最新刊期
      卷 0 ， 期 0 ， 2020
      • ZHAO Yujie1 SUN Yue 1 KONG Ruihong1 DU Qi1 FANG Wenzheng1 SUN Jinda 1 SHAN Xiaobin1 LIU Fuyi1 SHENG Liusi1 WANG Zhenya2 1
        Vol. 32, Issue 8, (2009)
        摘要：A differentially pumped rare gas absorption cell has been developed to suppress high order harmonic radiation on the atomic and molecule physics beamline at National Synchrotron Radiation Laboratory. The gas filter system contained a gas absorption cell and two differential pumping systems considering the present status of atomic and molecule physics beamline. The adjustment results indicated that the pressure of Ar in the gas cell should be lower than 1.333×103 Pa while preserving the beamline vacuum to <4.933×10-7 Pa. When the pressure of Ar in the gas absorption cell was set to 1.241×103 Pa,the filter factor of gas filter system was better than 99.975%. Generally speaking,the adjustment results of the gas filter system were in agreement with the design parameters and could meet the experimental requirement very well.  
        关键词：Synchrotron radiation;Gas filter;High harmonic radiation;Ultrahigh vacuum   
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        发布时间：2021-03-12
      • QIN Hongliang LI Ming SHI Hong
        Vol. 32, Issue 8, (2009)
        摘要：It was observed that the focused X-ray spots on the sample had an obvious shift and defocus as the beam currents decreased during the same run cycle at small angle X-ray scattering station,Beijing Synchrotron Radiation Facility (BSRF). A single bent crystal monochromator with a special geometry is proposed to solve those problems,and it meets the experimental requirements of small angle X-ray scattering station.  
        关键词：Bent crystal monochromator;Bragg diffraction;Small angle X-ray scattering;Synchrotron radiation   
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        发布时间：2021-03-12
      • HE Junyong ZHOU Qiaogen QIAN Zhenmei LI Yu
        Vol. 32, Issue 8, (2009)
        摘要：EPU100 at SSRF is an APPLE-II type variable elliptically polarized undulator. The magnet structure consists of four magnet arrays with standard Halbach-type. Two arrays at one diagonal can move longitudinally on the rails so that different magnetic field distributions are shaped to meet the requirements of varieties of polarization modes. With the longitudinal moving of the magnet arrays,the magnitude and the direction of the magnetic forces changed and the distortions of the backing beams both in vertical and horizontal directions will be different. In this paper we analyze and calculate the horizontal displacement of the beams in different gaps and phase shifts to create an equivalent beam mechanical model which is consistent with the measured deformations.  
        关键词：SSRF;EPU;Backing beam displacement;FEA   
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        发布时间：2021-03-12
      • LIAO Shuqing1 CHENG Cheng2 ZHENG Shuxin2 LIN Yuzheng2 JING Xiaobing1 ZHANG Kaizhi1 SHI Jingshui1 1
        Vol. 32, Issue 8, (2009)
        摘要：A new method of electron beam energy measurement by solenoid-induced beam rotation (SIBR) has been developed for measuring electron beam energy at the exit of the Mini-LIA,a compact electron linac developed jointly by CAEP and Tsinghua University. A planar beam formed by an 8 mm× 0.2 mm slit passes a magnetic solenoid,and measuring the solenoid-induced beam rotation on a YAG screen enables us to calculate the beam energy. The basic theory of SIBR and experiment of single-pulse electron beam energy measurement is presented in this paper. The beam energy at the exit of Mini-LIA can be determined by calculating the beam rotation angle in a solenoid. The result is in good agreement with that obtained from the acceleration voltage measurement. Finally,the error analysis is discussed,together with method characteristic of SIBR,and appropriate range for SIBR application.  
        关键词：Mini-LIA;Electron beam energy;Rotation beam   
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        发布时间：2021-03-12
      • LE Renchang WANG Ping DONG Xuefeng HE Zhijie YE Quanyi HONG Jinquan ZHOU Baoyong CHEN Jiandi
        Vol. 32, Issue 8, (2009)
        摘要：In this paper,a method for total-count γ-ray measurement of radon in activated carbon is presented,with correction for decay and time delay for the measurement based on the decay of radon and its progeny. Simulation of the total-counts of γ-rays from radon-absorbed activated carbon was performed. The results show that the time-dependent calculated curve of γ-ray total-counts agrees well with the measured one. The front part of the curve,where the counts increase first and decrease later,is the time delay for the measurement. The duration of delayed measurement is closely related to the duration of radon absorbed by activated carbon,but it has nothing to do with the radon concentration. And the longer the adsorption duration,the shorter is the time delay. Then,the counts follow the function of e-0.000125 t,which is also independent of the concentration of radon absorbed by activated carbon.  
