最新刊期
      卷 0 ， 期 0 ， 2020
      • JIANG Keyu ZHAO Zhenjie YANG Xielong
        Issue 8, (2001)
        摘要：Fe-K spinel structure is the predecessor of active phase of potassium promoted iron-based catalyst for dehydrogenation of ethylbenzene. Mssbauer spectroscopy has been used to study the formation process of Fe-K spinel structure which depends on the catalyst composition and preparing condition. The results may prove useful for production of industrial catalyst.  
        关键词：Dehydrogenation of ethylbenzene;Iron-based catalyst;Fe-K spinel;Mbsbauer spectroscopy   
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        发布时间：2021-03-12
      • CHEN Xinqing 2 ZHANG Yi 1 HU Jun 1 WU Shiying 1 HUANG Yibo 1 AI Xiaobai 1 QIU Xijun 2 LI Minqian 1 1
        Issue 8, (2001)
        摘要：Taking advantage of image processing technology, the contour length of DNA molecule was measured automatically by a computer. Based on the AFM image of DNA, the topography of DNA was simulated into a curve. Then the DNA length was measured automatically by inserting mode. It was shown that the experimental length of a naturally deposited DNA (180.4±16.4nm) was well consistent with the theoretical length (185.0nm). Comparing to other methods, the present approach had advantages of precision and automatism. The stretched DNA was also measured. It was shown that the experimental length (343.6±20.7nm) was much longer than the theoretical length (307.0nm). This result indicated that the stretching process had a distinct effect on the DNA length. However, the method provided here avoided the DNA-stretching effect.  
        关键词：Image processing;DNA;AFM;MATLAB   
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        发布时间：2021-03-12
      • DONG Yuean
        Issue 8, (2001)
        摘要：For the study of the neutron flux, secular equilibrium of chlorine-36 in the deep quaternary sediments of Hebei plain, the main chemical composition of water sand and confining bed was determined by neutron activation analysis. The mean neutron flux is 2.79×10 -5 cm -2 s -1 which was calculated by the chemical composition of the strata. The mean 36 Cl/Cl ratio in secular equilibrium is 1.27×10 -14 in the deep quaternary sediments, Hebei Plain. For the study of the groundwater age of the deep Quaternary sediments of Hebei Plain, the 36 Cl/Cl ratio of groundwater samples were determined by tandem accelerator mass spectrometry. The mixed groundwater 36 Cl/Cl ratio of the second and the third aquifer of Quaternary sediments in Baoding district is 247×10 -15 , that of the fourth aquifer in Baoding city is 224×10 -15 and the third aquifer in Cangzhou district is 40.5×10 -15 . The groundwater age of Baoding district was young and that of the third aquifer in Cangzhou was 229.2ka.  
        关键词：Neutron flux;36 Cl/Cl ratio in secular equilibrium;Accelerator mass spectrometry;Groundwater age;Hebei Plain   
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        发布时间：2021-03-12
      • LU Jianqin
        Issue 8, (2001)
        摘要：The Lie algebraic analyses for the pulsed beam transport in the electrostatic accelerating tubes were presented. The solutions through third order were obtained and could be extended to higher order if desired. In the analysis, the accelerating tube was divided into three elements: entrance aperture lens, uniform accelerating field and exit aperture lens. To obtain analytical forms of aberrations, the uniform accelerating region was also divided in several small segments, in which the Lie map was performed.  
        关键词：Electrostatic accelerating tube;Lie map;Third order approximation   
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        发布时间：2021-03-12
      • Issue 8, (2001)
        摘要：The cathode of MEVVA source was modified and co-implantation of V+C was carried out using the modified cathode at an average energy of 80keV to doses ranging from 1×10 17 to 8×10 17 cm -2 . The experimental result showed that the surface mechanical properties in the co-implanted layer were improved. The surface hardness increased 16 % - 82 %, and the wear resistance was 1.4-2.2 times of that of unimplanting surface. The maximum hardness and wear resistance were obtained from the sample with a dose of 4×10 17 cm -2 . By means of XRD, it was known that intermetallic compounds such as FeV, Cr 2VC 2, VC, Cr 23 C 6, and Fe 5C 2 were formed. These new Phases were contributed to the improvement of the surface properties for implanted layer. These results were also compared with that of V+C dual implantation. It showed that co-implanting method is more effective than dual-implantation for surface modification.  
