Accurate verification of Maxwell's velocity distribution law
Maxwell's velocity distribution law states that when a gas is in thermodynamic equilibrium, the number of gas molecules is distributed according to the velocity with a certain regularity. This law was derived theoretically in 1859 by J. C. Maxwell (Maxwell) using mathematical statistics. But in those days, to put the same type of gas molecules in a certain space for experimental verification is impossible. The law of the early verification of many people, there are the University of Birmingham, England, O. W. Richardson (Richardson) and China's Ding Xielin, etc. After 1920, due to the development of vacuum technology to a certain level, the famous German physicist O. Stern (Stern) with silver vapor molecular beam experiments with the silver molecules with a definite speed distribution of information, but failed to give quantitative results. Quantitative results. In the following years many workers [including the University of California Department of Physics Director E. E. Hall (Holl), I. F. Caitman (Cartman), etc.] made technical improvements, the verification results are still unsatisfactory. Ge Zhengquan was the first to obtain accurate verification of this law after a grueling journey.
After completing his master's thesis in 1930, Ge Zhengguan wanted to enter Berkeley University to pursue a doctoral degree. At that time, it was not easy for Chinese students to get into prestigious American universities because Western scholars were prejudiced against the Chinese. The examining professor, Mr. Robb, told Ge Zhengquan, "Chinese students can only read but not do anything, we don't welcome them," and named six Chinese students he didn't welcome. Ge Zhengguan retorted, "You're a China expert, aren't there any Chinese students who can do anything?" Prof. Robb froze for a moment and admitted that there had been a Chinese student who had obtained a doctorate degree at the same time as he did. So he changed his attitude and took out two scientific and technical books, one in German and the other in French, and asked him to make a partial translation in English on the spot. Ge Zhengquan successfully passed the exam and was awarded a scholarship. From then on, he quit all his work and devoted himself to his studies and research. His dissertation was entitled "Determination of Heat of Decomposition of Bi2 by Molecular Beam Method", which was divided into two parts. On the basis of completing the measurement of the heat of decomposition of Bi2, he then hoped to verify Maxwell's Law of Velocity Distribution by means of measured experimental data.
The University of Berkeley is well-equipped and has a large laboratory. Initially, Ge Zhengquan and F. F. Coleman collaborated to carry out this research using a molecular beam velocity analyzer designed by Hall and developed by Zeitman. After nearly a year of effort, the result was the same as the previous no progress. During this time his original collaborator, F. F. Coleman, left on a Rhodes Fellowship. Seeing this situation, his mentor, Prof. Robb, said to him with a touch of sympathy: "This problem is so difficult that no one before you has succeeded. If you don't want to waste your time, I can give you a different topic." In the face of difficulties, Ge Zhengquan did not discourage, thinking: foreigners did not do, the Chinese people do not necessarily not do, they have a solid foundation in physics, broad knowledge of engineering, and skillful turning, clamping, casting and other technologies, I believe that they can be completed. He carefully summarized the work of nearly a year, and found that the experiment does need to be improved. After careful consideration, he thanked Prof. Robb's goodwill, politely refused to change the title of the proposal, alone into a more intense, grueling research. He often buy enough bread, day and night in the laboratory, a whole week without leaving the laboratory door, test, observation, calculation, failure, summarize. Correction, and then start again. In the days and nights of arduous climbing, the ancients hanging beam, stabbing the stock, bag of fireflies, reflecting the snow and other stories of painstaking efforts to achieve, often inspired, spurred him to work without fatigue. After repeated experiments, gradually find out the key to the problem, began a series of improvements: modification of Caitman's method or use some fundamentally different methods, in the choice of materials, parts of the modifications and additions, experimental temperature control and motor rotation speed and other aspects of the careful, meticulous and ingenious arrangements. After many more repeated experiments, he finally achieved satisfactory and expected results in the 3rd year: in the measurement of the heat of decomposition of Bi2, he corrected the negligence and mistakes of his predecessors, and used his own carefully modified apparatus and experimental methods to achieve much more accurate results than his predecessors; more importantly, he quantitatively verified Maxwell's law of velocity distribution with measured data. He is internationally recognized as the first to prove the law with precise experimental data, for which he was awarded a golden key each by the American Physical Society and the Mathematical Society, and a doctorate in philosophy.
Ge Zhengquan also analyzed the errors that still existed in his own dissertation, arguing that the verification of the distribution law, while achieving its intended purpose, was not yet ideal. Part of the difficulty lies in the technical aspects, which can be eliminated in the future; another part of the difficulty lies in the low temperature molecular beam in addition to Bi and Bi2, there is also another molecule Bi8, and with this method of verification of the distribution law, the use of single-atom beams can obtain more accurate verification results. In the following decades, the distribution law was repeated in various ways, and Ge Zhengquan's experiment was regarded as a classic in the history of physics.