        关键词：Radon;Activated carbon;Delay duration;γ-rays total-counts   
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        发布时间：2021-03-12
      • WANG Guanquan YANG Yuqing ZHANG Huaming HU Rui WEI Hongyuan XIONG Xiaoling GAO Hui
        Vol. 32, Issue 8, (2009)
        摘要：Two kinds of silicon PN junction device were made for irradiation by titanium tritide sources of different activities,and the electrical outputs were measured and analyzed. The results showed that the Isc (short circuit current),Voc (open circuit voltage) and Pmax(maximum power output) increased with the tritium content,but the increases were not proportional to the tritium content. The electrical properties were affected by doping concentration and junction depth of the devices.  
        关键词：PN junction;Tritium-titanium source;Betavoltaic isotope battery;Electrical properties   
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        发布时间：2021-03-12
      • WANG Shaofeng HT-7 Nuclear Research Team
        Vol. 32, Issue 8, (2009)
        摘要：In tokamak plasmas,under the influence of longitudinal electric field the initial Maxwellian electron distribution function begins to grow a runaway tail. Above a certain threshold,instabilities can be excited. In this paper,we present the study of anomalous Doppler instability of runaway electrons in ohmic discharges on the HT-7 tokamak. The conditions of anomalous Doppler instability were analyzed. It was found that the instability is characterized by relaxations in the electron cyclotron emission due to relativistic anomalous Doppler instability which transfers energy from parallel to perpendicular motion. And the synchrotron radiation of the runaway electrons increased because of the increasing pitch angle. Therefore,energy of the runaway electrons was limited.  
        关键词：Tokamak;Runaway electron;Cyclotron frequency;Anomalous Doppler instability   
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        发布时间：2021-03-12
      • LIU Weibo1 GU Deshan2 LI Mingjuan3 GAO Kun1 1
        Vol. 32, Issue 8, (2009)
        摘要：Based on the ion source discharging experiment in NT50 neutron generator,effect of magnetic field variation in Penning ion source on discharge current is studied. The relation curves of discharge current and changing magnetic fields are obtained. The data are analyzed to discover the role of ion source discharge. The prime working state and parameters of the ion source were determined to improve performance of the neutron generator.  
        关键词：NT50 Neutron Generator;Penning ion source;Changing magnetic fields;Discharge characteristic   
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        发布时间：2021-03-12
      • ZHANG Fengbao1 YANG Mingyi2 WANG Guangqian1 1
        Vol. 32, Issue 8, (2009)
        摘要：7Be is a natural cosmogenic radionuclide with a relative short half-life of 53.3 d. It is mainly produced in the upper atmosphere as the product of the spallation of oxygen and nitrogen nuclei by cosmic rays. Through continuously wet and dry deposition,7Be is absorbed strongly by soil particle once it deposits onto the earth’s surface. Therefore,it has been regarded as a valuable tracer to document short-term and individual-event soil erosion in recent years. Moreover,It also can be combined with other radionuclides (such as 137Cs,210Pb,226Ra) to study soil erosion process. This paper reviewed the previous researches results,including the principle of using 7Be measurement to document soil erosion and the conversion models of soil erosion rates from 7Be data. The problems,suggestions and prospects for further application of 7Be measurement were also discussed.  
        关键词：Soil erosion;Tracing technique;7Be   
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        发布时间：2021-03-12
      • ZHU Jian1,2 CHU Jingyu1 WANG Xuetao2 GUAN Qingfeng2 LIANG Liang3 1
        Vol. 32, Issue 8, (2009)
        摘要：[111]-and [001]-Si single crystals were bombarded by high current pulsed electron beam (HCPEB) in energy density of 3?4 J/cm2. Surface morphologies of the irradiated Si samples were investigated with scanning electron microprobe. The results show that many craters were formed on the surface by 3 J/cm2 HCPEB. At 4 J/cm2 energy density,microcracks occurred on the bombarded surface. The shape of the microcracks was closely related to the crystal orientation of the bombarded sample. Under the HCPEB bombardment,severe plastic deformation occurred on the irradiated surface. Deformed shear bands were presented on the surface of [111]-Si,whereas the microbands are the dominating deformed microstructures on the bombarded surface of [001]-Si. In addition,a mass of micropores below 100 nm formed on the deformed regions,which provides a possibility of fabricating the surface porous materials.  
