最新刊期
      卷 0 ， 期 0 ， 2020
      • JI Te GE Min WANG Wenfeng ZHANG Zengyan YU Xiaohan XU Hongjie
        Issue 8, (2006)
        摘要：The terahertz time-domain spectroscopy (THz-TDS) measurements on some members of carbon family, including amorphous carbon, Q60, graphite powder and carbon nanotubes have been performed, and absorption coefficients and refractive indices of these samples have been calculated. It has been shown that the THz absorptions of graphite and carbon nanotubes are much higher than that of amorphous carbon and Qo. The experimental result has been qualitatively explained by analysing their collective vibration modes.  
        关键词：THz-TDS;Absorption coefficient;Refractive index;Carbon material   
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        发布时间：2021-03-12
      • HU Wei ZHU Xikai HE Tongqi CHAO Shuxuan ZHANG Yutian
        Issue 8, (2006)
        摘要：The core tube of the scanning magnet is one of the key components for the beam extraction in high power electron accelerators. The paper describes the material selection, structure design, and machining process of the core tube. The shape and position of ribs on the core tube are optimized by using FEA software, and the welding technology for the core tube is specified, which ensure that the core tube can run in good condition when the high power electron accelerator is used for desulfation of flue gas.  
        关键词：Core tube;Scanning magnet;Electron accelerator   
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        发布时间：2021-03-12
      • CHEN Yonglin JIANG Dikui XIAO Tiqiao ZHU Xikai GUO Panlin YAN Heping WANG Naxiu SHENG Shugang
        Issue 8, (2006)
        摘要：A collimating telescope was used to make alignment of the Shanghai Electron Beam Ion Trap (EBIT) facility. To get precise result, high precision adjustments and special tools were designed and adopted. Several experiments have been made to test the reliability and precision of these adjustments and tools. After careful alignment, the EBIT can be operated stably with an electron beam of 100kV/110mA. It was shown that the method of alignment is successful.  
        关键词：Shanghai EBIT facility;Collimating telescope;Alignment   
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        发布时间：2021-03-12
      • YANG Shiming GONG Guanghua SHAO Beibei LI Jin
        Issue 8, (2006)
        摘要：The PIN photodiode is often used in dose or dose rate monitoring of X or y rays. Comparing with ionization chamber, it has the advantages of small volume, high sensitivity, low cost and no need of high voltage. Unlike counter tubes and scintillation detectors, its current output mode makes it have no dead time in the pulse-mode radiation field. However, the radiation damage by high total dose of exposure affects its performance. The characteristics of PIN photodiode including sensitivity, bias voltage, temperature coefficient, radiation damage and annealing are studied by experiments. Also, a method to deal with the output current is introduced.  
        关键词：PIN photodiode;Total dose;Dark current;Radiation damage;Dose rate   
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        发布时间：2021-03-12
      • HAN Jun WANG Heyi GU Mei
        Issue 8, (2006)
        摘要：The nano-meter stainless steel powder was first deposited on porous stainless steel by paste coating process, and a micro-porous membrane with an average pore size of 200nm was obtained, its permeability for dry air was about 200cm3·cm-2·min-1 at room temperature and a pressure difference of 0.1 MPa. The micro-porous steel membrane was further coated with TiO2 membrane by Sol-Get method, and a composite membrane with pore size of 100nm was achieved, its permeability for dry air was about 100cm3·cm-2·min-1 at room temperature and 0.1 MPa. Then this membrane was electroless-plated to deposit Pd-Ag alloy,and a membrane with smooth surface and better alloy formation was obtained. The permeability of H2 for the Pd-Ag alloy membrane was about 35cm3·cm-2·min-1 under a normal condition of 0.1 MPa and 300℃, and the separation factor between H2 and He was about 500.  
