最新刊期
      卷 0 ， 期 0 ， 2020
      • LIU Qun1 HONG Xuan2 ZHOU Yingui1 LI Ge2 1
        Issue 3, (2007)
        摘要：An interlocked vacuum protection system based on complex programmable logic device(CPLD) has been developed for beam line protection in National Synchrotron Radiation Laboratory.Due to the implementation of the protection system with CPLD,reliability of the system is enhanced with fast response time.  
        关键词：Interlock;Vacuum protection;Control system;Complex programmable logic device   
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        发布时间：2021-03-12
      • LI Wei PAN Gang CHEN Hao ZHANG Meiyi HE Guangzhi YANG Yuhuan
        Issue 3, (2007)
        摘要：Microscopic structures of Zn(Ⅱ) adsorbed onto anatase TiO2 under different particle concentrations(Cp) were studied using the extended X-ray absorption fine structure(EXAFS) spectroscopy.Results of macroscopic adsorption-desorption isotherms indicated that Cp effect was obvious in the adsorption system.Adsorption isotherms decreased substantially with increasing Cp,and reversibility also decreased.Quantitative analysis on the EXAFS spectra showed that Zn(Ⅱ) was adsorbed onto the solid surface in the form of octahedral hydrous Zn(Ⅱ) ions,which were linked to the TiO2 surface by sharing the oxygen atoms,with an average bond length of RZn-O =(1.98±0.01) .EXAFS analysis of the second sphere resulted in two Zn-Ti atomic distances of(3.26 ± 0.01)  and(3.70 ± 0.01) ,corresponding to edge-sharing linkage(stronger adsorption site) and corner-sharing linkage(weaker adsorption site) respectively.For three adsorption samples with the same adsorption density and different equilibrium concentration,the number of stronger adsorption sites(N1) remained relatively stable while the number of weaker adsorption sites(N2) decreased with increasing Cp,making the proportion of two adsorption modes(N1/N2) rise from 0.629 to 0.690.These EXAFS results revealed the microscopic mechanism behind the macroscopic adsorption-desorption isotherm experiments.At the same time the basic hypothesis of MEA theory that the adsorption density is not a state variable has been verified.  
        关键词：Extended X-ray absorption fine structure;Zn(Ⅱ);TiO2;Microscopic structures;Particle concentration(Cp) effect;Adsorption reversibility   
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        发布时间：2021-03-12
      • MO Guang1,2 CAI Quan1,2 WANG Wei1,2 CHEN Xing1,2 ZHANG Kunhao1,2 CHEN Zhongjun1 WU Zhonghua1,2 1
        Issue 3, (2007)
        摘要：A series of alumina template are fabricated through altering oxidation condition of the first-step and the second-step.Scanning electron microscopy is used to observe and characterize the inter-pore distance and the pore diameter.The results show that a two-step anodic oxidation is enough to get good micrograph.The inter-pore distance is determined by the first-step oxidation.Templates with different pore diameters can be prepared by altering the second-step oxidation condition.The growing mechanism of alumina template is also discussed.  
        关键词：Alumina template;Anodic oxidation;Preparing method;Scanning electron microscopy   
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        发布时间：2021-03-12
      • LIU Chenglin1,2 YAN Xiaohui1 ZHANG Xinyi1 YANG Wentao3 SHI Daren3 HUANG Yuying4 HE Wei4 1
        Issue 3, (2007)
        摘要：The variation of relative contents of some typical trace elements in normal breast tissues,benign breast tumor tissues and breast cancer tissues is studied by the synchrotron radiation X-ray fluorescence(SR-XRF) technique.According to the results of SR-XRF,there exist the same kinds of trace elements in various breast tissues,but their relative contents are different.The differences for Ca,Fe and Zn are obvious between normal and breast tumor tissues.Comparing the contents of elements in breast tumor tissues with normal ones,S,Cr,Mn,Ni,Cu and Se are found to be of positive correlation,i.e.their contents in tumor tissues are increased;but K and Ca are of negative correlation.The contents of P in normal breast tissues are the same as in benign tissues,but a little decreasing in malignant ones.However,such correlation is positive for Fe and Zn in cancerous tissues,and negative in benign tissues.The above differences might be used to characterize changes that take place as breast tissues become diseased.  
