最新刊期
      卷 0 ， 期 0 ， 2020
      • DING Jiaxuan XU Jiayue XIAO Jingzhong TIAN Yulian ZHU Peiping YUAN Qingxi
        Issue 7, (2004)
        摘要：A synchrotron radiation white-beam topography experiment has been performed to investigate the defects of Nd:SGG laser crystals grown by Bridgman method for the first time. Clear images of some defects, such as boundaries and dislocations were observed. The formation mechanism of these defects was discussed. It’s anticipated that the results of this work will be useful for optimizing the growth conditions of Nd:SGG laser crystals.  
        关键词：Nd:SGG laser crystals;Synchrotron radiation white-beam topography;Crystal defects   
        8
        |
        11
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206868 false
        发布时间：2021-03-12
      • ZHANG Aimei WU Xiaoshan SUN Liang CAIHongling DUJun HU An JIANG Shusheng
        Issue 7, (2004)
        摘要：By magnetosputting technique, we have fabricated a series of NiO-containing Co/Cu/Co spin valves. Electromagnetic transport measurements show that the thermal stability behavior for NiO being on the top of the spin valve (TSV) is different from that for NiO being under the bottom of the spin valve (BSV). X-ray reflectivity and X-ray transverse diffuse scattering studies show that the interface roughness and the coupling between NiO layer and Co layer are two competitive factors in determining the MR effect of the NiO containing Co/Cu/Co spin valves. From this point of view, we have designed another sets of samples with varying growth parameters and the MRs reach to a nearly double value, i.e., -12% for BSV. The MR of symmetric spin valve is increased to 15%.  
        关键词：Ni-based spin valve;X-ray specular reflectivity and scattering;Interface roughness   
        9
        |
        11
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206808 false
        发布时间：2021-03-12
      • ZHU Jie CUI Mingqi ZHENG Lei ZHAO Yidong WANG Zhanshan
        Issue 7, (2004)
        摘要：A new multilayer film consisting of Mo/Si/C has been fabricated by magnetic sputter deposition. Its thermal stability and reflectivity(near Brewster angle 45° incidence) have been researched using synchrotron radiation at Beijing Synchrotron Radiation Facility (BSRF). It was found that the reflectivity achieved 42% (at 45°, 92eV) before the thermal treatment, thermal stability was increased because of the C sublayer’s entering, and its reflectivity was 6.8% at 97eV after annealing at 600 ℃. Due to the diffusion of amorphous carbon in interface layer, the structure of Mo/Si/C multilayer film was changed, and the double diffraction peaks during low-angle X-ray diffraction (LAXD) were observed.  
        关键词：Multilayer film;Annealing;LAXD;Synchrotron radiation;Soft X-ray;Polarization   
        8
        |
        10
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206969 false
        发布时间：2021-03-12
      • WUZhihao ZHOU Yinxue WEI Shiqiang CHEN Dongliang YU Gencai ZHANG Xinyi
        Issue 7, (2004)
        摘要：Effects of growth conditions including lattice mismatch and growth temperature on the local structures of ZnO films prepared by MBE have been investigated using fluorescence EXAFS at Zn K edge. The ZnO films were deposited on the Si substrate at 200℃ and on sapphire substrate at 200℃ or 300℃ respectively. The coordination number N in the first shell (number of O atoms immediately surrounding a central Zn atom) remains constant 4 or so for all samples. However, the degree of disorder σ2 (mean squared displacement) of the local structure is varied with the growth conditions. At the same growth temperature 200℃, the degree of disorder is reduced from 0.0080 A2 to 0.0054 A2 as the substrate is changed from Si to sapphire; on the same sapphire substrate, the degree of disorder decreases from 0.0054 A2 to 0.0039 A2 when the growth temperature is increased from 200℃ to 300℃. Therefore, the higher growth temperature and smaller lattice mismatch can improve the disorder of local structures; the crystal quality of ZnO film will be improved as well.  
        关键词：ZnO;MBE;XAFS   
        9
        |
        11
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206908 false
        发布时间：2021-03-12
      • ZHANG Jing XIEYaning HOU Kai HUTiandou LIU Tao
        Issue 7, (2004)
        摘要：X-ray filters are used to absorb Compton and elastic scattering of samples, and to improve the quality of fluorescence signal in X-ray absorption spectroscopy (XAS) experiments. In the paper, ZnO filter is prepared by mixing ZnO powder into polyurethane, and then ZnO film is obtained by the spraying method. XRD (X-Ray Diffraction), XRF(X-ray fluorescence) and X-ray absorption spectroscopy (XAS) experiments indicate that the ZnO structure remains in the preparation process of the filter. Further, the ZnO filter is used in the Ga K edge-XAS measurement of Ga2O3, showing a good signal noise ratio. Other X-ray filters can also be prepared by the same method, which proves to be practical.  
