Strengthening the classroom lighting design and design of the classroom to improve the visual ring mirror prevention and treatment of myopia before the son of Li Zihua Li Li myopia is caused by the deterioration of the visual environment, a modern patient only blames myopia on the students pay attention to the eyes Habits, did not further realize that this is a poor visual environment damage phenomenon, through the following analysis and analysis of data, we believe that myopia is mainly caused by the visual environment rather than by eye habits, and through the improvement of classroom lighting The design process can improve the visual environment and explore a preventive measure to prevent students' low vision and protect students' vision. Investigation and monitoring of the influence of classroom lighting on students' vision In order to understand the influence of lighting in school classrooms on students' vision, we conducted visual inspections on students in 20 primary schools in towns and counties in our county, and conducted lighting monitoring on classrooms in primary schools. . The survey respondents and methods of use randomly selected 80 classrooms in 20 primary schools as monitoring points, and the names of male and female students were used as visual examination objects. Using a 10 type lighting meter produced by the Shanghai Jiading Xuelian Instrument Factory, which is qualified and qualified, the same person chooses to monitor the lighting of 80 classrooms in the morning on a sunny day. The measurement method is based on the indoor illumination measurement method 1 and the lighting measurement method. carried out. The student's eyesight is based on the requirements of the Chinese Student Physical Health Monitoring Workbook. Those with lower eyesight are less visually impaired. Results 1 The classrooms measured by the desktop illumination were all equipped with artificial lighting. The light source was a fluorescent tube. Each classroom had a light tube. The average height of the tube suspension was in accordance with the electrical lighting design specifications. The standard of the desktop desktop illumination was not low. Yu Lux. The average illuminance of the tested classrooms reached the standard, and the number of sub-standards was less than the standard. Among them, the average illuminance of 54 classrooms was below 0 lux, and the uniformity of desktop illuminance in some classrooms was lower than the standard. There are blackboard lights, all of which are light tubes, and the blackboard has no local illumination. The vertical average illumination standard of the blackboard is not less than lux. The 80 blackboards tested, the highest vertical illuminance above 0 lux has the highest Dalux, the lowest is only 45 lux, the standard value of blackboard illumination uniformity. . the above. The natural lighting of the classroom adopts single-side lighting, and the classroom glass area ratio is the highest and the minimum is basically the same. The average value of the daylighting coefficient on the table is the standard for classrooms and 3/classroom failure. 4 students in the qualified lighting classrooms and the students in the unqualified classrooms are compared. See the table below. Lighting Qualified and unqualified classroom students Vision comparison Lighting illuminating survey Number of patients Having sickness rate Qualified unqualified Total engineering quality t Lighting Qualified classroom The prevalence of low vision and low prevalence of students with poor lighting and illumination is relatively obvious. The gap is very obvious. Factors affecting the visual environment that lead to low vision and visual fatigue are mainly written by students. The light source in the classroom is from natural lighting and lighting. The visual environment of the students is to illuminate the paper by light, and the chromaticity and height contrast between the paper and the font are formed, so that the eye can feel the shape and size of the font. The chromaticity is proportional to the purity of the reflected light, and the brightness is the same as the intensity of the reflected light. The brightness caused by the monochromatic light is also related to the spectrum of the light wave, and the visual brightness of the intermediate frequency light is the strongest. Therefore, the brightness and chromaticity of the light are the main factors affecting the visual environment. Brightness Regarding brightness, the state has clear regulations on various types of use environments. The school classroom is based on the standard that ensures that students can read and read books and see that the blackboard is clear and comfortable, the eyes do not produce glare, and the vision does not cause fatigue. Low brightness, difficulty in reading and writing, visual fatigue, excessive brightness, especially the intensity of white light is too large, reading and writing is actually under strong light stimulation, which will lead to the maximum viewing angle fatigue while obtaining the maximum brightness contrast. Chromatic white paper reflects white full-frequency light. People often only notice the advantage of white light visual brightness, but ignore the white light can only cause the weakest color perception, which is easy to cause visual fatigue. Snow blindness is a typical bad. The