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It is said to be a workshop, but it is actually a large factory building of 20x60 meters, which is divided into many work areas in the middle.
The rough lens blank is first milled here, which is actually rough grinding. The surface of the lens is processed to almost the required appearance, and then the R value is fixed by fine grinding.
The finished lens has only completed 15%~20% of the workload, and then it is polished-cleaned and cycled several times.Edge grinding, coating, and some lens combinations need to be glued in the workshop.
"Polishing powder is not a simple auxiliary material. We underestimated the importance of polishing powder when we started making it in 1952," said the chief engineer. "The first batch of polishing powder produced was not easy to use, and a batch of lenses were worn out. , luckily it’s just Su Liu’s lens.”
"The specification of the polishing powder used in the seventh workshop is the highest in the whole factory. We only made it in February this year. Before that, until January 2, we used the cerium oxide polishing powder imported from the Soviet Union."
The first requirement of polishing powder is that the particle size is absolutely uniform, and the hardness is slightly greater than that of the polished material.The optical lens of the lithography machine is made of hard glass, and the polishing powder must be made of cerium oxide with a slightly thicker diameter.
In addition to the absolutely uniform particle size, it is also required to be free of impurities, have a certain lattice shape and defects, and have appropriate self-sharpening.
When processing lithography machine lenses, the iron oxide polishing powder commonly known as "red powder" could not meet the requirements. From 1952 to 1955, Changguang also assigned a group of people to develop cerium oxide polishing powder, which took three years.
Moreover, the polishing of the glass surface not only uses polishing powder as a raw material, but also a raw material called polishing glue.For the processing of the glass surface, first apply polishing powder, and then apply polishing glue.
Chang Guang used rosin to polish the lens of the lithography machine for the first time, but the precision was not up to standard and failed.It is now replaced with an asphalt-rosin hybrid polish.
……
At the end of the seventh workshop, it is also the place with the highest technical content in the entire optical system manufacturing workshop, the dust-free fine polishing room.
Here, Tang Hua, Wang Dayan, and the chief engineer first went to the locker room, changed clothes and shoes, cleaned the whole body, put on a swimming cap, and put on a mask, just like when they entered the production line at the lithography machine factory next door.
The process of the first non-contact lithography machine was 10 microns during trial operation yesterday, which is the same as the previous generation production lines in Beijing and Shanghai. However, this lithography machine still has the potential to improve, and may support 7 microns or even 5 microns. micron process.
In this dust-free fine polishing room, the precision requirement of the mirror surface processing is 1 micron.
Therefore, the workshop has to be made into an absolutely dust-free clean environment.Dust, smoke, dandruff and even saliva can ruin a high-precision finish that has been machined for hours.
The three of them entered the dust-free fine throwing room, and new equipment was brought in. Tang Hua and Wang Dayan each pulled a small cart to the workshop.
"Changguang produces crucial parts for the lithography machine system. The process standards of your products can be said to largely determine the process ceiling that the lithography machine can achieve, which also determines the effectiveness of our computer system. How advanced."
Tang Hua spoke to the chief engineer.
"In other words, the technological progress or technological revolution of our computer system must be based on the technological progress and technological revolution of Changguang and Changguang No. [-] workshops."
"Fortunately, every category and every department of today's industrial system is related to each other. As I said just now, the optical instrument factory and the computer industry have already been linked, but what I want to emphasize is that the optical instrument The relationship with the computer industry is not one-way, but two-way."
"The optical instrument factory provides the computer industry with a working machine. Correspondingly, the computer industry can also support the optical instrument factory in turn, helping your technological progress and technological revolution. This can be regarded as reciprocal feeding, and it can also be regarded as a great roundabout of industrial technological progress."
When they arrived at the polishing station in the fine polishing room, Tang Hua and Wang Dayan stopped the trolleys and sorted out the equipment placed on the two trolleys:
Laser planar interferometer.
……
"The laser plane interferometer is a non-contact, high-precision and non-destructive optical surface measurement device. It is based on the principle of Fizeau interference, that is, phase-shifting interference, and determines the shape of the optical surface by analyzing interference fringes."
"The laser plane interferometer can be used for high-precision measurement and analysis of the radius of curvature of the plane and spherical surfaces. It can measure the plane wedge angle, that is, measure the right-angle deviation for the right-angle prism. In fact, it can also measure the processing deviation of any angle. It can also be used to measure the uniformity of optical materials, the angle of the cone and the deviation of the surface shape... In fact, it can be used in many places in your factory, especially in the seventh workshop. What you see is the first product, and the Suzhou side will next There are more than a dozen interferometers sent to Changchun."
Tang Hua explained the principle and structure of the laser plane interferometer to the chief engineer, workshop director and technicians on the spot.
"This is the host of the laser plane interferometer, including a high-precision mechanical adjustment frame, a helium-neon laser power supply, and a magnification imaging micrometer system. This is the penetrating inspection table, and this is the 300mm optical plane model."
"This is a computer workbench, with an industrial computer, a video system and a 14-inch display monitoring system."
Under the command of Tang Hua, several people worked together to disassemble the original light spot visual measuring tool and micron-level spiral measuring ruler on the polishing workshop station, and assemble the laser plane interferometer.
