最新刊期
      卷 0 ， 期 0 ， 2020
      • WEI Xun1,2 XIAO Tiqiao1 CHEN Min1 LIU Lixiang1 LUO Yuyu1 DU Guohao1 XU Hongjie1 1
        Issue 12, (2005)
        摘要：The microscopic morphology of plant cells and their ergastic substances is an important standard for the identification of Chinese traditional medicine. We have developed a new method, X-ray phase-contrast imaging (XPCI) based on the microfocus X-ray tube, to explore microstructures of Chinese herbal medicine. The results indicate that XPCI is capable of distinguishing the structures commonly used in the identification. Non-destructive detection and high sensibility are counted among the major advantages of XPCI. The possibility of future applications of XPCI in the field of medicine identification is discussed.  
        关键词：Phase-contrast imaging;Microfocus X-ray tube;Chinese traditional medicine;Microscopic identification   
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        发布时间：2021-03-12
      • ZOU Chongwen SUN Bai WANG Guodong ZHANG Wenhua XU Pengshou XU Faqiang PAN Haibin
        Issue 12, (2005)
        摘要：The determination of flux, the calibration of photon energy and the angle-resolved photoemission experiment were reported in this paper. During the process of commissioning of the station the photon flux was measured by photo-electronic diode (IRD AXUV-100) and the response curves for three different gratings were obtained. Photon energies of the whole range were calibrated using the second harmonic for high energies and the fermi edge of gold for low energies. And the resolution of the system was also calculated. At last the alignment of the electron detector was performed by the synchrotron radiation and laser beam and the ARPES for copper crystal was obtained to test the whole system. The results show that the surface station in the NSRL can satisfy the users for their ARPES experiments.  
        关键词：Beamline;Synchrotron radiation;Photon flux;Second harmonic;Energy dispersion   
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        发布时间：2021-03-12
      • ZHANG Zhong1 WANG Zhanshan1 WU Wenjuan1 WANG Hongchang1 WANG Fengli1 GU Chunshi1 QIN Shuji1 CHEN Lingyan1 HUA Wei2 HUANG Yuying2 1
        Issue 12, (2005)
        摘要：In this paper, the W/B4C periodic multilayer films are designed, and their optical characters （reflectivity） are calculated based on the Fresnel formula connected with the Nevot-Croce model. The W/B4C X-ray periodic multilayer films with small period （d=4.2nm） are fabricated by the high vacuum magnetron sputtering technology, and its structure was measured by D1 XRD from BEDE Company, UK. On the Beijing Synchrotron Radiation X-ray Fluorescence Analysis Spectroscopy （XFAS） beam line, the W/B4C multilayer film was used as the monochromator instead of the crystal for the XFAS experiment. The experiment results demonstrated that the quasi-monochromatic X-ray beam can be obtained by using such period multilayer film. The EFAS experiment of standard sample Nist612 proves that the tiny content element （about 50 μg/g） can be probed by the new XFAS optical setup based on W/B4C periodic multilayer film.  
        关键词：Multilayer film;Monochromator;Synchrotron radiation;X-ray fluorescence analysis   
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        发布时间：2021-03-12
      • WAN Tianmin1,2 LI Xiaolin1 YUE Weisheng1 LI Yan1 ZHANG Guilin1 1
        Issue 12, (2005)
        摘要：The micro-PIXE spectra of aerosol particles from different emitter sources have different characteristic peaks, due to different chemical compositions of these particles. Thus, the micro-PIXE spectra can be considered as fingerprints of the aerosol particles. In order to identify the sources of aerosol particles, a pattern recognition method was developed and the method was examined and the result shows that the method is reliable and efficient.  
        关键词：Aerosol particle;Spectrum feature;PIXE;Pattern recognition   
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        发布时间：2021-03-12
      • GUO Jianting LI Yufang XIONG Liangyue
        Issue 12, (2005)
        摘要：The measurement of positron annihilation lifetime of Zr containing Ni3Al showed that the lifetime parameters of positron in Ni3Al (Zr) alloys cooled in air after homogenized at 1150℃ decreased with an increase of Zr content, which indicated that Zr atoms diffused to grain boundaries (GBs) and segregated at GBs. When alloys were cooled in water, the lifetime parameters almost kept invariable with the increase of Zr concentration, meaning that Zr atoms couldn’t diffuse to GBs because of the rapid cooling speed, but existed in Ni3A as solid solution.  
        关键词：Positron annihilation;Ni3Al;Zr;Air-cooling;Water-cooling;Diffusion   
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        发布时间：2021-03-12
      • QUAN Lin ZHU Guangning HAO Jinlin TU Jing ZHANG Ying JIANG Xinbiao CHEN Wei YUAN Jianxin Zhao Zhumin
        Issue 12, (2005)
        摘要：The Monte Carlo code MCNP/4B and Matlab software were used to calculate the dose field of a radioactive samples depository and to determine the shield thickness for security. The calculated dose contour is available for real samples depositary.  
