最新刊期
      卷 0 ， 期 0 ， 2020
      • XU Ruinian ZHANG Jidong WANG Wenfeng LI Deming
        Issue 3, (2005)
        摘要：A new method of microsecond timing generator controlled by microprocessor is introduced in this article. With less periphery components, more output channels, and ability of online timing table download, the device has high performance and low price. It has been used as a key component in a laser photolysis facility and can be used in other fields.  
        关键词：Microsecond;Timing generator;Laser photolysis   
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        发布时间：2021-03-12
      • DING Jianguo SHEN Guobao LIU Songqiang
        Issue 3, (2005)
        摘要：This paper describes a high-resolution and cost-effective TDC (Time-to-digital converter) system, which mainly consists of a micro-controller and a general-purpose TDC chip based on the delay line technique. The system, in high-resolution mode, reaches a resolution of 125 ps with one channel and a dynamic range of 7.2 μs. The system has been used in an airborne laser depth sounding system in a shallow-water environment.  
        关键词：Time-to-digital converter (TDC);Digital delay line;Micro-controller   
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        发布时间：2021-03-12
      • LI Weimin XIE Dong HE Duohui LIU Gongfa XUAN Ke
        Issue 3, (2005)
        摘要：The HLS is a second generation synchrotron radiation source. After injected into the storage ring at an energy of 200 MeV, electrons will be ramped to 800 MeV. This article first describes the ramping control of the HLS storage ring, then introduces a simulation method by using Elegant code, which helps correct the tune and study the ramping progress carefully.  
        关键词：Ramping;Ramping table;Elegant code;Simulation   
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        发布时间：2021-03-12
      • ZHOU Sizhong YANG Xiaoxu SHI Huixia
        Issue 3, (2005)
        摘要：The bent focusing mirror used in BSRF-3B3 intermediate-energy X ray beamline is introduced. The method of gravity compensation is presented based on the analysis of slope error caused by gravity. The mathematics model of the error is built. The best position and value of the equilibrant are calculated through optimizing. The slope error is reduced greatly after the equilibrant is imposed properly.  
        关键词：Synchrotron radiation;X-rays;Bent focusing mirror;Gravity compensation   
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        发布时间：2021-03-12
      • IBRAHIM Kurash1 QIAN Haijie1 ABBAS Mamatimin1 SU Run1 WANG Jiaou1,2 WU Xiang1 HONG Caihao1 ZHONG Jun1 WU Ziyu1 DONG Yuhui1 WANG Yutian3 WEI Long3 1
        Issue 3, (2005)
        摘要：We have performed an experimental investigation of X-ray absorption at O K -edge on both Pr1- SrxMnO3 x for x=0, x=0.3 and MnO2. Experimental results show that the electron number in Mn 3d orbitals of the end-point compound would increase, instead of decrease, with the increase of the hole-doping dose(x value). This phenomenon has been discussed in terms of orbital hybridization and covalent characters between O 2p and Mn 3d orbitals.  
        关键词：CMR effects;Near-edge photoabsorption;Electronic structure   
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        发布时间：2021-03-12
      • CAO Wenling LI Jing JING Duohui GONG Yandao ZHAO Nanming ZHANG Xiufang
        Issue 3, (2005)
        摘要：Chitosan conduits were sterilized with 60Co γ ray irradiation at a dose of 25 kGy and their swelling properties, mechanical properties and biodegradability in lysozyme solution were measured. After γ ray irradiation, the swelling index of chitosan conduit was considerably reduced and the tensile strength and elastic modulus were markedly increased. The results from SEM and measurement of mechanical properties showed that the degradation rate of the irradiated conduits in lysozyme solution was lower than that of the nonirradiated conduits. In addition, the chitosan conduits were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and differential scanning calorimeter (DSC), and the influence mechanism of irradiation sterilization on the properties of chitosan conduits was explored.  
        关键词：Chitosan conduit;Irradiation sterilization;Biodegradation;Mechanical property;Nerve repair   
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        发布时间：2021-03-12
      • ZHANG Guohui1 TANG Guoyou1 CHEN Jinxiang1 SHI Zhaomin1 WANG Jianyong1 Gledenov Yu M2 Sedysheva M2 Khuukhenkhuu G2 CHEN Zemin3 LIU Tingjin4 1
        Issue 3, (2005)
        摘要：By using a gridded ionization chamber, the differential cross sections and angle integrated cross sections of the Li(n,t)4He reaction were measured at neutron energies of 1.85 and 2.67 MeV respectively. Neutrons were 6 produced through the T(p,n)3He reaction. The absolute neutron flux was determined through the 238U(n,f) reaction, while the relative neutron flux was monitored by a BF3 long counter. Present results are compared with the existing data.  
