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Table of Content

    20 June 2014 Volume 33 Issue 6
      
    著者文摘
    An approach to calculate the ratio of numbers of surface atoms to interior atoms in a material consisting of face-centered cubic lattice
    . 2014, 33(6):  1-1. 
    Abstract ( 988 )   PDF (351KB) ( 695 )  
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    Due to the well-known effect of large specific surface area of nano-materials, they tend to show distinct properties other than bulk materials at large scale, especially the nanoparticles of metals which have been paid much attention. Most of metals consist of face-centered cubic (one of close packing lattices) unit cells. In this pa- per, an approach to calculate the ratio of numbers of surface atoms to interior atoms in a bulk materials with face- centered cubic lattice is proposed. Supposing the metallic particles consists of repeated unit cells that are stacked e- qually in the three crystal axes directions, a recursion formula can be addressed on how to calculate the numbers of surface atoms to interior atoms of particles with different sizes. According to the method, the size of a certain material that shows considerable effect of specific surface area can be estimated.
    Equivalent electric dipole moment of dielectric sphere embedded in a matrix
    . 2014, 33(6):  4-4. 
    Abstract ( 1281 )   PDF (254KB) ( 939 )  
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    Based on the spatial distribution of electric potential of a dielectric sphere embedded in a matrix, the equivalent electric dipole moment and its origin are investigated when the uniform electric field is applied.
    The electric field of a charged cylinder between parallel ground connection conductor plate and its capacitance
    . 2014, 33(6):  7-7. 
    Abstract ( 907 )   PDF (853KB) ( 282 )  
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    The plate is obtained by of per unit length is electric field distribution of a charged cylinder between parallel ground connection conductor using conformal mapping, and the field pattern on its cross section is plotted. The capacitance calculated.
    Study of field distribution of infinite long column shell with uniform velocity in an external uniform magnetic field
    . 2014, 33(6):  11-11. 
    Abstract ( 733 )   PDF (227KB) ( 379 )  
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    The electric and magnetic field distribution of an infinite an external uniform magnetic field is calculated by using the separating The effect of field shielding of the column shell mobile is also analyzed. long column shell with variable method in the uniform velocity in pillar coordinates.
    Spectrum of infinitely deep well decorated with a Dirac delta function potential at the center
    . 2014, 33(6):  13-13. 
    Abstract ( 1170 )   PDF (249KB) ( 585 )  
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    Once the infinitely deep well decorated with a Dirac delta function potential at the center, the ground states can be greatly influenced, and as the potential changes from repulsive to attractive, the ground state energy decreases from positive to negative, while excited state energy remains positive.
    Measurement of a metallic rod' s elastic modulus with the cantilever vibration monitored by a mini-accelerometer
    . 2014, 33(6):  16-16. 
    Abstract ( 674 )   PDF (454KB) ( 555 )  
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    Natural frequency of a cantilever beam can be linked to the elastic modulus of the beam material. With a mini-accelerometer mounted on the free end, the bending vibration frequency of a steel rod is obtained, and then the elastic modulus of the rod steel is derived. The added mass of accelerometer to the beam has been taken into account to modify the frequency modulus relationship. Final measurement result of the elastic modulus is quite consistent with the given value, accompanying a relative uncertainty of 0.66%. The principle of the experiment is clear and the construction of used setup is simple. More convenience of minimum operation comes with the mentioned advantages.
    Experimental study of two-dimensional space charge limited current
    . 2014, 33(6):  20-20. 
    Abstract ( 732 )   PDF (616KB) ( 519 )  
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    Two-dimensional (2D) space charge limited current (SCLC) of an electron gun based cylinder pla- nar structure is studied. The relation of the 2D SCLC varying with many parameters, such as the distance between the cathode and the anode, cathode voltage, work function, cathode temperature as well as the cathode structure, is investigated in detail, which is more plentiful than that of Child-Langmuir law. A practical E-gun is designed and its SCLC and emitting performance are experimentally explored. The experimental result of the SCLC agrees well with that of 2D model.
    Investigation on the capacitance voltage selection of pulse device in static demagnetization
    . 2014, 33(6):  24-24. 
