最新刊期
      卷 0 ， 期 0 ， 2020
      • CUI Mingqi1 XI Shibo1 SUN Lijuan1 ZHU Jie1 CHEN Kai1 YAN Fen1 LIU Lijuan1 ZHAO Jia1 ZHENG lei1 ZHAO Yidong1 ZHOU Kejin1 MA Chenyan1 WANG Zhanshan2 ZHU Jingtao2 XUE Song3 1
        Vol. 32, Issue 10, (2009)
        摘要：A soft X-ray polarimeter with multilayer was developed at the Beijing Synchrotron Radiation Facility(BSRF).The polarimeter was designed to utilize reflection and transmission geometry,and it has four operational modes.Some experiments have been performed by using this polarimeter with various modes.Polarization properties of Mo/Si and Cr/C multilayer were measured,and polarizing characteristics of the Beamline 3W1B were measured systemically at BSRF.The degree of linear polarization is up to 0.995 from 0.585 at 206 eV when the beam is polarized by multilayer optical elements.We also measured magneto-optical Faraday rotation around the M2,3 edges(60–70 eV) of Ni film.The results demonstrate that the Faraday rotation angles are obviously large around Ni M2,3 edges,the rotation angles are 1.85±0.19° and –0.75±0.09°at the energy 65.5 eV and 68 eV,respectively.  
        关键词：Synchrotron radiation;Soft X-ray;Polarimeter;Multilayer polarizing element;Magneto-optical Faraday rotation   
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        发布时间：2021-03-12
      • LENG Yongbin CHEN Zhichu ZHOU Weimin
        Vol. 32, Issue 10, (2009)
        摘要：Digitizing and processing of broad band beam signals are common requirement for diagnostics of particle accelerator beams.An oscilloscope embedded IOC has been developed at SSRF,as a dedicated processor of broad band beam signals.This oscilloscope embedded IOC is a plug & play solution for EPICS based control system,and has been successfully applied in the bunch charge monitoring system of injector and the filling pattern monitoring system of storage ring at SSRF.Online performance of this processor is presented in this paper.  
        关键词：SSRF;EPICS;Input/Output Controller;Beam diagnostics   
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        发布时间：2021-03-12
      • FU Yuan XUE Song WEI Xiangjun JIANG Zheng GU Songqi CHEN Ming HUANG Yuying YU Xiaohan
        Vol. 32, Issue 10, (2009)
        摘要：This article discusses the development of harmonic rejection mirror(HRM) on the XAFS beamline at Shanghai Synchrotron Radiation Facility(SSRF).The HRM can apply pure spectrum for XAFS experiment.The HRM mechanism includes mirror holding system,horizontal switch system and three-points adjustment system.We make analysis and calculation in mechanism design.At last we evaluate the HRM capability based on the rocking curve got in test.  
        关键词：Harmonic;Rejection;Horizontal switch;Three-points adjustment;Rocking curve   
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        发布时间：2021-03-12
      • DENG Xiaoguo1 ZHOU Sizhong1 GUO Zhili1 YANG Xiaoxu1 JIANG Bo1 XIA Shaojian2 1
        Vol. 32, Issue 10, (2009)
        摘要：The theory of single-axis flexure hinge is applied to a four connecting rods hinge mechanism,which has been used on the sagittally focusing double-crystal monochromator at Shanghai Synchrotron Radiation Facility(SSRF).It outputs limit angular motion with an inputting force.Mechanism system errors were analyzed by elastic deformation of mechanism,and inputting force was analyzed,too.Correctness of the mechanism has been validated in online tests of the focused beam.  
