最新刊期
      卷 0 ， 期 0 ， 2020
      • LENG Yongbin ZHENG Lifang LU Chengmeng MIAO Haifeng LIU Songqiang
        Issue 8, (2002)
        摘要：The control system of Shanghai Synchrotron Radiation Facility is an EPICS-based distributed system. One of the key techniques to construct the system is the device-level control. This paper describes the design and implementation of the DeviceNet-based device controller. A prototype of the device controller was tested in the experiments of magnet power supply and the result showed a precision of 3×10 -5 .  
        关键词：Synchrotron radiation facility;Control system;EPICS;DeviceNet   
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        发布时间：2021-03-12
      • MING Ming LI Zheng WANG Jing CHENG Jianping WANG Xuewu KANG Kejun
        Issue 8, (2002)
        摘要：It is important to inspect the inner defects, density distribution of the multi-structure complex material. The conflict of resolution of reconstructed image and reconstruction efficiency baffled people long when applying radiation laminography to that kind of material. Limited angle swing laminography algorithm was put forward in this paper. A simulation of printed circuits board by MATLAB attested the rationality and high efficiency of this algorithm. Based upon the simulation, the principle of choosing optimal projection angle was discussed. Finally, an application example was given.  
        关键词：CT;Backprojection reconstruction;Laminography;Limited angle   
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        发布时间：2021-03-12
      • DENG Wen 1,2 ZHONG Xiaping 1 HUANG Yuyang 1 XIONG Liangyue 2,3 CAO Mingzhou 3 LONG Qiwei 2,3 1
        Issue 8, (2002)
        摘要：Positron lifetime measurements have been performed in binary TiAl alloys with Al contents from 47at.% to 53at.%. The experiment results indicate that the open volume of defect on grain boundary of all tested TiAl alloys is larger than that of a monovacancy of pure Al metal. In Al-rich TiAl alloys, with the increase of Al content, the open volume of defect on grain boundary increases while the density of free electron decreases. In contrast, in Ti-rich TiAl alloys, with the increase of Ti content, the open volume of defect on grain boundary decreases, and the density of free electron of the grain boundary increases, thus the cohesive strength between the grains increases. The duplex structure, α 2(Ti 3Al)+γ(TiAl), was formed in Ti-rich TiAl alloys, and this give rise to the increase of the phase boundaries and the traps of positron. The effect of the microstructure of the alloy on the mechanical property has been discussed.  
        关键词：Positron lifetime;Electron density;Microdefect;Mechanical property   
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        发布时间：2021-03-12
      • FU Luxin HAN Qian KANG Wen
        Issue 8, (2002)
        摘要：The SSRF requires high-amplitude half-sine pulse current (10kA) and relatively narrow pulse width(～60μs) for its eddy-current septum magnets. Moreover the machine will need a very high level of performance from the pulsers, particularly in terms of pulse amplitude stability and regulating range. For the convenience of maintenance the pulsers will be installed in the power supply hall and cabled to their eddy-current septum magnets by RG220/U.This paper presents the pulser design and R & D results.  
        关键词：Eddy-current septum magnet;Half-sine pulser;Pulse amplitude stability;Distrituted gate thyristor;Energy recovery circuit   
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        发布时间：2021-03-12
      • ZHANG Xianfeng 1 FAN Yangmei 1 JIA Shaojin 2 ZHOU Xianyi 1 WENG Huimin 1 YE Bangjiao 1 ZHANG Zhicheng 2 HAN Rongdian 1 1
        Issue 8, (2002)
        摘要：The variation of the electrical conductivity of high density polyethylene (HDPE) with the carbon black (CB) content was studied using positron annihilation lifetime spectroscopy (PALS) and free-volume model, the crystallinity of HDPE/CB composite and "percolation" effect were discussed with measurements of conductivity and DSC test.  
        关键词：Conductive composite polymer material;Free-volume;Percolation;Crystallinity   
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        发布时间：2021-03-12
      • LU Rongrong QIU Huiyuan ZHU Dezhang
        Issue 8, (2002)
        摘要：Ion beam induced charge technique (IBIC) with low beam current (fA level) and high efficiency is a new development of nuclear microscopy. It has been widely applied to the fields of semiconductor and microelectronical materials. The principle and the experimental method of the IBIC technique were described and reviewed its status and new trends were reviewed.  
        关键词：Nuclear microscopy;Ion beam induced charge   
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        发布时间：2021-03-12
      • FANG Yude LUO Jiarong KUANG Guangli LIN Jianan QIN Pinjian YANG Changchun
        Issue 8, (2002)
        摘要：In HT-7 tokamak discharge experiments, the low loop voltage start-up was realized by using the changeable N ∥ spectrum LH (lower hybrid) waves to assist much low loop voltage OH (Ohmic) heating. In assistance of 200kW LH waves, the breakdown loop voltage reduced from about 20V to the value less than 5V. That is, the field strength of OH heating was reduced dramatically from 2.5-3V/m to 0.6V/m. At the same time, some phenomena related to gas ionization, plasma radiation and the consumption of OH heating volt-second number for gas ionization and current set-up were observed.  