        关键词：HCPEB;Si single crystal;Deformed shear band;Micropore;Crater   
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        发布时间：2021-03-12
      • WANG Shilian1,2 BAI Tao3 SHI Quanlin3 ZHANG Xiaolin3 FAN Jinlong3 LI Qi 2 LIU Jie3 LU Jiachun3 CHANG Yongfu3 1
        Vol. 32, Issue 8, (2009)
        摘要：Solutions of enriched 235U were irradiated in thermal-neutron flux produced by a pulsed reactor,and 94Y and 95Y were separated chemically from the fission products immediately. The purified solution of 94Y and 95Y is diluted about ten times in sequence to three concentration solutions. Three sources were prepared with the solutions. The sources are measured,from the lower concentration to higher one,with a well-type HPGe detector to determine the half-life of 94Y and 95Y. The determined half-life results are (19.16±0.05) min and (10.35±0.04) min for94Y and 95Y,respectively.  
        关键词：Half-life;94Y;95Y;Well-type HPGe;Mass normalization   
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        发布时间：2021-03-12
      • TANG Ganghua1,2 TANG Xiaolan3 WANG Mingfang2 LI Baoyuan2 LIANG Mingquan2 WANG Quanshi21
        Vol. 32, Issue 8, (2009)
        摘要：Via one-pot procedure in a TRACERlab FXF-N synthesizer,the fully automated synthesis of 9-(4-[18F]fluoro-3-hydroxymethylbutyl)guanine (18F-FHBG) as a reporter gene expression PET imaging agent is described in this paper. 18F-FHBG was produced via two-step reactions including nucleophilic fluorination of the precursor molecule N2-monomethoxy trityl-9-[(4-tosyl)-3-monomethoxytrityl-methylbutyl] guanine with 18F-fluoride and subsequent hydrolysis of the intermediate with protecting group with 1 mol/L HCl at the same reaction vessel,and purification with SEP-PAK C18 cartridge. The decay-uncorrected radiochemical yield of 18F-FHBG was 7%–12% (n>10),with radiochemical purity of over 95%,and the total synthesis time was less than 40 min. One-pot synthesis procedure combined with SEP-PAK purification is easy to operate and can be used to fully automated synthesis of 18F-FHBG at an automated system such as a TRACERlab FXF-N synthesizer.  
        关键词：Enzyme reporter gene;18F-FHBG;Automated synthesis   
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        发布时间：2021-03-12
      • SONG Shaoli1,2 LIU Jianjun1,2 WANG Zhaohai3 WAN Liangrong1,2 SUN Xiaoguang1,2 HUANG Gang1,2 1
        Vol. 32, Issue 8, (2009)
        摘要：This study is to explore the feasibility of using 18F-FDG PET/CT as an in vivo individual chemosensitivity testing method. Forty-two VX2 rabbits bearing a total of 84 tumors were randomized into treatment group (n=32) and control group (n=10). 18F-FDG PET/CT was performed the day before intravenous administration of cisplatin (4 mg/kg) and at 95?100 min (Day 0),Day 1,Day 7,and Day 14 afterward. The control group,without cisplatin administration,received the 18F-FDG PET/CT imaging at the same time points. Maximum standardized uptake value (SUV) was analyzed. The animals on Day 7 with a tumor volume of at least twice as larger than Day 0,were regarded as the sensitive group (SG),while the others the insensitive group (ISG). The results showed that a significant difference (P<0.05) in SUV on Day 0 between SG and ISG,with SUV decrease rate of (?48.96±12.27)%,(21.26±18.26)% and (7.16±13.47)% for SG,ISG and the control,respectively. No significant difference in tumor volume was found among the three groups pre-therapy and on Day 0 and Day 1. On Day 7,however,the tumor volume with SG was smaller than with ISG,in a significant difference of P<0.05,while no significant difference was seen between ISG and the control on Day 7. On Day 14,no significant difference was observed among the tumor volume of the three groups (P>0.05). On Day 7 and Day 14,significant differences were seen in tumor necrosis rate in SG and ISG (P<0.05),but no significant differences were seen between ISG and the control. Paraffin section stained with haema-toxylin and eosin of sections obtained at different time showed that the number of viable tumor cells in sensitive group diminished than ISG and the control,and inflammation and necrotic cells were increased on Day 7 and Day 14. The study showed that 18F-FDG PET/CT can be used as an in vivo chemosensitivity testing method. According to the decrease rate when cisplatin adminstration,PET can early in vivo sensitively differentiate the sensitive and insensitive tumors.  
