reduction.

Because of this, in view of the previous characteristics of urban street lights that are easy to break, lack of light, and high energy consumption, Nanchang last year listed the urban road lighting energy-saving renovation project as one of the top ten livelihood projects of the Nanchang Municipal People’s Congress in 2020.

Liu Yigang told reporters that the iterative upgrade of more than 90,000 street lamps on 54 main and secondary roads, including Shanghai Road, Yangming East Road, and Qingshan Road in Nanchang, has been completed, all of which have replaced high-pressure sodium lamps with LED energy-saving lamps. The LED energy-saving street lamp adopts the silicon substrate LED chip technology “manufactured in Nanchang”. During the implementation of the project, the Nanchang Street Light Management Office also paid great attention to the on-site light environment experience of pedestrians and vehicles, emphasizing the overall coordination of the lamps and the surrounding environment and the comfort of the human body, and specially selected the medium and low color temperature light sources with the color temperature of 3500K warm white light. It doesn’t look dazzling.

“The energy-saving rate after the transformation reached 40%. After actual measurement, we found that the quality of the LED lighting on 54 main and secondary roads is better than the national standard.” Liu Yigang calculated an account for the reporter: the total energy consumption of 54 roads and street lights before the transformation the power is 2475.75 kilowatts, and the total power after the transformation is 1523.38 kilowatts. Based on the average lighting time of street lights for 10 hours a day, and the electricity price of street lights at 0.61 RMB per kilowatt hour, the electricity bill can be saved by 5,504.45 RMB per day, and at least 165,000 RMB a month.

Careful Nanchang citizens will find that street lights were often on during the day on the streets, but now the newly installed street lights will not happen again. This is mainly due to the empowerment of science and technology, and the more than 90,000 street lights in Nanchang City have become more and more “smart”.

Liu Yigang introduced to reporters that all current street lamp switching times are automatically judged and automatically generated according to the daily sunrise and sunset time and light conditions through an intelligent monitoring system. As the sun rises and sets time, as well as the sunshine duration and light intensity of the sun in different areas of Nanchang are different from day to day, so the street lights switch time in Nanchang city will be different every day.

“The purpose of this is also to save energy.” Liu Yigang said that the establishment of an intelligent monitoring system can not only accurately make the city’s street lights and landscape lighting lights automatically switch lights according to different weather conditions and activity needs, but also Line failures were discovered in time. The original street lamp failures were mainly discovered through inspections by the staff. From discovery to repair, it usually takes 3 days. Nowadays, through the empowerment of science and technology, through the installation of a single lamp control terminal in the lamp pole, the intelligent detection of the current, voltage and other parameters of the lamp can be realized. If the street light fails, the back-end staff will be dispatched to the maintenance personnel through the work order system as soon as possible, which greatly reduces the pressure of the patrol light duty personnel and the loss of vehicles.

“As the urban framework of Nanchang continues to expand and the total number of lamps continues to increase, we have mainly adopted a series of comprehensive measures such as energy-saving control, material energy-saving, equipment energy-saving, and management energy-saving. We have achieved a year-on-year decrease in the energy consumption of urban street lighting in Nanchang. “Liu Yigang told reporters that Nanchang is currently implementing the intelligent transformation and upgrading of 10,000 poles of single-lamp control. In the future, it will continue to increase the intensity and breadth of urban street lamp renovation in accordance with the requirements of the increasingly information and digitalized street lighting management. Serve the people well.

Lehman releases 138-inch Micro LED giant screen cinema

MicroLED’s advantages, in contrast, color gamut, resolution, and color rendering have brought a visual feast, making this “black technology” the “heart of the consumer”. From the perspective of application scenarios, MicroLEDs are mostly used in commercial applications.

Lehman releases 138-inch Micro LED giant screen cinema

And now, with the maturity of technology and the gradual decline in cost, Micro LED is completing a gorgeous transformation from commercial to civilian use and has become the first choice for home theater.

Micro LED has gradually become the new favorite of home theater

LEDinside, the Optoelectronics Research Division of TrendForce Consulting, pointed out that the indoor LED display market, including application scenarios such as home theaters, is growing steadily thanks to the market demand for high resolution and high dynamic contrast range (HDR).