Ge Zhengquan's success in verifying Maxwell's law of velocity distribution was reported by the press and became famous in Europe and the United States at that time, changing the status of Chinese scholars in the eyes of foreigners to a large extent, and influencing and encouraging Chinese students in Europe and the United States to a great extent. 1953, when Prof. Lu Hesheng was lecturing on Maxwell's law of velocity distribution at the University of Fudan, he talked about how he saw the Chinese Ge Zhengquan's experiment in the library of the library in the United States when he was studying in the United States. When he was studying in the United States, he told of the excitement and pride he felt when he saw a paper by a Chinese, Ge Zhengquan, in the library.
After the success of Ge Zhengquan's experiments, his experiments were constantly quoted in relevant specialized books at home and abroad. The United States Professor Robb in 1934 in the "gas dynamics" in the third chapter quoted his thesis; in Jeans's "gas molecular dynamics" of the classic work, Ge Zhengquan and Caitman is the same name; published in the United Kingdom, "the development of molecular beam experiments," the first chapter of a detailed account of his research. At home and abroad more and more college and university physics textbooks cite his experimental methods. Such as the United States F. W. Sears (Sears) Universi-tyPhysics (Chinese translation for the University of Physics, Guo Taiyun, etc., People's Education Publishing House); China Cheng Shou-su and other editors of General Physics (People's Education Publishing House, June 1982, 4th edition); Li Chun and other editors of Thermal (trial textbooks for higher education, People's Education Publishing House); and so on. People's Education Press); and so on. Some books to "Ge Zhengquan experiment" as the title of the special account.
Laying the foundation of China's oxygen industry
Ge Zhengquan was studying in the United States during the September 18 Incident in 1931, when foreigners were discussing the current situation in China. At that time, when foreigners were discussing the current situation in China, they always said in a sarcastic tone that the Chinese people were so big that they had given the three northeastern provinces to Japan in a week. Driven by strong national pride, Ge Zhengguan declined the invitations from the physics circles of some countries after he finished his research work and obtained his doctoral degree, and immediately returned to China to realize his long-cherished dream of "education to save the country". After his return to China, he was employed by Wuhan University in 1933 as a professor of physics for 5 years, and in 1938, the Japanese invasion forces came to Hubei. After a Japanese aircraft bombing Wuchang, Ge Zhengquan saw with his own eyes the bloody limbs splattered plastered on the broken walls, heartbreaking as burning, y national survival of the issue of the major, without the motherland which still talk about "education", "save the country"! So I decided to join the military, and went to the front line of the war against Japan.
At that time, there were some Soviet air force and our own airplanes in Wuhan. The tactical advantage in an air war is to gain higher air control. But it is impossible for high-altitude flight crews to fully utilize their combat power in oxygen-deprived conditions. At that time, China did not have its own oxygen industry, the air force needs oxygen is not a long way from home, or rely on the domestic two or three foreign factories temporary supply, sometimes due to the lack of timely supply, resulting in my air force setbacks. Ge Zhengquan thought that China must have its own oxygen plant, so he took the initiative to propose the task of oxygen production to the government. Aviation Committee in charge of mechanical Qian Changzuo said: "You come to us very welcome, but the military pay is limited, only 180 yuan per month, much lower than your 300 yuan of professor's salary, the military work is difficult and dangerous ......." Did not wait for Qian Changzuo finished, Ge Zhengquan resolutely said: "I came to participate in the anti-Japanese war, not for the money, in the country's life and death only care about personal safety and danger, only seek personal comfort is shameful!" He thus took off his suit and changed into a military uniform and assumed the post of director of the first gas manufacturing institute of the Aviation Commission. Because of the war oxygen equipment can not be imported from abroad, in order to solve the urgent need, he bought all the equipment of the Hankou oxygen factory run by foreign businessmen, and in Wuhan before the loss of custody of the transfer to Hengyang, through the Xianggui Railway to Guilin, and then change the large trucks to Guiyang, long-distance transfer of the hardship and suffering is difficult to say. The Japanese airplanes' air raids made Ge Zhengquan's life in danger several times. The most dangerous time was when the Japanese planes bombed the Guiyang city, the tiles and glass of the houses he lived in fell down one after another, and he survived by hiding under a square table with his son. Fortunately, one of the bombs dropped by the Japanese planes on the wall outside the house was not detonated. Oxygen production equipment was installed in Guiyang outside the town of Sanqiao near the gourd cave. 1939 May officially started production of oxygen, solving the Air Force high-altitude combat oxygen problem. At that time, there were outsiders willing to pay a lot of money to buy oxygen, but he strictly refused. He went on to produce hydrogen, carbonic acid and other types of military gases, and also made gasoline, diesel fuel, caustic soda, paint for airplanes and other military materials that were extremely scarce in the local area at that time. At the time of great success in all aspects, he posted a couplet written by himself on the wall of his home: "Don't talk about people's lengths and shortcomings, and don't claim credit for what you do". He lives frugally at home, usually eat green vegetables with a little more oil, it feels delicious. Ge Zhengquan is so conscientious, law-abiding, hard and simple, and the people of the country with life and death, *** sweet and bitter, in the critical juncture of the survival of the nation to do their best for the victory of the war of resistance against Japan set up a sweat and toil. 1945 Japanese invasion forces unconditionally surrendered, he was ordered to send a technician to take over the Japanese and U.S. troops left behind the oxygen plant across the country. The oxygen plant in Guiyang was moved back to Hankou and renamed the Aviation Commission Oxygen General Plant, while the other plants taken over in various parts of the country were called branch plants. Ge Zhengquan was appointed director of the General Factory.
