最新刊期
      卷 0 ， 期 0 ， 2020
      • WANG Jie GUO Yuxian
        Issue 4, (2005)
        摘要：A data acquisition and control program has been developed for soft X-ray magnetic circular dichroism based on LabVIEW 5.1. The friendly interface of the program makes user to access it quickly and easily. The graphic panel of the program consists of three functional areas of setting up the status of the instruments, inputting the initial parameters of the experiment and plotting the experimental data. The experimental data are also stored as ASCIIfiles which can be processed by other programs.  
        关键词：Data acquisition;LabVIEW;Soft X-ray magnetic circular dichroism;X-ray near-edge absorption   
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        发布时间：2021-03-12
      • WANG Guofeng QU Huamin DAI Xuwen
        Issue 4, (2005)
        摘要：The reconstruction of Beijing Electron Positron Collider (BEPCII) is a great national scientific project. To install and adjust B magnet, Q magnet, S magnet and vacuum in a support accurately, a laser tracker is adopted in the process of pre-assembly and pre-alignment of BEPCII. Transforming instrument reference frame into B magnet reference frame by coordinate-transformation represents more visual relations among all parts. The survey precision and accuracy are confirmed by error analyses.  
        关键词：Pre-assembly;Pre-alignment;Coordinate transformation;Error analyses   
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        发布时间：2021-03-12
      • CHEN Nian ZHANG Pengfei LI Ge XU Hongliang LI Yuhui ZHANG Shancai CAI Genwang HE Duohui
        Issue 4, (2005)
        摘要：An undulator consists of many magnets. The unavoidable remanence divergence and dimension divergence of these magnets cause the undulator magnetic field error, including the peak magnetic field error, phase error, etc, which will affect the quality of the spontaneous emission spectrum. This paper presents the simulation method of permanent magnet magnetic field, undulator magnetic field and spontaneous emission. The normal school random numbers generator is applied to produce groups of magnets of different remanences or different sizes. Each group of the magnets can constitute the undulator. Then the spontaneous emission is calculated. And accordingly we can make a study of the influence of undulator magnetic field errors on spontaneous emission. Finally, the correlations between intensities of spontaneous emission and various magnetic filed errors are illustrated, including RMS magnetic remanence error, RMS magnetic width error, RMS phase error and RMS field error.  
        关键词：Undulator;Spontaneous emission;Magnetic field error;Phase error   
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        发布时间：2021-03-12
      • LI Shihong1 LI Xiaomei2 MAO Xueying1 XU Diandou1 OUYANG Hong1 ZHAO Junlin2 CHAI Zhifang1 1
        Issue 4, (2005)
        摘要：The sediments and buried plant remainders from a drilling core in Xihu Lake, Fields Peninsula, Antarctic, were analyzed with instrumental neutron activation analysis method. Data analysis showed that the sediments at different depth had the identical multi-elemental distribution patterns. The same characteristic was also found in the plant remainder samples. Moreover, the sediments and the remainders showed similar multi-elemental distribution patterns including REEs, indicating that they had similar material resources. The elemental enrichment factors were also calculated to differentiate selective uptake of elements by the plant. The depth profiles of many elements of the remainder displayed significant and similarly regular changes. A conclusion can be drawn that the multi-elemental composite characteristics of the plant remainders were more responsive to the environmental changes than those of the sediments, which therefore could provide the important evidence to track the environmental and climatic evolution.  
        关键词：Sediment;Plant remainder;INAA;Biogeochemistry   
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        发布时间：2021-03-12
      • LI Yongdong1 LIU Chunliang1 ZHANG Dianhui2 WANG Jianguo2 1
        Issue 4, (2005)
        摘要：The conventional particle-moving algorithm for particle-in-cell simulation of plasma is investigated by numerical experiments, which are conducted in three typical fashions of the charged particle motions in electromagnetic fields, that is, cyclotron, drift and spiral drift. The origins of numerical error are identified, and then eliminated by correcting the cyclotron coefficient and half-accelerating coefficient of the finite difference scheme. The corrected algorithm not only improves the accuracy but also relaxes the time step condition for the simulation. It can increase the computation efficiency, especially for large-scale plasma devices with strong magnetic fields.  
        关键词：Plasma;Particle-in-cell simulation;Particle-moving;Time step   
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        发布时间：2021-03-12
      • ZHENG Liping XU Zijian ZHU Zhiyuan
        Issue 4, (2005)
        摘要：The nanotubes-rope is a large single crystal with the super-lattice structure, and it has been recently produced. Channeling of energetic charged particle in the nanotubes-rope exhibits a large diameter of the channels and weak de-channeling factors. In particle-beam physics field, the most intriguing applications of the nanotubes-rope- channeling are connected with the possibility of particle acceleration in high gradient accelerating fields, and with the possibility of construction of TeV colliders. This paper introduces the progress of applied studies.  