In fact, the current large-size display technology is still dominated by LCD, while MiniLED backlight and OLED are competing in the field of high-end TV. But these three technologies are more difficult to break through 100 inches, which also makes it difficult for these three technologies to provide a more shocking and immersive viewing experience in home theater application scenarios.

In addition, even if a product of 100 inches or more is successfully produced, it is very difficult to enter the product due to the large size. In March 2017, a citizen in Wuhan bought a 100-inch Sony 100Z9D. Due to the large size, the TV can only be sent into the consumer’s home by hanging into the home, and the whole process costs 20,000 RMB.

Although the laser technology is suitable for the market above 100 inches, the color of the image of the laser technology is greatly affected by the ambient light, and the display effect is not satisfactory.

Compared with other technologies, Micro LED has an excellent display effect, and the technology has a smaller restriction on product size, and because Micro LED is a modular technology, it is very easy to install in the home. Based on this, Micro LED is focusing on super-sized race tracks and gradually entering the fields of high-end residences, private theaters, high-end clubs, high-end office spaces, and e-sports venues.

At CES2018, Samsung launched the “The Wall” Micro LED TV, which was a rallying call for Micro LED products to enter the home market. Subsequently, LG, Leyard, Skyworth, C-Seed and other companies have released Micro LED household products, opening up the competition of Micro LED technology on the C-end track.

In terms of price, the 118-inch, 4K version of the Smart Wall released by Konka in 2019 is priced at 1.68 million RMB, and the largest 236-inch, 8K version is 8.88 million RMB; while LG’s LG MAGNIT released in September last year has a size of 163 Inches, the price is 306,000 US dollars.

In contrast, the latest private giant screen theater launched by Lehman Optoelectronics shows full sincerity in terms of price.

From B to C, Lehman Optoelectronics announced its entry into the home consumer market

On September 27th, Ledman Optoelectronics held a new Ledman Micro LED private giant screen theater new product launch conference with the theme of “Giant Screen Enjoyment, the future Is coming” simultaneously online and offline. At the meeting, Li Mantie, chairman of Ledman Optoelectronics, announced the official release of the new 4K flagship 138-inch series of “Ledman Micro LED Private Giant Screen Cinema”. At present, the product has been pre-sold in the flagship store of Lehman Optoelectronics on JD.com and Lehman’s official website, with a starting price of 499,999 RMB.

In terms of display technology, the Lehman Micro LED private giant screen theater is based on COB technology, using self-luminous nano-black crystal coating Micro LED can be spliced with ultra-high-definition black jade screens, with a contrast ratio of 1,000,000:1, a color gamut of 125%, and a viewing angle Up to 170°, it has nanosecond response speed and HDR display effect, and the unbounded field of vision brought by the 4K ultra-high-definition high-screen ratio makes watching movies more immersive.

In terms of function, the Lehman Micro LED private giant screen cinema is paired with the self-developed giant screen cinema intelligent system to establish a new interactive form. At the same time, the Lehman Micro LED private giant screen theater can be equipped with panoramic sound to create an immersive sound effect of 7.1.4 Dolby panoramic sound.

In terms of patents, based on 17 years of packaging experience, 16 years of display manufacturing experience, and 7 years of Micro LED research and development experience, Ledman Optoelectronics has accumulated more than 300 domestic patents, including 60 COB related patents, forming a complete independent Intellectual property system.

Osram’s new upgraded white LED illuminates new agricultural development

With the continuous advancement of urbanization, by 2050, two-thirds of the earth’s people will live in urbanized metropolitan areas. Rapid urbanization is causing urban malnutrition. A “city based on indoor planting technology” The farm” revolution is also on the rise. According to a study published in Earth’s Future in 2018, urban agriculture may be the key to feeding the future urban population. It may produce up to 180 million tons of food each year, accounting for approximately global 10% of the production of beans and vegetables.

