最新刊期
      卷 0 ， 期 0 ， 2020
      • GU Yuehua GAO Hengjing WANG Qi ZHAO Ling
        Issue 7, (2006)
        摘要：The DNA damage of wheat root tip cells induced by different doses (0—288 J·cm-2) of synchrotron radiation (SR) soft X-rays was measured by using the single-cell gel electrophoresis (SCGE) technique. The DNA removal in electrophoresis was observed and the results showed that 20%—92% of wheat root tip cells were damaged with the increase of radiation dose, and the DNA damage level (expressed by Tail Moment) was positively correlated with the dose of synchrotron radiation soft X-rays.  
        关键词：Single cell gel electrophoresis;Soft X-rays;DNA damage;Radiation dose   
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        发布时间：2021-03-12
      • LIU Changshi
        Issue 7, (2006)
        摘要：The first level plasmons of Si in pure Si state, SiO2 state and Si3N4 state (corresponding to bonding energy of 116.95, 122.0 and 127.0 eV respectively) were investigated directly with X-ray Photoelectron Spectroscopy (XPS) before and after Co irradiation. The experimental results demonstrate that there exist two interfaces, one consists of 60 plasmons of Si in Si3N4 state and in SiO2 state, while the other is made of plasmons of Si in pure Si state and in SiO2 state. When the Si3N4/SiO2/Si samples were irradiated by Co, the interface at Si3N4/SiO2 was extended and at the 60 same time the center of this interface moved towards the surface of Si3N4. The concentration of plasmons in SiO2 state was decreased at the SiO2/Si interface, and effects of radiation bias field on plasmons in the SiO2/Si interface were observable. Finally, the mechanism of experimental results is analyzed by the quantum effect of plasmons excited by photoelectrons.  
        关键词：Plasmons;Si3N4;SiO2-Si;Dose;Bias field   
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        发布时间：2021-03-12
      • SHEN Shuifa1,3 LI Yan3 GU Jiahui3 1
        Issue 7, (2006)
        摘要：In this paper, the detection systems and the data acquisition methods used in the nuclear decay study in our laboratory are introduced. These two detection systems include the low-background Compton-suppressed spectrometer and the three-parameter (γ-γ-t) coincidence system of HPGe-HPGe detectors, both of which are used to measure the γ rays following the nuclear decay. In addition, as examples, the detection of γ rays following the decay of 252Cf spontaneous fission fragments and the β++EC decay of 74As, by using these two spectrometers, is briefly described.  
        关键词：Low-background Compton-suppressed spectrometer;γ-γ-t coincidence system;Decay;γ-ray   
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        发布时间：2021-03-12
      • WANG Siguang1 MAO Yajun1 TANG Peijia2 LI Ze2 1
        Issue 7, (2006)
        摘要：One γ ray spectrum analysis method is introduced in the paper. A spectrum composed of different compo- nents is analyzed by considering the branching ratios of various γ rays from the same nuclide and the relative detec- tion efficiencies to get the optimized results. The function of describing the background of the γ-ray spectrum is also given. With this method to determine contents of various radioactive nuclides, some analysis steps can be merged and the measurement error will be reduced.  
        关键词：Isotope abundance;Multi-channel γ-ray spectrum;Non-destructive assay;Data analysis   
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        发布时间：2021-03-12
      • HU Bitao WANG Lili SONG Yushou GU Jiangang CHEN Chunhua
        Issue 7, (2006)
        摘要：In the present work, with C++ program STARF under COBM, we have investigated the neutralization process of slow highly charged Xeq+ and dependence of its charge state on the distance from Al(111) surface when it’s scattering on Al(111) surface at grazing angle. In addition, the image energy gain of differently charged Xeq+ was calculated and compared with the experimental results. The present simulated image energy gain agrees very well with the existent experimental results.  
        关键词：Highly charged ion;Hollow atom;Classical over barrier model;Image energy gain   
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        发布时间：2021-03-12
      • HE Baoping1,2 ZHOU Heqin1 LUO Yinhong2 ZHOU Hui2 GUO Hongxia2 YAO Zhibin2 ZHANG Fengqi2 1
        Issue 7, (2006)
        摘要：A radiation response model of total dose effect for CMOS devices in a space environment is presented to predict the radiation-induced leakage current. Total effects for CC4007RH and C4007B devices at different dose rates irradiation of γ rays were calculated by using the established model. So long as total dose irradiation test and post-irradiation annealing test at room temperature were carried out by choosing one dose rate at random, total dose irradiation effects at other dose rates can be predicted by using the established models. Finally, the prediction results of 10-4-10-2 rad·s-1 low dose rate irradiation for CC4007RH and C4007B devices in space environment were presented.  
