最新刊期
      卷 0 ， 期 0 ， 2020
      • XU Zengyu PAN Chuanjie WEI Wenhao CHEN Xiaoqiong ZHANG Yanxu
        Issue 2, (2002)
        摘要：Experimental simulation results of magnetohydrodynamic (MHD) effect instabilities caused by coating cracks on insulating layer in pipes are presented. The results showed that the cracks induced not only a great increase of MHD pressure drop, but also unsteadiness of MHD effect. Deviated from the classical laws, both the boundary potential difference U and MHD pressure drop Δ P jumped to an extent over 100%. Moreover, under the same experimental parameters, U vibrated with time and Δ P vibrated with velocity V 0.  
        关键词：Liquid-metal;Crack;MHD effect instabilities   
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        发布时间：2021-03-12
      • ZHU Jiazheng YANG Bingfan HU Yueming ZHANG Canzhe
        Issue 2, (2002)
        摘要：Irradiating by electron beams has been widely adapted in the fabrication of fast switching power thyristors. However, accompanying beneficial reduction in switching speed there is a deleterious increase in forward voltage drop. Methods which minimize the voltage drop increase as the switching speed is reduced are highly desirable, one such method would achieve this by introducing the traps or recombination centers into well defined narrow regions where they will be more effective in reducing the switching speed than in increasing the forward voltage drop. Because the proton rang-energy relationship is relatively well defined, such kind of well defined narrow region can be formed by the precise control of irradiation proton energy. Dual energy proton beams from the HI-13 tandem accelerator were used in the experiments. The results indicate that this is a preferred technique for processing fast switch thyristors with superior characteristics.  
        关键词：Dual energy proton beans;Irradiating thyristors;On-off time   
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        发布时间：2021-03-12
      • GONG Ye L Wenyan LIU Jinyuan ZHENG Shu GONG Jiquan
        Issue 2, (2002)
        摘要：The energy equations were simplified by the correct electrostatic ordering under electrostatic approximation. The effects of the external axial magnetic field, the current profiles and arc currents on the helical instabilities of arcs were studied by using numerical method. In the presence of the external magnetic field, numerical results show that when the current profile of an arc column is the uniform distribution, the short wavelength perturbation can be stabilized by positive direction magnetic field, whereas the long wavelength perturbation can be stabilized by reverse magnetic field. When the current profile of an arc column has a parabolic distribution, in the short wavelength perturbation case, the effect of positive direction magnetic field on the arc stability is very small. However, its stabilizing effect is enhanced for the long wavelength perturbation. The intermediate and long wavelength perturbations can also be stabilized by reverse magnetic field.  
        关键词：Electrical arc;Helical instability;Numerical analysis   
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        发布时间：2021-03-12
      • CUI Yonggang 1 LI Yuxiong 2 SHAO Beibei 1 LI Juexin 2 LI Weimin 2 1
        Issue 2, (2002)
        摘要：The electrons lost from the storage ring beam produce a shower of particles when striking the vacuum chamber, and the beam losses can be probed by detecting the shower electrons distributed on the surface of beam pipe. Based on this principle, a new Beam Loss Monitoring System (BLM System) was designed and installed during the upgrading of accelerator in NSRL. In this paper, the selection of BLM detectors, the position to install them, and also the structure of BLM system were discussed in detail.  
        关键词：Accelerator;e-storage ring;Beam loss   
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        发布时间：2021-03-12
      • TAO Xiaoping WANG Guicheng GAO Yunfeng ZHOU Yuehua
        Issue 2, (2002)
        摘要：There is RF electromagnetic leakage in klystron corridor of NSRL of Hefei. In order to ensure communication signal in the corridor not to be disturbed, the leaked noise has been suppressed using anti-interference technique. A contrast test of leaked noise has been made before and after suppression. The result shows effectiveness of anti-interference technique.  
