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Table of Content

    20 August 2007, Volume 29 Issue 4
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    Articles
    Some Considerations on Magnetic Field of Gamma-Ray Bursts
    ZHANG Jia-lü
    2007, 29(4):  187-192. 
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    The frequently cited fireball-shock model of Gamma-Ray Burst (hereafter, GRB) can explain well the main features and processes after the burst. This model, however, is challenged by the latest high-resolution observational results during the last few years, which present some clues on the incompleteness of its theoretical considerations. For example, one basic assumption of the fireball model is using the standard synchrotron radiation mechanism to approximate the high energy emissions from GRBs. This is equivalent to claim that the magnetic field inside GRB is uniformly distributed, which smears out most of the important information of magnetic field configuration other than the field strength. In the study of GRB shocks, it is generally believed that most of the physical quantities, such as density and pressure, are inhomogeneous throughout the shocked region. Then why is it plausible to assume the shocked magnetic field alone to be homogeneous, which originates from perturbation mechanism?
    In this paper, we analysis this problem in details, and regard that the radiation induced by curvature of shocked magnetic field lines plays a significant role in GRB emissions. The traditional fireball-shock model meets difficulties in explaining some latest observational results. This may be caused by ignorance of that important portion of radiation above. Making application of the formulae of synchro-curvature radiation, which can treat analytically the particle radiations in the curved magnetic field, we fit well a series of new GRB spectra, and present a unified interpretation toward the turnoff point and energy excess in the high-energy portion of the spectra. These features above are difficult to explain within the past synchrotron radiation framework. Furthermore, the fitting of a series of GRB spectra allows us to give some new constraints on the magnetic structure of the emission district, origin of the shocked magnetic field, and the mechanism of shock acceleration.
    Multiwavelength Astronomy
    ZHAO Jun-liang
    2007, 29(4):  193-199. 
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    After the telescope was invented in 1608, the astronomical telescope was firstly used to observe variable celestial objects by the Italian famous scientist, Galileo Galilei, in 1609, and a number of important discoveries were made soon, and a new era for astronomical observations and studies ushered in. As technical developments and knowledge improvements, radio astronomy, infrared astronomy, ultraviolet astronomy, X-ray astronomy and -ray astronomy were developed one by one during some decades from 1940s, and astronomers can cover the whole wavebands of electromagnetic radiation emitted from celestial objects, which means multiwavelength astronomy came in being, and step into a new phase to know better physical nature of the Universe and different kinds of celestial objects in it.
    Pulsar, Neutron Star, and Quark Star
    XU Feng;YUE You-ling;XU Ren-xin
    2007, 29(4):  200-203. 
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    Neutron stars and quark stars are currently two kinds of speculated bodies when one is modeling observed pulsars. After a brief introduction to the related history, the characters and possible observational features of these objects are focused on. A future perspective on the pulsar research in China is presented.

    The Status of Aeolian Desertification and its control in China
    WANG Tao
    2007, 29(4):  204-211. 
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    The aeolian desertification is a land degradation characterized by wind erosion mainly resulted from the excessive human activities in arid, semiarid and part of sub-humid regions in Northern Chian. At present,the aeolian desertification is still facing the situation of “ partly controlled but whole worsen ”. In the interest of more effectivly prevent and cure aeolian desertification, we should to improve the understanding on the cause,development or reverse process of aeolian desertification and the space-time distribution of aeolian desertified land so that the strategy and approach could be confirmed. Accoding to some research and summarize, we advance the stratagem,guidelines,basic principle and measures for combating aeolian desertification in China.
    A Concept Introduction to Biometrics
    FANG Yuchun;WANG Zhan
    2007, 29(4):  219-224. 
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    Biometrics adopts the differences in biological or behavioral characteristics for personal identification. With the advance of related technologies and the emergence of grand requirements, the biometrics technology is undergoing rapid and extensive development. This article summarizes the applications of biometrics, introduces several popular biometrics, discusses the general techniques for realizing a biometrics system and the key problems related to biometrics application, and finally points out the future development and prospect of biometrics.
    New Investigation for Mechanism of the 11 yr Period in Solar Activity
    NIE Qing-xiang;ZHANG Hai-xia;ZUO Qing-lin;HAO Juan
    2007, 29(4):  225-228. 
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    Summarization of ecological environment protection in the Three Gorge Project
    Sun zhiyu
    2007, 29(4):  239-243. 
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    The impact on ecological environment of Three Gorge Project (TGP) was paid close attention to worldly. It was a focus on construction and operation of the TGP too. It is very important to adopt workable measures to protect ecological environment. It can insure that TGP work smoothly for long time, and improve ecological environment along the Yangtze Rive. This paper introduced the working and progressing for ecological environment of the TGP.
    WU Wen-jun: The Famous Mathematician
    ZHANG Wei
    2007, 29(4):  244-248. 
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    Research on Caricaturing Technology of Auto-Portrait Robot
    NI Fei;FU Zhuang;CAO Qi-xin;ZHAO Yan-zheng
    2007, 29(4):  312-218. 
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    Robot Research Institute of Shanghai Jiaotong University, ShangHai 200240
    Abstract: Utilizing computer to draw a caricaturing portrait is a front field of machine vision. In a digital photo that be shot by CCD, for obtaining some lines that can exhibit image with caricature feature and draw these lines by robot, a appropriate image processing algorithm should be involved. The algorithm should include face recognition and extracting feature of face. Obviously, the caricature should be generated according to some feature of face. Finally, after vectoring these represent lines, an Auto-Portrait robot will be controlled to draw cartoon portrait on a paper. This paper discuss proposed method for portrait and caricature, comment at existing system of Auto-Portrait robot. Further, future prospect of development and target is presented.

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