    Abstract ( 578 )   PDF (622KB) ( 399 )  
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    It is hard to select capacitance voltage of pulse device in static demagnetization. The critical voltage which turns the remanence direction is the best demagnetization voltage by experimental methods. The formula of capacitance voltage is given by solving the peak of magnetic field and pulse circuit parameters. The voltage can be selected quickly by combining formulas and experimentation conclusion.
    Michelson: a normal scientist in the whirlpool of scientific revolution
    . 2014, 33(6):  28-28. 
    Abstract ( 728 )   PDF (663KB) ( 510 )  
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    Albert Abraham Michelson was one of the pioneers of the American scientific cause. He won the Nobel Prize for physics in 1907. He was the first Nobel Prize winner in American history. He witnessed the process to establish relativity and quantum mechanics, but as a normal scientist, he did not want to discard any knowledge of classical physics. His academic career in some degree were difference from others, he won the Nobel Prize but not without controversy, he was the representative personage of experimental physicist who had no interest in theo- ry. Researching these aspects of Michelson could be good helpful for deeply understanding the process of scientific revolution.
    The exploration on the integration of teaching and scientific research to advance them promote each other
    . 2014, 33(6):  33-33. 
    Abstract ( 722 )   PDF (2272KB) ( 432 )  
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    To train the innovative talents,we have realized the integration of teaching and scientific research based on the course of " College Physics Experiments" for the natural science or engineering undergraduates. Through innovation practice activities in and out laboratory courses, the undergraduates together with their teachers researched and developed a series of innovative experiments and published some of their works with high level on the international teach-researching journals. These works deliver to those undergraduates,who have made efforts,a peek experience, and advance teaching and scientific research to promote each other in the fundamental practice courses.
    The exploration of teaching and research reformation--" space optical communication innovation experiment" course
    . 2014, 33(6):  41-41. 
    Abstract ( 608 )   PDF (910KB) ( 531 )  
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    This paper focuses on the educational idea of theoretical model, strong engineering practice, and standing out the innovation design. Combining with the forefront of science and technology, we explore the teaching and research reformation of the space optical communication innovation experiment course, and obtain some successful experience. The intent is to foster students' application of theoretical knowledge and three-dimensional visual simulation. And cultivate student' s ability to solve practical problems, with the space optical communication platform of innovation practice.
    The maximum overhang of four stacking blocks
    . 2014, 33(6):  45-45. 
    Abstract ( 774 )   PDF (161KB) ( 501 )  
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    Five different methods of stacking blocks are given. The maximum overhang is derived from the torque equilibrium conditions.
    Experimental design of Fourier transforms spectrometer and its application on the measurement of the spectrum of white light
    . 2014, 33(6):  47-47. 
    Abstract ( 838 )   PDF (394KB) ( 627 )  
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    Fourier transforms spectrometer is based on Michelson' s interferometer,which can be used to obtain the spectrum of incident light. A homemade Fourier transforms spectrometer is established where a light dependent resistor( LDR) is used as sensor. During the moving mirror moves through the normal direction of the mirror, the changes of interferometric pattern are recorded as intensity curve, and the intensity varies depend on the changes of optical path difference (OPD). The coherence length of the incident white light is given based on this curve, and the spectrum of the incident white light is also obtained based on the Fourier transform of this curve.
    Improved method of laser biprism interference experiment
    . 2014, 33(6):  51-51. 
    Abstract ( 759 )   PDF (905KB) ( 469 )  
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    This paper proposes a new laser biprism interference experiment light path, as an improvement of the classical laser biprism interference experiment. The problems in the calssical experiment are solved, such as a smaller field of view, inconvenient to observe, measure and demonstrate.
    The semi-analytical solution of wave particle in one-dimensional functions and energy levels of a micro- infinite trapezoid potential well
    . 2014, 33(6):  55-55. 
    Abstract ( 904 )   PDF (554KB) ( 946 )  
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    A new type of potential well, namely one dimensional infinitely trapezoid potential well, which is simple in form but rich in content, is studied by us with the help of special functions and the semi-analytical solutions of the wave functions and energy levels for a micro-particle confined into it is obtained. Those results can help us better understand the physical mechanism of the two-dimensional electron gas in trapezoid channel potential well. Besides, the connection and difference between the model proposed in this paper and the well-known models, i.e. rectangular/triangular potential well are illustrated. We also discuss the properties of the wave function based on the correspondence principle.