        关键词：γ-ray;Monte Carlo method;Shielding;Dose contour   
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        发布时间：2021-03-12
      • WU Xinmin1 LIU Qingcheng1 YANG Yaxin1,2 ZHENG Yongming1 ZHANG Baosong1 1
        Issue 12, (2005)
        摘要：This work deals with the determination of natural radioactivity of soil in Guangdong Province Xiazhuang granite uranium ore field by using a γ-ray spectrometer. The activity concentrations for 226Ra, 232Th and 40K obtained were 112 (from 40.2 to 442), 71.5 (from 32.6 to 88.1), and 672 (from 442 to 913) Bq/kg, respectively. Compared with the average value of countrywide and worldwide, the activity concentration of 226Ra was obviously greater than them. To assess the radiological hazard of the natural radioactivity in soil, the absorbed dose rate and annual effective dose rate were calculated. The results show that there is a normal level of natural radioactivity of soil in the Xiazhuang granite uranium ore field.  
        关键词：Natural radioactivity;γ-ray spectrum analysis;Soil;Environment   
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        发布时间：2021-03-12
      • ZHU Guanghua1 WANG Guangfu2 ZHANG Renjian3 1
        Issue 12, (2005)
        摘要：The concentration of H element is measured using PESA method, the total mass is determined by PTEL analysis and the concentrations for about 20 elements are obtained with PIXE for the atmospheric aerosol samples collected on mylar or quartz film. It is shown that the IBA (ion beam analysis) is an important and powerful tool for the study of atmospheric aerosol.  
        关键词：PIXE;PTEL;PESA;Atmospheric aerosol   
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        发布时间：2021-03-12
      • LU Wu YU Xuefeng REN Diyuan E RKIN GUO Qi
        Issue 12, (2005)
        摘要：Radiation effects and ageing characteristics were investigated for different types of domestic and/or imported bipolar junction transistors with five dose rates ranging from 100 to 0.002 rad(Si)/s at the same total dose. The results showed that the enhanced low-dose-rate sensitivity (ELDRS) exists in either domestic or imported bipolar transistors, and the NPN transistors are more obvious than PNP ones. Possible mechanism for the effect was discussed.  
        关键词：Bipolar transistor;60Co γ irradiation;Dose rate effects;Ageing   
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        发布时间：2021-03-12
      • YANG Min1,2 WANG Guangji1 XIANG Jingde2 XU Yuping2 WANG Songpei2 LI Xiaomin2 PAN Shangren2 XU Xijie2 YE Wencai3 1
        Issue 12, (2005)
        摘要：The purpose of this work is to study the preparation and pharmacokinetics in mice of tritium-labeled 23-hydroxylbetulinic acid (3H-23-HBA). 3H-23-HBA was synthesized by oxidation with manganese and deoxidization with tritium-labelled sodium borohydride. The purity and stability of 3H-23-HBA were evaluated by HPLC and TLC, and the dynamic distribution in ICR mice and liver cancer HepA tumor-bearing mice were studied. The results showed that the radiochemical purity was over 95% and the specific radioactivity was 3.33×105 Bq/μg (23-HBA); 3H-23-HBA in tetrahydrofuran was stable at –20℃; 3H-23-HBA cleared slowly in blood (MRT=32.68 h) and about 60% of the total radioactivity in plasma was contributed by 23-HBA; and 3H-23-HBA was concentrated in gallbladder, liver and small intestine. In tumor-bearing mice, the uptakes of lung and gallbladder were higher than the normal mice, especially in the gallbladder. At 8 h post intravenous injection, the uptake of gallbladder was still as high as 106.89%±47.4%ID/g organ. The tumor-to-muscle ratio was about 2. The purity of 3H-23-HBA is high and 3H-23-HBA is stable. So 3H-23-HBA appears to be fit for the pharmacokinetic study of 23-HBA.  
        关键词：23-hydroxylbetulinic acid;Tritium(3H);Biodistribution;Tumor   
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        发布时间：2021-03-12
      • XIE Bo LIU Yunnu HOU Jianping GUAN Rui WENG Kuiping REN Xingbi
        Issue 12, (2005)
        摘要：A gas chromatographic concentrating system has been built for D-H mixture gas. The abundance ratio of D/H reaches 30% from 0.1%, and more than 90% from 10%. The ratio is less than 10-5 in the depleted gas. The treatment capacity of this apparatus reaches 40 m3/d.  
