19 13, entered Zoumafu Village Primary School. 19 17 entered Laoting County Senior High School. 19 19 entered the junior middle school of Mei Cheng Middle School in Changli County. 1923 entered Beijing Academy High School.
1924, sent to yenching university. In college, Meng chose to study science. The wonderful lecture given by C.H.Corbett, a physics teacher at that time, made Meng interested in physics. Paul anderson and Professor Xie are both experimental physicists. Under their influence, Meng cultivated a strong practical ability and laid a good foundation for the later research work of experimental physics.
1928 obtained the bachelor of science degree, and won the golden key award of Fei Taofei (φ T φ) honorary society with excellent performance. After graduating from college, Meng stayed in the Department of Physics as a teaching assistant and studied for a master's degree under the guidance of two professors, Anderson and Xie.
193 1, the thesis Contact Ionization of Hydrogen with Platinum, Copper and Nickel obtained a master's degree and was promoted to a lecturer. This article was published in Journal of chinese chemical society, Volume III, 65438-0935. During my time as a lecturer, I cooperated with Chen Shangyi and others to complete the research work of "Transmission of Ultraviolet Radiation through China Window Paper".
65438-0933 On the recommendation of yenching university, Meng was funded by Rockefeller Foundation and went to California Institute of Technology to study for a doctorate. At that time, California Institute of Technology was presided over by the famous experimental physicist R.A. Millikan, and it has become one of the most dynamic scientific research and education centers in the United States. Under the guidance of Professor G. Potapenko, Meng studied the Backhausen-Courths effect. After three years of hard work, he obtained a continuous oscillation with a wavelength of 65438±0cm with a self-made miniature electron tube. This is the world record of the shortest oscillation wavelength obtained by the electron tube at that time.
During the period of 1933, when Meng went to California Institute of Technology for his Ph.D., he was very interested in several papers about Backhausen-Courths oscillator published by the professor in Physical Review. He is determined to explore the possibility of using this device to generate extremely short wavelength electromagnetic waves under the guidance of Professor Pote Pan Ke. After three years of hard work, he finally produced a continuous oscillation with a wavelength of only 1 cm with his own electron tube, setting a world record for the continuous oscillation of microwave produced by triode. Meng Zhaoying received his Ph.D. and read this paper in the Los Angeles branch of the American Society of Radio Engineers (IRE). He became famous for "developing an electron tube with the shortest oscillation wavelength".
The anode of this electron tube made in Bangladesh is a nickel tube with an inner diameter of only 65438±0mm, the grid is a spiral tube made of fine tungsten wire, and the cathode is a straight tungsten wire. It is not easy to assemble such a small electrode accurately, so he made a small spot welder. Some places are not easy to spot weld, so he glued them with colloidal graphite and visually adjusted the center line. After the successful development of the electron tube, he carefully adjusted the voltage of each electrode and finally obtained an oscillation with a very short wavelength. At that time, there was no ready-made instrument to measure such a short wavelength, so he adopted short bridge parallel double line (commonly known as Loescher line). When the short bridge moves to a certain position, the electrode current changes, and the distance between two identical changes is half a wavelength. The oscillation wavelength measured by this method is 65438±0cm.
1936, Meng received a doctorate in philosophy from California Institute of Technology. Meng won the title of "vacuum electronics expert" for his outstanding work.
From 65438 to 0936, Meng Qicheng returned to China and served as an associate professor in the Department of Physics of yenching university, teaching radio and electronics courses. He is one of the early scholars who offered such courses in China.
1In July, 937, the Chinese Physical Society planned to hold an annual academic conference in Hangzhou, and Meng arrived in Tianjin from Beiping and other ships went south. Just as the July 7th Incident broke out, the meeting was cancelled. In Tianjin, he met Wu, Zhou Peiyuan, and other Tsinghua University physics professors who were also going south. After learning about the situation in Peiping, he went south from Tientsin with Tsinghua University, and went to Changsha alone to teach at Changsha Temporary University, which was jointly composed of Peking University, Tsinghua University and Nankai University. In Changsha, he also set up an amateur radio station to teach some students to master radio transceiver technology.