        关键词：Hydrogen;Purification;Porous stainless steel;Sol-Gel method;Electroless-plating   
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        发布时间：2021-03-12
      • TANG Ganghua TANG Xiaolan WANG Mingfang LUO Lei GAN Manquan
        Issue 8, (2006)
        摘要：The fully automated synthesis of tumor imaging agents 18F-fluoroacetate (18F-FAC) and 1-H-1-(3-[18F]fluoro-2-hydro-xylpropyl)-2-nitroimidazole (18F-FMISO) via "one-pot" procedure in TRACERlab FXF-N synthesizer is described. 18F-FAC injection was prepared via two-step reactions including nucleophilic fluorination of the precursor benzyl bromoacetate with 18F-fluoride and subsequently hydrolysis with NaOH at the same reaction vessel, and purified with Sep Pak cartridges. The uncorrected radiochemical yield of 18F-FAC was about 45%, the radiochemical purity was more than 99%, and the whole synthesis time was less than 40 min. 18F-FMISO injection was prepared by the similar method. The uncorrected radiochemical yield of 18F-FMISO is above 40%, the radiochemical purity is above 95%, and the total synthesis time was less than 40 min. The fully automated one-pot synthesis procedures of 18F-FAC and 18F-FMISO injection are easy to operate and can be performed in any automated system designed for the synthesis of 2-18F-2-deoxy-D-glucose (18F-FDG) by the nucleophilic substitution.  
        关键词：18F-fluoroacetate;18F-FMISO;Tumor imaging agent;Hypoxia imaging agent;Fully automated synthesis   
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        发布时间：2021-03-12
      • GUO Chuanling WANG Jufang JIN Xiaodong WEI Wei YANG Jianshe LI Wenjian
        Issue 8, (2006)
        摘要：The study was performed to investigate the feasibility and advantages of tumor therapy with heavy ions by observing the radiosensitivity and its discrepancy for two kinds of human malignant tumor cell line after respectively irradiated with 60Coγ-rays and 12C6+ ions with high LET. After exposed to 60Coγ-rays and 12C6+ ions, cell survival of two human carcinoma cell lines, SMMC-7721 and A375, was determined by an in vitro clonogenic assay. The survival fractions of cells irradiated with 12C6+ were considerably lower than those of cells irradiated with y-rays in both single irradiation and dividual irradiation. For cells irradiated with heavy ions, there was an evidently decreasing discrepancy of radiosensitivity and there was not an obviously increasing survival as dividually irradiated. The assay showed that heavy ions with high LET could kill tumor cells more efficiently and decrease the discrepancy of radiosensitivity between different cell lines, as well as lead a lower repair of cells. Associated with the depth-dose curve of heavy ions, tumor therapy with heavy ions demonstrates special advantages.  
        关键词：Tumor cells;Heavy-ions;Survival fractions;Radiosensitivity   
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        发布时间：2021-03-12
      • LIU Yuxia LIU Ning YANG Yuanyou ZAN Liangbiao LIAO Jiali JIN Jiannan
        Issue 8, (2006)
        摘要：Nicotinic Acetylcholine Receptors (nAChRs) are involved in various pharmacological effects or diseases, such as Alzheimer’s Disease, Parkinson’s Disease and tobacco addiction. It will be very appealing to image nAChRs in vivo, diagnose and treat the above diseases, and probe the mechanism of nAChRs in tobacco addiction if the suitable radioactive labeled compound can be synthesized. In this study, (s)-5-(tri-butylstannyl)-3{[1-(tert-butoxycarbonyl)-2- azetidinyl]methoxy}pyridine, a precursor for imaging nAChRs, was synthesized with commercial 2-furfurylamine and (s)-2-azetidinecarboxylic acid as starting materials, and was further labeled with 125/123I.The whole procedure for radiosynthesis needs 50 - 55 min and more than 30% of the 125I are found in the purified 5-[125I]-A-85380. Even staying for 3 days at room temperature in vitro, the purified 5-[125I]-I-85380 can maintain its stability, with a radiochemical purity of more than 95%.  
        关键词：nAChRs;Imaging agent;Precursor;125I;Labeling   
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        发布时间：2021-03-12
      • WANG Zhuanzi LI Wenjian SU Xu QIU Rong LIU Bing DUAN Xin
        Issue 8, (2006)
        摘要：The premature chromosome condensation technique was used to estimate the dosage effect on the G2-chromosome breaks in HO8910 after exposure toγ-rays, and to investigate the time effect on the rejoining of the G2-chromosome breaks. The results show that the number of G2 chromatid-type breaks linearly increased with doses and the number of G2 iso-chromatid breaks increased with dose in a linear-square manner. With the prolongation of culture time, G2 chromatid-type breaks obviously got repaired, and almost 65% chromatid-type breaks got repaired in the early 24 hour post-irradiation, whereas only about 20% iso-chromatid breaks got repaired during the same time. Furthermore, the rejoining of the two types of chromatid breaks occurred mostly in 2 hours after irradiation and from 12 to 24 hours after irradiation, the number of chromatid breaks was found to get stabilized basically, which indicates that the repairing process is over in the early 24 hours of post-irradiation.  
