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Table of Content

    20 March 2012 Volume 31 Issue 3
      
    著者文摘
    New comprehension for Taylor series expansion --Moebius inversion of convolution-type series
    . 2012, 31(3):  1-1. 
    Abstract ( 1005 )   PDF (356KB) ( 453 )  
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    The modified Moebius inversion of convolution-type infinite series is justified based on the Taylor series expansion of analytic functions. A series of expansion and inversion coefficient pairs are given. A preliminary application to the special functions, e.g. spherical Bessel functions, Laguerre polynomials, hypergeometric functions and confluent hypergeometric functions, are made to deduce the inversions of their functional relations, including the multiplication and addition formulas.
    The derivation of conductivity of ionic conduction based on entropy
    . 2012, 31(3):  5-5. 
    Abstract ( 894 )   PDF (377KB) ( 536 )  
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    Conductivity is a measurement of the strength of the conductive ability.It is known that the conductivity of the ionic conduction can be obtained by calculating the average drift velocity of the ion.We present here a new derivation by using entropy.We identify a competition between the system entropy and the environment entropy.The entropy competition determines the most probability electric current from whose form the same conductivity is extracted.Finally,we compare the methods based on entropy and drift velocity and generalize this method to general conductor.This method may be extend to study other conductors.
    The quantum mechanical correspondence for classical Fresnel operator
    . 2012, 31(3):  9-9. 
    Abstract ( 856 )   PDF (243KB) ( 596 )  
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    The quantum mechanical correspondence for the classical Fresnel transformation is introduced, which is quantum Fresnel operator corresponding to the symplectic motion of the representing point for coherent state in phase space.
    Symmetry and conserved quantity of time-dependent quantum system
    . 2012, 31(3):  11-11. 
    Abstract ( 659 )   PDF (249KB) ( 481 )  
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    Symmetry of time-dependent quantum system is discussed. The criterion is given for proving the conservation of a time-dependent mechanic quantity.
    An approximate formula of oscillation period of spring system
    . 2012, 31(3):  13-13. 
    Abstract ( 816 )   PDF (270KB) ( 806 )  
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    An approximate formula of oscirlation period of spring system with high precision and large range of application is derived by using variable transform.
    The magnetic field of a linear current and a bar-type ferromagnetic material plate
    . 2012, 31(3):  16-16. 
    Abstract ( 732 )   PDF (346KB) ( 947 )  
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    On the base of existing conclusion of Zhukovssky transform, the magnetic field of a linear current and a bar-type ferromagnetic material plate is calculated by using the cylindrical images method, and its magnetic vector distribution and magnetic induction line equation are obtained. The magnetic induction line maps are plotted by using the software MATLAB.
    The relativistic Hamilton-Jacobi equation and its application
    . 2012, 31(3):  20-20. 
    Abstract ( 1027 )   PDF (333KB) ( 508 )  
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    The relativistic equation of motion for the electron in the laser field is solved analytically by use of the Hamihon-Jacobi method. For a given arbitrary elliptically polarized laser field, we obtain the exact analytical expressions in the case of the laboratory frame where the laser and the electron meet collinearly, the frame where the electron is initially at rest and the frame where the electron is on the average at rest, respectively.
    On the teaching of uncertainty principle in university physics
    . 2012, 31(3):  24-24. 
    Abstract ( 766 )   PDF (386KB) ( 681 )  
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    The Heisenberg uncertainty principle is one of the foundations of quantum mechanics, although meaning of this principle is disputed in the region of physics. The teaching of this principle should help students to discard the conventional conception of orbit and establish the idea of wave-particle duality. However, the conventional conception of orbit is still used in many domestic textbooks of university physics. The students tend to be confused consequently. Therefore, tens of textbooks of university physics are investigated and different accounts about uncertainty principle are compared, and then advice of teaching on this principle is brought forward.
    Dependence of the inertial mass on velocity
    . 2012, 31(3):  27-27. 
    Abstract ( 732 )   PDF (516KB) ( 820 )  
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    The source of wrong in some papers about "inertial mass has nothing to do with velocity" are pointed out, the reasons that dependence of inertial mass on velocity are expounded. The differences of "state" in classical mechanics and relativity are discussed.
    Investigation on optimization method for measuring coefficient of liquid surface tension
    . 2012, 31(3):  32-32. 
    Abstract ( 1263 )   PDF (291KB) ( 1055 )  
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    In response to the system errors in a series of questions about measuring the liquid surface tension coefficient, an improved method is suggested. With automation down instead of manual to pull, the stability of process is improved ; with a pair of π wire instead of a π wire, the part with membrane becomes smooth; with the initial state of a sudden change process and compensation as measuring states, the influence of buoyancy and membrane weight is effectively eliminated. The accuracy of experiment is improved 3% by the use of impsoved method.