        关键词：Trace elements;Breast tissues;X-ray fluorescence analysis;Synchrotron radiation   
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        发布时间：2021-03-12
      • YAO Deqiang1,2 WANG He1,3 LIU Peng1 1
        Issue 3, (2007)
        摘要：A new beamline 1W2A for small angle X-ray scattering is going to be constructed in Beijing Synchrotron Radiation Laboratory.It can provide higher intensity at two wavelengths of 1.54 and 0.97.The design and the optical characters of the beamline are described in detail in this paper.  
        关键词：Synchrotron radiation;Small angle X-ray scattering;Bent crystal;Beamline   
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        发布时间：2021-03-12
      • WANG Fengqin1 CAO Chongzhen1 GAO Xueguan2 WANG Jidai1 LI Yushan1 1
        Issue 3, (2007)
        摘要：It is a key performance requirement for a double-crystal monochromator that the exit is fixed,and in order to improve the height accuracy of the exit in T-shaped exit fixed mechanism,the expression between the height of the exit and various original errors was put forward using geometrical analysis method.According to the independent action principle of original errors,accuracy synthesis of T-shaped exit fixed mechanism was studied by using the equal accuracy method,and the tolerance ranges of original errors were obtained.How to calculate the tolerance ranges of original errors was explained by giving an example.  
        关键词：Accuracy synthesis;T-shaped exit fixed mechanism;Double-crystal monochromator   
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        发布时间：2021-03-12
      • WU Wensheng XIAO Lizhi
        Issue 3, (2007)
        摘要：To estimate casing thickness with litho-density logging in cased hole,the ratio of low energy counts NS to high energy counts NH in γ spectrum and the relationships between the ratio and photoelectric absorption coefficient Pe as well as casing thickness HC in different mineral compositions are calculated with Monte Carlo program MCNP.The results show that litho-density logging is insensitive to formation of lithology,so that Pe cannot be obtained from the ratio NS/NH.However,since there is a good linear relation between log NS/NH and logHC,the HC can be estimated through the ratio NS/NH.  
        关键词：Litho-density logging;Cased hole;Casing thickness;Photoelectric absorption coefficient;MCNP program   
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        发布时间：2021-03-12
      • TANG Shibiao YIN Zejie ZHU Daming HUANG Huan
        Issue 3, (2007)
        摘要：The characteristic gamma spectrums of different elements stimulated by neutrons have been studied using Geant4(Geant4.7.0,2005),a Monte Carlo simulation software.The results show that for different incident neutrons,the yield of different characteristic gamma photons are variational,from which the conception of optimal incident neutron energy is suggested.These results indicate that optimal energy for different elements is varied and the ener-gies of characteristic gamma photons for all the elements are mainly in the range of 0.8—7 MeV.  
        关键词：Geant4;Optimal energy;Incident neutron;Characteristic gamma photon   
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        发布时间：2021-03-12
      • SHEN Jiarong SHEN Liren LIU Yajuan
        Issue 3, (2007)
        摘要：Nowadays the distributed control system is used in most of large accelerator control systems.The system exchanges various kinds of data on the network.Since the control operation and data access require the CPUs to be regulated based on time,a time system is very important for the distributed control system.This paper describes the time protocol and its principle used in the time synchronization system,and introduces how to use software to build the system and to test its precision.  
        关键词：Distributed control system;Time synchronization;Time protocol;Simple network time protocol;Adaptive communication environment   
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        发布时间：2021-03-12
      • DAI Jianping ZOU Yi ZHUANG Jian YANG Xueping YU Ying
        Issue 3, (2007)
        摘要：The control system is one of the key items for Beijing Free Electron Laser(BFEL) upgrade project.This paper presents the design and implementation of the Programmable Logical Controller(PLC) control system based on Experimental Physics and Industrial Control System(EPICS).The system is steady,reliable and easy to expand.Design of both software and hardware,and the EtherNet/IP driver for the communication between PLC and EPICS are also described.  
