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Table of Content

    20 April 2015 Volume 34 Issue 4
      
    著者文摘
    A nonperturbative solution to induced transitions between atomic states
    . 2015, 34(4):  1-1. 
    Abstract ( 686 )   PDF (559KB) ( 795 )  
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    An introduction is presented to a recently established nonperturbative approach to the transitions between atomic states induced by weak electromagnetic waves. A special case of the general solution is calculated and discussed in detail. Results of the nonperturbative approach reduce under perturbation condition to those obtained by the time- dependent perturbative method, but overcome the difficulty that the perturbative results are obviously unreasonable in the near resonant region. According to the nonperturbative solution, the electric-dipole selection rules are approximately recovered for short time. For large time, however, probabilities for forbidden transitions may become comparable with those for allowed ones.
    Analysis of spring pendulum motion affected by unstable constraint
    . 2015, 34(4):  6-6. 
    Abstract ( 835 )   PDF (406KB) ( 714 )  
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    Using Lagrange equation we establish the kinetic equation about an unstable constraint spring pendulum movement. U- sing numerical simulation with Matlab software, we depict the evolution curve, trajectory and phase diagram. The movement is analyzed and thus a more intuitive law of motion is obtained.
    A note on the thermodynamic treatment of the number of photon gas
    . 2015, 34(4):  11-11. 
    Abstract ( 938 )   PDF (195KB) ( 1084 )  
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    In thermodynamics, the photon gas for a given the volume and the temperature has following proper- ties: the number of photons is fixed once in an equilibrium and is variable once out of the equilibrium, and thechemical potential is zero for the former whereas it is non-zero for the latter.
    The infinite circle plane steady divergent magnetic field generated by current
    . 2015, 34(4):  13-13. 
    Abstract ( 998 )   PDF (234KB) ( 466 )  
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    The infinite circle plane steady divergent magnetic field generated by current is analyzed, and a problem is related to the new solution using this result.
    Investigation on efficiency of Diesel cycle of ideal Bose gas
    . 2015, 34(4):  16-16. 
    Abstract ( 1063 )   PDF (250KB) ( 601 )  
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    Based on the equation of state and the thermodynamic properties of ideal Bose gas, we obtain the ex- pression of efficiency of Diesel cycle which work substance is ideal Bose gas. It is shown through the comparison that the efficiency of heat engine is improved when the Diesel cycle works under quantum degeneracy condition. The resuits obtained should provide theoretical basis for the design of Diesel cycle working under quantum degeneracy conditions.
    The application of Wigner function in mesoscopic LC circuit at finite temperature
    . 2015, 34(4):  19-19. 
    Abstract ( 692 )   PDF (247KB) ( 383 )  
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    The marginal distribution of Winger function in mesoscopic LC circuit at a finite temperature is in- vestigated by means of the Wigner function. The results show that the marginal distributions statistical average for p^2/2L and q^2/2C of the Wigner function are exactly the energy stored in inductance and capacity of the mesoscopic LC circuit, respectively at finite temperature.
    Experiment and analysis of an interesting paraffin flame formed solid electrostatic jump ball
    . 2015, 34(4):  22-22. 
    Abstract ( 809 )   PDF (677KB) ( 360 )  
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    By loading paraffin flame formed solid in plastic boxes, a plastic comb with electrostatic implements the simple static jump ball experiment. In addition, we observe still and analyze the different phenomenon.
    Measuring Permeability of vacuum by using the Helmholtz coil
    . 2015, 34(4):  26-26. 
    Abstract ( 1199 )   PDF (269KB) ( 575 )  
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    The magnetic induction intensity of Helmholtz coil common axis point is measured by using both the FD-HM-I type Helmholtz coil and high sensitivity of milli Tesla meter. Through changing the positive and reverse direction of current of Helmholtz coil, the effect of magnetic field is eliminated, and then the permeability of vacuum is measured accurately.
    High conductivity material electromagnetic levitation and melting demonstration experiment
    . 2015, 34(4):  28-28. 