        关键词：X-ray absorption spectroscopy;Filter   
        9
        |
        11
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206760 false
        发布时间：2021-03-12
      • LIU Gongfa LI Jingyi LI Weimin LI Chuan XIE Dong WANG Jigang BAO XunXUAN Ke CHEN Liping
        Issue 7, (2004)
        摘要：HLS (Hefei Light Source) storage ring control system is a distributed control system based on EPICS. At first, the hardware structure and software design are introduced. Then some tools software such as ramping control, closed orbit correction, machine status online query, data archiving and history data query are described in detail. The machine operation shows that HLS storage ring control system can satisfy the demands of HLS machine operation and machine study.  
        关键词：Control system;EPICS;Storage ring;Synchrotron radiation light source   
        19
        |
        14
        |
        12
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206925 false
        发布时间：2021-03-12
      • ZHUYi FU Yuan WANG Naxiu XIA Shaojian ZHU Peiping Zhou Sizhong
        Issue 7, (2004)
        摘要：The toroidal mirror coated with nickel on the fused silica substrate is an important part at the BSRF-3B3 beamline, which focuses a beam of synchrotron radiation from the bending magnet on the sample in both vertical and horizontal directions, and a four-point bender is used to bend the mirror. In this paper, a new method to test the four-point bender is introduced. Using a laser beam instead of a beam of synchrotron radiation, we have tested the performance of the four-point bender, and groped for the imaging rule by observing images of the beam focused.  
        关键词：Beamline;four-point bender;Imaging   
        9
        |
        11
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206773 false
        发布时间：2021-03-12
      • DU Guohao XIAO Tiqiao XIAShaojian WEN Li XUHongjie
        Issue 7, (2004)
        摘要：The control of linear guided stage and image capturing system in the novel Long Trace Profiler (LTP) are discussed. Diffraction pattern capturing and data processing are completed through Area Scan CCD camera, frame grabber and computer. Communication between the Matlab and VC++ is established. The measuring pattern and reference pattern are separated by the law of centroidal method. Higher precision of the light spot determination is obtained using Neural Networks Algorithms.  
        关键词：Area Scan CCD camera;Linear guided stage;Phase plate diffraction;Centroidal method;Diffraction picture   
        9
        |
        11
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206954 false
        发布时间：2021-03-12
      • ZHOU Fan GU Ming CHEN Zhihao FU Luxin FAN Xuerong
        Issue 7, (2004)
        摘要：Based on analyzing the modulator’s hardware and the characters of the circuit, the 110MW pulse modulator’s controller has been designed. And the purpose of this work was to ensure the modulator’s stability, credibility and safety, and to make the modulator accord with the control-demand of the 100MeV linear accelerator. After being debugged and tested, it was found that the design achieves the request of controlling and guarding the modulator safely.  
        关键词：Modulator;Controller;Monitor and control   
        8
        |
        11
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7208825 false
        发布时间：2021-03-12
      • ZOU Jianxin QIN Ying WU Aimin HAO Shengzhi WANG Xiaogang DONG Chuang
        Issue 7, (2004)
        摘要：A mathematical physics model is established to describe the surface modification process of High Current Pulsed Electron Beams (HCPEB) of pure aluminum alloy. Computer simulation is used to reveal the phenomena of fast heating and cooling, melting, solidification, evaporation, and thermal stress wave associated with the HCPEB bombardment. The calculated melting depth is about 1-10μm, which is close to the experimental results. The evaporated layer is at nanometer level, which can be omitted in the calculation of temperature field. The thermal stress wave, though as weak as about 0.1 MPa in peak amplitude (proportional to pulsed energy density), has strong impacts on material’s structure and properties.  
        关键词：High Current Pulsed Electron Beams(HCPEB);Numerical simulation;Thermal stress wave   
        8
        |
        11
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206855 false
        发布时间：2021-03-12
      • GONG Peirong LIU Ping LI Jiming GUO Honglei LI Minxi
        Issue 7, (2004)
        摘要：A PLC ( Programmable Logic Controller) based control system for 3.0 MeV high frequency high voltage electron accelerator (HFHVEA) was presented. An energy feedback control circuit was introduced to stabilize the output energy and its stability is less than 1 % of the rated value of accelerator energy. The scanning current always tracks output energy of the HFHVEA. It is convenient for diagnosing and analyzing failure of the HFHVEA.  
        关键词：HFHVEA;Monitor and controller;PLC;Flow chart   
        9
        |
        11
        |
        4
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7208749 false
        发布时间：2021-03-12
      • HE Chengdan LI Heqi LI Chunxu YING Lei LUOYan
        Issue 7, (2004)
        摘要：The design and experimental process of an automatic tracking system applied to local vacuum electron beam welding are dealt with in this paper. When the annular parts of an exactitude apparatus were welded, the centre of rotation of the electron gun and the centre of the annular weld are usually not superposed because of the machining error, workpiece’s setting error and so on. In this teaching process, a little bundle of electron beam is used to scan the weld groove, the amount of the secondary electrons reflected from the workpiece is different when the electron beam scans the both sides and the centre of the weld groove. The difference can indicate the position of the weld, then a computer will record the deviation between the electron beam spot and the centre of the weld groove. The computer will analyze the data and put the data into the storage software. During the welding process, the computer will modify the position of the electron gun based on the deviation to make the electron beam spot centered on the annular weld groove.  
