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Table of Content

    20 December 2014 Volume 33 Issue 12
      
    著者文摘
    The performance characteristics of a class of generalized Carnot heat engine cycles with weak dissipation
    . 2014, 33(12):  1-1. 
    Abstract ( 807 )   PDF (344KB) ( 409 )  
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    The weak-dissipation assumption is used to the model of a class of generalized Carnot heat engine cycles composed of two adiabatic and two polytropic processes, from which the expressions for the power output and efficiency of these cycles are derived. The lower and upper efficiency bounds of these cycles at the maximum power output are determined and the performance characteristics of these cycles are discussed.
    Landau spectrum of biased AA-stacked bilayer graphite in a nonuniform magnetic field
    . 2014, 33(12):  4-4. 
    Abstract ( 886 )   PDF (363KB) ( 487 )  
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    Based on the elementary concepts of quantum mechanics, the combined effects of a nonuniform magnetic field and a vertical electric field on the Landau levels in AA-stacked bilayer graphite are investigated within the symmetric gauge by means of special function theory. The results show that the Landau levels in this system are high degenerate quantization, especially at the Dirac points. Furthermore, the accidental degeneracy of zero-energy states can be effectively modulated by the interlayer bias voltage.
    A reverse algorithm for one-dimensional quantum scattering
    . 2014, 33(12):  7-7. 
    Abstract ( 937 )   PDF (424KB) ( 919 )  
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    A reverse algorithm is presented for computation of one-dimensional quantum scattering. It is assumed that there is only the transmitted wave in transmission side. The Schroedinger equation is solved from the transmission side to the incident side according to the initial value problem, the real part and the imaginary part of the wave function, probability density function and then in the incident side, the maximum and minimum value of the function are obtained, the transmittance and reflectance arealso calculated simply. Variation of the quantum phase in scattering process is studied by using this method, an interesting phenomenon of π-jump' s in the reflection wave phase at transparent points is found.
    The motion of a spring's tips
    . 2014, 33(12):  12-12. 
    Abstract ( 861 )   PDF (767KB) ( 369 )  
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    The motion of an ideal spring's tip on the ground or in the gravitational fields is an uniform speed motion. Data from the falling slinky experiment confirm this conclusion.
    Establishment of Einstein' general principle of relativity
    . 2014, 33(12):  15-15. 
    Abstract ( 859 )   PDF (722KB) ( 1302 )  
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    The interference of Mach' idea and the process of establishment of the general principle of relativity are reviewed. The Gauss coordinate and its application is introduced. The property of metric coefficient of gravitational field is illustrated.
    Direct measurement on the speed distribution of thermoelectron using magnetron
    . 2014, 33(12):  21-21. 
    Abstract ( 932 )   PDF (278KB) ( 1040 )  
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    We use magnetron to address the direct measurement on the speed distribution of the thermoelectron, and prove that the speed distribution of the thermoelectron does not obey the Maxwell law. However, due to the space charge effect, our data deviate from the theory in the large-magnetic-field regime.
    Investigation process of quantum Hall effect and quantum anomalous Hall effect
    . 2014, 33(12):  23-23. 
    Abstract ( 1375 )   PDF (403KB) ( 2651 )  
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    This paper investigates history of Hall effect, quantum Hall effect, and quantum anomalous Hall effect. It emphasizes the Nobel prize in physics about quantum Hall effect research results in 1985, 1998 and 2010 as well as great achievement of the first time observed the quantum anomalous Hall effectin in Chinese laboratory.
    The contribution of JIANG Ren-shou to the viscosity of liquid metal and surface tension
    . 2014, 33(12):  27-27. 
    Abstract ( 1051 )   PDF (722KB) ( 863 )  
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    Based on document analysis, the contribution of physicist JIANG Ren-shou to the viscousity of the liquid metal and surface tension is discussed. It is concluded that he worked on the viscosity of the liquid since the 1830s began, improved the Helmholtz double suspension spinning ball design method, used the improved suspension wire rod inertia ball experimental device to measure the viscosity of water, liquid alkali metals sodium, potassium viscosity and viscosity of sodium-potassium alloy. The measured accurate data was internationally recognized and was a long-term follow. JIANG Ren-shou expanded the scope of the study to the surface tension of the liquid metal, he has made important contributions to the development of the modern fluid physics in China.
    Nucleation mechanisms of charged micro-granules in the air
    . 2014, 33(12):  32-32. 