        关键词：Hydrogen isotopes;Gas chromatograph;Separation;Enrichment   
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        发布时间：2021-03-12
      • ZHOU Rifeng ZHANG Ping ZHANG Zehong
        Issue 12, (2005)
        摘要：The signal-noise ratio of detectors and the image quality will be affected by the detector cross-talk noise. In this paper we use EGSnrc to research the cross-talk noise in the CdWO4 detector module, and analyze various factors which can bring about the cross-talk noise. The work will facilitate the selection of detector module and offer some parameters for the correction of cross-talk noise with software.  
        关键词：EGSnrc code;X-ray detectors;Cross-talk noise;X-ray   
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        发布时间：2021-03-12
      • BAI Yun YING Yangjun ZHANG Ben’ai PENG Xianjue
        Issue 12, (2005)
        摘要：In this paper, the feasibility of measuring α eigenvalue for a subcritical reactor in the present experiment condition by the pulsed neutron method is discussed. A new experiment method of measuring γ intensity in the subcritical system to gain α eigenvalue is raised and the validity of this method has been proved. The limitation of using the DPF DD and DPF DT neutron source is also discussed.  
        关键词：Subcriticality;Pulsed source;Time multiplication constant   
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        发布时间：2021-03-12
      • LU Xiang ZHAO Shujun LI Suxiao ZHANG Lei
        Issue 12, (2005)
        摘要：To make all PMTs’ gains identical through auto-adjustment is important for ensuring the PET imaging quality. The response output depends on the light collecting efficiency in the position where the event happens and the energy of light quantum. Light collecting efficiency of PMT in the position is in proportion to solid angle of the PMT at the position. The adjusting value was calculated by the algorithm described in the paper. The result showed that the algorithm was effective in practice.  
        关键词：PET;Detector;PMT;Gain adjustment   
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        发布时间：2021-03-12
      • YU Tao1 SHI Yongqian2 LUO Zhanglin2 OU Bingcai1 QIN Huan1 1
        Issue 12, (2005)
        摘要：In this paper a rapid micro-current amplifier used to measure the Keff of the sub-critical reactor of accelerator driven system(ADS) was introduced, which is based on the noise analysis method used in the stochastic neutron and photon transport theory, and a micro-current source was designed. At last the circuit was debugged by the Protel tool and the test result was given.  
        关键词：Noise analysis method;Accelerator driven system(ADS);Sub-critical reactor;Micro-current amplifier   
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        发布时间：2021-03-12
      • CHENG Daowen1,2 GU Deshan1 YI Jie1 LIU Linmao1 1
        Issue 12, (2005)
        摘要：Although pulse fast thermal neutron analysis technology has many technical advantages, it is difficult to meet the requirement of precision for industrial application because of the error brought by data processing. Therefore, reducing the error is the key for this technology. We have found a better way of data processing, which make the measurement precision fulfill the requirement of coal industry, and have developed a pulse neutron coal fast analyzer.  
        关键词：Measurement precision;Smoothing;Peak position;Characteristic peak area   
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        发布时间：2021-03-12
      • LI Xiaoyan 1,2 WANG Yan 1,2 ZHENG Baoshan 1 WANG Xue 1 1
        Issue 12, (2005)
        摘要：Using Model 1027 continuous radon monitor, a test of reducing radon level by ventilation in underground space was done. Four different types of ventilation, i.e. by air pump (P), by air intake blower (B), by air pump and air intake blower simultaneously (PBS), and by air pump and air intake blower in turn (PBT), were examined. We found that efficiency of PBS is the highest among these ventilation types. Having ventilated the underground space with PBS for 1, 2 or 3 hours in three different days, and having observed the radon concentration change in the following 24 hours, we can conclude that it is safe for people to stay there during the eight working hours if the underground space is ventilated for 2 hours everyday in the morning.  
        关键词：Radon;Underground space;Ventilation   
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        发布时间：2021-03-12
      • DONG Jinquan1 YUAN Wanming1 WANG Shicheng1 FAN Qicheng2 1
        Issue 12, (2005)
        摘要：Like fission-track dating, alpha-recoil track (ART) dating is based on the accumulation of nuclear particles that are released from natural radioactivity and produce etchable tracks in solids. ARTs are formed during the alpha-decay of uranium and thorium as well as of their daughter nuclei. When emitting an alpha-particle, the heavy remaining nucleus recoils 30—40 nm, leaving behind a trail of radiation damage. Through etching the ART tracks become visible with the aid of an interference phase-contrast microscope. Under the presupposition that all tracks are preserved since the formation of a sample their total number is a measure of the sample’s age. The research for etching model is to accurately determine ART volume density, i.e., the number of ARTs per unit volume. The volume density of many dots in many layers may be determined on a sample using this etching model, and as decreasing the error and increasing the accuracy.  
        关键词：Alpha-recoil track;Dating;Etching model;Biotite   
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        发布时间：2021-03-12
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