最新刊期
      卷 0 ， 期 0 ， 2020
      • CAO Xizheng1 JING Shiwei1,2 TIAN Yubing1 CHI Yantao1 ZHAO Xinhui1 REN Wanbin1 QIAO Shuang1 GU Deshan1 LIU Linmao1 1
        Issue 11, (2005)
        摘要：In this article, the experimental research on the detection of explosives with pulsed fast/thermal neutron analysis is introduced. The elemental composition and contents of the tested materials can be determined by analyzing the characteristic gamma ray spectra. The explosives differ in the content and ratio of elements, such as H, C, O and N, from other non-explosives, which leads to their identification.  
        关键词：Pulsed fast/thermal neutron analysis;Explosives;Characteristic gamma rays   
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        发布时间：2021-03-12
      • WANG Ying LIN Jiasheng
        Issue 11, (2005)
        摘要：The objective of the work is to assess the clinical value of 18F-FDG images with a dual head coincidence SPECT ( DHC SPECT ) in the diagnosis of tumors and compare the diagnostic accuracy obtained with a DHC SPECT with those obtained with CT and ultrasound (US). Total 109 patents with known or suspected malignancies underwent 18F-FDG images 40-50min after injection of 222—296 MBq 18F-FDG. The images were reconstructed using iterative algorithms after attenuation correction with a CT map. 89 of 109 patients were proven to have malignancies. There were 87 patients with positive images including 3 cases of false positive, the sensitivity was 94.38% ( 84/89 ) with positive predict value of 96.55% ( 84/87 ) . The specificity was 90% ( 18/20 ) with negative predict value of 81.81% ( 18/22 ) . There were 26 patients with 18F-FDG coincidence images matched with CT or US, and 73 cases mis- matched with CT or US. 52 patients had more lesions on 18F-FDG imaging than on CT or US, only 5 patients less than on CT or US. The 18F-FDG coincidence imaging is therefore a valuable tool for diagnosis of tumors with higher sensitivity and specificity. Combined FDG image with CT will facilitate the precise localization of tumors. It is useful for differentiating malignancy from benign tumor;for tumor staging and restaging;for detecting recurrence or re- sidual tumor;for monitoring the response to treatment including surgery, chemotherapy or radiotherapy; and for pre- dicting the prognosis. With accumulation of clinical experience and improvement of technology, 18F-FDG coincidence imaging will be popularized. But due to the limitation of SPECT’s resolution and the false positive from various in- flammation, a correct diagnosis must be based on the combination of SPECT imaging with clinical and other imaging data.  
        关键词：18F-FDG;Coincidence circuit imaging;Image infusion;Tumor   
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        发布时间：2021-03-12
      • PENG Chengxiao1 WENG Huimin1 YANG Xiaojie2 YE Bangjiao1 ZHOU Xianyi1 HAN Rongdian1 1
        Issue 11, (2005)
        摘要：Native defects in ZnO films grown by radio frequency (RF) reactive magnetron sputtering under variable oxygen fraction conditions have been investigated by using monoenergetic positrons beam technique. The results show that the same type defects dominate in these ZnO samples grown at oxygen fraction less than 70% in the proc- ess chamber; and zinc vacancies are preponderant in the ZnO films fabricated in richer oxygen environment. The concentration of zinc vacancies increases with oxygen partial fraction rising. While oxygen fraction reaches 85%, zinc vacancies that could trap positrons decrease, which suggests that impurities could shield zinc vacancies. A com- bination between hydrogen atoms and the dangling bonds in the lattice could weaken the trap of positrons under the 50% oxygen fraction condition. The concentration of zinc vacancies varies in different oxygen fraction films, which is in agreement with the conclusion of photoluminescence spectroscopy.  
        关键词：Zinc oxide;Defect;Monoenergetic positrons;Oxygen fraction   
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        发布时间：2021-03-12
      • HUANG Xingbin1 WANG Guorong1 SUN Punan1 YANG Dazhan2 MA Yonghe2 1
        Issue 11, (2005)
        摘要：Backscattering techniques for determining the ash content of coal are introduced. Optimum sensitivity and optimum geometric configuration are studied. The effect of constituent’s variation on measuring results is calculated and some compensation methods can be established to correct the effect of variation of Fe2O3 contents on practical measurement. Measuring range is 8%—15%, and the r.m.s. of measuring deviation is less than ± 0.37%.  