        关键词：Co-implantation;Surface modification;Hardness;Wear resistance   
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        发布时间：2021-03-12
      • WEI Mengfu XIAN Xiaobin LIU Jidong
        Issue 8, (2001)
        摘要：The interaction between primary X-ray with Al plating and U matrix materials, characteristic X-ray with Al plating thickness and the effect of U matrix’s radioactivity on measurement of Al thickness has been discussed. A mathematical model of the relationship between intensity and plating thickness has been developed. UM or UL X-ray has been selected by the model to measure the thin or thick samples respectively. A measuring method of Al plating thickness (8.2-55.5μm) on U matrix has been established. The precision is better than 3% for 8.2-18μm samples and better than 5% for 18-55.5μm samples.  
        关键词：Nondestructive measurement;Uranium;Plating thickness;X-ray fluorescence   
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        发布时间：2021-03-12
      • ZHU Linfan FENG Renfei LIU Xiaojing WANG Yingxue XU Kezun YANG Tao NING Yujin HUANG Jianfu YU Xiaoqi
        Issue 8, (2001)
        摘要：A new by developed high resolution fast electron-energy-loss coincidence spectrometer was described. It consists of high resolution fast electron-energy-loss spectrometer, positive ion time-of-flight mass spectrometer, negative ion time-of-flight mass spectrometer, the corresponding electronics and data acquisition system. Using this apparatus, the scattered electrons, the ionized or dissociated positive ions, the dissociated negative ions or ionized electrons produced from the electron impact with atom or molecule can be measured simultaneously. The photoionization efficiency curve and the partial optical oscillator strength densities for different fragments of CO was determined by this work.  
        关键词：Time of flight (TOF);Electron energy loss spectrometer (EELS);Dissociation of molecule   
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        发布时间：2021-03-12
      • LING Daijun CAO Jinxiang LU Runlong ZHANG Chuanbao
        Issue 8, (2001)
        摘要：This article introduces the genotoxicity of low-temperature air plasma (LTAP), as a new mutagen with safety and non-pollution. With Saccharomyces cerevisiae as the index organism, the genotoxicity of LTAP in the dose-effect relationship of lethality and mutagenesis was discussed. The results showed the survival curve of the treated cells was fluctuating under 150W discharge power of LTAP. This special lethality made the 150W LTAP present exclusive feature of obvious mutagenesis with relatively low damage to treated cell. Our results showed the LTAP, as a new kind of mutagen, was efficient and distinctive.  
        关键词：Low-temperature plasma;Saccharomyces cerevisiae;Genotoxicity;Mutagen   
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        发布时间：2021-03-12
      • LI Zhengkui PU Peimin
        Issue 8, (2001)
        摘要：For purification of eutrophic lake water, immobilized nitrogen cycle bacteria (nitrobacteria- denitrifying) made from radiation copolymerization at low temperatures by means of glass forming monomers, i.e. 2-hydroxyethyl acrylate (HEA) and polyethylene glycol dimethacrylate (14G) were used. The Sequencing Batch Reactors (SBR) system and cell growths of nitrogen cycle bacteria techniques were carried out in order to treat eutrophic lake water. The results showed that the removal efficiencies for total N (TN), NH + 4-N and COD with immobilized nitrogen cycle bacteria were 75%, 91.5% and 75% respectively. The results demonstrated that the optimum temperature of immobilized nitrogen cycle bacteria system was 28℃. Immobilized nitrogen cycle bacteria system was more resistance to low temperature (10℃). The disolved oxygen (DO) concentrations have effect on removal efficiencies for TN.  
        关键词：Immobilized nitrogen cycle bacteria;Radiation technique at low temperature;Purifying water quality;Preradiation copolymerization;Water of Taihu lake   
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        发布时间：2021-03-12
      • ZHANG Jianmin DENG Li XIE Zhongsheng
        Issue 8, (2001)
        摘要：A study on detection efficiency of the neutron detector used in oil logging by Monte Carlo method. Detection efficiency of the thermal and epithermal neutron detectors used in oil logging was calculated by Monte Carlo methed using the MCNP code. The calculation results were satisfactory.  
