Yuan jialiu

Yuan jialiu

Luke Chia Liu Yuan (April 5, 1912 - February 11, 2003), a Chinese American physicist, is the son of Yuan Kewen, the second son of Yuan Shikai, and his wife Wu Jianxiong, known as "Madame Curie of the East". Due to his outstanding achievements, he has won two American science and technology awards.

He was born in Anyang, Henan Province on April 5, 1912, and his ancestral home is Xiangcheng, Zhoukou. He graduated from the Department of physics of Yanjing University in 1932 and obtained his master's degree in 1934. In 1936, he went to the United States to study in the Research Institute of California Institute of technology, and in 1940, he received a doctorate from the University. Since 1942, Mr. and Mrs. yuan jialiu have been working in the Institute of Radio Corporation of the United States. They are physics researchers at Princeton University, physics researchers at Brookhaven National Laboratory and senior physics researchers. They joined the United States in 1954 and only have one son, Yuan Weicheng, who is also a doctor of Physics. In 1973, he returned to visit his relatives and stayed for 53 days. Since then, the couple has returned to China many times to give lectures and have been received by Zhou Enlai, Deng Xiaoping and other party and state leaders. He retired in 1979. He is still a consultant of the laboratory after retirement. In September 1986, yuan jialiu went back to visit his relatives in the hometown of yuanzhai, Xiangcheng, and was warmly welcomed by the people of his hometown. He died in Beijing in 2003.

He won the Guggenheim prize in 1972. He was appointed member of the academic committee of Institute of high energy physics, Chinese Academy of Sciences in 1979, Honorary Professor of University of science and technology of China in 1981, chairman of the board of directors of Taiwan Synchrotron Radiation Research Center in 1983, Honorary Professor of Nankai University in 1984, and honorary doctor's degree of Nanjing University in 1986.

Life of the characters

On April 5, 1912, Mr. Yuan jialiu was born in Anyang, Henan Province. His father, Yuan Kewen, was Yuan Shikai's son born out of concubines. He was put under house arrest and fell out of favor because he wrote a poem that "I feel sorry for the high place, but I don't want to go to the top of Qionglou". As a result, Mr. Yuan jialiu was far away from Peiping and lived with his mother in his hometown for a long time. When Mr. Yuan jialiu was 13 years old, he went to Nankai Middle School in Tianjin. Only a month later, he transferred to Xinxue academy, a school run by London Missionary Association.

In 1928, he was admitted to Business University to study engineering.

In 1930, he transferred to the Department of physics of Yanjing University and studied with Professor Xie Yuming, a famous Chinese physicist. He was particularly interested in radio, and used his spare time to study radio communication.

After graduating in 1932, he entered the Graduate School of the university to study for a degree.

He got his master's degree in 1934. Under the promotion of Leighton Stuart, then president of Yenching University, he won the international scholarship.

He was admitted to California Institute of technology in Berkeley in 1936. One afternoon in August of the same year, introduced by Victor Yang, President of the student union, Wu Jianxiong met Mr. Yuan jialiu. He took Wu Jianxiong to visit the Department of physics and met with department director Burke, who made an important contribution to Berkeley's becoming an important physics town in the United States. From then on, Wu's plan to go east to the University of Michigan was cancelled and they became classmates.

In 1940, yuan jialiu received his doctorate.

He became a U.S. citizen in 1954.

Mr. Yuan jialiu, a Chinese American and world famous high energy physicist, died in Peking Union Medical College Hospital on the afternoon of February 11, 2003 at the age of 91.

Character contribution

Mr. Feng Duan, academician of the Chinese Academy of Sciences and professor of Nanjing University, commented on Mr. Yuan jialiu and Ms. Wu Jianxiong: they have "the invaluable qualities of the first-class experimental physicists; they have a deep understanding and high insight of physics, so that they can design exquisite experiments to make nature bow to their ears and reveal its secrets; they are skillful in hands-on, sensitive in experiments, and can make people understand physics The blueprint in the mind turns into the equipment in the laboratory; can get along well with the cooperators, and maximize their enthusiasm for common cause; more perseverance, overcome the obstacles and difficulties on the way forward, and never give up halfway; in addition, treat each experimental result with a cautious attitude, so that it can withstand many aspects It's a test of the future. " Perhaps just like Mr. Wu Jianxiong, Mr. Yuan jialiu has made outstanding contributions in the field of science. His research fields are very extensive, involving radio directional detectors, cosmic rays, high-energy physics, high-energy accelerators and particle detection systems. To sum up, there are mainly the following aspects:

1. In his early years, he studied radio technology and principle, and made gratifying achievements in the aspects of UHF radio direction finding and the best route of homing device.

