最新刊期
      卷 0 ， 期 0 ， 2020
      • LI Chenxi LU Kunquan NIU Xiaojuan WU Zhonghua
        Issue 10, (2003)
        摘要：There are two types of morphologies of crystalline GeO2: quartz type (q-GeO2) and rutile type (r-GeO2) . The former is a good piezoelectric and optical material and the latter is important in electronics. The melting points of the two kinds of GeO2 are different: 1115℃ for q-GeO2 while 1086℃ for r-GeO2. We proposed a method to overcome the difficulties in the XAFS measurements for oxide melts under high temperature and have collected the XAFS spectra with high quality for molten q-GeO2 and r-GeO2. The structures of different melts from different crystalline solids and their correlation have been discussed, especially for temperatures between the two melting points.  
        关键词：XAFS;Absorption spectra;Liquid structure;GeO2;Melt   
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        发布时间：2021-03-12
      • FAN Rong XU Chaoyin PAN Guoqiang HUANG Zhigang DONG Xiaohao
        Issue 10, (2003)
        摘要：The paper describes the measurement of main parameters of the X-ray diffraction and scattering beamline and station in NSRL, including X-ray imaging(4mm×0.5 mm) with CCD camera, X-ray wavelength calibration and the measurement of photon flux (0.4×109-2.1×109 photons ·s-1· (100mA)-1). A preliminary experiment of protein X-ray diffraction was carried out using a commercial imaging plate detector system, and the results were reported. Five sets of diffraction data of protein crystals were successfully collected on this bealine and station. Good structure results were obtained from the data  
        关键词：Wavelength;Photon flux;X-ray diffraction   
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        发布时间：2021-03-12
      • ZHANG Zhiyong CHAI Zhifang
        Issue 10, (2003)
        摘要：The basic concept, experimental methods, merits and drawbacks of molecular activation analysis (MAA), and its applications in biological, environmental and geological sciences are reviewed. The perspects of MAA are also briefly outlined.  
        关键词：Trace elements;Chemical species;Activation analysis   
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        发布时间：2021-03-12
      • XIAO Tiqiao XU Hongjie CHEN Min DU Guohao WEI Xun LUO Yuyu LIU Lixiang
        Issue 10, (2003)
        摘要：Up to now, X-rays used for the phase-contrast imaging mostly come from synchrotron radiation facility. Radiation from X-ray tubes with a source size of the order of micrometer is also applicable for X-ray phase-contrast imaging (XPCI), because of its fairly good spatial coherence. In this paper, a new type of laboratory system for XPCI, based on a nanofocus X-ray tube with the source size of 500 run, is reported. The experimental results show that this XPCI lab system is applicable to the high resolution imaging of the inner structure for low Z samples, such as soft tissues, organic materials etc.. Resolution of a few micrometers was achieved. Compared to the system reported earlier, spatial resolution and effective flux for the new one have been greatly improved. Open angle for the cone-shaped X-ray beam is about 30? Distance between the sample and source can be easily adjusted to meet the specified magnification ratio through projection, so that the limits to the resolution of X-ray detectors can be reduced. It is possible for the system to investigate the samples with relatively large size, while a mechanic system is designed to ensure the transverse 2-d scanning of them. Important application potentials for the XPCI lab system can be found in the fields of clinical medicine, biology, material science, chemical reaction dynamics, etc..  
        关键词：Phase-contrast imaging;Spatial coherence;Nanofocus X-ray tube   
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        发布时间：2021-03-12
      • LUO Zhenlin FU Yang GENG Bin LIU Wenhan GAO Chen
        Issue 10, (2003)
        摘要：A novel high throughput structure and composition characterization method for combinatorial materials based on polycapillary X-ray lens and energy dispersive X-ray diffraction (EDXRD) was proposed, and its prototype was setup in our group. We also demonstrated its applicability. Meanwhile its performance was also discussed.  
        关键词：Combinatorial materials;Polycapillary X-ray lens;EDXRD (Energy dispersive X-ray diffraction)   
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        发布时间：2021-03-12
      • LI Rong JIANG Guoqiang SUN Ying WANG Qinguo SHUAI Maobing
        Issue 10, (2003)
        摘要：The XRD researches of tritium aging of U and LaNi5 have been presented. The major effect of tritium exposure present in the XRD patterns for LaNi5 is peak broadening. It was found that the effect disappeared after the helium-3 was removed by 1230 K. On the contrary, the peak broadening of the XRD patterns for aged uranium samples was inconspicuous. The tritium aging effects in the equilibrium desorption isotherms were also slight.  
        关键词：LaNi5;Uranium;Tritium;Helium-3   
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        发布时间：2021-03-12
      • WANG Wensheng HE Duohui QIU Aici SUN Fengrong LUO Jianhui ZHOU Haisheng
        Issue 10, (2003)
        摘要：A Ni-film bolometer driven by the pulsed constant-voltage supply was developed for measuring soft X-ray energy under 1 keV generated from the Qiang-Guang-I, while the measuring system of the soft X-ray power was established with an X-ray diode detector. Results of the soft X-ray energy and power measurements were obtained at the experiment of Kr gas-puff high-power Z-pinch plasma.  
        关键词：Plasma;Soft X-ray diagnostic;Bolometer;X-ray diode detector;Power   
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        发布时间：2021-03-12
      • LU Xiangdong XIE Dong TIAN Dongfeng
        Issue 10, (2003)
        摘要：The regularities followed by γ-ray self-absorption corrections of nuclear materials under common geometry conditions have been studied by the numeric simulation. Many models were adopted. The results show that the self-absorption corrections are not related to shape and size of the sources. The method is succinct, and the conclusions are useful for actual situation and offer bases for data analyzing. The component of a sample is analyzed by means of the self-absorption correction.  
