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Table of Content

    20 May 2008 Volume 27 Issue 5
      
    著者文摘
    Two-parameter variational approach to the ground state energys of the helium atom and quasi-heliumion
    . 2008, 27(5):  1-1. 
    Abstract ( 573 )   PDF (221KB) ( 374 )  
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    A variational method of two parameters for studing ground state energys and wave functions of the helium atom and quasi-heliumion is proposed. We have designed the tested the wave function and derive the ground level expression by solving the radial Schroedinger equation. The ground energy is evaluated by means of the optimized computation of Mathematica 5.0. Our result is compared with the experimental data and the result of other variational methods. It is shown that our result is much precision and the number of variational parameters is less than that of other methods. Meanwhile the importance of permutation symmetry and entanglement of quantum state in the system of two-electron atom is emphasized.
    Calculation of the optic axial angle of the biaxial crystal
    . 2008, 27(5):  4-4. 
    Abstract ( 1381 )   PDF (193KB) ( 556 )  
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    The optic axial angle of biaxial crystal is calculated by coordinate transforming the index ellipsoid equation X^2/n1^2+y^2/n2^2+z^2/n3^2=1from the principal dielectric coordinate system to another new coordinate system.This new coordinate system Ox′y′z′is gained by rotating the coordinate system Oxyz. It is confirmed that z′axis is optical axis if the intersection of the new index ellipsoid and x′y′ plane is a circularity.
    Analysis of the negative refraction phenomenon in the common uniaxial crystals by using the Huygens construction
    . 2008, 27(5):  6-6. 
    Abstract ( 582 )   PDF (356KB) ( 565 )  
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    The Huygens construction is used to elucidate that the negative refraction phenomenon may occur in the common uniaxial crystals under the appropriate condition. The critical angle of incidence for occurrence negative refraction is calculated and the equation for numerically computing the negative refraction angle is obtained. This is beneficial for the students giving a right overall understanding while the left-handed materials and the negative refraction phenomenon are introduced in the teaching.
    A suppliment to the sliding speed, acceleration and time of particle from the freely mobile concave surface
    . 2008, 27(5):  10-10. 
    Abstract ( 537 )   PDF (138KB) ( 252 )  
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    A curve equation for the dropping trajectory of a particle is obtaind by using the time-dependent expression of the particle sliding down a free mobile-concave surface. The minimum of time required for the curve motion of the partide is found.
    Optimal throw angle of arbitary throw on the inclined plane
    . 2008, 27(5):  12-12. 
    Abstract ( 978 )   PDF (192KB) ( 637 )  
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    Optimal throw angle and its calculating method for arbitary throw on the inclined plane is investi-gated
    Golf ball range under both drag force and Magnus force
    . 2008, 27(5):  15-15. 
    Abstract ( 621 )   PDF (362KB) ( 452 )  
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    The movement of a golf ball against air with spinning is analyzed. The numerical results show that a golf ball with dimpled surface flies much farther than one with smooth surface. Magnus force which generated by the ball's spinning prolongs the range,but a too fast spinning rate is not always conducive to the range.
    A method for calculating the charge distribution of non-static off axis field with axial symmetry
    . 2008, 27(5):  20-20. 
    Abstract ( 458 )   PDF (382KB) ( 214 )  
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    A method for calculating non-static off axis fields of axial symmetric charge distribution is proposed by using the Maxwell's equation and axial symmetry.
    The relation of ordinary index of refraction between left- handed light and right-handed light refractive index in gyrotropic crystal
    . 2008, 27(5):  26-26. 
    Abstract ( 904 )   PDF (139KB) ( 567 )  
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    We demonstrate that the susceptibility tensor X exists certainly the non-opposite angle symmetrical conjugate imaginary elements in terms of the light wave equation when the medium is the rotatory medium. The relation of ordinary index of refraction no between the left-handed light refractive index n h and the righthanded light refractive index nR is derived from the gyrotropic crystal. The result is consistent in the theoretical analysis with the experimental data.
    Estimation of two-dimensional magnetic field distribution by the effect of magneto-optic rotation
    . 2008, 27(5):  28-28. 