    Experimental study on periodic stratified oscillation of automatic exchange between gasoline and alcohol
    . 2012, 31(3):  35-35. 
    Abstract ( 709 )   PDF (463KB) ( 459 )  
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    The periodical oscillation and exchange between gasoline and alcohol are explored. It is found from experiment that periodical oscillation can be generated between gasoline and alcohol, and obvious stratification is found in both inner and outer containers. We get the experimental conclusion that oscillation cycle time is proportional to the length of capillary and inversely proportional to the inner diameter of capillary to the power of 4( T L1/d4). However, the initial level of alcohol in inner container almost does not affect the oscillation cycle time. We also explore the relation between the change of the level of alcohol in inner container and the change of the length of Capillary and cycle order. Finally, the expression for the change of the level of alcohol in inner container between two unstable equilibrium points is given.
    Design of an infrasound measurement device based on thin film moving coil sonic-electric converting principle
    . 2012, 31(3):  40-40. 
    Abstract ( 787 )   PDF (331KB) ( 416 )  
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    This paper introduces a method to measure infrasound wave by the use of moving coil sonic-electric converting principle.Air-core under the shield is forced to vibrate by the air micro-pressure flow coursed by infrasound wave,then the value of magnetic flux is changed and the generation of induced electromotive force is caused,thus infrasound signal is converted into electrical signal.According to the result testing in the simulation environment of infrasound,this device can measure the infrasound signal correctly.
    Investigation on the method of measuring field current in the experiment of measuring electron charge mass ratio using electron magnetic focusing
    . 2012, 31(3):  44-44. 
    Abstract ( 1214 )   PDF (289KB) ( 804 )  
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    According to the motion characteristic of the charge in the electric and magnetic fields, the principle for measuring electron charge mass ratio using electron magnetic focusing is analyzed. The method for measuring field current with magnetic focusing is discussed from the theoretical point of view by using principle of magnetic fields superposition, and vaious methods are compared. The experimental data are analyzed and managed from the experiment point of view, the one of the main reason of error production is pointed out and the new method for measuring the value of field current with magnetic focusing is obtained.
    Open college physics education on the Internet
    . 2012, 31(3):  47-47. 
    Abstract ( 776 )   PDF (492KB) ( 1692 )  
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    A review is presented for open college physics of Internet self-leaning system, open physics learning sources, son of the ways of e-leaning with others and the prospects for education on the Internet, including the composition the statistical analysis of open courses, the comparifuture developments of open physics education.
    Applications of electromagnetic wave polarization
    . 2012, 31(3):  52-52. 
    Abstract ( 1630 )   PDF (317KB) ( 3923 )  
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    Polarization is not only an important parameter of the electromagnetic wave but also a key concept in the electrodynamics and the electromagnetic field and wave courses. In this paper, applications of this concept in communication, radar and anti-jamming are introduced. By utilizing the characteristic of polarization, the optimal radio signal transmission and reception are achieved and the communication capacity is improved as well. The applications of polarization in the radar target recognition, detection, imaging and anti-jamming are discussed.
    The six ideas shaping physics ——Appreciation of 《Six Ideas That Shaped Physics》
    . 2012, 31(3):  55-55. 
    Abstract ( 1213 )   PDF (527KB) ( 550 )  
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    In this paper, we give a full analysis anddeep evaluation to the introductory physics' classical teaching material--《Six Ideas That Shaped Physics》 (six units), we think of from the ideas, curriculum system, features these three parts to find the reason that this book leads the world trend in physics. We believe that these six units of this book will provide a great reference value to introductory physics teaching material in our country.
    Research on teaching methods for quantum mechanics in engineering major
    . 2012, 31(3):  60-60. 
    Abstract ( 736 )   PDF (299KB) ( 534 )  
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    In order to inspire the student' s interest and improve the teaching quality, we investigate the teaching methods for quantum mechanics from the developing history of quantum mechanics, the concepts of quantum mechanics, the application of muhi-media technologies and the practices of engineering majors.
    A new formula of thermal conductivity
    . 2012, 31(3):  62-62. 
    Abstract ( 1251 )   PDF (366KB) ( 1121 )  
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    Some shortcomings in one-dimensional heat transfer model of thermal conductivity are found.A more rigorous three-dimensional heat transfer model is proposed.With more scientific consideration of sidewall cooling effect,a new formula of calculating thermal conductivity is developed.The rationality of the new formula proposed is proved by carrying out the experiment with rubber disks.An impact factor P that describes the degree of sidewall cooling effect is introduced and found to rise with the increase of the sample's thickness.