        关键词：Leakage current;Low dose rate effect;Prediction method;Total dose   
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        发布时间：2021-03-12
      • HUANG Chaoqiang CHEN Bo
        Issue 7, (2006)
        摘要：Based on Parratt’s formula, the algorithms of rough interface multilayer reflectivity and the resolution of scattering vector Q in the neutron reflection experiment are discussed. The differences and the use conditions have been described of the exponent method and the lames method, which are two algorithms to deal with the roughness of interfaces. Combined with experimental data of polarized neutron TOF reflection, the two fitting methods have been compared. The results indicate that the split lames algorithm of reflectivity is more suitable for the model in which interfacial roughness is in the order of thickness. As for resolution, the convolution considering angle or wavelength resolution is better than the convolution considering scattering vector.  
        关键词：Neutron reflection;Rough interface;Resolution;Data analyses   
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        发布时间：2021-03-12
      • HUANG Qunce 1 LI Yufeng 2 LI Guoping1 1
        Issue 7, (2006)
        摘要：The N+ implantation experiment, taking autotetraploid rice with nucleus male sterility as materials, was finished. The off-spring colonies via N+ implantation were selected, gaining some mutants in autotetraploid rice. The characters of infertility expression of the variant single plants, treated by the abnormal low temperature during male differentiation, were studied. As a result of 25 keV N+ ion implantation with a low dose (1 × 1017 cm-2), there were some variant single plants in the autotetraploid rice. The variant single plants represented specially in infertility. Treated by the abnormal low temperature during male differentiation, some mutants showed obviously variant characters in infertility following the morphological variation, but others preserved infertility of its parent. The segregation phenomena in the agronomic characters were visible in the lines of M3 generation, but they kept the stable infertility. It is thought that the characters of the infertility variation in the mutants may be allocated in the M3 generation .  
        关键词：Autotetraploid rice;Nucleus male sterility;N~+ion implantation;Infertility expression   
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        发布时间：2021-03-12
      • SHEN Yumei
        Issue 7, (2006)
        摘要：The paper introduces the basic concept of chirality, target specific selectivity and their relationship in radiopharmaceuticals. If the ligands labeled by radionuclides have chiral centers, the enantiomers must be separated, or the target specific selectivity will not be good. Chirality is one of the most important factors which must be considered in the study of the structure-activity relationship of radiopharmaceuticals.  
        关键词：Chirality;Target specific selectivity;Radiopharmaceuticals   
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        发布时间：2021-03-12
      • WANG Mingwei YIN Duanzhi CHENG Dengfeng LI Gucai ZHENG Mingqiang ZHOU Wei WANG Yongxian
        Issue 7, (2006)
        摘要：O-(2-[18F]fluoroethyl)-L-tyrosine was synthesized via “one-step” method of nuclephilic radiofluorination with a precursor N-BOC-(O-2-tosyloxyethyl)-L-tyrosine methyl ester which is easy to obtain. Separation was per- formed on Sep-pak cartridge with solid phase extraction, instead of HPLC (high pressure liquid chromatography). The operation process was simple and the total synthesis time was less than 50 min. The radiochemical yield was about 40% (without decay-correction), and the radiochemical purity was more than 97%.  
        关键词：O-(2-[(18)~F]fluoroethyl)-L-tyrosine;Nucleophilic radiofluorination;One-step method   
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        发布时间：2021-03-12
      • ZHAN Hongwei YE Xiaojuan BAO Chengkan SUN Da HE Gangqiang ZHANG Hong
        Issue 7, (2006)
        摘要：Inner radiotherapy using radionuclide has been used more and more in clinic, and it is important to predict and enhance its therapeutic effect. In this study, 99mTc-HL91 imaging was performed in mice bearing S180 tumor before P-colloid interstitial treatment and some of mice inhaled carbogen gas as a method to solve hypoxia of tumor 32 tissue. Although 99m Tc-HL91 retention in tumor was decrease significantly after carbogen breathing, and tumor mass was less in the carbogen-breathing mice than in the air-breathing mice, 99m Tc-HL91 retention was not related to tumor mass after P-colloid interstitial treatment, which implied that carbogen breathing could improve therapeutic effect of 32 32P-colloid interstitial treatment, and 99m Tc-HL91 imaging was useful to detect effect of hypoxia intervention but was unable to predict therapeutic effect of P-colloid interstitial treatment. 32  
        关键词：99mTc-HL91 imaging;32P-colloid interstitial treatment;Effect;Carbogen;Hypoxia   
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        发布时间：2021-03-12
      • TANG Ganghua1 TANG Xiaolan2 WANG Mingfang1 GUO Xiaojun1 1
        Issue 7, (2006)
        摘要：Automated synthetic technology of 2-[18F]-fluoro-2-deoxy-D-glucose (18F-FDG) was described. Automated synthesis of F-FDG was performed by “one-pot” and “two-step reaction” procedures in TRACERlab 18 FXF-N system. 18F-FDG injection was obtained via “two-step reaction” including nucleophilic fluorination of the precursor 1, 3, 4, 6-tetra-O-acetyl-2-O-trifluoromethanesulfony-β-D-mannopyranose with F-fluoride and hydrolysis 18 with NaOH in the same reaction vessel, and subsequently purificated with Sep-Pak cartridges. The uncorrected radiochemical yield of 18F-FDG was about 60% and radiochemical purity was more than 99% within the total synthesis time about 24 min. Improved synthesis method of F-FDG injection is simple to operate and can become a 18 practical method of preparation.  