Osram's new upgraded white LED illuminates new agricultural development

This has also given birth to the development of many new agricultural technologies. With the gradual maturity of environmental control agricultural technology and the obvious decline in the cost of lighting products, the indoor planting mode that uses artificial light to replace sunlight has become the development trend of urban agriculture, boosting the rapid development of urban agriculture. Compared with traditional agricultural planting, plants planted under plant lighting are not affected by the natural environment, can receive more suitable light, nutrition and humidity, and can be produced normally and continuously even under severe conditions or disasters. But this places very high requirements on artificial light sources used in plant lighting systems.

As a leader in lighting technology, Osram is at the forefront of the advancement of plant lighting. Ams Osram’s latest horticultural lighting product OSCONIQ? S 5050 Horti White covers the horticultural white spectrum and promotes more use of non-converted red photons for plants. The lighting provides excellent lamp-level luminous efficiency.

Currently, indoor plant lighting mainly uses a combination of red and blue LEDs, or a combination of red and white LEDs. In fact, the standard white LED used in plant lighting will also emit light in the red wavelength range. However, compared with the direct red LED, the standard white LED emits almost the same amount of red light, and the energy consumption is much higher. many. Therefore, the red light required in plant lighting is often replaced by LEDs that directly emit red light in the lighting system.

Guangdong local standard for classroom lighting in primary and secondary schools

On October 22, the Guangdong Provincial Department of Education and the Guangdong Provincial Market Supervision Administration held a press conference to introduce the prevention and control of myopia in children and adolescents in Guangdong Province, as well as the preparation of the Guangdong Provincial-Local Standard “Technical Specifications for Primary and Secondary School Classroom Lighting.” The reporter learned from the meeting that the standard has been released a few days ago and will be formally implemented on December 1 this year to ensure that the province completes the task of meeting the lighting standards for classrooms in primary and secondary schools in 2023.

Guangdong local standard for classroom lighting in primary and secondary schools

The lighting environment of classrooms in primary and secondary schools is closely related to the health of children and adolescents. The provincial local standard “Technical Specifications for Primary and Secondary School Classroom Lighting” stipulates the technical requirements of fluorescent lamps, LED lamps, classroom lighting quality and energy-saving requirements, installation and maintenance requirements, and acceptance rules for classroom lighting technology in primary and secondary schools. It is suitable for new construction and expansion. , Reconstruction and implementation of lighting transformation of classrooms in primary and secondary schools, including ordinary classrooms, laboratories, reading rooms, dance classrooms, art classrooms, calligraphy classrooms, computer classrooms, memory electronic reading rooms, and other classroom places.

“On the basis of ensuring compliance with national standards, the standard has added a series of innovative indicators.” Gao Xiaodong, director of the electrical department of Guangdong Product Quality Supervision and Inspection Institute, introduced that the provincial local standard “Technical Specifications for Primary and Secondary School Classroom Lighting” clarified the LED lamps Product and installation requirements, add new clauses such as increasing the illuminance at the top of the classroom, adding stroboscopic inspection items, and using products that are beneficial to visual health. Encourage the use of full-spectrum lamps that simulate sunlight to ensure that the classroom light environment continues to meet the standards and provide students with a learning environment conducive to healthy eyesight.

In addition, Guangdong Province has also taken the lead in the country to clarify two levels of indicators for the lighting environment of classrooms. The first level is the minimum requirement of the national standard, and the second level is the higher requirements that are conducive to the health of eyesight and lighting energy saving. It encourages qualified classrooms. Reference use.

Myopia in children and adolescents is caused by many factors, including genetic factors and environmental factors, among which classroom lighting is a major aspect of environmental factors. Zhuo Yehong, deputy director and deputy dean of the Zhongshan Eye Center of Sun Yat-Sen University, said that the important goal of formulating the provincial local standard “Technical Specifications for Classroom Lighting in Primary and Secondary Schools” is to provide teachers and students with a comfortable and healthy light environment to effectively prevent and control myopia in primary and secondary school students.