        关键词：γ ray backscattering;Ash content;Sensitivity   
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        发布时间：2021-03-12
      • PAN Lin1 CHEN Zhihua1 LI Gang2 SUN Wei1 ZHU Peiping2 XIA Qisheng1 ZHOU Donghui1 ZHAO Tiande1 CHEN Weichang1 JIANG Xiaoming2 WU Ziyu2 TANG Jintian3 1
        Issue 11, (2005)
        摘要：To explore whether synchrotron radiation hard X-ray has any effects on biological tissue structure and re- lated antigen expression of fixed bone, cartilage, liver and lung, diffraction-enhanced X-ray imaging (DEI) and in-line holography with synchrotron radiation hard X-ray from Beijing Synchrotron Radiation Facility (BSRF) were applied to observe the morphology of the bone defect of rabbit, the lung cancer of mouse, the hepatic fibrosis and hepatocir- rhosis of SD rat as well as their respective control. The histologic changes were observed by microscope. The semi- quantitative analysis of antigen-III, S-100, FN and ubiquitin were also performed by immunohistochemistry. Imaged tissue was found to be intact, and there was no difference in these antigen expressions between the imaged and control groups. It is concluded that synchrotron radiation hard X-ray has no effect on biological tissue structure and related antigen expression of fixed bone, cartilage, liver and lung. The present results have provided experimental evidences for the development of synchrotron hard X-ray-phase technique of in vitro biological and medical studies.  
        关键词：Synchrotron radiation;Phase-contrast imaging;Tissue damage;Antigen;Immunohistochemistry   
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        发布时间：2021-03-12
      • WANG Xiaohong1,2 ZHAN Xiuchun1 HUANG Yuying3 HE Wei3 LIU Shuqin4 FAN Xingtao1 TANG Lijun1 WANG Yimin1 1
        Issue 11, (2005)
        摘要：Seamount Co-rich crust has the same stromatolithic structure with marine manganese nodule. It contains rich information of paleoceanic environment recorded during its growth period. In this paper, the distribution features of the main mineral-forming elements Mn, Fe, Co, Ni, Cu, P and Ca in two seamount Co-rich crusts, collected from the west Pacific, have been studied using SR-XRMP. These distribution features of main mineral-forming elements can be used as the tracer for phosphatization ( an important paleoceanic event ) .  
        关键词：SR-XRMP;Seamount Co-rich crust;Micro-structure;Element distribution;Paleoceanographic event   
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        发布时间：2021-03-12
      • SU Qiong ZHENG Rui CHEN Yong CHENG Jianping
        Issue 11, (2005)
        摘要：This paper reports the observed changes for equilibrium factors between 226Ra and 222Rn with sealing time of the samples. The samples include soil, raw coal, mineral water, cement, rock, etc. Especially the conceptions of “pre-equilibrium time” and “pre-equilibrium factor” have been put forward and methods of measuring and processing data have been given which can be used for rapidly reporting activity of 226Ra in samples with unknown equilibrium factor. It is definitely concluded that, using methods given in the paper, a test report will be completed in 3—7 days, instead of one month, after receiving the sample whose activity is not lower than LLD of the spectrometer.  
        关键词：γ spectrometer;226Ra-222Rn sample;Secular radioactive equilibrium   
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        发布时间：2021-03-12
      • MAO Shuhong1,2 JIN Genming1 WEI Zengquan1 XIE Hongmei1 GU Ying3 MA Qiufeng1 1
        Issue 11, (2005)
        摘要：Screening of the respiration deficiency mutants of Saccharomyces cerevisiae induced by 5.19 MeV/u 22Ne5 + ion irradiation is reported in this paper. Some respiration deficiency mutants of white colony phenotype, in a condition of selective culture of TTC medium, were obtained. A new and simplified method based on mtDNA restric- tion analysis is described. We found that there are many obvious differences in mtDNAs between wild yeasts and the respiration deficiency mutants. The mechanism of obtaining the respiration deficiency mutants induced by heavy ion irradiation is briefly discussed.  
