最新刊期
      卷 0 ， 期 0 ， 2020
      • WU Weifang WANG Yunbo YUE Yong
        Issue 10, (2000)
        摘要：A novel linear polynuclear spin transition compound with a higher transition temperature was synthesized. The M ssbauer spectroscopic study showed that the spin transition temperature lay above liquid nitrogen temperature and the change between higher and lower spin states was reversible with change of temperature.  
        关键词：Mossbauer spectroscopy;Chemical shift;Quadrupole splitting;Complex;Spin transition   
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        发布时间：2021-03-12
      • REN Chunsheng MOU Zongxin LIU Zhenmin LONG Zhenhu YANG Liming
        Issue 10, (2000)
        摘要：TiN thick films were prepared by multi-ion-beam dynamic mixing implanting (MBMI) technology and their structure and characteristics were analyzed by XRD, microhardness analysis and scratch test. The structure analysis results indicate that the phase structure of TiN films are affected by the implantation angle of nitrogen ion, the nitrogen to titanium atom ratio and the pressure of nitrogen gas. The performance tests show that higher temperature of substrate Ts and suitable RN/Ti are important for increasing the microhardness (HK) of TiN films and the stickiness between TiN film and substrate.  
        关键词：Multi-ion-beam dynamic mixing;Ion beam enhanced deposition;Ion implantation;Preferred orientation   
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        发布时间：2021-03-12
      • FENG Renjian ZHANG Dan ZHANG Haibo
        Issue 10, (2000)
        摘要：Harmonics of the ripple have been investigated experimentally at a self-made model Cockcroft-Walton (C-W) voltage multiplier, as a function of the circuit asymmetry and load. The results showed that the odd harmonics of the ripple was due to the circuit asymmetry and the even harmonics due to the charge-discharge process of capacitors. Under a light load condition, the fundamental harmonics was dominant compared with other harmonics, which could be considered to be the alternating ripple caused by the circuit asymmetry in the linear circuit approximation. When the circuit was asymmetrical, asymmetry of the diode conduction could increase the odd harmonics of the ripple.  
        关键词：Voltage multiplier;Ripple;Harmonics;Asymmetry   
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        发布时间：2021-03-12
      • ZHAO Weijiang YAN Sha LE Xiaoyun HAN Baoxi XUE Jianming WANG Yugang
        Issue 10, (2000)
        摘要：In this paper the intense pulsed energy effects of high power pulsed ion beams (HPIBs) are proved to be very important and useful in ion beam implantation. Three groups of 45# steel samples were implanted with the pulsed ion beams of Cn+ + H+ at the acceleration voltage of 150-260kV for the pulse duration of 50-150ns with the current density of 15-120A/cm2, while a low ion dose of about 1 ×1014cm-2 was kept for all implanted samples. Then their tribological properties as well as microhardness were measured, and their morphology and structure information were given by using SEM and X-ray diffraction analysis. The results showed that the materials’ surface properties and microstyucture have been modified due to the HPIB implantation even at such low level of ion dose, and the modifications strongly depended on the pulsed power density and pulsed energy density of HPIBs. These phenomena were considered as the intense pulsed energy effects and discussed on the basis of one dimensional heat conduction model. Meanwhile, the hardly changed surface microhardness and friction coefficient of 45# steel samples implanted with traditional (C++H+) ions at an ion dose of 1 ×1014cm-2 was given for a demonstration, in which the intense pulsed energy effects are relatively independent of the ion doping effects.  
        关键词：Intense pulsed ion beam;Ion implantation;Pulsed energy effects;Materials surface modification   
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        发布时间：2021-03-12
      • LU Diantong HUANG Dong
        Issue 10, (2000)
        摘要：The SOI (silicon-on-insulator) technology was regarded as a very important technique of the silicon-integrated circuit in the 21 century. The SIMOX (separation by implanted oxygen) and SIMNI (separation by implanted nitrogen) films were formed by O+ or N+ ion implantation into silicon with several methods. The SR (spreading resistance), Hall effects and DLTS (deep-level transient spectroscopy) measurements were used to analyse the surface electrical properties of the SOI structures. The results show that the step-implanted SOI films have good electrical properties.  