        关键词：Electron beam welding;Secondary electrons;Teaching;Automatic tracking   
        8
        |
        12
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206839 false
        发布时间：2021-03-12
      • XU Hui LI Wenxin
        Issue 7, (2004)
        摘要：Terahertz (THz) radiation occupies the electromagnetic (EM) spectrum region between approximately 30 μm and 1 mm (10 THz-300 GHz). Recent advances in methods of producing THz radiation have stimulated interest in studying mechanism and application of THz radiation. Applications of THz radiation in biomolecular sensing and spectroscopy are very important due to the benefits of THz-TDS. This paper briefly summarizes various methods used to generate and detect THz radiation and reviews particularly current understanding of the interactions between THz radiation and biomolecules (protein and DNA).  
        关键词：Terahertz radiation;Biomolecules;THz-TDS   
        8
        |
        10
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7208581 false
        发布时间：2021-03-12
      • SONG Shiping LI Bin WANG Huiqiong HU Jun LI Minqian
        Issue 7, (2004)
        摘要：A simultaneous multiplexing immunoassay system has been developed which allow to detect multiple analytes based on antibody microarray. Technical data are optimized for the manufacture of the arrays. This system has been applied to determine three tumor markers: α-fetoprotein (AFP ), carcinoma embryonic antigen (CEA), and human chorionic gonadotropin beta (β-HCG). Our method has the advantage of showing the high throughput of microarray, specificity of "sandwich" immunoassay and sensitivity of avidin-biotin system. Simultaneous multiplexing immunoassay based on our antibody microarrays may find feasible application in the measurement of series markers in oncology and other areas of bioscience.  
        关键词：Antibody microarray;simultaneous multiplexing immunoassay;Tumor marker   
        8
        |
        11
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206789 false
        发布时间：2021-03-12
      • GE Min ZHAO Hongwei JI Te YU Xiaohan WANG Wenfeng
        Issue 7, (2004)
        摘要：Terahertz time-domain spectroscopy (THz-TDS) is a new technique based on femto-second laser technology. In the article we present well-resolved absorption spectra of benzoic acid and its 2-, 3-, and 4-methyl substitutes in the spectral region between 0.1 and 2.0THz using THz-TDS. Comparing absorption spectra of the different chemicals, we can distinguish the four substances easily. The THz-TDS is demonstrated to be highly sensitive to minor changes of molecular structures, and can be applied to detect and analyze materials.  
        关键词：Benzoic acid;THz;Time-domain spectroscopy (THz-TDS)   
        14
        |
        11
        |
        4
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7207064 false
        发布时间：2021-03-12
      • XU Qichu ZHANG Lixing YANG Yusheng
        Issue 7, (2004)
        摘要：The extraction behavior of Am3 +, Nd3 +, Eu3 + and Tm3 + from NaClO4 solution by di (2-ethylhexyl) di-thiophosphoric acid (DEHDTP) combined with trioctylphosphine oxide ( TOPO ), 4,7-diphenyl-1,10-phenanthroline (DPPHEN) and trioctylphosphine sulfide (TOPS) was studied. While TOPO and DPPHEN give strong synergism and higher selectivity toward Am3 + ( TOPO: β(Am/Eu)= 3.9, DPPHEN: β(Am/Eu)= 2), TOPS presents no synergism. Using DEHDTP combined with TOPO, the separation factor β(Am/Eu) increases as high as 71 in the presence of macroNd(ClO4)3.  
        关键词：Synergism;Americium;Lanthanide   
        8
        |
        11
        |
        3
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206943 false
        发布时间：2021-03-12
      • WEI Mengfu ZHANG Lianping WEI Yanbo QI Honglian WU Lunqiang
        Issue 7, (2004)
        摘要：In the design of industrial CT, the knowledge of energy and flux distributions for bremsstrahlung photons through crystals is necessary to select scintillator’s type and dimension. Based on the principle of Monte Carlo simulation of photon transport, the transport processes of 2 MeV and 9 MeV bremsstrahlung in Nal, Csl and CdWO4 scintillators have been simulated. Light spots and energy and flux distributions of bremsstrahlung have been presented.The results show that the method can accurately and visually determine both on energy and flux distributions of bremsstrahlung photons in any position in the scintillator.  
        关键词：Monte Carlo simulation;Bremsstrahlung;Scintillator;Energy distribution;Flux distribution   
        9
        |
        12
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206893 false
        发布时间：2021-03-12
      • CHEN Xianzhong WU Songtao
        Issue 7, (2004)
        摘要：The action of the shaft support structure under multi-load condition is studied by the ANSYS code in this paper. The research aims at optimizing the parameters of the support structure of HT-7U Tokamak.  
        关键词：Finite element analysis;Load condition;Bacillifonn support structure   
        19
        |
        11
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7206884 false
        发布时间：2021-03-12
      0