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Table of Content

    20 December 2012 Volume 31 Issue 12
      
    著者文摘
    Additional transformation formula applicable to the integrals with periodic integrand
    . 2012, 31(12):  1-1. 
    Abstract ( 839 )   PDF (293KB) ( 456 )  
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    As a complementary of the original paper, additional transformation formulas applicable to the integrals of periodic integrand are deduced. These formulas, as well as their equivalent forms, can be used as a transformation between such integral and corresponding integral with one limit of infinity. Some infinite integrals are evaluated 'in terms of these formulas.
    Additional transformation formula applicable to the integrals with periodic integrand
    . 2012, 31(12):  4-4. 
    Abstract ( 604 )   PDF (326KB) ( 449 )  
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    As a complementary of the original paper, additional transformation formulas applicable to the integrals of periodic integrand are deduced. These formulas, as well as their equivalent forms, can be used as a transformation between such integral and corresponding integral with one limit of infinity. Some infinite integrals are evaluated 'in terms of these formulas.
    Rotation inertia of a rigid triangular frame about its center-of-mass axis
    . 2012, 31(12):  8-8. 
    Abstract ( 1367 )   PDF (240KB) ( 1325 )  
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    The center of mass for an arbitrary and even triangular frame is determined by using pure geometrical method ; based upon it, the rotation inertia formula of a rigid triangular frame about its center-of-mass axis is derived; and thus lay a theoretical foundation for the calculation of rotation inertia about a grid-like rigid body.
    The magnetic field between two non-coincident tube current
    . 2012, 31(12):  10-10. 
    Abstract ( 644 )   PDF (238KB) ( 479 )  
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    Using a special translation method to solve the vector magnetic potential between two non-coincident tube current, the magnetic field distribution is given.
    Diffaction, interference and resonance transition of probability in time-dependent perturbation quantum system
    . 2012, 31(12):  13-13. 
    Abstract ( 881 )   PDF (749KB) ( 595 )  
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    This paper mainly discusses the quantum transition in the quantum mechanics education by using Mathematica software. Based on the analytical and numerical calculations,the probability diffraction and interference in the state transition process are investigated in detail. Analogy to the light wave, the corresponding wave properties of the probability wave and the resonant transition induced by the coherent superposition are clearly explained to the students. Under the perturbation theory, the resonant transitions on the constant perturbation related to probability d P iffraction and on the harmonic perturbation related to probability interference are explained by a time-dependent robability superposition mechanism.
    A proof of conjecture on equivalent resistance of 6×n-rectangular network
    . 2012, 31(12):  17-17. 
    Abstract ( 791 )   PDF (573KB) ( 595 )  
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    Study on equivalent resistance formula of any k×n-resistor netwok is a scientific problem, so far people have educed the equivalent resistance formula in the five cases that k = 1,2,… ,5. But it is only given as a conjecture for the universal formula of equivalent resistance when k ≥6. Based on the established method of the ex- isting achievements which studied equivalent resistance of any k×n resistor network, we prove the corretness of conjecture of the equivalent resistance formula when k = 6, and give the formula of the equivalent resisance of the infinite network. We obtain some new trigonometric identities when the result is compared with others.
    Study of experimental improvement of measuring electronic specific charge with the magnetic focusing method
    . 2012, 31(12):  24-24. 
    Abstract ( 768 )   PDF (268KB) ( 399 )  
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    In modern physics experiments, the magnetic focusing method is an effective and commonly used method of determining the electronic specific charge. On the basis of the standard laboratory equipment and experimental method, the relationship between the scan line length on screen and the excitation current is studied. An improvement of the experiment is suggested.
    Experiment exploration and practice of electromagnetic field and wave
    . 2012, 31(12):  27-27. 