2. During my work in Princeton University, I was mainly engaged in the study of neutron sources in cosmic rays. At that time, it was generally believed that the neutrons in cosmic rays came from space, based on the data obtained by sounding balloons, which showed that the density of neutrons could be increased even if they rose to an altitude of 30000 meters. The actual lifetime of neutrons is only half an hour. In this way, there is an obvious contradiction. Mr. Yuan jialiu and Ladenburg questioned the results of the radiosonde experiment and boldly thought that there might be problems. They pointed out: the atmosphere at high altitude is thin, and the detector is connected with a high-voltage power supply, which will inevitably produce spark discharge at low pressure, resulting in the appearance of a false neutron signal. They inflated and sealed the neutron detector and high-voltage device completely to avoid spark discharge. At the same time, balloon, airplane and telemetry and receiving system with excellent design performance are used for radiosonde research to measure the distribution of slow neutrons in the atmosphere, the absolute intensity of neutrons at various altitudes, and the distribution of neutron generation rate and absolute neutron intensity with altitude in cosmic radiation. The results show that the neutron density reaches the peak when it rises to 1.5km, and the neutron density reaches the peak when it rises to 30000 meters The number of people in the market has been reduced to one tenth of the original. The result is that the neutrons in the earth's atmosphere are produced by three years of hard work of cosmic rays. This completely overturns the wrong conclusion that neutrons come from space.

3. While working at Brookhaven National Laboratory in the United States, he participated in the preparatory work for the construction of the 3gev high energy proton accelerator with the highest energy in the world at that time, and was responsible for the design and construction of the high frequency system. At the same time, he has carried out research on particle detectors, high-energy accelerators and high-energy physics. He collected data with scintillation counter tracer, determined the position of particles with scintillation detector, and discussed the application of solid state detector in high energy physics.

4. He is known as the most important contribution in his life, which is in the field of high energy physics. He is engaged in the generation and energy spectrum measurement of positive and negative π mesons and positive and negative K mesons, and the determination of P-P, P-P, π - P, π - P, k-p, k-p reaction cross sections, scattering cross sections and total cross sections under different high energy conditions. In the history of science, it is acknowledged that Mr. Yuan jialiu is the first scientist to prove the resonance phenomenon between pion and proton by π - P scattering. In the 1960s, he used X-ray penetrating radiation to detect ultra-high energy particles and successfully studied the penetrating radiation produced by relativistic charged particles. The total energy of X-ray is proportional to the energy of particles. He improved the penetrating radiation detector when he studied the penetrating radiation effect of superheated superconducting particles. As Mr. Feng Duan said, we are happy and gratified to comment on the above outstanding and immortal achievements. At the same time, through the historical track left by them, "we can see the person standing behind" - the immortal Mr. Yuan jialiu!

research field

It involves high energy physics, high energy accelerator and particle detection system, cosmic ray, radio directional detection, frequency modulation radar system, etc. He was the first to prove that neutrons over the earth do not come from space, but secondary particles produced by primary cosmic rays in the atmosphere.

In 1949, he was responsible for the design and construction of the first special high frequency system in the world at Brookhaven National Laboratory.

In 1953, the world's highest energy proton accelerator was successfully operated. He was one of the first physicists to apply electronics to the detection of high-energy particles. He was also an early researcher who used scintillation counter tracers and automatic methods to collect data. He has edited "the nature of matter: the purpose of high energy physics" and "methods of experimental physics: nuclear physics".

Personal life

On May 30, 1942, he married Miss Wu Jianxiong, who will be 30 years old. The wedding was presided over by Professor Milligan, President of Caltech and Nobel Laureate in physics, and his wife. It was held in Milligan's garden. On September 19 after the marriage, Wu Jianxiong wrote to his best girlfriend and said, "in three months of living together, I know him better. His dedication and love in his heavy work won my respect and admiration. We love each other so much. " Since then, they have been together for more than half a century until Wu Jianxiong died in 1997.

Anecdotes of characters

In the early 1930s, Mr. Yuan jialiu and Mr. Zhang Wenyu, a famous Chinese physicist, were close friends at Yanjing University. They went to the United States to study. After the end of World War II, Mr. Yuan jialiu was engaged in research work in Princeton, and Mr. Zhang Wenyu also worked there. Both of them carried out frontier experiments on cosmic rays. Later, Mr. Zhang Wenyu returned to China in 1956 with the help of his British mentor, Mr. kokraofu, and others to participate in the revitalization

Chinese PinYin : Yuan Jia Liu