        关键词：Limited angular motion;Single-axis flexure hinge;Connecting rod mechanism   
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        发布时间：2021-03-12
      • LIN Feiyu1,2 QIAO Weimin1 WANG Yanyu1 GUO Yuhui1 1
        Vol. 32, Issue 10, (2009)
        摘要：A synchrotron requires extremely high time constraints for timing signals,so timing system is very important for a synchrotron control system.A FPGA+ARM+Linux+DSP architecture has been mainly used in timing control of the HIRFL-CSR control system.In this paper,we report the development of the SOPC(System On a Programmable Chip) based on FPGA and uClinux.It can integrate all the functions of ARM+Linux in one single FPGA chip,hence no need of the dedicated ARM chip,and the reduced cost.The maximum operation frequency of this system is 185 MHz.The hardware consumes less than 4% of total resources of FPGA chip.And both the hardware system and the operating system of the SOPC are reconfigurable.The SOPC system has a wide prospect of applications in accelerator engineering and many fields of scientific research.  
        关键词：Synchrotron;Timing system;FPGA;uClinux;SOPC   
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        发布时间：2021-03-12
      • YAO Zeen LIANG Yi YUE Weiming HU Jifeng JIN Sunjun
        Vol. 32, Issue 10, (2009)
        摘要：A D-T neutron source model was constructed.The n-γ field distribution of the intense neutron generator with 260 keV deuteron beam at Lanzhou University was simulated using MCNP code.The interactions between neutron and the materials of neutron generator and the shielding walls were included in this study.The neutron energy spectrum,the angular distribution of neutron and γ-ray,and the n-γ ratio were presented.The M-C simulation results were compared to the experimental data to verify the reliability of the D-T neutron source model.  
        关键词：D-T neutron generator;MCNP code;n-γ field;Neutron energy spectrum;Augular distribution;n-γratio   
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        发布时间：2021-03-12
      • XIE Feng HE Xiaobing JIANG Wengang BAO Min SHI Quanlin
        Vol. 32, Issue 10, (2009)
        摘要：This paper describes the preparation and measurement system about gas radioactive source 133Xe, and the method and technique of the absolute measurement are discussed. After deducting the radioactivity of impurities, the radioactive concentration of 133Xe is determined by length-compensated method. The result of measurement for the 133Xe source is 42.86±0.82% Bq/mL at reference time.  
        关键词：133Xe;Internal gas proportional counters;Length-compensated method;Radioactive concentration   
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        发布时间：2021-03-12
      • YU Huawei1 SUN Jianmeng1 LI Xiaopeng2 ZHANG Qiongyao2 LI Na3 1
        Vol. 32, Issue 10, (2009)
        摘要：Cuttings debris may be deposited in the bottom of a horizontal hole because of gravity of the earth.It has lower density than the formation,so cuttings beds can have a significant effect on the density log responses.Monte Carlo method was used to study the effect of cuttings bed on the computed log density,with various formation densities and cuttings bed thicknesses of 0?5 cm in the horizontal borehole.In order to guarantee the reliability of results,simulation results were compared to the experimental data.MC simulations show that the density measurement can be corrected using the ridge-rib graph,if the thickness of the cutting bed is less than 2cm.Otherwise,it is difficulty to correct the effect of the cutting bed on the formation density measurement.Finally,the cuttings beds correction charts and formulas for DSDL-8723 double-detector density logging tool which is in the horizontal borehole are made preliminarily.  
        关键词：Density log;Horizontal well;Monte Carlo simulation;Cutting bed;Correction   
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        发布时间：2021-03-12
      • REN Xiang GE Liangquan ZHANG Qingxian YU Xinhua LIANG Wenjun
        Vol. 32, Issue 10, (2009)
        摘要：In in situ X-ray fluorescence logging,the variation of thickness of drilling fluid between the detector and wall affects the measurement result.A new correction method is established by acquiring the characteristic parameter of the XRF spectrum.The experimental results show that it is a simple,rapid,and practical correction method to samples of high concentration.After correction,deviation of peak area of the characteristics X-rays is 5% less than those measured without interference from the drilling fluid.  
