Based on archival materials discovered in America,Britain,and China,this paper carefully examines the history of the short-lived and completely overlooked Department of Physics in the Premedical School of Peking Union...Based on archival materials discovered in America,Britain,and China,this paper carefully examines the history of the short-lived and completely overlooked Department of Physics in the Premedical School of Peking Union Medical College(PUMC),and uncovers this department’s extensive interconnections with its counterpart at Yenching University.This project also looks into the Master of Science(MS)program in the Department of Physics at Yenching University,which,founded in 1927,was the first graduate program in physics in China.It was this MS program that transformed the Yenching Department from a largely premedical training center serving the PUMC into a prominent cradle of Chinese physics research.This Yenching Department,despite its small faculty and brief existence,nurtured many eminent Chinese physicists,such as Chao-Ying Meng孟昭英,Wen-Yu Chang张文裕,Ming-Chen Wang王明贞,Chia-Liu Luke Yuan袁家骝,Cheng-Shu Wang(Chang)王承书,Ho-Fu Lu卢鹤绂,Ting-Sui Ke葛庭燧,Kun Huang黄昆,and Chia-Lin Hsieh谢家麟.It would have been impossible to achieve these outstanding accomplishments without the effective leadership and pioneering work of C.H.Corbett,P.A.Anderson,Y.M.Hsieh,and W.Band—the first four Department Chairs—in combination with relatively abundant private funding,mostly from America,and extensive educational connections with Western institutions.This paper not only introduces in detail these four department heads and their contributions,but also discloses the unique role played by the Rockefeller Foundation via the China Medical Board and the PUMC in the development of the Yenching Department of Physics.展开更多
The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence ...The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence of the FPU β lattice, is first calculated from the energy autoeorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. We find that the relaxation rate as a function of wave number k is proportional to k^1.688, which leads to a N^0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This is also in good agreement with the data obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of the thermal conductivity as 0.415. Our results confirm the N^2/5 divergence in one-dimensional FPU β lattices. The effects of the heat flux on the thermal conductivity are also studied by imposing different temperature differences on the two ends of the lattices. We find that the thermal conductivity is insensitive to the heat flux under our simulation conditions. It implies that the linear response theory is applicable towards the heat conduction in one-dimensional FPU β lattices.展开更多
文摘Based on archival materials discovered in America,Britain,and China,this paper carefully examines the history of the short-lived and completely overlooked Department of Physics in the Premedical School of Peking Union Medical College(PUMC),and uncovers this department’s extensive interconnections with its counterpart at Yenching University.This project also looks into the Master of Science(MS)program in the Department of Physics at Yenching University,which,founded in 1927,was the first graduate program in physics in China.It was this MS program that transformed the Yenching Department from a largely premedical training center serving the PUMC into a prominent cradle of Chinese physics research.This Yenching Department,despite its small faculty and brief existence,nurtured many eminent Chinese physicists,such as Chao-Ying Meng孟昭英,Wen-Yu Chang张文裕,Ming-Chen Wang王明贞,Chia-Liu Luke Yuan袁家骝,Cheng-Shu Wang(Chang)王承书,Ho-Fu Lu卢鹤绂,Ting-Sui Ke葛庭燧,Kun Huang黄昆,and Chia-Lin Hsieh谢家麟.It would have been impossible to achieve these outstanding accomplishments without the effective leadership and pioneering work of C.H.Corbett,P.A.Anderson,Y.M.Hsieh,and W.Band—the first four Department Chairs—in combination with relatively abundant private funding,mostly from America,and extensive educational connections with Western institutions.This paper not only introduces in detail these four department heads and their contributions,but also discloses the unique role played by the Rockefeller Foundation via the China Medical Board and the PUMC in the development of the Yenching Department of Physics.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.50976052,51136001,and 50730006)the Program for New Century Excellent Talents in University,China+1 种基金the Tsinghua University Initiative Scientific Research Program,Chinathe Tsinghua National Laboratory for Information Science and Technology TNList Cross-discipline Foundation,China
文摘The phonon relaxation and heat conduction in one-dimensional Fermi Pasta-Ulam （FPU） β lattices are studied by using molecular dynamics simulations. The phonon relaxation rate, which dominates the length dependence of the FPU β lattice, is first calculated from the energy autoeorrelation function for different modes at various temperatures through equilibrium molecular dynamics simulations. We find that the relaxation rate as a function of wave number k is proportional to k^1.688, which leads to a N^0.41 divergence of the thermal conductivity in the framework of Green-Kubo relation. This is also in good agreement with the data obtained by non-equilibrium molecular dynamics simulations which estimate the length dependence exponent of the thermal conductivity as 0.415. Our results confirm the N^2/5 divergence in one-dimensional FPU β lattices. The effects of the heat flux on the thermal conductivity are also studied by imposing different temperature differences on the two ends of the lattices. We find that the thermal conductivity is insensitive to the heat flux under our simulation conditions. It implies that the linear response theory is applicable towards the heat conduction in one-dimensional FPU β lattices.