        关键词：Nanotubes;Channeling;Particle beam transmission   
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        发布时间：2021-03-12
      • CHEN Changchun1 YU Benhai1 LIU Jiangfeng1 CAO Jianqing2 ZHU Dezhang2 1
        Issue 4, (2005)
        摘要：How to characterize strain stored in SiGe epilayer is very vital to performance of SiGe devices. In this article, the principles of characterizing strain by RBS/C, HRXRD and Raman spectra were thoroughly described. Utilizing these technologies, strain status of the SiGe/Si films annealed at O2 /Ar ambience and the SiGe films grown on Ar+ implanted Si substrate was verified.  
        关键词：Strain;SiGe;RBS/C;HRXRD;Raman spectra   
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        发布时间：2021-03-12
      • SONG Yan XU Diandou PEI Jing OUYANG hong FENG Weiyue ZHANG Zhiyong MAO Xueying CHAI Zhifang
        Issue 4, (2005)
        摘要：Duolun, a small town of the Inner Mongolia, was selected as a sampling site to collect the local sand, TSP and PM2.5 during dust storm period in the spring of 2002. The elemental compositions of TSPs were measured by instrumental neutron activation analysis (INAA). The relationship between aerosols mass concentrations and meteorological conditions was studied, and the sources of TSP were also investigated by the correlation analysis, principle factor analysis and cluster analysis. The results showed that most elements in the Duolun’s TSPs came from the crust, whereas Br and Zn were from both anthropogenic activity and the crust. Since Cl exhibited an exceptional correlation with other elements, its existence could be attributed to the coal combustion.  
        关键词：Aerosol;Duolun;TSP;PM2.5;Instrumental neutron activation analysis (INAA)   
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        发布时间：2021-03-12
      • WAN Qian1 BAI Xinde2 LIU Xiaoyang1 1
        Issue 4, (2005)
        摘要：In order to investigate effect of ion implantation on corrosion resistance of zircaloy-4, N+ ions from an accelerator at doses ranging from 4×1014 to 1×1016 cm-2 were employed. Effect of N+ ion implantation on passive current density was studied by electrodynamic polarization measurements in a 0.5 mol/L H2SO4 solution at room temperature, and Transmission Electron Microscopy (TEM) was used to examine the change of microstructures in the implantated surface. The potentiodynamic tests showed that with the increase of implanted dose, surface passive current density decreased remarkably. The enhancement of corrosion resistance can be attributed to the amorphous phase formation in the implanted surface.  
        关键词：Zircaloy-4;N+ ion implantation;Corrosion resistance   
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        发布时间：2021-03-12
      • LIN Shu1 XUE Jianming1 LAI Jiangnan1 WEI Xionghui2 YAN Sha1 WANG Yugang1 1
        Issue 4, (2005)
        摘要：The molecular dynamics method was used to simulate the conformation changes of the secondary structure of peptide molecules induced by MeV proton irradiation. The simulation results indicate that the sample’s secondary structure was changed from α-helix to β-sheet gradually when the sample got energy higher than 3—5 eV from the incident ion, and the energy transfer mode has significant effect on final secondary structure of the sample. Besides, the proton irradiation causes manifold final secondary structures compared with that caused by raising the sample temperature.  
        关键词：Irradiation;Peptide;Secondary structure;Molecular dynamics   
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        发布时间：2021-03-12
      • WANG Siguang1,2 Bouwhuis M3 Holler Y4 Lenisa P5 Reggiani D5 Marukyan H6 Tait P7 YE Zhenyu8 YE Yunxiu8 1
        Issue 4, (2005)
        摘要：The magnetic flux density of the HERMES transverse polarized gas target changing with time and an automatic compensating system for stabilizing the strong magnetic field are described in this paper. The instability of magnetic field was found to be related to temperature change of the ferromagnetics. With the automatic system, the field in the monitoring point around 338.6 mT can be stabilized with the accuracy of ±0.004 mT(Stat) or ±0.045 mT (Syst) instead of ±0.45 mT without the system.  
        关键词：Polarized target;Magnetic flux density;Automatic compensating system   
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        发布时间：2021-03-12
      • DING Yinfeng ZHANG Zhibin KE Xuezhi ZHU Zhiyuan ZHU Dezhang WANG Zhenxia XU Hongjie
        Issue 4, (2005)
        摘要：The single carbon atom transporting through the single-walled carbon nanotube has been studied by molecular-dynamics (MD) simulation. We got different trajectories of the carbon atom by changing the input parameters. The simulation results indicate that the single carbon atom with low energy can transport through the carbon nanotube under some input conditions and result in different trajectories being straight line or “rosette” or circular.  