        关键词：Klystron;Electromagnetic leakage;Anti-interference;Suppression   
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        发布时间：2021-03-12
      • LI Rong JIANG Guoqiang XUE Yan ZHANG Yitao
        Issue 2, (2002)
        摘要：In order to investigate the mechanism about the effects of tritium aging on metal hydride, experiments were performed on some aged LaNi 5 materials which had been loaded with DT and stored at room temperature for 2140 days. Tritium aged LaNi 5 retains nearly all the decayed 3He within the bulk. The tritium aging effects were observed by determining the deuterium desorption isotherms in various states. These effects included (1) a right shift of the isotherms, (2) an increase in the plateau slope, (3) a reduction in the reversible storage capacity, and (4) the formation of tightly bound tritium, which was often referred to as the tritium heel. It was found that these effects were completely removed after the 3He had been removed by 1230K heating of the samples. This provides a direct evidence for the mechanism that tritium aging is caused by 3He.  
        关键词：LaNi 5;Tritium;Aging;3He   
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        发布时间：2021-03-12
      • LI Zhen BAO Borong WU Minghong XIANG Qun
        Issue 2, (2002)
        摘要：Extraction of uranium (Ⅵ) from nitric acid solutions with N-octanoylpyrrolidine (OPOD) in a series of diluents has been studied. The dependence of the extraction distribution ratios on the concentrations of aqueous nitric acid, extractant, salting-out agent and the temperature was investigated. The experimental results showed that the extracting capacity of OPOD in different diluents increases in the order: chloroform, CCl 4, 1,2-dichloroethane, n-dodecane, n-octane, c-hexane, toluene and benzene. It can not be expounded only on the basis of polarity of the diluents. The interaction between extractant or extracted complex and diluent was discussed.  
        关键词：N-octanoylpyrrolidine (OPOD);Extraction;Uranium (Ⅵ);Diluents   
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        发布时间：2021-03-12
      • FANG Ping CHEN Zhengping ZHOU Xiang
        Issue 2, (2002)
        摘要：The ligand of N-(3-fluoropropyl)-2β-carbomethoxy-3β-(4’-iodo phenyl)nortropane (FP-β-CIT) and its tributylstannyl precursor were synthesized by hydrolysis of cocaine, and then dehydration, esterification, Grignard reaction, n-demethylation, iodination, n-alkylation and tributylstannylation. 125/131 I-FP-β-CIT were prepared by oxidation radioiododestannylation, using peroxyacetic acid as oxidant, of its tributylstannyl precursor. The stable labeled compound was synthesized with high radiochemical purity at pH 4-7.  
        关键词：Cocaine derivatives;Tropane derivatives;Dopamine transporter;FP-β-CIT;Imaging agent;Synthesis   
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        发布时间：2021-03-12
      • YE Qingfu 1 WU Jianmin 2 SUN Jinhe 1 1
        Issue 2, (2002)
        摘要：The chemical purity of 14 C-labeled chlorsulfuron was determined by HPLC, its radiochemical purity was measured by HPLC-LSC (Liquid scintillation counter) and TLC-Isotope imaging analysis, respectively. The results showed that the chemical and radiochemical purity of synthetic 14 C-chlorsulfuron are 94.4% and 94.7-95.2%, respectively. Results determined by LC-MS showed that the retention time of synthetic 14 C-chlorsulfuron was consistent with that of its standard sample, and the molecular weight determined by MS was 357 that is equal to the molecular weight of chlorsulfuron.  
        关键词：C-labeled chlorsulfuron;Chemical purity;Radiochemical purity   
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        发布时间：2021-03-12
      • HUANG Minsheng ZHENG Leping 1
        Issue 2, (2002)
        摘要：This paper introduced researching results in bio-accumulation and reduction of U(Ⅵ) in water. Microbes, pH, temperature and coexisting metal ions as well as electron donors are the key factors to affect accumulating and reducing results of uranium. Some microbes have very high accumulating capacities for uranium. Effects of pretreament of biomass on uranium accumulation are highly dependent on microbial species, pretreating methods and uranium accumulating time as well as initial uranium levels. Uranium reduction by biomass was driven by cytochrome C3.  