        关键词：Premature chromosome condensation (PCC);G2 chromatid-type breaks;G2 iso-chromatid breaks;Repairing   
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        发布时间：2021-03-12
      • HAN Yang BAOBorong CAOWeiguo CHEN Jie SHAO Min
        Issue 8, (2006)
        摘要：A new extractant, 4-p-methylbenzoyl-2,4-dihydron-5-methyl-2-phenyl-pyrazol-3-thione (HMeBMPPT), was synthesized. The structure of the compound was confirmed by means of elemental analysis and X-ray diffraction. The solvent extraction of U(VI) from nitric acid solution by HMEBMPPT in toluene was studied. The results show that the distribution ratio of U(VI) increased with the increasing of the aqueous phase pH. When the concentration of HMeBMPPT increases, the distribution ratio of U(VI) also increases rapidly. Meanwhile, the chemical composition of extracted complex and the mechanism of extraction were also discussed.  
        关键词：Thiopyrazolone;Extraction;U(VI)   
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        发布时间：2021-03-12
      • WAN Danjing ZHONG Gaoren Zhu Jianhua DING Jianhui ZENG Mengsu
        Issue 8, (2006)
        摘要：The aim of this study was to evaluate magnetic resonance (MR) signal variations of transplanted human gastric adenocarcinoma cells (SGC-7901) in athymic mice after the administration of folate-receptor- targeted MR contrast agent gadolinium- diethylenetriaminepentaacetic acid-folate (Gd-DTPA-Folate). A paramagnetic contrast agent, Gd-DTPA-Folate was synthesized by conjugating folic acid to diethylenetriaminepentaacetic acid (DTPA) , then reacting with GdCl3. The athymic mice with a human tumor cell implant were divided into either the study group or the control group. The 0.4mL Gd-DTPA-Folate was injected into the abdominal cavity of the mice in the study group, while the control group received Gd-DTPA with equivalent Gd3+. The signal features of the tumor precontrast and postcontrast were observed on TtW] MR scanning was carried out at 0, 1, 2, 3, 4, 6, 12 and 24 hour post-injection. The tumor signal intensity at 0, 1,2 and 3h postcontrast in the study group was significantly higher than that of precontrast. The biggest difference appeared at one hour and the difference was retained about 3 hours. In the control group, there was no statistical difference between the tumor signal intensity at any time point post injection and that of prior to injection except 0 and 1h postcontrast. Gd-DTPA-Folate can produce a sustained increase in the signal intensity of the transplanted human gastric adenocarcinoma cells in athymic mice, thus, it may become a promising folate-receptor-specific magnetic resonance contrast media.  
        关键词：Magnetic resonance imaging (MRI);Contrast media;Gadolinium;Folate receptor;DTPA-Folate   
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        发布时间：2021-03-12
      • ZHU Chuanhe HE Yanan LU Fuping DU Lianxiang
        Issue 8, (2006)
        摘要：Mutagenic effects of avilamycin-producing strain induced by N+ ion implantation have been investigated. The experimental results indicated that the survival rate curve took a "saddle" shape and the unique mutation effects of N+ ion implantation were presented. To obtain high-yield avilamycin-producing strain, the ion implantation dose of 5×1015 cm-2(the mutation rate was 20.9%-26.2%) was used and screening of streptomycin-resistant mutant was done in the study on breeding mutation. The SVN-116 mutant was obtained, with an avilamycin yield of 79.6-82.9 mg·L-1 that was 1.414-1.472 times as much as the original strain.  
        关键词：Ion implantation;Avilamicin;Mutation breeding;Mutagenic effects   
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        发布时间：2021-03-12
      • LI Feng JIN Ge YANG Tao YU Xiaoqi
        Issue 8, (2006)
        摘要：In this paper, the working environment and the functions of Amplifier-Shaper-Discriminator (ASD) boards for TGC in ATLAS Muon Spectrometer is introduced and a special inspection system for ASD boards is described based on the requirement in the ATLAS experiment. The testing principle and inspection results of a large quantity of ASD boards inspected by the system are also described in detail.  