        关键词：Molecular-dynamics (MD) simulation;Single-walled carbon nanotube   
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        发布时间：2021-03-12
      • WANG Wenjin LUO Shunzhong HE Jiaheng WANG Guanquan YANG Yuqing WEI Hongyuan JIANG Shubin BING Wenzeng PU Manfei LIU Guoping
        Issue 4, (2005)
        摘要：On the basis of first synthesizing NEPTDD (2,2,9,9-tetramethyl-4,7-diaza-4-piperidinyl-ethyl- 1,10-decanedithiol), 188 Re-NEPTDD was prepared with SnCl2 as the reducing agent. The biodistribution of 188Re-NEPTDD injected through the tail vein into normal mice and that of lipiodol solution of 188Re-NEPTDD injected through the hepatic arteries into rabbits were studied, and the whole body imaging of rabbit after injecting the lipiodol solution was performed. The results showed that liver uptake of 188Re-NEPTDD was the highest and uptakes in other organs were relatively lower.  
        关键词：188Re;NEPTDD;Liver cancer;Biodistribution   
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        发布时间：2021-03-12
      • JI Hong YU Jianfang YUAN Zhibin ZHU Ruisen
        Issue 4, (2005)
        摘要：The diagnosis value of BAP and PSA in prostate cancer with bone metastases was studied and its application in the classification of bone metastases was investigated. 68 patients of prostate cancer undertook bone scintigraphy, and according to the result they were divided into 2 groups, with and without bone metastases. Furthermore the bone scan results were divided into 4 grades accoeding to Soloway standard. BAP and PSA tests were done in all patients and the correlation was calculated among various groups. Relation was studied between BAP and bone metastases grade. The result showed a positive correlation between BAP and bone metastases grade (r=1.1083, P<0.01), while PSA only showed significant difference between M0 and M1—M3. The best value of BAP for prostate cancer metastases is 25—35 u/L, because the positive predictive value was 96.6% and negative predictive value was 75%. When using BAP in 35 u/L and PSA in 20 ng/mL, the positive predictive value was 97.5%. When using BAP in 25 u/L and PSA in 20 ng/mL, the negative predictive value was 73.9%. We can conclude that BAP is more effective in predicting bone metastases in prostate cancer than PSA, and has more diagnosis value in the grading of metastases. And the combination of BAP and PSA can increase the positive predictive value of bone metastases of prostate cancer.  
        关键词：Prostate cancer;BAP;PSA;Bone metastases   
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        发布时间：2021-03-12
      • WANG Nanping1 XIONG Shengqing2 ZHOU Xihua2 LIU Shaomin1 CHENG Yexun1 1
        Issue 4, (2005)
        摘要：ion peak responding to 137Cs sources using airborne gamma-ray spectrometer (GR-820) in the experiment. The data were processed and have been interpreted by the energy band and ratio of VMMGC . We discussed the validity of these two methods. The results are of great significance for the research on airborne survey for nuclear emergency and spectral data deconvolution.  
        关键词：Airborne gamma ray spectrometry;137Cs source;Radiation environment estimation   
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        发布时间：2021-03-12
      • WANG Xinggong LUO Yisheng ZHANG Hong ZHOU Yu GUO Yong
        Issue 4, (2005)
        摘要：The chemical etching condition of CR-39 solid state nuclear track detector for neutron measurement was optimized by experiment. According to the literature and experience, three factors, i.e. solution concentration, etching time and etching temperature, mainly affect the etching results and have been tested by orthogonal design. A series of experiments were followed to reinforce and verify the orthogonal design. It is shown that under the etching condition of 5.5 mol/L NaOH-70℃-24 h the nuclear tracks generated by neutrons on CR-39 solid state nuclear track detector can be etched at best etching efficiency. The tracks have clear profile and appropriate size, and are therefore easy to be identified.  
        关键词：CR-39 solid state nuclear track detector;Orthogonal design;Chemical etching;Track   
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        发布时间：2021-03-12
      • SHAO Xin’an ZHUANG Ming BAI Hongyu JIN Yibin
        Issue 4, (2005)
        摘要：EAST is an advanced device for the study of nuclear fusion around the world. The cryogenic system is one of primary subsystems of EAST. The cryogenic control system is based on DCS, which has high stability and expansibility. And every part of the control system is independent and performs parellelly. The paper describes the cryogenic-control system of EAST and flow design during the cooldown, steady-state operation and quench situation.  
        关键词：Experimental advanced superconducting tokamak (EAST);Cryogenic system;Nuclear fusion;DCS   
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        发布时间：2021-03-12
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