          
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        发布时间：2021-03-12
      • GUO Leiming CHEN Tao SUN Xiaoguang HUANG Gang
        Issue 11, (2005)
        摘要：The absorbed radiation dose from internally deposited radionuclide is a major factor in assessing risk and therapeutic utility in nuclear medicine diagnosis or treatment. The quantification of absolute activity in vivo is necessary procedure of estimating the absorbed dose of organ or tissue. To understand accuracy in the determination of organ activity, the experiments on 99Tcm activity quantification were made for a body phantom using dual-head SPECT with the two-view counting technique. Accuracy in the activity quantification is credible and is not affected by depth of source organ in vivo. When diameter of the radiation source is ≤2 cm, the most accurate activity quantification result can be obtained on the basis of establishing the system calibration factor and transmission factor. The use of Buijs’s method is preferable, especially at very low source-to-background activity concentration rations.  
        关键词：SPECT;Quantitative planar imaging;Activity quantification;Body phantom   
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        发布时间：2021-03-12
      • YANG Jianshe1,2 ZHAO Jing1,2 LI Wenjian1 GAO Qingxiang3 WANG Zhuanzi1,2 1
        Issue 11, (2005)
        摘要：To investigate the radiation response of hepatoma cells SMMC-7721 the G2 premature chromosome con- densation technique was used. SMMC-7721 cells ( human hepatoma cells ) were irradiated with 60Co γ -rays. Then cell killing was documented by a colony assay. Initial chromatid breaks were measured by counting the number of chromatid breaks and isochromatid breaks immediately after prematurely chromosome condensed by Calyculin-A. A dose-dependent increase in radiation-induced chromatid / isochromatid breaks was observed in G2 phase. A good relationship was found between cell survival and chromatid breaks. This study implied that low LET radia- tion-induced chromatid / isochromatid breaks can be possibly used as a good predictor of radiosensitivity of SMMC-7721 hepatoma cells, also it could be used to design radiotherapy schedule for liver cancer patients.  
        关键词：Premature chromosome condensation technique;Predict;Hepatoma;Radiation;Response   
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        发布时间：2021-03-12
      • WU Zhizong JIANG Meiling LIANG Pingzhi
        Issue 11, (2005)
        摘要：A prototype of a 10-element photodiode array coated by 10-element CsI(Tl) scintillator array has been made and used as an X-ray detector. Its active area of photodiode is 0.75mm×1.25mm, apparent size is 10.25mm×1.75mm and the pitch of that is 1.25mm. Test results have been presented in this paper. The noise voltage of photodiode is about 10-4V; the non-uniformity is 0.08; the crosstalk between pixel to pixel has been obversed; moreover, some other performances of our detector have also been given as curves in this paper. Discussions on how to improve signal amplitude, how to decrease noise of detector system, how to amend crosstalk between pixels have been given.  
        关键词：Photodiode;CsI (Tl) crystal;X-ray detector   
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        发布时间：2021-03-12
      • XIE Changhui MA Zhihai LI Xiujiang DENG Shaojie
        Issue 11, (2005)
        摘要：A method of observing the blood supply of rabbits with replanted limb by Na99TcmO4 trace imaging ( TTI ) is described and compared with clinical routine method( CRM ) . 40 healthy adult rabbits with replanted limb were divided into and A ( n = 25) and B ( n = 15 ) groups by 20 min after operation. Locally freezing ( < 5°C ) 10 min was given to group A and locally warming ( 40—45°C ) was given to group B. Group C ( 5 normal control rabbits ) was kept at common temperature ( 20 — 25°C ) . Dynamic and static images were performed on all rabbits. The radioac- tivity uptake of replanted limb/ normal limb ratio ( T/NT ) was analyzed using the region of interest analysis. The vascular crisis ( VC ) in 45 rabbits was evaluated with explorative operation. The Ο ,ⅠandⅡscales were classified according to their radionuclide distribution and the T/NT were 0.142 ± 0.061, 0.472 ± 0.055, 0.843 ± 0.184 ( t = 7.23, 13.65, 2.71, P < 0.01 ) , respectively. The Ο scales ( T/NT < 0.25 ) of TTI can be regarded as a semi-quantitative and qualitative standard on diagnosing VC. 25, 3, 0 cases in groups A, B and C was confirmed with VC by explorative operation. The success rate of making VC model by locally freezing was 100%. The sensitivity( 96.4% ) in diag- nosing VC by TTI was much higher than CRM ( 39.3% ) ( χ 2 = 20.9, P < 0.01 ) . It is conclude that the blood supply of rabbits with replanted limb could be reported more accurately and directly by TTI than CRM. TTI could play an important role on early and no traumatic diagnosing VC in patients with replanted finger or limb.  