        关键词：VX2 tumor model;18F-fluorodeoxyglucose(18F-FDG);Positron emission tomography/computed tomo-graphy(PET/CT);Chemosensitivity;In vivo;Monitor   
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        发布时间：2021-03-12
      • YANG Xiaochun1 SHEN Yongmei2 SHI Yizhen2 XIE Xiaofang2 1
        Vol. 32, Issue 8, (2009)
        摘要：Nude mice bearing human B cell lymphoma were divided into four groups:control,Fab antibody,single injection and duplication injection. Radioimmunoimages were taken after injection with 131I-labeled Fab antibody through tail vein. The cancer-bearing mice were detected by MRI combined with microscopy coil every 5 days,and tumor sizes were measured. On the 25th day after injection,the tumors were taken out for pathology and apoptosis analysis by flow cytometry (FCM) and TEM,respectively. The results of ECT showed that radioactive nuclide enriched in the area of the tumor obviously at 8 hour after injection,and the mass could be displayed clearly. The growth suppression effect could be displayed in 5 days in Fab antibody group and the apoptotic rate was (2.48±0.6)%. The growth suppression effect was obvious in the prophase in single injection group,and the plateau phase could be seen in the tumor growth curve,with the apoptotic rate of (10.67±1.6)%. The growth suppression effect was more obvious in duplication injection group and the local tissues of tumor necrosed and fallen off,with the apoptotic rate of (14.00±1.9)%. The pathologic results showed tissue necroses in both single group and duplication injection group. The MRI image conformed to the results of pathology,and could provide accurate pathology information by contrast medium enhancement. 131I labeled Fab antibody against B cell lymphoma can image the tumor early through ECT,locate the tumor mass accurately and suppress tumor growth through the mechanism of apoptosis and cell death. It can be a kind of potential and effective bioengineering medicine to treat the tumor in the area of radioimmunotherapy. Large high field MRI can provide effective,atraumatic and dynamic detection to the little animal model,and have wide application for little animal model.  
        关键词：Lymphoma;B-cell;Antibodies;Iodine-131;Radioimmunotreatment;Magnetic resonance imaging   
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        发布时间：2021-03-12
      • XU Mei KUANG Chunxiang
        Vol. 32, Issue 8, (2009)
        摘要：Increasing attention has been focused on synthesis radiopharmaceuticals for positron emission tomography (PET). The recent years witnessed applications of click chemistry to PET radiopharmaceutical synthesis,because of its distinctive advantages including high speed,yield and stereospecificity under mild conditions. Synthesis of 18F-labeled and 11C-labeled radiopharmaceuticals and intermediates via click chemistry are reviewed. The future trend of click chemistry for the synthesis of PET radiopharmaceutical is prospected.  
        关键词：PET radiopharmaceutical;Click chemistry;Radiosynthesis;Copper-catalyzed   
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        发布时间：2021-03-12
      • LIU Xiaohua1 AN Qi1 LIU Shubin1 SU Hong2,3 ZHAN Wenlong2,3 1
        Vol. 32, Issue 8, (2009)
        摘要：Multi-wire drift chamber at external target experiment in HIRFL-CSR measures drift time of charged particles to obtain the track information. A 64-channel TDC module hosting high density connectors and high performance TDC chips (HPTDC) are used to perform the time digitization. Data of the module is transferred to computer through PXI bus.The test results show that a 100 ps resolution has been achieved.  
        关键词：HPTDC;INL;DNL;RMS time resolution   
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        发布时间：2021-03-12
      • JIN Qing QI Yujin ZHAO Cuilan ZHANG Mengjiao
        Vol. 32, Issue 8, (2009)
        摘要：A novel trigger circuit of signal sampling was designed for developing modularized high-resolution compact gamma camera. The design idea is to transfer the peak position detection of the signal of gamma camera into high-precision measurement of pole-zero timing. The unipolar input signal is shaped by a full-pass filter into a bipolar signal. The peak position of signal is determined by measuring the polar-zero position while a trigger pulse is generated corresponding to the peak position. The width and delay of the trigger pulse are adjustable by mono-stable trigger circuits. The pulse is used to trigger the data acquisition system. The experimental results show that the performance of the trigger circuit is stable and reliable. It can provide a high-precision determination of the peak position and well meet the requirements of the high-resolution compact gamma camera.  
        关键词：Modular gamma camera;Trigger circuit;Peak detection;Zero crossing discriminator   
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        发布时间：2021-03-12
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