        关键词：Tokamak;Plasma discharge;Start-up process;Strong microwave   
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        发布时间：2021-03-12
      • WANG Zhijiang ZHAI Kan WEN Yizhi WAN Shude YU Changxuan PAN Gesheng WANG Cheng SUN Xuan WANG Jun
        Issue 8, (2002)
        摘要：The time correlation and dispersion relation analysis of toroidal propagation of the turbulent perturbation in magnetically confined plasma were carried out to estimate the phase velocity of the perturbation. The results show that the phase velocities obtained by different methods are in good agreement with the electron fluid velocity, and indicate that the time correlation and dispersion relation analysis are effectively equivalent methods in the research of the propagation velocity of the turbulent fluctuation.  
        关键词：Turbulent perturbation;Propagation speed;Time correlation analysis   
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        发布时间：2021-03-12
      • Issue 8, (2002)
        摘要：A new surface modification technology-high current pulsed electron beam treatment method was applied to the surface of die steel to improve its properties. It has been shown that as a result of the HCPEB treatment, the most pronounced changes of the structure-phase state occur in the near-surface layers quenched from the liquid state, where the crystallization front velocity reaches its maximum. In these layers partial or complete dissolving of second phases and formation of over saturated solid solutions and ordered nanosized structures may take place. This makes it possible to improve substantially the electrochemical and strength properties of the surface layers. We found that the thickness of remelt layer is about 10μm, and the sectional microhardness increased accompanied by the enhancement of the wear resistance of the material. After modification, the relative wear resistance of D2 steel have inereased 5.63 times and that of H13 steel increased 11.76 times.  
        关键词：HCPEB;Die steel;Surface modification;Wear resistance   
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        发布时间：2021-03-12
      • YANG Xingcun 1 BAO Borong 2 CAO Weiguo 2 1
        Issue 8, (2002)
        摘要：N-Decanoylmorpholine has been used as novel extractant for HNO 3 and U(Ⅵ) in benzene from aqueous nitric acid medium for the first time. The dependence of extraction distribution ratio on the concentration of aqueous nitric acid and extractant was discussed. The extraction mechanisms of HNO 3 and U(Ⅵ) were confirmed. DMPHL was found suitable for extraction of U(Ⅵ) at high acidity.  
        关键词：N-Decanoylmorpholine;Solvent extraction;Extractant;Uranium (Ⅵ)   
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        发布时间：2021-03-12
      • WANG Zhiming LI Shushen JIN Yueru FAN Yaoguo MA Ruwei
        Issue 8, (2002)
        摘要：It can be seen from the tracer migration test results that the centers of mass of specific activity distribution of radionuclides, 60 Co, 85 Sr and 134 Cs, in unsaturated loess medium are still within tracer source layer under natural rainfall condition during about 3 years. And lateral specific activity distribution variance of 85 Sr is equivalent to that of longitudinal distribution. Migration distances of the radionuclides under artificial sprinkling condition are also small. It is shown from the result that unsaturated loess has stronger sorption capacity to the radionuclides. In other words, unsaturated loess can be one of the candidate of geological media for disposal of ILRW. Moreover, it can be seen that the amount of water infiltration affects obviously downward migration velocity and longitudinal spread of radionuclide, and hence control of water infiltration amount through repository is a very important measure for decreasing effect of radionuclides in disposed waste on environment according to fitting and analyses to the tracer migration test results.  
        关键词：Unsaturated zone;Unsaturated loess;Migration;Field tracer migration test   
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        发布时间：2021-03-12
      • LI Wei WANG Wenfeng LI Rongqun YAO Side
        Issue 8, (2002)
        摘要：This review presents a general view of the development in the field of intelligent nanogel and its bio-medical application, introduces the methods about synthesizing the nanogels and controlling the diameter size under 100nm. Finally focuses on the on-off mechanism of the Nano-based Drug Delivery System (NDDS), and the bio-medical application such as gene therapy.  
        关键词：Nanogel;Phase transition;Emulsion polymerization;Nano-based drug delivery system (NDDS)   
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        发布时间：2021-03-12
      • XU Fei 1,2 XIAO Zhisong 3 CHENG Guoan 2 YI Zhongzhen 3 ZENG Yuxin 2 ZHANG Tonghe 3 GU Lanlan 1 1
        Issue 8, (2002)
        摘要：Er ions were implanted into Si substrates using metal vapor vacuum arc (MEVVA) ion source implanter, and Er-doped Si thin films have been formed after rapid thermal annealing (RTA). It was analyzed by Rutherford back-scattering spectroscopy (RBS) that Er concentrations in the thin films were close to 10at% corresponding to the level of ～10 21 atoms/cm 3 and Er segregation in the surface layer of the thin films appeared with increasing the temperature of RTA. The recovery of irradiation damage, Er segregation and Si solid phase epitaxy of Si amorphous layers were closely dependent on annealing temperature, which would influence on photoluminescence around 1.54μm from Er-doped Si thin film.  
        关键词：Ion implantation;Erbium-doped silicon;Rapid thermal annealing;Photoluminescence   
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        发布时间：2021-03-12
      • CHEN Ying 1 WEI Henghua 1 SUN Demin 1 XUE Meisheng 1 YAO Chenggui 2 1
        Issue 8, (2002)
        摘要：In order to improve the efficiency of measurement, we introduced the control theory to the magnetic measurement system in NSRL. We succeeded in building a closed loop system, and peformed measurement on the fly. While keeping the same accuracy as before, the efficiency has been greatly improved. It can be concluded that feedback is an effective method to advance measure system.  
        关键词：Magnetic measurement;Synchro precision;Controll theory   
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        发布时间：2021-03-12
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