        关键词：Organ transplantation;Limb;Replantation;Vascular crisis;Trace imaging;Na99TcmO4;Radionuclide imaging   
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        发布时间：2021-03-12
      • YE Haihong HAN Jiansheng LIU Chunping LI Hua ZHANG Huabei
        Issue 11, (2005)
        摘要：A new target chelator was synthesized through five steps with mercaptoacetic acid as primitive materials, which was identified on the basis of the spectroscopic data, such as IR, 1HNMR, and elementary analysis. The chela- tor was labeled with technetium 99m and its biological activities in mice given in %ID/g values were determined to explore new renal imaging agent. The bio-distribution results in mice indicate that 99Tcm-MVGQ has high kidney up- take as well as quick blood and kidney clearance, thus showing promising application as an ideal kidney imaging agent.  
        关键词：Kidney imaging agent;Technetium-99m labelling chelator;Bio-distribution   
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        发布时间：2021-03-12
      • XIANG Yongchun XIONG Zonghua HU Gungchun ZE Rende ZHANG Jianhua
        Issue 11, (2005)
        摘要：In this paper, the principal and techniques of activity interrogating the explosives have been illuminated. Some factors affecting the results have been analyzed. We adopted high pure germanium γ-detector to measure γ-ray from the simulated dynamite irradiated by 252Cf neutron source. The feasibility of the method was and analyzed and advantages and shortages of detecting 1H, 12C, 16O and 14N were discussed.  
        关键词：Army control;Active detection;Explosive;HPGe γ-detector;Capture reaction   
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        发布时间：2021-03-12
      • ZHANG Lianping WEI Mengfu LI Ju
        Issue 11, (2005)
        摘要：Sphere symmetry of nuclear weapon, is one of the most significant attributes discussed in arms control verification and nuclear disarmament. In this paper, the absolute detection efficiency distribution of HPGe γ detector in respect to spontaneously gamma radiation field of special shape assembly was simulated by Monte Carlo method. The results of simulation have shown that passive gamma spectroscopy mode could be used in recognizing the sym- metric attribute of quasi-sphere.  
        关键词：Symmetric attribute;Monte-Carlo method;Absolute detection efficiency;Gamma spectroscopy   
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        发布时间：2021-03-12
      • ZHANG Hongbin1 LU Ziwei1 XU Guoji2 XU Hushan1 TAN Jilian1 XIAO Guoqing1 ZHANG Xueying1 MA Yue1 LI Wenfei1 CHEN Ruofu1 XU Huagen1 JIA Fei1 JIN Genming1 1
        Issue 11, (2005)
        摘要：Preparation process of the isotope 208Pb target with the required size, thickness and configuration was in- troduced. The target had a sandwich structure of C/208Pb/C. The thickness and uniformity of 208Pb target were con- trolled and measured. Through rotating the substrate, the utilization efficiency of 208Pb was considerably increased. The prepared target has a structure of 30 μg/cm2 C + 361μg/cm2 208Pb + 15 μg/cm2 C, and the average thickness of the target that was prepared in the same procedure is 361 μg/cm2. The test results show that the inhomogeneity of the tar- get is less than 9.8%. This can meet the requirements of the experiment in the super-heavy element study.  
        关键词：Isotope 208Pb target;Rotation evaporation;Sandwich structure;C film   
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        发布时间：2021-03-12
      • XIE Dongzhu
        Issue 11, (2005)
        摘要：The development, during annealing, of periodic one-dimensional ripple structure has been investigated. The nanoscale ripple array was fabricated on silicon ( 001 ) crystal surface using focused ion beam ( FIB ) . Annealing was performed isothermally in a flowing argon gas ambient at 670°C. The morphology of the ripple before and after annealing was analyzed by use of atomic force microscope. The height of the ripple decreased after thermal annealing. Furthermore, after annealing, spikes of gallium and / or gallium-rich precipitate were also observed on the surface of the ripples and the FIB milled areas.  
        关键词：Focused ion beam;Nanostructure;Thermal stability   
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        发布时间：2021-03-12
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