"Let me see, after the last process is over, what is the mirror reading you recorded just now... Let's use this as a reference."
The lens being processed is fixed at the fixed place, aligned sideways, and the laser plane interferometer is turned on.
The monitor showed a bright round spot with some stripes in the middle, and the text description on it was also loaded:
M1; M2.
M1 and M2 are two wave surfaces, one incident wave and one reflected wave.There is a wedge angle between them, and when the two wavefronts are superimposed and coherent, several equally spaced parallel straight line interference fringes will be obtained.If there is curvature in the plane to be inspected, the reflected wave M2 will have some deviation, and the interference fringe between it and the incident wave M1 will be bent.
The interferometer is swept across the surface of the lens, and the fringes of bright circular spots show the curvature of the mirror.After scanning for a short time, the flaws on the mirror surface were found: the stripes of the round spots were not straight or arced, but trembled.
Continue to scan, and the total reading of the curvature of the lens will be read on the monitor. This number can be compared with the theoretical value when designing the lens to see if there is any major adjustment that needs to be made.
……
"This is a magic weapon!" Coming out of the dust-free room, the chief foreman was still dizzy, not because he couldn't understand the principle of the interferometer, but because he was too excited and his blood pressure rose. "With it, what is a micron?"
Tang Hua: "This laser plane interferometer has a theoretical measurement accuracy of 0.05 microns and 50 nanometers. Of course, you may not be able to fully utilize its effectiveness when you first use it, but if you master the interferometer and analysis computer skills , and make some adjustments to the polishing process, then this goal can be achieved, and the speed of processing lenses will also be significantly accelerated."
Chief engineer: "This is feedback, I finally understand."
……
"You have to take off your shoes and clothes when you enter this workshop, right? Old Wang, why don't we just take a look outside, and forget it if we don't go in."
Outside the optical fiber drawing tower of the optical fiber factory, Tang Hua said to Wang Dayan.
Wang Dayan: "I don't want to go in either. Everything is running very well now, and I don't think there is anything that needs to be improved."
Tang Hua: "Let's go around to the back to see the construction site of the second tower."
The first workshop (Tower No. 20) of the optical fiber factory has been put into operation for more than two months, and now the construction of optical fiber communication lines is a bit crazy.Last year, Jilin applied for the construction of a longer optical fiber communication line: an optical fiber from Changchun to Jilin.Previously, the line from Changchun Post Office to Changchun Airport was only [-] kilometers, which was too short.
It is not a computer data communication network, but an integrated communication line of telephone and cable telegraph. After passing through the modem, the telegraph signal and telephone voice are sent to the optical fiber for transmission. One optical fiber can connect hundreds of telephones at the same time, which is infinitely stronger than the copper cable.The demand for long-distance telephone and telegraph communication from Changchun to Jilin is very high, after all, it is a city with a high degree of industrialization.If optical fiber communication lines are laid on these 100 kilometers, more than 100 tons of cables can be saved immediately.
This cable is all copper.
As of today, the optical fiber from Changchun to Jilin has been laid...
When the optical fiber from Changchun to Jilin was being laid, two semi-new optical fiber lines were also planned: Beijing-Tianjin-Tangshan-Shenyang-Changchun-Harbin is one, and the branch line from Shenyang to Dalian counts as half.Beijing-Jinan-Nanjing-Shanghai is another.
As long as it is mentioned that copper can be saved, both eyes shine from the center to the place, and the work efficiency is extremely high. Moreover, even with the current cost standard of optical fiber, it is cheaper than a large bundle of copper cables.Therefore, before Tang Hua put forward the concept of "computer information superhighway", the optical fiber project was first rolled out vigorously in the post and telecommunications department.
"I saw a Japanese newspaper in Beijing before my business trip," Tang Hua said. "The Japanese author said that the gossip showed that the technological breakthrough of American computers came from espionage harvesting, and the original source of the technology was China. This Japanese gossip It’s very accurate. But he made a mistake in one of the following texts. He said that American computer technology comes from China, and Chinese computer technology is based in Shanghai. He was wrong, and Changchun is the root of computer technology.”
Chapter 92, Fertilizers Take Effect
Hubei, Wusan Mechanized Farm.
With the arrival of summer, the [-] mu of wheat fields have changed from green to yellowish green, and now they are golden yellow that symbolizes harvest.
Wusan Mechanized Farm is located in the north of Hubei. The terrain here is flat but high, and it is impossible to divert water for irrigation. The annual precipitation in Jiangbei, Hubei is not uniform. In 1949, only two villages in this large area lived by growing potatoes and sweet potatoes, and 90% of the land was barren. .
In 1951, Soviet agronomists felt that this place could be completely transformed, so they established a mechanized farm here. They used large machines to build irrigation systems, level the land, and improve soil quality. It became a state-owned farm with mechanized farming and mainly wheat.
In 1953, the first mechanized farming was carried out, and in 1954 and 1955, this year is the third season of wheat.However, Wusan Farm experienced a flood in 1954, and thousands of acres of wheat fields were soaked in water, and the soil quality that was being improved deteriorated a bit.