          
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        发布时间：2021-03-12
      • JIA Xiuqin DONG Jinquan HAN Song
        Issue 3, (2005)
        摘要：A preconcentration INAA method is used for the analysis of very low REE concentrations of the Hongguleleng ophiolite and the normal INAA method for the trace elements of the ophiolites. The analyses show that the lherzolite (sample X-49) may be representative of primary mantle, while the harzburgite (sample X-44) is probably the residual mantle material from partial melting of the upper mantle, and the dunite (samples X-55 and X-57) may be accumulated from mafic magma.  
        关键词：Metaperidotite;Preconcentration INAA method;REE;Trace elements   
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        发布时间：2021-03-12
      • ZHANG Tonghe WU Yuguang XIAO Zhisong LIU Andong
        Issue 3, (2005)
        摘要：Erbium ions were implanted into Si and thermally oxidized SiO2/Si by MEVVA (Metal Vapor Vacuum Arc) ion source implanter. Depth profiles of Er concentration were measured by Rutherford Backscattering Spectrometry (RBS). The results show that the Er concentration is greater than that by using conventional methods. The maximum Er concentration in Er implanted Si and SiO2 is 4.71×1021 cm–3 and 7.67×1021 cm–3 respectively. But increase of the concentration was limited by some factors, such as heavier ion, shallow implanted layer and serious sputtering. Out-diffusion effects were increased with the increase of ion flux and annealing temperature. The relations between lost Er atom amount and the implantation condition were studied. Lost Er atom amount was increased with the increase of ion flux, dose and out-diffusion. In other words, retained amounts in implanted layer was decreased with the increase of these factors.  
        关键词：Er ion implanted Si;SiO2;MEVVA ion source;Sputtering;Depth profiles   
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        发布时间：2021-03-12
      • HU Chunming DAI Junlong SHEN Wende LIU Xiankun
        Issue 3, (2005)
        摘要：To promote its development in China, a set of Neutron Scattering Experimental Facility (NSEF) will be installed at a new research reactor. A cold neutron source (CNS), one of the most important components of NSEF, is a mono-phase liquid hydrogen moderator of vertical thermosiphon type. Nice working capacity and safety are main advantages of the CNS with a sub-cooled liquid hydrogen thermosiphon. Cooling helium from refrigerator removes the total heat load from the CNS in the heat exchanger. In the paper, an introduction of the principle and arrangement of the CNS is given, and technical parameters of the CNS are described in detail.  
        关键词：Reactor;Cold neutron source;Liquid hydrogen thermosiphon   
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        发布时间：2021-03-12
      • HUANG Wentao WANG Jilin LIU Zhinong CHEN Changchun CHEN Peiyi QIAN Peixin
        Issue 3, (2005)
        摘要：The change of electrical performances of 1 MeV electron irradiated silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) and Si bipolar junction transistor (BJT) was studied. After electron irradiation, the collector current IC decreased while the base current IB did not change, and the current gain β decreased for SiGe HBT. For conventional Si BJT, both IC and IB increased and β decreased much more obviously than SiGe HBT at the same fluence. It was shown that SiGe HBT had a better anti-radiation performance than Si BJT. The mechanism of electrical performance changes induced by irradiation was preliminarily discussed.  
        关键词：Electron irradiation;SiGe HBT;Si BJT;Electrical performance   
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        发布时间：2021-03-12
      • TANG Pingying DAI Jingyi TAN Xiaohua JIN Dazhi LIU Tie DING Bonan
        Issue 3, (2005)
        摘要：Discharge behavior of the vacuum arc ion source working in pulse mode was investigated using high-speed photography and spectrum diagnosis. The evolvement of cathode spot on hydrogen-impregnated electrode was captured by high-speed photography, and the emission spectra of cathode spot at different pulse currents were analyzed. The experimental results show that in most cases, only one cathode spot can be found in the discharge zone of vacuum arc ion source, and the spot moves a little during the same discharge. Temperature of the cathode spot may rise while the discharge current increases, and ultimately the density of hydrogen ion will be increased. At the same time, sputtering of the electrode is enhanced and the quality of ion plasma will be reduced.  