          
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        发布时间：2021-03-12
      • WANG Zhaorong 1,2 ZHANG Zhaofeng 1.2 PENG Zicheng 1,2 ZHOU Jie 2 LIU Weiguo 2 Ma Zhibang 3 1
        Issue 2, (2002)
        摘要：Experimental results of coral dating and paleoenvironment studies by using the thermal ionization spectrometry (TIMS) uranium series method were introduced. The TIMS result for BKM-4 standard coral measured by the MAT-262 MS instrument is consistent with that by α spectrometry method.  
        关键词：TIMS with uranium-series aging method;Coral;Paleoenvironment   
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        发布时间：2021-03-12
      • JIA Xiuqin HUANG Zhongxiang HAN Song 1
        Issue 2, (2002)
        摘要：The neutron activation analysis is applied for analyzing the rare earth elements (REE) and trace elements in the ancient porcelains of Yao Zhou and Ru. The results show that there are differences or even significant differences between glazes and roughcasts of these two ancient porcelains in the gross amounts of REE, normalized diagrams of REE and characteristics of trace element contents, which reflecting the composition differences in glazes and roughcasts of the two kinds of porcelains. Thus, the contents of REE and trace elements can be taken for discriminating the ancient porcelains.  
        关键词：NAA;Yaozhou old china;Ru old china;REE marks;Discrimination of old china   
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        发布时间：2021-03-12
      • ZHAO Weijuan 1 XIE Jianzhong 1 LI Rongwu 2 GAO Zhengyao 1 LI Guoxia 1 ZHANG Bin 3 1
        Issue 2, (2002)
        摘要：samples of glazes and bodies of the ancient Chinese Ru porcelain, Jun porcelain and imitative ancient ceramics were analyzed by neutron activation analysis (NAA). The contents of 36 elements in each sample were measured. The NAA data were statistically treated by fuzzy cluster method and the trend cluster diagram was obtained. Their classes and raw material sources were determined. The results show that although these samples spaned hundreds of years, came from different kilns and had different glazes colors, the bodies of the ancient Chinese Ru porcelain and Jun porcelain belong to the same kind, the glazes of the ancient Chinese Ru porcelain is similar to the glazes of the ancient Chinese Jun porcelain. The originating places of the body raw material were concentrated, and that of the glaze raw materials were scattered, the source of the glaze raw material covered that of the body raw material. The ancient Chinese Ru porcelain and Jun porcelain have basically the same raw material sources and the sources of raw material are stable in long time. It is found that most modern Jun porcelain samples are similar to the ancient Chinese Jun porcelain. Two modern Ru porcelain samples are similar to the ancient Chinese Ru porcelain, but another one drifts apart from the ancient Chinese Ru porcelain. Jingdezhen porcelain has no relation to Ru porcelain and Jun porcelain.  
        关键词：Neutron activation analysis;Fuzzy cluster analysis;Provenance relation between Ancient Chinese Ru Porcelain and Jun Porcelain   
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        发布时间：2021-03-12
      • JIA Wenhong LIU Yonghao LI Deming CHEN Zhihao SHI Xuelan HUANG Zhenguang CHEN Guosheng
        Issue 2, (2002)
        摘要：The autocontrol system of the vertical rotatable multi-sample device in SMCAMS (Shanghai Minicyclotron AMS) was introduced and it’s principle as well as application were presented. The multi-sample device together with this aotocontrol system has been put into routine measurements on SMCAMS.  
        关键词：SMCAMS;SCM;Pneumatic control valve   
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        发布时间：2021-03-12
      • SUN Lingxia WEI Kentang YE Yunchang
        Issue 2, (2002)
        摘要：To avoid the interference of high density material for the quality assay of beryllium welding line, a slice by slice scanning method was proposed based upon our research results of the Industrial Computerized Tomography (ICT) diagnostics for weld penetration, weld width, off-centered deviation and weld defects of beryllium-ring welding seam with high density material inside.  
        关键词：Beryllium;Industrial Computerized Tomography;Welding quality;Non-destructive test   
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        发布时间：2021-03-12
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