最新刊期
      卷 0 ， 期 0 ， 2020
      • Gao Zhengyao Chen Songhua
        Issue 3, (1992)
        摘要：The firing temperature dependence has been studied of the quadrupole splitting （QS）and isomeric shift （IS） for the structure iron in Yuan dynasty Jun porcelain glaze and simulated ancient blue Jun glaze by Mossbauer spectroscopy. The QS and IS for the two kinds of glaze were compared. Firing temperature for the former was determined to be above 1250℃, and coordination number for Fe2+ and Fe3+ was four. The latter has been found will a broad process of dehydroxylation and vitrification, which may be profitable to form the unique glaze colour of Jun porcelain. When firing temperature is above 1200℃, coordination number for the latter becomes 4 too.  
          
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        发布时间：2021-04-09
      • Zhang Shunkai Lin Chenglu Zhou Zuyao Zhu Wenhua Zou Shichang
        Issue 3, (1992)
        摘要：Si+ was implanted into top silicon of SOI （silicon on insulator） material formed by N+ implantation to amorphize its surface, interface area between the top and the buried layer, and the whole top silicon. Then these SOI wafers and those without implantation were implanted by ET at 25 keV with dose of 1× 1015/cm2 and annealed in dry N2 ambient at different temperatures in the range of 500℃ to 900℃for 30 min. Glancing RBS/C measurement has shown that a solid phase epitaxial regrowth from the inner part of top silicon towards the surface or in the opposite direction exists respectively during post annealing if the surface or interface area of top silicon is amorphized. When the whole top silicon is amorphized, there is a phase transition from amorphous silicon to polysilicon for top silicon during post annealing in the temperature range from 500℃ to 600℃, and no solid phase epitaxial regrowth is found when the temperature is increased to 900℃. Spreading resistance probe measurements show that the activation rate of implanted boroh in the top silicon is lower than that in crystalline bulk silicon. The activation rate of implanted boron in the top silicon can be increased either by using Si+ implantation （to amorphize the surface or the interface area of top silicon） and the solid phase epitaxial regrowth.  
          
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        发布时间：2021-04-09
      • Xiong Xingmin
        Issue 3, (1992)
        摘要：A method of measuring positron lifetime is used to investigate temperature dependence of positron trapping at defects in neutron-irradiated silicon crystals. The lifetime spectra can be separated into two components. The long lifetime component, attributed to negatively charged divacancies, is found to be a constant value of 325±9 ps in the temperature range of 109-300K.The positron trapping displays a negative temperature dependence and the behavior can be described in terms of a cascade model of positron trapping. In the low temperature region the positron trapping cross section varies with temperature as T-1.7  
          
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        发布时间：2021-04-09
      • Issue 3, (1992)
        摘要：The quality of the LM soap film crystal is determined by means of the positron annihilation life spectroscopy. It is found that the technology to be used to make soap film will influence the film quality and the latter can be improved by a reasonable heat treatment.  
          
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        发布时间：2021-04-09
      • Wang Weijie Han Peigang Wang Tianmin
        Issue 3, (1992)
        摘要：Diamond-like carbon films, deposited by a dual-ion beam sputtering method on glass substrates at temperature less than 50℃, were irradiated by 114 keV carbon ions with doses of 2 × 1016 ions/cm2 and 1 ×1017 ions/cm2, respectively. Raman spectroscopy, infra-red transmittance spectroscopy and electrical resistivity were used to characterize the as-deposited and the irradiated films. It was shown that the as-deposited films contain SP3C-C,SP2C-C, SP3C-Hand SP2C-H bondings with bond-angle disorder. The C+ irradiation led to decrease of SP3C-H bonds and increase of SP2C-H bonds in films. Meanwhile, the bond-angle disorder was decreased, the crystallization degree increased, and the number and/or size of microcrystals also increased due to irradiation. All these structural changes led to considerable decreases of electrical resistivity as well as infra-red transmittance of irradiated films.  
          
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        发布时间：2021-04-09
      • Chen Jiansheng Du Guoping
        Issue 3, (1992)
        摘要：A new ground water tracing instrument and its principle, features, and applications are described. Signals from G-M tubes are transported through a 3-wire cable. A low-power liquid crystal scan display circuit controlled by a microcomputer is employed. Both groundwater flow direction and velocity can be determined precisely. The instrument can be used in the survey of many parameters, such as coefficient of permeability, vertical flow, effective porosity, transmissivity, coefficient of dispersion and seepage of dam or reservoir bottom.  
          
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        发布时间：2021-04-09
      • Sun Fengxian
        Issue 3, (1992)
        摘要：Using the analyzer the average density and water percent of water-cut, gas-cut oil can be measured based on different absorption degrees of low energy photons for the media with various density and composition. The measurement accuracy is not influenced by the mixing state of oil and water, the gas content and the properties of oil. The measurement range of water percent is 0-100%. An 241Am source is used to irradiate the coned silver sheet to form a realistic photon source. The escape peak of 50 keV gamma rays is correctly dealt with and a newly derived equation is utilized to make calculations, thus the standard error of water percentage measurement is reduced to equal or less than 1.1%.  
          
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        发布时间：2021-04-09
      • Zhou Sichun Xie Tingzhou Ge Liangquan
        Issue 3, (1992)
        摘要：Methods and techniques of using home-made portable X-ray fluorescence analyzers to prospect copper deposits have been investigated based on the elements association in geochemical anomalies of different types of copper deposits. The test result with the methods and techniques at somewhere in north-east China is given.  
          
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        发布时间：2021-04-09
      • Xi Dexun Zhuang Ya
        Issue 3, (1992)
        摘要：The frequency stability of the power source for a feedback LINAC depends on the slow shift, stability and form of power spectrum of the magnetron. The first two factors affect the short-term frequency stability and the last one relates to the long-term frequency stability. The control exactness of the frequency stabilization system can be increased by means of a method in which the area change of output signal from the detector of the frequency discriminator is used to indicate frequency shift and to drive a stepping servo motor. The frequency corresponding to a performance index, i.e. the maximal area of the superposition envelop at the entrance of the accelerating tube, is tracked by the oscillation frequency of the magnetron for improving the long-term frequency stability. In order to eliminate the influence of the modulator when the CPU is running, the CPU can be forced to reset periodically to keep the control function.The frequency stability is 7×10-6.  
          
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        发布时间：2021-04-09
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