result of a visual environment damage. Today's book papers are becoming whiter and smoother, reflecting the white spectrum of light to the eye with almost the original spectrum and intensity. White light causes the weakest color vision, inhibits the normal function of color vision, reduces visual ability, and becomes the cause of the gradual approach of line of sight. Therefore, when the brightness and chromaticity are not up to the standard or exceed the requirements, no matter the intensity of the light, it is necessary to see the object image continuously, and the line of sight can only be shortened continuously. Over time, it is easy to accumulate disease and lead to functional myopia. . Improve the visual environment, improve the school's teaching and lighting lighting design, lighting design students study time is mainly during the day, so it is very important to do a good job of natural lighting design. In the design specifications of primary and secondary schools, the regulations and standards for the design of lighting in teaching buildings are proposed. In the design of the primary and secondary school building, we should arrange the classroom in a well-lit and well-ventilated place. The classroom should have at least one wall outside the window to directly receive natural light, and there should be no tall buildings and tall trees around. Etc., the ratio of the area of ​​the door and window glass to the floor area of ​​the classroom should meet the requirements of the regulations. At the same time, it is necessary to ensure that the uniformity of the entire classroom space and plane lighting meets the requirements of the regulations. The color of doors and windows and interior decoration in the classroom should be bright and comfortable, so that the window is clear. Lighting design light source should choose lamps with high efficiency and good long life. Fluorescent lamps have the advantages of high brightness and good color rendering. The light color is close to sunlight, so fluorescent lamps are very suitable for use in school classrooms. Of course, the choice of fluorescent lamps should choose high-quality qualified products, otherwise, stroboscopic noise will occur, and the life expectancy will not meet the requirements of qualified products. The chromaticity is reasonably used, and the spectrum of white illumination light can be reduced to improve the visual environment. One of the easiest and most effective ways to reduce white spectrum is to change the color of the book paper. The selective absorption of light waves by colored paper reflects only the color spectrum of a particular spectrum. Experiments have confirmed that the yellow light of a specific chromaticity reflects a small spectrum of color light and is in the mid-range light range, which can cause the strongest color sensation with minimum light waves and the brightness after white light, chromaticity and brightness. Get the most out of it to minimize visual fatigue. 3 Brightness After selecting the luminaire and taking the measures to improve the color vision, the illuminance requirement in the environment is very important. The design specification strictly stipulates the illumination requirements in the classroom, and the brightness is low, and the illumination cannot meet the requirements. Therefore, we strictly follow the rules of architectural lighting design, carefully designed and strictly calculated to meet the desktop illumination and blackboard vertical illumination and illumination uniformity requirements in the learning environment. To do a good job of illumination design, you should pay attention to the installation height of the following aspects. The installation of the luminaire is too high. In order to meet the requirements of the desktop illuminance, it is necessary to increase the power and affect the cost. If the installation is too low, the students will have a sense of depression, affect the interior beauty, and easily cause shadows, stroboscopic and noise phenomena. Therefore, the installation height has an optimum value, which is generally best at one meter from the ground. Lamp installation location. The installation position of the luminaire should be aimed at achieving uniform illumination. At the same time, we must take into account the overall aesthetics, vertical rows, horizontal rows, evenly arranged, and highly consistent. The arrangement of the lamps. The lamps in the classroom are generally fluorescent tubes, and the length of one tube is horizontal or vertical, and is also specified in the specification. We should install the long axis of the lamp perpendicular to the direction of the blackboard according to the requirements, so that the angle of the light emitted by the lamp is close to the angle of the sun's rays, which is good for visual good. Other measures The unqualified lighting illumination is also related to the dirty and dirty lamps of the lamps and the blackboard and blackboard painting. Therefore, to improve the visual environment should also clean the classroom health, often keep the door and window glass and lamp clean and regular time to paint the indoor wall canopy in time to replace the damaged lamp tube and paint the blackboard paint on time to avoid glare. In summary, through the analysis of the above survey data and the interpretation of the factors affecting the visual environment, we have realized that the visual environment harms the students' vision and the measures to eliminate the environmental factors caused by creating a safe and comfortable visual environment will help. In the prevention and treatment of myopia, the work from passive to active. 