    Abstract ( 784 )   PDF (399KB) ( 1178 )  
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    For the features of profound theories and abstract concepts of the course of electromagnetic field and wave, the practice of the course is studied. Micropower incandescent lamp and high frequency detection ammeters are used as microwave frequency electromagnetic receiving indicators to replace the traditional microwave receiving equipments, which are expensive. The teaching with experiment auxiliary is realized, which deepens the classroom teaching and stimulates the interest of the students in the theoretical knowledge learning.
    Summary of important prehistoric figures of the Gottingen physical school
    . 2012, 31(12):  30-30. 
    Abstract ( 1060 )   PDF (996KB) ( 799 )  
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    The tradition of the Gottingen mathematics school was laid by Gauss. As a spirit it had been well in- herited and further developed by several generations. The Gottingen physical school of Born, which founded the quantum mechanics, was the inevitable product when the tradition met the times when physics had special need on mathematics. The continuous inheritance of the tradition or spirit of a school is very important, which can be illus- trated by the academic diagram of the Gottingen physical school.
    Application research on polarization of uniform plane electromagnetic wave
    . 2012, 31(12):  38-38. 
    Abstract ( 1100 )   PDF (358KB) ( 734 )  
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    Polarization is an important characteristic of electromagnetic wave, which has a wide range of appli- cations in different fields such as satellite radio, wireless communication, radar, remote sensing in aerospace, and so on. This paper analyzes the causes of polarization of uniform plane electromagnetic wave, presents the physical image of polarization, and discusses many applications of polarization.
    The intuitional teaching method of the standing wave
    . 2012, 31(12):  42-42. 
    Abstract ( 913 )   PDF (345KB) ( 428 )  
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    Combining the rotating vector method and geometry figure, we analyze the constructed process of the wave function of the standing wave, explain the reason that caused the characteristic of the standing wave, and then discuss the energy distribution of the standing wave qualitatively. The method describing the standing wave in this paper makes the model of standing wave so visual and intuitive that one could understand it very easily.
    Investigation on resistance of a tubular resistance network
    . 2012, 31(12):  45-45. 
    Abstract ( 900 )   PDF (324KB) ( 441 )  
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    The resistance between two grid points on tubular resistance network is calculated exactly by using the periodic condition. The function between resistance of any two grid points on tubular resistance network and the period of tubular network is established. Then the influence of the periodic condition on the resistances is analyzed by constructing a three-dimensional parameter space. Meanwhile, it is pointed out that infinite plane and infinite ladder shaped resistance networks are some special cases of the infinite tubular resistance network.
    The magnetic levitation of diamagnetic materials
    . 2012, 31(12):  48-48. 
    Abstract ( 947 )   PDF (1068KB) ( 654 )  
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    Diamagnetic levitation, whose compactness and simplicity are important, thas a bright application prospect. This paper presents a study of the magnetic material's suspension in magnetic field of 2×2 magnet array. First, we use MATLAB to get the magnetic field of any position near the magnet array. Then, we obtain quite clear figures of Hz,Hz, -HzHz at any height above the surface of the magnet array. The experimental results by virtue of a thin graphite piece levitating above the center of the 2×2 magnets array confirm the theoretical model. Due to Fz =-xVHzHz, -HzHz indicates the force of the material in the magnetic field. The results of the experiment and theory indicate that the steady levitation of diamagnetic materials above magnet arrays can be well realized. We also get the relationship between the suspension height of graphite pieces and the size of graphite pieces.
    Dynamic simulation of the only clear fingerprints on the glass wall displayed based on MATLAB
    . 2012, 31(12):  54-54. 
    Abstract ( 866 )   PDF (665KB) ( 1004 )  
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    The numerical and graphical functions of MATLAB language are used in the simulation of the only bright and clear fingerprints displayed on the wall of a glass filled with water. The "bright-clear" and "only" of the fingerprints are analyzed via the simulated images. The effects of the distance from the fingerprints to water sur- face and the thickness of the glass are discussed, and the least squares method is used to fit function by using MAT- LAB. The linear function relationship between the distance from the fingerprints to water surface and the outgoing light to the glass-lined wall is established.