最新刊期
      卷 0 ， 期 0 ， 2020
      • LI Guizhi YE Meiling SHI Lianghe XU Jian
        Issue 3, (2002)
        摘要：o-Ps lifetime and intensity of PMMA/ladderlike PPSQ in-situ blend sversus percentage of PPSQ showed that some interactions involved between PMMA and PPSQ. Positron annihilation lifetime spectra of PMMA/PPSQ blends at three different compositions (PMMA/PPSQ, 95/5, 90/10, 80/20) over 20—150℃ were studied. Two structural transitions were observable. β transition temperatue ( T β) of PMMA/PPSQ (95/5) was the highest among three blend samples due to good miscibility and strong interactions.The similarity of T g for samples M5 (PMMA/PPSQ 95/5) and M20 (PMMA/PPSQ 80/20) indicated that phase-separation occurred (PPSQ>5%). Characteristics of free-volume voids in the blends were also analyzed. Size and fraction of free-volume voids in PMMA/PPSQ (90/10) were the largest among three blend samples, so its T g was the lowest.  
        关键词：PMMA/ladderlike PPSQ in-situ blend;Positron annihilation;Free volume;Structural transition   
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        发布时间：2021-03-12
      • DAI Jianping ZHAO Zhentang
        Issue 3, (2002)
        摘要：The computational model of the code used to simulate the longitudinal instabilities of the asymmetric bunches was introduced. The growth rates of the longitudinal instabilities of the symmetric bunches got by this code were compared with those got by the code ZAP, and they were almost the same. As an example, the simulation results of the BEPC-Ⅱ were presented.  
        关键词：Asymmetric bunches;Instability;ZAP   
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        发布时间：2021-03-12
      • ZHANG Li WANG Jicheng ZHAO Jinhua YANG Yongfeng ZHENG Jiwen QIN Zhi ZHANG Chun GUO Tianrui HU Qingyuan
        Issue 3, (2002)
        摘要：ray signals detected by a HPGe detector were coincided with β-ray signals detected by a 4πΔ E β detector, and anticoincided with 511keV γ-ray from positron annihilation detected by a large BGO detector. This special coincident-anticoincident system was proved to be very successful in suppressing interfering γ- and β- rays emitted from β-deficient siotpes, and has played an important role in the obervation of the new neutron-rich nuclide 209 Hg.  
        关键词：Isotope;Characteristic γ ray;β decay;EC decay;Positron annihilation;Coincidence and anticoincidence;Compton background;Detection efficiency   
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        发布时间：2021-03-12
      • ZHAO Zhanxia 1 JIANG Shan 2 HE Ming 2 WU Shaoyong 2 1
        Issue 3, (2002)
        摘要：In order to improve the ability of particle identification in accelerator mass spectrometry (AMS) measurement, a new particle identification method called energy loss and flight time (Δ E-T ) parabola was proposed. The result of on line test with 36 Cl was described.  
        关键词：Particle identification;Δ E-T parabola;Two dimensional plot   
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        发布时间：2021-03-12
      • FU Chengdong WANG Xiaolian LI Cheng XU Zizong
        Issue 3, (2002)
        摘要：The multi- wire proportional counter (MWPC) has been intensively applied to the image formation measurement in high energy physics. The interaction of various energy X-rays (20—100keV) with Xe atoms in a MWPC filled with high pressure Xe gas was studied by Monte Carlo simulation. The influence of scattered X-ray and Xenon’s KX-ray on the accuracy of position determination with the counter was investigated. The distortion of image coused by scattered and KX-rays was studied by low density virtual model simulation. A method was proposed to correct the image distortion.  
        关键词：MWPC with high-pressure;KX-ray;MC simulation   
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        发布时间：2021-03-12
      • LUO Deli 1,2 XIONG Yifu 2 MENG Daqiao 1,2 1
        Issue 3, (2002)
        摘要：A 0.5nm molecular sieve absorption column and a hot decomposing magnesium bed was found to be one of the effective means to collect and decompose HTO in glove box atmosphere. The absorption characteristics of the 0.5nm molecular sieve column and water decomposing characteristics of the hot Mg bed were obtained. The results showed that the column absorbs water vapour from air with efficiency up to 99.99%. Water in tested gases was between 3.4×10 3 to 4.2×10 3 μg·g -1 and the total water absorbed on the column was up to 162g, under this condition no water was detected in output gases. Using the hot magnesium bed more than 99.9% desorption water from the column was decomposed.  
        关键词：HTO;Tritium waste;0.5nm molecular;Mg   
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        <引用本文> <批量引用> 7222428 false
        发布时间：2021-03-12
      • ZENG Xianxian 1 ZHANG Shifeng 1 LI Qian 1 WANG Jun 1 WANG Yanfei 2 LIOU Jun 2 1
        Issue 3, (2002)
        摘要：Stomulation mutagenesis on crossbreeds of sugar beet was carried out by using 35keV N + implantation. The dosages were 4×10 16 and 6×10 16 N +/cm 2 respectively. The sugar content and output of the crossbreeds beet were much improved after the implantation.  
        关键词：Sugar beet;Ion implantation;Inducing sources   
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        发布时间：2021-03-12
      • GAN Zaiguo GUO Junsheng QIN Zhi
        Issue 3, (2002)
        摘要：A simple apparatus for measuring α-decay of mother-daughter nuclei was developed. Decays from the mother nuclei or daughter nuclei were measured separately by using this apparatus. Decay relations of the nuclei were also obtained from the results measured by the equipment.  