        关键词：Logging;X-ray fluorescence elemental analysis;The influence of drilling fluid;Correction   
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        发布时间：2021-03-12
      • WANG Shilian1,2 LI Qi2 WANG Jun2 FAN Yuanqing2 JIA Huaimao2 ZHANG Xinjun2 LIU Shujiang2 1
        Vol. 32, Issue 10, (2009)
        摘要：This article introduces a new method to measurement the activity of radioxenon isotopes.The plastic tube-type gas cell and samples transfer apparatus were researched and manufactured.Peak efficiency of well-type HPGe detector was calibrated with the archive sample of CTBT noble gas exercise.The minimum detectable activity reaches 10.2 mBq to 81 keV gamma ray of 133Xe in 24 h measurement time.  
        关键词：Well-type HPGe;Xenon;Activity;Peak efficiency   
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        发布时间：2021-03-12
      • HU Baofu1 WANG Huixin1 LI Ming1 GE Yongxia2 WANG Haiying2 1
        Vol. 32, Issue 10, (2009)
        摘要：In this paper,the intermetallic compound MgB2 systems are studied by positron annihilation and theoretical calculation.The results show that,under increasing pressure,the electronic structure changes,and the electrons transfer from Mg layers to B layers.The holes in the B layers are partially filled.Density of states of MgB2 near Fermi level decreases,hence the reduction of matching electrons.Because of the decreased flexibility of sample lattice and degree of electron-phonon coupling,the superconductivity can be inhibited.Based on the positron annihilation,we speculate that a proper dose of laser irradiation can improve the superconducting characteristics of MgB2 samples.  
        关键词：Electronic structure;Superconductivity mechanism;Local electronic density;DOS;BCS theory   
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        发布时间：2021-03-12
      • XU Xiaoya JIN Weifang GAO Jianjun ZHOU Yi
        Vol. 32, Issue 10, (2009)
        摘要：In this paper,we investigate the radiation effect on the differentiation of bone marrow stromal cells(BMSCs).The local femoral head of rats was irradiated to 30 Gy by 137Cs γ-rays.The BMSCs were cultured two weeks after irradiation.The alkaline phospatase staining,oil red staining and immunohististochemistry were made after the induction,while observing the expression level of Cbf-α1,PPAR-γ,VEGF-a and KDR detected by RT-PCR technology.It was found that the local radiation depressed the differentiation of the BMSCs,with the expression level of Cbf-α1,PPAR-γ,VEGF-a and KDR being all down regulated.Induction could promote the irradiated BMSCs differentiation obviously to osteoblasts,adipocytes and endothelial cells,while the expression of Cbf-α1 and KDR were up-regulated obviously,but the PPAR-γ and VEGF-a were similar to that of the normal BMSCs.These indicate that the radiation depressed the BMSCs to differentiate to osteoblasts,adipocytes and endothelial cells,and after the special induction the differentiation of irradiated BMSCs could recover partly.The expression of correlated genes up-regulated obviously,but the numbers were still fewer for BMSCs differentiated to osteoblasts,adipocytes and endothelial cells.  
        关键词：Radiation;Bone marrow stromal cells(BMSCs);Core binding factor alpha 1(Cbf-α1);Peroxisome proliferator-activated receptor-γ(PPAR-γ);Vascular endothelia growth factor(VEGF)   
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        发布时间：2021-03-12
      • LIU Fang1 CHEN Xiaoming1 LI Xiaoyan2 ZHU Jie1 ZHENG Chun2 YAN Wanli1 ZHOU Liwei1 LI Chenglong1 HU Yuxue1 ZHOU Bin1 LU Zhenyuan1 ZHU Hailan1 1
        Vol. 32, Issue 10, (2009)
        摘要：In order to investigate the protective effect of SOD,Bacillus subtilis vegetative cells treated with SOD of different concentrations were irradiated to different doses by 60Co γ-rays.Cell survival rate was examined with the standard plate-count method.Intercellular SOD activity was measured by SOD kit with xanthine oxidase method,and DNA double-strand breaks was analyzed by pulsed-field gel electrophoresis(PFGE).The results showed that the cell survival rate increased obviously with the SOD-added Bacillus subtilis,though we did not find a clear relation among the intercellular SOD activity,concentration of added SOD and irradiation dose.The DNA release percentage(PR) value decreased evidently with the SOD-treated Bacillus subtilis.Basically,the trend of cell survival rate with concentration of the added SOD and irradiation dose is consistent with the PR value.It can be concluded that exogenous SOD could protect Bacillus subtilis vegetative cell from damage induced by γ-rays,and the protective efficiency of added SOD is related to the concentration.  