粼Company Profile, Beijing Construction Engineering Group Co., Ltd. Beijing Construction Engineering Group Co., Ltd., formerly known as Beijing Construction Engineering Bureau, was established in the year and changed to Beijing Construction Engineering Corporation. It was approved by the municipal government to be reorganized into Beijing Construction Engineering. The group was reorganized into Beijing Construction Engineering Group Co., Ltd., which is the largest construction and installation enterprise group in North China. Beijing Construction Engineering Group Co., Ltd. is composed of more than 30 enterprises. It integrates design, construction, construction and installation materials supply. It has a large-scale enterprise that manages real estate development and management, as well as international engineering contracting foreign trade qualifications and strengths. group. With an annual completion capacity of 10,000 years, the National Bureau of Statistics of the People's Republic of China and other authoritative units announced China's top 50 state-owned enterprises in the backbone, and the Construction Engineering Group ranked first. As the backbone of the capital construction, Beijing Construction Engineering Group Co., Ltd. has completed a total of more than half of the large and medium-sized buildings in the past 47 years. Among the top ten buildings, the Great Hall of the People, the National Culture Palace, the Beijing Workers Stadium, and other famous buildings, the Capital Gymnasium in the 1960s and 1970s, the Great Building of the Beijing Hotel, the East Building, the Chairman Mao Memorial Hall, and other large buildings in the ten new buildings of the Beijing Library International Hotel The central video TV tower of the Central Color TV Center of the hotel, such as the West Railway Station main station, the Henderson Center Oriental Plaza and other large-scale projects. In addition, Construction Engineering Group Co., Ltd. has built the vast number of foreign embassies and a large number of diplomatic apartments since the liberation. The Beijing Municipal Construction Engineering Group Co., Ltd., the main industrial zone in Beijing, has insisted on creating quality projects to create quality projects. Luban is the first of its kind in the country. Received the National Quality Engineering Award, the Ministry of Construction Quality Engineering, and Beijing Quality Engineering. So far, the Group Co., Ltd. and the Jian'an Company and the decoration company supervision company have passed the 15 quality system certification. The foreign name of Beijing Construction Engineering Group Co., Ltd. is Beijing Great Wall Engineering Corporation. The head office and the member companies of the group worked hard to open up the international market, and successively built a large number of projects in Pakistan, Zanzibar, Sri Lanka, Botswana, Thailand, Malaysia, Macao and other countries and regions. We have established joint ventures with Japan, the United States, Germany, Hong Kong, Taiwan and other countries and regions, and established branches in Mauritius and other places in Malaysia. We have set up branches in Macao and other places to set up branches in coastal areas along the coast of Shenzhen, Hainan, Zhuhai and Xinjiang. . In the year of the international economic and technological cooperation industry of the largest service enterprises in China, the Construction Engineering Group was successively ranked as one of the world's largest international engineering contractors. Beijing Construction Engineering Group Co., Ltd. adheres to the tenet of quality first, customer first, abide by the contract and wholehearted service, and is willing to create a better future with friends from all walks of life at home and abroad. The communication location is located at No. 19, South Lishi Road, Fuxingmen, Beijing. The telephone number is transferred to the relevant departments to welcome the medical education service facilities. Less engineering quality Diamond turning and diamond boring Precision Machining,Casting Exhaust Manifold,Stainless Stee Milling,Custom Cnc Machining Part Tianhui Machine Co.,Ltd , https://www.thcastings.com
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honing
Honing is to use the oil stone (also called honing bar) inlaid on the honing head to finish the hole.
grinding
Grinding is the use of coated or pressed abrasive particles embedded in the grinding tool, through the grinding tool and workpiece in a certain pressure of the relative movement of the surface for finishing processing.
superfinishing
Ultra-finishing is the finishing of the finished surface by using fine-grained whetstone mounted on the vibrating head.
Abrasive belt grinding
Belt grinding is the grinding of workpiece surface with high-speed annular belt.
Mirror grinding
Mirror surface grinding is a grinding method to achieve the optimum surface roughness. After grinding the workpiece, the surface roughness is not more than 0.01 micron, the light is like a mirror, can be clear imaging