    Abstract ( 743 )   PDF (1045KB) ( 586 )  
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    Electromagnetic levitation melting is a processing technology of without crucible high conductivity materials levitation melting. In the process of smelting, avoid contact with the vessel wall, there are many advantages, is indispensable of research and preparation the high purity material. In this paper, we introduce self- developed high conductivity material electromagnetic levitation melting demonstration experiment device and interesting experiment phenomenon. The theoretical analysis for electromagnetic suspension phenomenon is conducted. The electromagnetic levitation force distribution of several different excitation coil structure is calculated numerically. All sorts of experimental phenomena are explained. The experimental device demonstration effect and phenomena reveal physical principle. Which is suitable for intuitive teaching to students for studying physics in school, also suitable for science and technology museum show to young people.
    Homemade diffraction grating and experimental studying in college physics teaching
    . 2015, 34(4):  33-33. 
    Abstract ( 1002 )   PDF (930KB) ( 621 )  
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    Based on the characteristics of university physical optics, we make the corresponding knowledge expansion, let the students to make diffraction grating and to do related experimental research in the teaching process, teaching results greatly improve the students' scientific research quality and its various aspects ability.
    Improvement ofphotographic emulsion and discovery of the pion by Ceil Frank Powell
    . 2015, 34(4):  37-37. 
    Abstract ( 853 )   PDF (868KB) ( 334 )  
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    We narrate briefly Powell's lifetime and review his contribution to improve the photographic emulsion which was applied to nuclear research and his discovery for pion. We also discuss his style of work, such as he is good at organizing large-scale research and cooperation of many groups, his scrupulousness about every detail, as well as his consciousness of making innovations bravely.
    Pascual Jordan:a brilliant physicist and his important contributions
    . 2015, 34(4):  44-44. 
    Abstract ( 1218 )   PDF (902KB) ( 868 )  
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    Pascual Jordan was one of the three key founders of matrix mechanics. Due to the limitation of do- cuments, the research from Jordan's perspective on the Gottingen physical school was very lacking. Based on the document which was translated recently, reality has changed. The paper corrects some wrong describing and assessment on Jordan; describes and discusses the process by which Jordan became a brilliant physicist, and his important contributions to physics. The reminiscence of Jordan is a good help to resolve some problems left from the history of quantum mechanics.
    The Rockefeller foundation and development of modern physics
    . 2015, 34(4):  52-52. 
    Abstract ( 907 )   PDF (820KB) ( 764 )  
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    The Rockefeller foundation is set up by Rockefeller and his son to sponsor the development of educa- tion, medicine, public health, agriculture and pure science. In the 1920s and 1930s, aiming at enhancing the lev- el of physical research, the Rockefeller foundation hired famous teachers from Europe for the young generation which boosted the trend of the young Americans studying in Europe. It participated in the construction of major sci- entific institutes around the world actively. It also promoted the hot topics in physics in Europe by offering learning grants and scientific research funds. In short, the Rockefeller foundation made glorious contributions in the history of modern physics.
    Electromagnetic radiation and human health
    . 2015, 34(4):  58-58. 
    Abstract ( 635 )   PDF (412KB) ( 1093 )  
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    By measuring electromagnetic radiation released by household appliance through experiment, and an- alyzing experimental data, this article summarizes characteristics of electromagnetic radiation from household appli- ance and provides recommendation on household using.
    Acoustic propagating and transmission through periodical obstacle
    . 2015, 34(4):  61-61. 
    Abstract ( 824 )   PDF (470KB) ( 484 )  
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    We establish a periodical obstacle with 1D grating as an acoustic model and simulate with Comsol Muhiphysics. The acoustic wave propagating though obstacle during a long period of wavelength is also discussed. We change the parameters of the obstacles and have some comparison with the acoustic field and transmission. A- nalysis of the sound wave propagation and transmission characteristics with theory are performed. We compare and analyze the transmission calculated by Comsol Multiphysics to illustrate the origin of the acoustic transmission peaks and the abnormal phenomenon of transmission.