        关键词：Superoxide dismutase;Bacillus subtilis var.niger;Radiation resistance;DNA double-strand breaks   
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        发布时间：2021-03-12
      • SU Zhanglei QI Yanlei GU Yunhong SHEN Jinhu QIN Guangyong
        Vol. 32, Issue 10, (2009)
        摘要：Ion beam technology is an effective technique in inducing breeding and transformation.Some valuable wheat variation materials were obtained using ion beams.The agronomic traits,quality traits,seed gliadin of these materials were studied.The results show that the plant height,main stem panicle length,grain weight,leaf traits,protein content,and wet gluten content of the variations have obvious changes compared with the control and reach a significant level.Seeds gliadin bands of the variation materials changed exactly compared with the control,bands changes of some variation materials have been stable,and that of other materials exist polymorphism,which show that the materials are not stable.The results show that ion beam biotechnology can generate all kinds of variations and new germplasm resources.The results provide a theoretical basis for application of ion beam biotechnology in wheat.  
        关键词：Ion beam;Mediated transformation;Agronomic traits;Quality traits;Gliadin   
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        发布时间：2021-03-12
      • CHEN Liang OUYANG Xiaoping ZHANG Zhongbing ZHANG Xianpeng
        Vol. 32, Issue 10, (2009)
        摘要：This work is aim at finding the reason why the measured n/γ sensitivity ratio of film detectors is lower than the theoretical result.It was found that in theoretical calculation,the influences of air and detector’s window are omitted,but secondary electrons produced from gamma interaction with this material will deposit energy in the film,and this increases the detector’s gamma sensitivity.Through MCNP simulation and measurements in vacuum,it is approved that the impact of secondary electrons is obvious,and the thinner the film,the higher the interference.As air is the main source of secondary electrons that limits the improvement of the film detector’s n/γ sensitivity ratio,vacuum structure is needed for new film detector with high n/γ sensitivity ratio.  
        关键词：Film scintillator;Sensitivity;Pulsed neutron detector;n/γ sensitivity ratio   
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        发布时间：2021-03-12
      • HAO Kuihong1 LI Yanjun1 ZHAO Lin1 WANG Huaxiang2 DING Honglin3 1
        Vol. 32, Issue 10, (2009)
        摘要：Detectors applied in Compton backscatter imaging and low-noise amplifier including charge-sensitive amplifier and main amplifier were developed,through analyzing the performances of CdZnTe detector and considering the noise characteristics of the circuits.At room temperature,energy resolution of the detection system with a 5 mm×5 mm×5 mm discriminator grade CdZnTe detector and nuclear electronic circuit is better than 4% to the 662 keV 137Cs γ-ray.  
        关键词：Backscatter;Discriminator grade CdZnTe detector;Nuclear electronic circuit;Energy resolution   
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        发布时间：2021-03-12
      • ZHENG Wei LIU Shubin LIU Xuzong AN Qi
        Vol. 32, Issue 10, (2009)
        摘要：The TOF trigger sub-system on the upgrading Beijing Spectrometer is designed to receive 368 bits fast hit signals from the front end electronics module to yield 7 bits trigger information according to the physical requirement.It sends the processed real time trigger information to the Global-Trigger-Logic to generate the primal trigger signal L1,and sends processed 136 bits real time position information to the Track-Match-Logic to calculate the particle flight tracks.The sub-system also packages the valid events for the DAQ system to read out.Following the reconfigurable concept,a large number of programmable logic devices are employed to increase the flexibility and reliability of the system,and decrease the complexity and the space requirement of PCB layout.This paper describes the implementation of the kernel trigger logic in a programmable logic device.  
        关键词：TOF;Trigger;FPGA   
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        发布时间：2021-03-12
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