        关键词：Ion implantation;SOI materials;Electyical properties   
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        发布时间：2021-03-12
      • ZHANG Linwen
        Issue 10, (2000)
        摘要：The resonant coupling mode of (1 +1/2) cavities was discussed in this paper. By analyzing the equivalent circuit, a chromatic dispersion equation for chain of unsymmetrical short cavities was obtained and a conclusion, i.e. (1+1/2) cavities worked under the condition of π/6, π/2 and 5π /6 modes, was derived. This mode is different from the traditional 0, π/2 and π modes for chain of symmetrical cavities.  
        关键词：Standing--wave cavity;Coupling;Chromatic dispersion equation   
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        发布时间：2021-03-12
      • LIU Zhongyang SUN Guanqing ZHANG Dazhong CHEN Jianxuan ZHONG Guangwu
        Issue 10, (2000)
        摘要：Characteristics of an electron cyclotron resonance (ECR) plasma source at a frequenccy of 2.45GHz were briefly described. The experiments showed that both plasma ion density and electron temperature in the charge chamber depended on the magnetic field, microwave power and gas pressure. It was found that the microwave breakdown occurred easily at the static magnetic field of 87.5mT. However, the highest plasma density was obtained at about 93mT. The microwave introducing window consisted of three dielectric plates of quartz, aluminum and BN, which allow better impedance matching with the plasma. The source can operate at gas pressure of 0.l-1Pa. The power reflection coefficient is about 1%. Plasma ion density of 5.8 × 1011cm-3 and electron temperature of 3-12eV have been obtained at the microwave power of 200-700W. The lifetime of the source is more than 300h.  
        关键词：Electyon cyclotron resonance;Plasma source;Characteristics   
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        发布时间：2021-03-12
      • JIANG Dikui WU Guanyuan ZHAO Feiyun SUN Baogen DONG Sai
        Issue 10, (2000)
        摘要：Corrosion and leak happened at brazing of a beam current monitor(BCM ) under the radiation environment of linac and transport line. Corrosion products were analyzed with a rotating anode X- ray diffractometer, and Fe2F5. 7H2O, CuF2. 2H2O and CuF2 were indentified. They are believed to be the compounds of gas and metal ions at brazing with F-from Teflon that is decomposed by radiation.  
          
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        发布时间：2021-03-12
      • JIANG Shan HE Ming JIANG Songsheng WU Shaoyong DONG Yuean BAN Yiwen
        Issue 10, (2000)
        摘要：To increase the power of isobaric identification in the accelerator mass spectrometric measurements, a new gas detector called gas-filled time-of-flight spectrometric detector was set up. Its principle, construction and results of the first on-line test were introduced.  
        关键词：Accelerator mass spectrometry;Isobar;Gas-filled time-of-flight detector   
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        发布时间：2021-03-12
      • LI Guishan ZHAO Youxin LIU Baolu ZHAO Langtao
        Issue 10, (2000)
        摘要：This paper described testing techniques with approved computer aided ADC characterization methods for both heavy ion and prompt gamma environments. The results show that measurements of dc parameters and linearity at major code transitions are adequate for evaluation of A/D reinforce designing, with considerable cost saving compared to full dynamic testing.  