        关键词：Beijing Free Electron Laser facility;Programmable logical controller;Experimental Physics and Industrial Control System;EtherNet/IP   
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        发布时间：2021-03-12
      • WANG Yang1,2 GONG Jinlong1 ZHU Dezhang1 WANG Huabin1,2 1
        Issue 3, (2007)
        摘要：A novel experimental setup was designed to fabricate tungsten tips for scanning tunneling microscope(STM),based on simple mechanical lever principle.The equipment can quickly separate the tip from electrolyte to avoid the further etching of the fine-shaped tungsten tip.The setup is advantageous for its simplicity over complex electronic control systems.The use result in scanning electron microscope demonstrates that the radius of the tip can reach 50 nm.The tip was applied to scan the surface of highly-oriented pyrolytic graphite,and the results were satisfactory.It is shown that the tip can be used for the scanning of atomically resolved images.  
        关键词：Scanning tunnel microscope;Tip;Electrochemical etching;Lever principle   
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        发布时间：2021-03-12
      • ZENG Minfeng1 CHEN Ning1 JI Genzhong1 SUN Xudong1 ZHAO Rener1 XIAO Huiquan1 WANG Baoyi2 QI Chenze1 1
        Issue 3, (2007)
        摘要：The free volume properties of epoxy/hydroxyl terminated butyl nitrile rubber(EP/HTBN) have been studied by means of positron annihilation technique.The toughness effect is found to be correlated with the content of HTBN and the free volume properties of the EP/HTBN interfaces.When the content of HTBN component is 5%,the free volume size in the interface is close to that of EP,and the toughness effect is strong.But with further addition of HTBN,holes with big size free volume are formed in the interface,and the toughness effect is limited.  
        关键词：Hydroxyl terminated butyl nitrile rubber;Epoxy resin;Free volume;Compatibility;Positron annihilation   
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        发布时间：2021-03-12
      • YANG Tianli LIU Xuemei LIU Zhao TANG Lei LONG Kaiming
        Issue 3, (2007)
        摘要：Based on the fission track technique,the determination of uranium particles from swipe samples has been studied.This work includes the separation of particles,disposing of the particle sample on the surface of nuclear track detector,irradiation of the sample by thermal neutrons and chemical etching,selection of uranium particles and so on.There are the following results obtained.First,the ashing in 400℃ furnace for 6 hours is a useful way for ashless filter,cotton and TX304 cloth which are the sample’s carriers during separation process.Second,after irradiation and chemical etching,the fission tracks on the nuclear track detector,which have either star shape or crater shape,can be seen clearly under the microscope.The uranium particles with less 235U may correspond to the star shape tracks and those with more 235U correspond to the crater shape tracks.Third,the uranium particle can be identified and selected exactly through the marks made by special tool in small area.  
        关键词：Swipe sample;Uranium particle;Fission track   
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        发布时间：2021-03-12
      • TENG Yuancheng1 CHE Chunxia2 ZHANG Chaobin3 ZHU Jianhong1 1
        Issue 3, (2007)
        摘要：Using simulated radioactive incineration ashes and natural zirconite as main raw materials,adopting the formula design,and by means of thermogravimetry-differential scanning calorimeter(TG-DSC) analysis,X-ray diffraction(XRD) analysis etc,the high temperature solid-state synthesis of zirconolite and sphene has been realized.The experimental result indicates that zirconolite and sphene with high purity can be synthesized at lower temperature.The most appropriate and lowest temperatures of synthesizing zirconolite and sphene are dependent on the content of the simulated radioactive incineration ashes.The lowest synthesis temperature may be below 1140℃.When the content of the simulated radioactive incineration is 0,20%,40% and 60%,the optimal synthesis temperature is 1260℃,1260℃,1230℃ and 1200℃,respectively.  
        关键词：Zirconolite;Sphene;Simulated radioactive incineration;Zirconite;Actinides   
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        发布时间：2021-03-12
      • TAO Shengxiang WU Yican
        Issue 3, (2007)
        摘要：An accurate patient positioning method in radiotherapy based on binocular vision photogrammetry is described in the paper.The patient’s images taken by two calibrated cameras from different points of view are reconstructed in stereo,then the difference of three-dimensional coordinates between the referenced and real-time positions of the patient’s focus is figured out to resume the planned radiotherapy position.The experiment shows that the three-dimensional coordinate’s difference between the referenced and real-time positions can be measured accurately.  