According to Chen Jiansheng, director of the Sports, Health and Arts Division of the Provincial Department of Education, the Provincial Department of Education will popularize the main content and technical requirements of the local standards to the provincial education administrative departments and all primary and secondary schools in various regions, and promote the implementation of school lighting facilities in place and the lighting environment to gradually meet the standards, To create a light environment conducive to the physical and mental health of teachers and students. He pointed out that it is necessary to promote the standardized construction and transformation of the teaching lighting environment to ensure that 100% of the school classroom lighting meets the national standard requirements by 2023, and to fully complete the task of meeting the lighting standards of the primary and secondary schools in our province.

According to reports, the provincial local standard “Technical Specifications for Classroom Lighting in Primary and Secondary Schools” was initiated by the Provincial Department of Education and under the guidance of the Provincial Market Supervision Administration. The writing units include testing agencies, disease control centers, and eye hospitals. Relevant social opinions, and the compilation process is scientifically standardized.

Scientists can greatly improve the brightness and stability of LED light-emitting nanocrystals

Recently, the U.S. Department of Energy (DOE) Argonne National Laboratory in Lemont, Illinois led the development of an important LED material.

Scientists can greatly improve the brightness and stability of LED light-emitting nanocrystals

The researchers of the reform laboratory team said: “LEDs are highly efficient, emit less heat, and last for a long time.” “Scientists are studying new materials to make LEDs more efficient and longer-lasting, and are used in consumer electronics, medicine, and Security field.”

Researchers and partners from Brookhaven National Laboratory, Los Alamos National Laboratory, and SLAC National Accelerator Laboratory reported that they have prepared stable perovskite nanocrystals for this LED.

“Nature Photonics” published a paper describing the work of the group. “Our research shows that this method allows us to greatly improve the brightness and stability of luminescent nanocrystals,” commented Xuedan Ma, a scientist at the Argonne Nanomaterials Center.

Perovskite nanocrystals are the main candidates for a new type of LED material. But for a long time, it proved to be unstable in testing.

The research team stabilized the nanocrystals in a porous structure called a metal-organic framework (MOF).

Based on the abundant materials on the earth and manufactured at room temperature, these LEDs may one day enable lower-cost TVs and consumer electronics, as well as better gamma-ray imaging equipment, and even for medicine, security scanning, and science. Researched self-powered X-ray detector.

“We solved the stability problem by encapsulating the perovskite material in the MOF structure,” said a scientist at the Argonne Center for Nanomaterials (CNM), Office of the US Department of Energy’s Office of Scientific User Facilities. “Our research shows that this method can help greatly improve the brightness and stability of luminescent nanocrystals.”

“The operating concept of combining perovskite nanocrystals in MOF has been proven in powder form, but this is the first time we have successfully integrated it into the emission layer of an LED.”

Previous attempts to manufacture nanocrystalline LEDs were hindered by the degradation of nanocrystals back to an unwanted volume phase, losing the advantages of nanocrystals and weakening their potential as practical LEDs.

Bulk matter usually consists of billions of atoms. Materials like perovskites are composed of a few to a few thousand atoms in the nanometer stage, so they behave differently.

In their new method, the research team stabilized the nanocrystals by creating nanocrystals in a matrix of MOF, which they described as “like a tennis ball caught by a barbed wire.” They used lead nodes in the framework as metal precursors and halide salts as organic materials.

The halide salt solution contains methyl ammonium bromide, which reacts with the lead in the framework to assemble nanocrystals around the lead core in the matrix.

The matrix keeps the nanocrystals separated, so they do not interact and degrade. This method is based on a solution coating method, which is much cheaper than the widely used vacuum process for manufacturing inorganic LEDs.

MOF stable LEDs can produce bright red, blue, and green light, as well as different shades of each light.

Wani Nie, a scientist at the Center for Integrated Nanotechnology at Los Alamos National Laboratory, said: “In this work, we have demonstrated for the first time that perovskite nanocrystals that are stable in MOF will create bright and stable colors of various colors. LED.” “We can create different colors, improve color purity, and increase photoluminescence quantum yield. This is a measure of the luminous ability of materials.”

The research team used an advanced photon source (APS) for time-resolved X-ray absorption spectroscopy, a technique that allowed them to discover changes in perovskite materials over time. Researchers can track the movement of electric charges through the material and understand important information that occurs when light is emitted.