        关键词：AD574A;Total dose;Radiation degradation;Dynamic test   
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        发布时间：2021-03-12
      • YANG Gaochuang MAO Xueying LU Yan OUYANG Hong WANG Jinchun ZHANG Zhaohui CHAI Zhifang
        Issue 10, (2000)
        摘要：Several hens were fed by adding ammonium chloroiridate into their forage. After two weeks, the Ir concentration in three fractions (eggshell, albumen, egg yolk) of their eggs were measured by INAA. Ir was found in all of the three parts. However, the highest concentration of Ir was found in the egg yolk fraction, which was about 10 times higher than that in the eggshell and albumen. Moreover, the longer the Ir-containing feedstuff was used, the higher the Ir concentration in the egg fractions was. After 7-8 days feeding, it kept stable. On the other hand, as soon as adding the Ir-containing additives were stopped, the Ir concentration in the egg fractions fell down quickly. The experimental results indicated that the ratio from the feedstuff to the eggshell via gastrointestinal pathway to be about 0.07 percent. The new result might be beneficial to explain the iridium-enriched dinosaur eggshell fossils and to interpret the origin of the mass extinct event of dinosaur occurred at the end of Cretaceous.  
        关键词：NAA;Iridium;Hen egg;Dinosaur eggshell   
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        发布时间：2021-03-12
      • SU Yiyun
        Issue 10, (2000)
        摘要：The constriction and manufacture of the detector used in the 4 ring/7 layer PET device was described in this paper. The influences of structural design and mechanical processing on its parameters were considered. The rational distribution and adjustment of tolerance for various parts guaranteed the assembling quality of the detector. Comprehensive performance tests and clinical applications have shown that the design is reasonable and the construction is reliable.  
        关键词：Position emission tomography;Detector;Tolerance;Structural design   
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        发布时间：2021-03-12
      • TAN Mingguang WANG Yinsong QIAN Yine ZHANG Guilin
        Issue 10, (2000)
        摘要：By using streptozotocin (STZ) injection to induce model diabetic rats, instrumental neutron activation analysis was applied to analyze elemental concentrations in liver, kidney and pancreas tissues in diabetis and control rats. Results obtained for As, Br, Ca, Co, Cl, Cu, Fe, Hg, Mg, Mn, Na, Rb, S, Se and Zn in those tissues show that some elemental contents in diabetic group change obviously when compared with those of the controls. The changes of elemental contents and their significance are discussed.  
        关键词：Neutron activation analysis;Diabetes;Trace element   
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        发布时间：2021-03-12
      • WU Qinghua LI Yunfeng JI Shaowei WANG Yubing ZHAO Yingjie
        Issue 10, (2000)
        摘要：Diffusivity of 3H was measured in soil aerated zone on both natural and artificial rainfall conditions, migration of 3H tracer was also studied in loess aerated zone at the same time. The results implied that the migration velocity of 3H tracer in aerated zone was 0.03cm/d on natural condition in loess plateau of Huabei Region, the vertical diffusivity Dx was 0.10cm2/d. In the experiment pit, the migration velocity was 2.27cm/d under an artificial condition of 5mm/h sprinkling intensity for 3 hours each day, the vertical diffusivity Dx was 7.75cm2/d.  
        关键词：Aerated zone;Diffusivity;Nuclides migration;Tritium;Tracing experiment   
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        发布时间：2021-03-12
      • Hang Desheng LAI Qiji GAO Peng ZHU Yizhang YANG Congqun WANG Houwen XI Dexun FENG Wenquan
        Issue 10, (2000)
        摘要：The high energy (12MeV) electrons were used to irradiate the high-power switch transistors. The irradiated transistors had good switch performance, high thermal stability and parameter consistency.  
        关键词：Electron irradiation;Switch transistor;Annealing test   
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        发布时间：2021-03-12
      • SU Qiong
        Issue 10, (2000)
        摘要：Two correction methods were introduced and evaluated for coincidence summing effect of γ-γ cascade radiation in γspectrometry. It is concluded that the method in which the angular correlation of γ-γ cascade radiation is ignored should not be adopted in general.  
        关键词：γ-rays;Cascade radiation;Angular correlation;Coincidence summing effect;Correction method   
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        发布时间：2021-03-12
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