        关键词：Binocular vision photogrammetry;Position validating;Camera calibration;Three-dimensional coordinate reconstruction   
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        发布时间：2021-03-12
      • LI Guoli1 SONG Gang2 WU Yican2 1
        Issue 3, (2007)
        摘要：Inverse treatment planning for radiation therapy is a multi-objective optimization process.The hybrid multi-objective optimization algorithm is studied by combining the simulated annealing(SA) and genetic algorithm(GA).Test functions are used to analyze the efficiency of algorithms.The hybrid multi-objective optimization SA algorithm,which displacement is based on the evolutionary strategy of GA: crossover and mutation,is implemented in inverse planning of external beam radiation therapy by using two kinds of objective functions,namely the average dose distribution based and the hybrid dose-volume constraints based objective functions.The test calculations demonstrate that excellent converge speed can be achieved.  
        关键词：Inverse treatment planning;Multi-objective optimization;Algorithm;Hybrid   
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        发布时间：2021-03-12
      • ZHANG Yuehua LI Feng JIN Ge YU Xiaoqi JIANG Xiao
        Issue 3, (2007)
        摘要：Neutron time-of-flight(TOF) can provide important information about the fuel-ion burn temperature in various inertial-confinement-fusion(ICF) target designs.The sensitive neutron detector array is used to increase sensitivity while maintaining good time resolution for low-yield targets.It has been a standard technique to diagnose the average density-radius product ? ρ R?,which is a very important parameter in ICF experiments.The time resolution of the sensitive neutron detector array which will be used in “Shen Guang III” system is expected to be 1 ns,and the one of the electronic system connected with the detectors is 100 ps.Based on the next generation of TDCs from ACAM,TDC-GP2,a VME-plug-in multi-chanel TDC module,with a time-resolution of less than 61 ps,has been designed.  
        关键词：Inertial-confinement-fusion;Neutron time-of-flight(nTOF);GP2;TDC;VME bus   
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        发布时间：2021-03-12
      • ZHANG Fuli QU Decheng YANG Guoshan
        Issue 3, (2007)
        摘要：In order to study the relationship between the counting efficiency and the point source positions,a Monte Carlo code(MCNP4C) has been used to calculate the counting efficiency of NaI detector for the standard γ-ray point sources in different space positions.For the 137Cs and 60Co point sources,the counting efficiency function of the NaI detector and its parameters have been determined by fitting the calculated data.The results indicate that the Monte Carlo method is simple and effective in determining the counting efficiency function of NaI detector and its parameters for the γ-ray point sources.  
        关键词：NaI detector;Point source;Monte Carlo method;Counting efficiency   
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        发布时间：2021-03-12
      • ZHANG Qiang1 DENG Yuequan1 GU Yongmei1 DONG Faqin1 XU Guangliang1 HE Dengliang2 1
        Issue 3, (2007)
        摘要：The grain size of building materials products has a great influence on the radon release level.The release amount of radon is the greatest when the grain size is 5 mm,and the release levels will reduce for any other dimensions.Temperature has also important effect on the release of radon from building materials products.The concentration of radon will double when temperature raises 5℃ at 20℃ or higher,especially,when temperature is higher than 25℃,the concentration rises even more rapidly.The activation energy Ea of radon release for the fly ash samples is measured to be 77194.19 J.mol-1,and the factor A is 4.54×1015 s-1.The concentration of radon increases gradually with time,the release and decay of radon will reach equilibrium 36 h later,and the relative standard deviation of the fluctuating value of radon concentration is 2.1% at that moment.The relative standard deviation of the rate of preventing radon for the radon prevention coating is 3.8%.The results are reliable when the method is used in the research of radon prevention mortar and putty.  
        关键词：Building materials products;Radon;Radon prevention;Influencing factors   
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        发布时间：2021-03-12
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