    Abstract ( 1053 )   PDF (381KB) ( 982 )  
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    The aspects of nucleation and growth mechanisms of charged aerosol particles in the air are dis- cussed. Due to the thinning ozone layer in the atmosphere, the extent of high-energy radiation to the earth surface increases, which causes two reactions when the high-energy radiation exposure to coal combustion and car discharges including SO2 and CO: CO and O2 reaction to generate ozone, and ozone reacts with SO2 and H2O to generate H2SO4 . H2O aerosols; hydrogen bonding with the aqueous aerosol surface condensation of tiny solid particles. In addition, based on the mechanism of polaron in condensed matter theory, the particles of two mutually exclusive with the same charge in the surrounding medium can produce attraction under the action of gathering and cohesion. Shielding potential model is used to derive conclusion that when the induced charge of polar small molecules between two aerosol particles by aerosol charges reaches a quarter of charge of an aerosol charge, two aerosol particles will attractive each other to merge a big one. The increase of charge quantity and density of polar small molecules in the air will lead to enhance attraction between the aerosol particles and degree of haze.
    A comparative study on the teaching of physics course for medical students between China and Japan
    . 2014, 33(12):  35-35. 
    Abstract ( 781 )   PDF (418KB) ( 884 )  
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    A deep investigation for physics course teaching in heahh science center of Japan Keio university is presented. A comprehensive understanding is acquired through listening to introduction,discussing with faculties, and visiting laboratories. A comparison is conducted between China and Japan with regard to the teaching of physics course for medical students. The finding of the study is reported here for the reference of domestic related teaching.
    A stochastic dynamics model for the nano-friction between Kinesin and microtubule
    . 2014, 33(12):  39-39. 
    Abstract ( 787 )   PDF (295KB) ( 440 )  
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    The nano-friction between Kinesin and microtubule is investigated. By using the rupture bond model based on the Kramers theory, we obtain the nonlinear relationship between friction and velocity. Our theoreticalresults are in agreement with experimental data.
    Calculation of the transmission coefficient for one-dimensional trapezoid potential barrier
    . 2014, 33(12):  42-42. 
    Abstract ( 1450 )   PDF (454KB) ( 648 )  
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    We construct a one-dimensional trapezoid potential barrier model with potential application in super -lattice physics, and obtain the transmission coefficient for the tunneling of particles analytically. By using the low energy approximation and small slope approximation, we get the asymptotic behavior of the transmission coefficient, which can be treated as the correction for square potential barrier model. Besides, unlike the square model, the peak values of the trapezoid barrier are not necessary to be the resonance tunneling. The incoming energy of the particles at peak satisfies the rule that it is the sum of the height of the potential barrier and the corresponding energy level for particles confined into trapezoid potential well approximately.
    Influences of the second excited state on Fano resonances in 2D electron waveguide/quantum dot structure
    . 2014, 33(12):  46-46. 
    Abstract ( 852 )   PDF (462KB) ( 304 )  
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    The Fano resonance transmission in electron waveguide/quantum dot system is investigated theoretically. In the first energy window, the influence of second excited state on Fano resonance is considered. The calculation results show that the resonance energy, the resonance peak height, and the stopping energy are not affected, but the transmission in off-resonance energy region changed apparently. In the second energy window, there exist two incident eigenmodes, each incident mode can excite two transmission modes. For any incident mode, the corresponding transmission Fano resonance is attributed to the transmission mode possessing the wave victor same with the incident mode. The two incident modes bring the Fano resonances at the same energy point. The response of the Fano resonance position to external electric potential exhibits the linear characteristics.
    Establishment of Einstein' general principle of relativity
    . 2014, 33(12):  51-51. 
    Abstract ( 850 )   PDF (459KB) ( 518 )  
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    The interference of Mach' idea and the process of establishment of the general principle of relativity are reviewed. The Gauss coordinate and its application is introduced. The property of metric coefficient of gravitational field is illustrated.
    Influences of the control grid voltage on the anode current in Franck-Hertz experiment
    . 2014, 33(12):  56-56. 
    Abstract ( 982 )   PDF (533KB) ( 1015 )  
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    To explain non-monotone variation trend of anode current with the increasing of the control grid voltage, the mechanism of the control grid voltage on the anode current is discussed with a series of IA-UG2K experimental curves based on Franck-Hertz experiment. Besides the positive effect of control grid voltage, whose essence is to restrain the space charge limited currents (SCLCs) , this paper bases on Ramsauer-Townsend effect, the Kinetic-Molecular theory and the collision space and probability theory, focus on giving the negative effects in which the increase of the control grid voltage can cause the diminishing of the cathode background current and the rise of the inelastic collision probability. Depending on the above mentioned theory and the cathode emission theory, we introduce the changing of the dominant role of these dual effects in different control grid voltage intervals, which eventually makes the "dual contrary effects" action mechanism complete.