        关键词：TGC;ASD;Inspection system;Design   
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        发布时间：2021-03-12
      • WANG Yanyu HUANG Jijiang QI Huirong MA Xiaoli XU Zhiguo
        Issue 8, (2006)
        摘要：This paper describes the current status, working principles, design requirement and method for high density muti-channel front-end electronics and multi-channel charge sensitive preamplifer of array detector briefly. Specially a new 48-channel charge sensitive preamplifier developed for the silicon strip array detector system in IMP is introduced, which has low cost, high density, 1% energy resolution and good stability.  
        关键词：Silicon strip array detector;Multi-channel charge sensitive preamplifier   
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        发布时间：2021-03-12
      • LIU Ying LUO Jiarong MENG Yuedong QU Lianzheng LI Guiming ZHANG Mingxin
        Issue 8, (2006)
        摘要：To keep the 2MW equipment for producing acetylene by coal H-plasma pyrolysis running stably and safely, and to improve acetylene yield, an multi-function control system has been designed and implemented. In this system, the time slice division method has been adopted to collect important signals at high speed and in continuous mode for a long time. For improving the stability and the response speed of the control system, Integral Separation Control Arithmetic has been used. Moreover, to meet local user and remote user requirements, the control system has provided fast and visual information by the combination of C/S mode and B/S mode. The control system has shown favorable stability, reliability and usability in many experiments.  
        关键词：Coal plasma pyrolysis;Stable state;Control   
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        发布时间：2021-03-12
      • GAO Song LU Wu REN Diyuan NIU Zhenhong LIU Gang
        Issue 8, (2006)
        摘要：A method of enhancing radiation damage for JFET-input op-amps has been studied in this paper. The results show that a circulative irradiation-annealing method can make the radiation damage of JFET-input op-amps enhanced , and radiation damage of the devices at low dose rate can be evaluated through adjusting parameters such as radiating dose rate, annealing temperature and time, etc. The possible mechanism of this method is discussed.  
        关键词：Operational amplifier;Junction field effect transistor;Radiation damage;Low dose rate;Accelerated evaluation   
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        发布时间：2021-03-12
      • ZHAO Yongfu LI Lili WANG Chao YANG Ping JI Ping
        Issue 8, (2006)
        摘要：A new apparatus for canning radiation dosimeter solution (Patent No. ZL200320174.9) has been developed. Experiments on the background stability and dispersity showed that the canning mode was a main factor making the background values dispersive. The uncertainties of the absorbed dose were comparatively estimated for the two modes. The dose verifications for different canning modes and under different environmental conditions indicate that the total uncertainty of the absorbed dose for this canning apparatus is less than 1 %.  
        关键词：Radiation;Dose;Background dispersity;Uncertainty;Canning   
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        发布时间：2021-03-12
      • QIAN Yi SU Hong LI Xiaogang PENG Yu
        Issue 8, (2006)
        摘要：The paper discusses a circuit to restrain the dc drift in high-gain dc coupling amplifier . The circuit is composed of a second order Bessel low-pass filter and an inverting summer circuit. The circuit described in the paper has been used in a high-gain (Av≥1000) dc coupling fast amplifier developed by ourselves. The output dc drift of the amplifier is very low. For example, an output dc drift of less than±3mV was found for an operation of a long period of 100 hours.  
        关键词：Dc drift;Restraining method;Circuit   
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        发布时间：2021-03-12
      • ZHAO Jingwu SU Weining
        Issue 8, (2006)
        摘要：Based on the spatial integral and approaching method, the slice collimator is proposed for SPECT imaging. It has the advantages of high sensitivity and fast scanning over the conventional SPECT. Rotation of the gamma camera is not necessary, thus resulting in the reduction of the patient motion artifact and the improvement of image quality. The ideal 2-D simulation data were generated without considering scattering and noise. A checking computation was carried out with the relaxation solution method of the linear equations set. Results show that the activity distribution regions can be approached gradually, and the distribution pattern can be distinguished by using this method.  
        关键词：SPECT imaging;Slice collimator;Spatial integral;Approaching method   
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        发布时间：2021-03-12
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