        关键词：18F-FDG;Fully automated synthesis   
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        发布时间：2021-03-12
      • YUAN Zhibin1 Katsumi TOMIYOSHI2 Tetsuya HIGUCHI2 Noboru ORIUCHI2 Keigo ENDO2 1
        Issue 7, (2006)
        摘要：Infection imaging is an important field in radionuclide imaging. But there are few reports about positron radionuclide labeled agents. To investigate a kind of specific infection imaging agent which can differentiate bacteria caused infection, we have radiosynthesized fluorine-18 labeled Levofloxacin (LVFX) for infection imaging. A typical Hamacher method was used to label LVFX. Radiochemistry purity was more than 98%, yield rate was about 40% and the pyretogen test result was negative. The labeling result showed that the labeling method was easy, procedure was simple and labeled agent was stable. The biodistribution and imaging of F-LVFX in animal model was also studied. 18 Both biodistribution and imaging result showed higher uptake of F-LVFX in infected tissues. The accumulation of 18 labeled agent in infected and normal tissue showed significant difference (P<0.05). This labeled agent was mainly excreted through kidney and liver. It is suggested that fluorine-18 labeled LVFX is a potential infection imaging agent.  
        关键词：Levofloxacin;Infection;Animal;Radionuclide imaging   
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        发布时间：2021-03-12
      • TAN Haibo1 GU Yili2 LIU Xingdang1 LIU Congjin1 ZHU Huiqing1 LI Ding1 LIN Xiangtong1 1
        Issue 7, (2006)
        摘要：The normal values of parotid function were investigated using parotid 99m TcO-4 dynamic imaging and the time-radioactivity curve of parotid was drawn using ROI computer program. The experiment indicated that parotid uptake index, excretion ratio and excretion time were effective parameters for the evaluation of the parotid function.  
        关键词：Parotid gland;Normal function;Radionuclide imaging;Quantitative analysis   
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        发布时间：2021-03-12
      • YUAN Xi1 ZHENG Jian2 SHI Liang1 JIANG Dazhen3 1
        Issue 7, (2006)
        摘要：This article summarizes the fundamental principle of ion mobility spectrometry (IMS) applied to explosive detection. The design of field IMS analyzer used for explosive detection is described in detail. The alternative designs of some key parts of drift tube are also discussed.  
        关键词：Ion mobility spectrometry;Explosive;Trace analysis;Field detection;Drift tube   
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        发布时间：2021-03-12
      • ZHENG Shiqiao1 HUANG Wenda1 SUN Zhenning1 SHI Zhiyuan2 CHEN Mouzhi1 1
        Issue 7, (2006)
        摘要：Design techniques of a gamma-ray energy spectrum remote-measurement system based on Lab VIEW are described, including data acquicition and client control program, and network communication by DataSocket. The gamma-ray energy spectrum of 137Cs was measured by the system, indicating that performance of our re- mote-measurement system based on LabVIEW is better than that based on Java Applet.  
        关键词：Data acquisition;Remote control;LabVIEW   
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        发布时间：2021-03-12
      • LI Shaoqing1 SHEN Lianguan2 Pei Yuanji3 1
        Issue 7, (2006)
        摘要：Numerical simulation and optimization in the design of a cooling system for a 2 m long accelerating tube are introduced. Some parameters of the cooling system are calculated and optimized by means of Finite Element Analysis. The work is done with the CAD/CAM/CAE software I-DEAS. As a result, a compact jacket style structure of stainless steel is chosen and employed in the accelerator. The system is very robust against surrounding tempera- ture change. Now the facility is running well.  
          
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        发布时间：2021-03-12
      • LIU Fenglin LU Yanping WANG Jue
        Issue 7, (2006)
        摘要：Computed tomography (CT), which uses penetrating radiation from many directions to reconstruct cross-sectional or 3D images of object, has widely applied in medical diagnosis and treatment, industrial NDT and NDE. So it is significant for college students to understand the fundamental of CT. In this article we describe the CD-50BG CT instrument developed for experimental teaching at colleges. With 50 mm field-of-view and the transla- tion-rotation scanning mode, the system makes use of a single plastic scintillator + photomultiplier detector and a 137Cs radioactive source with 0.74 GBq activity, which is housed in a tungsten alloy shield. At the same time, an im- age processing software has been developed to process the acquired data, so that cross-sectional and 3D images can be reconstructed. High quality images with 1 lp·mm-1 spatial resolution and 1% contrast sensitivity are obtained. So far in China, more than ten institutions including Tsinghua University and Peking University have already applied the system to elementary teaching.  
        关键词：Computed tomography;Teaching;Scanning   
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        发布时间：2021-03-12
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