        关键词：Vacuum arc ion source;Cathode spot;High-speed photography;Spectrum diagnosis   
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        发布时间：2021-03-12
      • LI Gongping1,2 ZHANG Xiaodong1 DING Baowei1 DING Yinfeng2 LIU Zhengmin1 ZHU Dezhang2 ZHANG Zhibin2 BAO Liangman1 1
        Issue 3, (2005)
        摘要：Mon cluster beam was produced by a new type magnetron sputter gas aggregation cluster source. The – beam was accelerated by the voltage of 0, 1, 3, 5, 10 kV and deposited onto polished p-type Si(111) substrate surface at room temperature, respectively, and then the thin film samples of Mo/Si(111) were prepared. X-ray diffraction analysis showed that there was no MoSi2 thin film formation in the area interface of Mo/Si(111) samples deposited by using both regular magnetron sputter and new type cluster source when the accelerated voltage was no more than 5 kV, whereas at the voltage of about 10 kV, there was MoSi2 thin film formed in the area interface of Mo/Si(111) samples deposited by using the new type cluster source. Only for the accelerated voltage higher than a threshold voltage (≥3 kV in this experiment), can the (110)oriented Mo thin film by the cluster beam deposition grow up.  
        关键词：Molybdenum cluster beam;Monocrystalline silicon;Collision deposition;MoSi2   
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        发布时间：2021-03-12
      • ZHAO Ziqiang DAI Junfeng CHEN Zhiying GUO Zhiyu
        Issue 3, (2005)
        摘要：The optical absorption of CR39 radiated by Cn (n=1—5)cluster ions with the same energy of 600 + keV/atom and different doses and doses rate was studied. It indicates that cluster effect is materialized by electron stopping power in the interaction of cluster ions with solid.  
        关键词：Optical absorption;Cluster ions;Ion implantation   
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        发布时间：2021-03-12
      • LU Wu1 REN Diyuan1 GUO Qi1 YU Xuefeng1 ZHENG Yufeng2 ZHANG Jun2 1
        Issue 3, (2005)
        摘要：By comparing the characteristic changes of transistors, subsidiary and entire circuits of CMOS amplifiers with different thickness of gate oxide layer, influence of the thickness of gate oxide layer on the op-amps’ irradiation response was investigated. It was shown that by lessening the thickness of gate oxide layer properly, degradation of transconductance of the op-amps’ transistors induced by radiation-generated oxide charges and interface states can be reduced, therefore, the ability of CMOS amp to resist radiation can be improved.  
        关键词：CMOS op-amp;Transconductance;Gate oxide layer;Oxide charges;Interface states   
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        发布时间：2021-03-12
      • GUO Liping1,2 LI Jizhou1 1
        Issue 3, (2005)
        摘要：Neutron diffraction is so far the only nondestructive method which may be used to measure the stress distribution deep inside materials or components directly and thus has important applications in engineering. A neutron diffractometer dedicated for stress measurement is under construction at China Advanced Research Reactor (CARR) by the Neutron Scattering Project, and its main function is to determine residual stress and applied stress in materials. In this paper we report the conceptual design of the instrument. The design was studied by simulation with the Monte Carlo ray-tracing software, MCSTAS, and a part of the component parameters was optimized.  
        关键词：Neutron diffractometer;Residual stress;Monte Carlo simulation;China advanced research reactor (CARR)   
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        发布时间：2021-03-12
      • LI Zhengping YIN Zejie WU Ruisheng WANG Hujian
        Issue 3, (2005)
        摘要：This article analyzed the relationship between sensitivity of a γ -ray density meter and the radiation source. All work was based on the numeric simulation by GEANT4 system. We conclude that a lower energy radiation source gives higher sensitivity, and the position and collimation characteristic of the source have little influence on sensitivity of the system.  
        关键词：Sensitivity;Monte Carlo method;γ -ray density meter;Geant4   
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        发布时间：2021-03-12
      • CHEN Jiansheng DONG Haizhou CHEN Liang YANG Songtang
        Issue 3, (2005)
        摘要：The oxygen and hydrogen isotope tracer method can be used to study the leakage of dam. The leakage of right dam of Xin’anjiang Reservoir was investigated. With the analysis of environmental isotopes δD, δ18O and T, the by-pass leakage of right dam of Xin’anjiang Reservoir is proved. All results are important to the next reinforce work.  
        关键词：Dam;Leakage;Environment isotope;Tracer method   
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        发布时间：2021-03-12
      • YANG Yanqiu XING Pifeng YANG Tongzai YE Shiyou LIU Yinong
        Issue 3, (2005)
        摘要：Perfluorocycloalkane tracer technology is commonly used in such fields as dispersion and transport study of atmospheric pollutants and its environmental effects evaluation, disposal of radioactive wastes and leak detection of containers for nuclear materials. In this paper, the features of perfluorocycloalkane tracers and the sampling methods were presented. The tracer analysis techniques and their advances were reviewed, and the prospects of this technology in China was discussed briefly.  
        关键词：Perfluorocycloalkane;Tracer technology;Chromatography;Atmospheric dispersion;Leak detection   
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        发布时间：2021-03-12
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