The pioneer of radar research and application in China
Shortly after Ge Zhengquan was appointed director of the Air Force's Oxygen Plant, he thought that since the war against Japan was over, it would be better to return to Wuhan University to resume his old career, so he tendered his resignation to the Air Force Headquarters. At the same time, the Ministry of National Defense established the Sixth Office, known as the Office of National Defense Science Research and Development. Qian Changzuo, who was appointed as the director of the department, invited him to be the director of the first division of the department and to preside over the work of national defense scientific research and design. Ge Zhengquan was very interested in some of the new weapons that appeared in the Second World War and gladly accepted the invitation. During his tenure as Director of the Design Division, he was ordered to go to Shanghai and Qingdao to take over the remaining military supplies of the U.S. Army. When some people were overwhelmed by the victory of the anti-Japanese busy in the "robbery of wealth", he was clean and self-love, law-abiding. He devoted himself to national defense scientific research, fancy the U.S. military left more than 400 military radar vehicles and more than 3,000 tons of radar equipment. With these equipments and the short-wave knowledge he learned from the U.S., he single-handedly broke through the heavy resistance and overcame all kinds of difficulties, and firstly set up a radar repair center in Denglong Lane of Nanjing, and then built China's first radar research institute in Miaolu Mountain of Nanjing, and wrote a paper on the development of radar and its role in the Second World War. Soon after, he was appointed as the director of the Radar Research Institute, and from then on, China had its own radar research and radar production industry.
In 1948, a radar detection exercise was conducted at Miaoru Mountain, where the monitor showed the distance, direction, height or view of the object being probed. The important members of the Nanjing government thus felt the importance of radar in national defense. In order to control this institute, they planted some Junta agents among the deputy directors and technicians. Ge Zhengquan realized the complexity of the situation, and thinking of the KMT's past and some of its policies at that time which were against the people's will and unpopular, he lost his confidence in the KMT.
When the Nanjing government fled from Nanjing in 1949, the Ministry of National Defense ordered Ge Zhengquan to relocate the Radar Research Institute to Taiwan, and the relocation committee also allocated 50 train cars and landing craft and other means of transportation. He started the civil war against the Kuomintang, corruption, soaring prices, put the people in the act of abhorrence, how can this penetration of their own years of hard work, the vital national defense facilities sent to the bullet-ridden Taiwan it? The soft resistance dragged some time, on the eve of the People's Liberation Army crossing the river, in order to avoid the radar was damaged by the fire, only part of the complete radar car 50, through the Beijing-Hangzhou highway to Hangzhou to take refuge. The Ministry of National Defense and 30,000 silver dollars as bait, he wanted to drive the radar car to Ningbo out to sea to Taiwan. He did not take the bait and stayed put. At that time, the secret agents planted in the institute instigated some of the staff of the institute to use force to escort him to Hangzhou Gymnasium and detained him in an attempt to assassinate him. In October 1949, he moved the radar back to Nanjing, trained 180 radar technicians, and formally set up the radar unit of the People's Liberation Army (PLA). in early 1950, the unit was ordered to take part in the liberation of the Zhoushan Islands, and when passing through Shanghai, the radar made its first contribution to the defense of Shanghai. in May 1950, the unit was ordered to take part in the liberation of the Zhoushan Islands, and when passing through Shanghai, the radar made its first contribution to the defense of Shanghai. In May 1950, he was ordered to fight against the United States and aid North Korea, he also transferred the radar unit to Shenyang to the Yalu River along the railroad line defense, guarding the Yalu River Bridge.
Because of the long and intense run, Ge Zhengquan accumulated laborious disease, need treatment and long-term recuperation. He resigned as director of the Radar Research Institute and went to the hospital of the Second Military Medical University in Shanghai for treatment. After recovering from his illness, he was recruited as a first-class professor and director of the Mathematics and Science Teaching and Research Department of the Second Military Medical University. In the following years, he actively engaged in teaching and scientific research. He was the chief editor of the physics textbook of the Second Military Medical University; he directed the development of the first DC amplifier of brain wave in China, which was used to observe the response wave of the human brain to things; he assembled a field emission electron microscope with a magnification of 500,000 times by using a van der Graaf high-voltage generator, which could directly observe the atomic arrangement of the organism benzene dicarbocyanin pigment. At the age of 85, he presided over the translation of the book "Fundamentals of Modern Physics and Its Applications" by P. A. Tipler of the United States, which was published in January 1981 by Shanghai Science and Technology Press.
In 1984, Ge Zhengguan finally realized his long-cherished dream and joined the Chinese ****anization party.
On March 22, 1988, Ge Zhengquan, who had devoted himself to teaching physics and scientific research for more than 60 years, died at Changhai Hospital of the Second Military Medical University in Shanghai.