        关键词：decay;Mother-daughter nuclei;Decay relation   
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        发布时间：2021-03-12
      • JIA Xiuqin 1 HAN Song 1 WANG Changsui 2 1
        Issue 3, (2002)
        摘要：The geochemical features of different types of Dushan jade are differentiated based on trace element and REE geochemistry using neutron activation analysis (NAA). For white, green and black Dushan jade, the ∑REE values are 1.45, 6.895 and 3.867μg/g respectively; La/Yb 14.277, 4.936 and 0.849; Sr contents 754, 434 and 115μg/g; Cr contents 5.53, 1095 and 851μg/g; Fe contents 2777, 2838 and 28750μg/g; Mn contents 68, 65.5 and 532μg/g, separately. There is the highest positive Eu abnormity in the green Dushan jade and the lowest positive Eu abnormity in the black Dushan jade. These characteristics are of important significance for both deep study and discrimination on ancient jade.  
        关键词：Dushan jade;Distinction mark;Characteristics of trace element geochemistry;NAA   
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        发布时间：2021-03-12
      • WANG Jinchun MAO Xueying YANG Gaochuang OUYANG Hong CHAI Zhifang
        Issue 3, (2002)
        摘要：Through 192 Ir radiotracer technique, the adsorption and desorption behaviors of iridium on AG1-X8 anion resin were studied. An AG1-X8 anion exchange enrichment procedure for iridium in geological samples was established, and the recovery of the whole procedure reached 92%. The Ir concentration in the Danish standard reference material FC-1 obtained by our procedure agreed well with the reference value. The concentrations of Ir in three Japanese candidate geological reference materials were determined by this technique.  
        关键词：Anion exchange resin;Iridium;Neutron activation;Geological samples   
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        发布时间：2021-03-12
      • WANG Renbo 1,2 ZHOU Rongsheng 1 MA Yingjie 1 FANG Fang 1 LE Renchang 2 1
        Issue 3, (2002)
        摘要：A high sensitivity X-ray fluorescence analyzer for fieldwork is presented. It consists of a miniature X-ray tube, a Si-PIN dectector with peltier cooler and a portable PC spectrometer. Results of the preliminary application on exploration of copper mine in Xiaoqingshan, sichuan are also presented.  
        关键词：Miniature X-ray tube;Si-PIN detector;Cu content   
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        <引用本文> <批量引用> 7225330 false
        发布时间：2021-03-12
      • LU Wu GUO Qi REN Diyuan YU Xuefeng ZHANG Guoqiang YAN Rongliang
        Issue 3, (2002)
        摘要：The total dose radiation responses of transistors, subsidiary and entire circuits of CMOS amplifiers with P channel transistor pair inputs have been investigated. It was shown that the main mechanisms of performance degrade of op-amps is unbalance of the current mirror caused by the non-symmetry output characteristics of the differential input transistors. So good match of the op-amps’ structure and the I-V characteristic of its transistors are the key issues to determine the tolerance of an op-amps to total dose radiation.  
        关键词：CMOS amplifiers;Radiation effects;Damage analysis   
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        发布时间：2021-03-12
      • LI Wenjian 1 LIANG Ke 2 SHEN Yu 2 1
        Issue 3, (2002)
        摘要：The survival fraction in HeLa cells irradiated by low dose X-rays was observed using clone method. The results showed that the survival fraction in the cells irradiated by less than 0.5Gy X-rays was higher than control, ”hormesis” of HeLa cell survival was obtained and was significant at doses near 0.25Gy; also, the damage degree of cells induced by the following irradiation was reduced because of pre-treating the cells with low dose D 1 of 0.05, 0.75Gy; it was found from above that ”adaptive response” of cell survival was induced by the low dose irradiation.  
        关键词：X-rays;HeLa cells;Survival fraction;Hormesis;Adaptive response   
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        发布时间：2021-03-12
      • YANG Xingcun
        Issue 3, (2002)
        摘要：A novel extractant, N,N’-didecanoylpiperazine (DDPEZ), was synthesized and characterized. Extraction of U(VI) with DDPEZ in carbon tetrachloride from aqueous nitric acid media was studied. The dependence of distribution ratio on concentration of aqueous nitric acid, extractant, salting-out agent and temperature was investigated and enthalpy of the extraction was calculated.  
          
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        发布时间：2021-03-12
      • YU Shaoning 1 BAO Borong 2 FAN Zhengping 1 TAO Yonghua 1 ZHAO Shanyin 1 1
        Issue 3, (2002)
        摘要：The extraction separation of Am(Ⅲ) and some lanthinides from nitric acid media by HBMPPT and TOPO in toluene was studied. The ligand HBMPPT or TOPO gave no detectable extraction in the pH ranges studied, but when two ligands were combined, a synergistic extraction was observed with a selectivity for Am(Ⅲ) over trivalent lanthinides (pH3.5—4.5). The separation coefficient was from 10 to 156 for selected lanthinides. From the results obtained, the extraction complexes were different for these trivalent elements.  
        关键词：Solvent extraction;Separation;Lanthinide;Am(Ⅲ)   
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        发布时间：2021-03-12
      • CAI Qi YU Jun JIN Jiashan SUN Fengrui
        Issue 3, (2002)
        摘要：Reliability analysis on operation process in nuclear power plant is the key basis of ensuring safety and the requirement to improve the effectiveness of plant. Taking the background of operation process reliability as a starting point in consideration, the adaptability of reliability analysis method was reviewed and technical ways of analyzing related problems were discussed.  
        关键词：Nuclear power plant;Operation;Reliability analysis   
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        发布时间：2021-03-12
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