        关键词：Gamma-ray self-absorption correction;Numeric simulation test;Geometrical condition   
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        发布时间：2021-03-12
      • CHEN Yixue WU Yican Fischer U
        Issue 10, (2003)
        摘要：A rigorous 2-step (R2S) method has been developed to calculate the shutdown dose rates in full three-dimensional geometry. Based on the Monte Carlos code MCNP and automated interfaces, this method has been successfully validated by the ITER shutdown dose rate experiment T-426 and compared with the direct 1-step (D1S) method. Both methods show good agreement with the experiment and R2S gives more reliable estimation compared to D1S. The results imply that R2S method can be applied in shutdown dose rates calculation of large and complex nuclear fusion devices.  
        关键词：Rigorous-2-step method;Monte Carlo method;Shutdown dose rate;Nuclear fusion   
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        发布时间：2021-03-12
      • GONG Jian HUANG Ling
        Issue 10, (2003)
        摘要：Los Alamos National Laboratory and Lawrence Livermore National Laboratory have researched and developed the non-destructive accounting technology for many years. They used HPGe detectors with very good energy resolution to detect the y rays emitted from plutonium and analyze its isotopic abundances. The results can satisfy the requirements of SNM Accountability. A comparative experimental study was carried out to test the two techniques and to comment on their specifications.  
        关键词：Plutonium isotopes;Abundance;Non-destructive analysis   
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        发布时间：2021-03-12
      • WEI Lun WANG Changzheng CAI Yingwen LI Aiguo ZHANG Guilin WANG Songyou LI Jianguo
        Issue 10, (2003)
        摘要：A magneto-optic chip of Fe-(Co6Ag94) granular film was fabricated by combinatorial implantation of Fe ions into co-sputtered Co6Ag94 films. Structures of the as-prepared and annealed films have been estimated by XRD, and evidenced the precipitation and growth of granular phase. The AFM has been employed to study the surface morphology and the grains size. The changing of surface morphology with annealing temperature indicates that nanoparticles embedded in the Ag matrix have been formed during annealing. The effects of Fe content, as well as the annealing temperature on the magneto-optic polar Kerr effect have been investigated. It suggests that the Kerr rotations rise with increasing Fe content, which contribute to the magnetic moment. Precipitation and growth of Co, Fe, FeCo granules resulting from the annealing also lead to the increases of MOKE. The study shows that the addition of Fe increases the Kerr rotation of CogAg94 granular films, while the Mossbauer study shows that the precipitation of nanocrystallites plays a major role in the enhancements of MOKE.  
          
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        发布时间：2021-03-12
      • SHI Lei HE Xiaoping QIU Aici
        Issue 10, (2003)
        摘要：In this paper, operational principle of the pinch-reflex ion diode is analyzed, effects of various pinch-reflex ion diode parameters on beam electrical parameters are studied. From a large number of experiments, the peak ion current of 2.1 kA and ion beam energy of 5.5 J with a pulse width of about 20 ns are obtained, with the best ion current generation efficiency being 6.2 %.  
        关键词：Intense pulsed ion beam;Pinch-reflex ion diode;Biased charge collector;Space charge effect   
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        发布时间：2021-03-12
      • CHEN Guiming YANG Nengjun DONG Zhenqi ZHANG Baojun
        Issue 10, (2003)
        摘要：This paper gives several formulae and technology for designing and preparing the nuclear radiation protection materials, based on the interaction of radiation interaction with matter. The radiation protecting and mechanical capabilities of such a series of samples are tested. According to the test and analysis, a new radiation protection material with excellent performance is manufactured with the radiation cross-linking method. The use of this new material is also discussed.  
        关键词：Nuclear radiation;Protection;Radiation cross-linking   
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        发布时间：2021-03-12
      • GENG Jianhua CHEN Yingmao CHEN Shengzu
        Issue 10, (2003)
        摘要：Beta dose point kernels were investigated in this paper. The derivation, advantage and disadvantage of various tabulated dose point kernels and formulated dose point kernels proposed were discussed, respectively. The accuracy of these formulated dose point kernels were compared with each other. And the suggestion of what formulated dose point kernel should be used was put forward.  
        关键词：Beta ray source;Dose point kernels;Absorbed dose   
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        发布时间：2021-03-12
      • HAN Xuehui
        Issue 10, (2003)
        摘要：Based on the analysis of measured results of radon exhalation rate and the related influencing factors, a new measuring method is developed. It can further depress the effects caused by various influencing factors. Also, it has the merits such as simple device, batch and repeated measurement, low cost, high efficiency and so on.  
        关键词：Direct measurement;Radon exhalation rate   
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        发布时间：2021-03-12
      • HE Bin XIAO Gang LU Ming YAO Xueming JIA Dounan
        Issue 10, (2003)
        摘要：Three-dimensional transient process of transport of indoor radon has been imitated with numerical differential method, and effects of air pressure, temperature and wind have been quantitatively discussed. The calculation results show that the radon concentration indoors is decreased with the height increasing, and while the air pressure, temperature and wind outside the room change, the pressure differences and radon concentrations indoors will change too, but their phase differences are more than 180°. The experiment proved the measured results consistent with the calculation.  
        关键词：Environment;Radon;Numerical simulation   
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        发布时间：2021-03-12
      • TANG Guoyou ZHANG Songbai ZHANG Guohui CHEN Jinxiang SHI Zhaomin
        Issue 10, (2003)
        摘要：The angular distributions and total cross sections of 10B(n, α)7Li reaction were measured from 4.0 to 6.5 MeV by using a gridded ionization chamber. The results show that the angular distributions are backward peaked in the center of mass reference system, and this trend becomes more obvious as the incident neutron energy increases.  
          
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        发布时间：2021-03-12
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