From 1938 to 1943, Meng was a professor at Kunming Tsinghua Radio College and an honorary professor at the Physics Department of Southwest Associated University. Together with Professor Ren Zhigong, he teaches radio and electronics courses to physics and electrical engineering departments. During this period, Meng completed the research of linear amplitude modulation of triode RF amplifier. The research results were published in DIRE》65438-0940, the journal of American Radio Society, which attracted the attention of international colleagues.
1943, Meng visited California Institute of Technology again. At this time, microwave research has made great progress in the United States. Meng chose the accurate measurement of metal waveguide impedance as the research topic. At that time, metal waveguide was a new type of microwave element that had just come out. His method is to place a choke movable short-circuit device at the waveguide terminal to form a resonant cavity. Movable short-circuit piston resonator is a precise instrument for measuring microwave frequency. Because of the high quality factor of the resonator, this method has high sensitivity and precision in measuring the impedance in the waveguide. After a year of research, it finally succeeded and obtained an American patent.
1944, Meng was transferred to work in the radiation hall of MIT to study the radar transceiver switch (t? r？ This work was not published because it involved wartime secrets. When the United States exploded the atomic bomb in Hiroshima and Japan surrendered unconditionally, wartime research stopped, and Meng turned to study the absorption spectrum of oxygen in microwave. The research results were published in the American Physical Review. This is one of the earliest research results of microwave absorption spectrum, and it is also the beginning of millimeter wave application in scientific research. The basic experimental techniques used in the study were widely used by later researchers.
From 65438 to 0945, Meng immediately turned to the usual basic research. In the 1940s, the research of quantum mechanics theory and material microstructure developed vigorously. Theoretical research shows that many energy level transitions of atoms or molecules are in the microwave frequency band, but they have not been confirmed by experiments due to the lack of experimental means in this frequency band. Meng used the excellent microwave experimental conditions in the radiation laboratory to study the absorption spectrum of oxygen in 5 mm band in cooperation with M.W.P.Strandberg, a graduate student at that time and a later professor at MIT, and another technician. The signal source used is a reflective klystron with resonant cavity frequency stabilization system, and the 1 cm oscillation generated by it is multiplied by a silicon crystal diode to obtain a 5 mm signal. The receiving system is a microwave heterodyne receiver composed of harmonic converter, intermediate frequency amplifier and phase shifter. The oxygen absorption spectrum of pure oxygen and oxygen-nitrogen mixed gas is measured experimentally, and its absorption capacity and spectral shape are in good agreement with the calculated values of quantum mechanics. Their paper "Millimeter Wave Absorption Spectrum of Oxygen" was published in 1949 in American Physical Review. Meng and others are considered as one of the pioneers of microwave spectroscopy, which is an important branch of experimental physics.
During the period of 65438-0984, Meng served as the consultant of the single atom detection application laboratory under construction in the Department of Modern Applied Physics of Tsinghua University, and directed the research work of the laboratory with great enthusiasm, including making the completed laboratory an open experimental unit of the State Education Commission, undertaking the key scientific research project "Application of laser single atom detection technology in geological prospecting" during the Seventh Five-Year Plan, and achieved initial results in atomic spectroscopy and ultra-sensitive analysis of gold and platinum elements. In addition, he also served as a doctoral supervisor of 9 atomic detection majors, guiding Ma Chenggong to develop the first self-made sputtering atomic chemistry * * * vibration ionization time-of-flight mass spectrometer, filling the gap of ultra-high sensitivity micro-area analysis in China; And despite the fatigue of trekking across the ocean, he communicated with American authoritative scholar G.S.Hurst and his laboratory, which promoted academic exchanges between China and the United States.