    Abstract ( 583 )   PDF (437KB) ( 288 )  
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    For overcoming the limitation of existing measurements of magnetic field, those measurements which can only measure single point,according to the principle of Faraday magneto-optic rotation effect,we estimate the distribution of two-dimensional magnetic field. Using this measurement, the efficiency of the measuring magnetic field is improved, and the intuitionistic distribution is obtained. The experimental equipment is established. The magnetic field of permanent magnet is measured. The picture of polarized light via magnetic field is collected by CCD. By program processing to these pictures, the two dimensional distribution of the partial magnetic is obtained. The value of the two-dimensional distribution of the partial magnetic is obtained.
    Theoretical study on optical bistability switching based on photoisomerization reverse saturable absorption of azobenzene molecules
    . 2008, 27(5):  33-33. 
    Abstract ( 616 )   PDF (280KB) ( 270 )  
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    The characteristic of optical bistability switching of azobenzene molecules is discussed. First, we compute the coefficient of reverse saturable absorption based on the model of photoisomerization of azobenzene molecules. Second,we simulate and compute the process of bistability switching based on reverse saturable absorption. The result shows that the reverse saturable absorption based on photoisomerization of azobenzene molecules can realize full optical switches of bistability. We also discusse the Trans isomer σT, the Cis isomer σC and the thermal constant K to the optical bistability influence.
    Optical fiber Mach-Zehnder interferometer system
    . 2008, 27(5):  37-37. 
    Abstract ( 1864 )   PDF (366KB) ( 2084 )  
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    The configuration of optical fiber Mach-Zehnder(MZ) interferometer system is introduced. The principle of signal optic beam intervening reference optic beam and the factors of influencing the intensity of interferential optic beam are prestented. Meanwhile, the cross coupling of optical fiber coupler is analysed. The effect of PZT is studied. The configuration and principle of the optical fiber polarization controller are described. The polarizing state of optical fiber reference arm how to be controlled is discussed. Finally, the application of the interferometer system is also shown.
    Mechanics model analysis of car collision with pedestrian
    . 2008, 27(5):  41-41. 
    Abstract ( 411 )   PDF (219KB) ( 248 )  
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    The dynamics process of a car colliding with a pedestrian is analyzed in terms of a proposed mechanics model. The critical velocity of the car causing the pedestrian upside down is produced from our calculation and discussion, which matches the laboratory result.
    Emphasis of demonstrative experiments for research teaching of college physics
    . 2008, 27(5):  44-44. 
    Abstract ( 418 )   PDF (160KB) ( 478 )  
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    Some opinions and experiences on the teaching college engineering physics are provided and the importance of the physical demonstrative experiments is shown.
    Study on the decay characteristic of the thermal wave
    . 2008, 27(5):  46-46. 
    Abstract ( 684 )   PDF (215KB) ( 410 )  
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    The periodic variation of temperature of the sample with time is regarded as a vibration based on the principle of vibration and wave. The temperature disturbance traveling through the sample is regarded as a wave motion. The temperature wave is defined to express the temperature varied with time and position, one - dimensional model is adopted to represent the temperature wave equation. The decay coefficient is introduced into showing dispersion of the copper bar. The temperature amplitude varies with the frequency and the transmitting distance. The experimental data is analyzed by using the Fourier transform. We get the temperature wave ampli- tude corresponding to the frequency and position. According to the decay formula, we get the decay coefficients of the fundamental and multiple frequencies. There is a correlation between the decay coefficients and the frequency of temperature wave. The higher temperature wave frequencis,the bigger decay coefficientis, and the faster temperature wave amplitude decays.
    Energy distribution of three-body decay in relative theory conditions
    . 2008, 27(5):  49-49. 
    Abstract ( 915 )   PDF (283KB) ( 556 )  
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    The problem of 3-body decaying with equal mass under the condition of no initial momentum is analyzed. With the Dalitz diagram, we pressent s the energy distribution of three body and its shape in the Dalitz diagram based on the Newton's dynamics, extreme and non-extreme relativity theory. The shape differences and its reasons using math language and introduces its preliminary applications is also discussed