        关键词：Monte Carlo method;Neutron logging;Detector;Efficiency   
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        发布时间：2021-03-12
      • XU Hongliang SUN Baogen WANG Lin LI Weimin LIU Jinying HE Duohui
        Issue 8, (2001)
        摘要：The injection parameters, including the dispersion functions, β functions and corrected chromaticities etc., for Hefei electron storage ring were measured. Especially, the influence of the direct current clear electrode on injection state parameters was measured and analyzed.  
        关键词：Direct current clear electrode;β functions;Dispersion function;Horizontal oscilating frequency;Corrected chromaticties   
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        发布时间：2021-03-12
      • HU Zhaohui LIU Shijie LIU Pingsheng HUANG Yuying LIU Peng FENG Guohua
        Issue 8, (2001)
        摘要：A study on the performances of wavelength-dispersive position sensitive spectrometer with a flat crystal (PSS) using micro-synchrotron radiation light beam (μ-SRL) as exciting source was made. The energy resolution of 14.2eV for Ti Kα, which was one order of magnitude better than that measured by Si(Li) detector, was obtained. The overlap between Cr Kβ and Mn Kα observed by Si(Li) detector for a stainless steel sample was clearly resolved by PSS. The detection limit for Cr in a sample of K 2Cr 2O 7 was <200μg/g and detect limit for Ti in an aerosol sample could reach 10 -9 -10 -10 g order. These indicated that with further decrease of detection limit of PSS, the research of trace element analysis with high-energy resolution would be feasible by using PSS combined with the exciting source of μ-SRL beam.  
        关键词：SRL;μ-SRXRF;PSS;Energy resolution;Trace element analysis;Detection limit   
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        发布时间：2021-03-12
      • YU Mingfeng GAO Yihai ZHANG Shenghu ZHENG Qiwen YU Qi GUO Yingxiang LEI Xiangguo
        Issue 8, (2001)
        摘要：This paper introduced the principle, method and results of the RF cavity high voltage measurement by using X-ray energy spectrum, and explained its advantages by comparing with RF voltage direct measurement method. Through practical operations, the accuracy and reliability of the energy spectrum measurement method was proved.  
        关键词：RF electric field;Bremsstrahlung;Continuous energy spectrum;Energy maximum value;Photoemission effect;Semiconductor detector   
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        发布时间：2021-03-12
      • DIAO Caozheng LIU Jinying HE Duohui JIA Qika LI Weimin XU Hongliang ZHANG Shancai
        Issue 8, (2001)
        摘要：The physical process of coherent harmonic SRFEL was studied, and a 3D program was written by the measured magnetic field values. The factors affected on the modulation rate of the spontaneous radiation were discussed; and the optimization of the external laser power and N d were presented.  
        关键词：Modulation rate;Coherent emission;Coherent enhance factor   
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        发布时间：2021-03-12
      • YANG Ruiying 1 YE Jun 1 WANG Ke 2 ZHANG Yongbao 2 WEI Long 1 1
        Issue 8, (2001)
        摘要：The areas of endemic arsenic disease in the Azuoqi belong to the drinking water type arsenism diseace area. A simple and sensitive method to identify the chemical forms of As was presented. Inorganic arsenic, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) were separated by the use of coprecipitation and cation exchange chromatography combined with neutron activation analysis. Separation of inorganic and organic arsenic (MMA and DMA) was based on coprecipitation with Fe(OH) 3, inorganic arsenic was coprecipited quantitativelly, but MMA and DMA was not coprecipited at all. Experiments showed that MMA and DMA in solution were adsorbed on cation exchange resin in pH2. MMA was eluted by 60mL of 0.5mol/L acetic acid-ammonium acetate buffer (pH4.7) and then 60mL of 3mol/L NH 3·H 2O was used to strip the DMA. The recovery of MMA and DMA was 96% and 103%, respectivery.  
        关键词：Chemical forms of As;Coprecipitation;Cation exchange chromatography;Neutron activation analysis   
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        发布时间：2021-03-12
      • ZHANG Peiqun LIU Nianqing CHEN Chunying
        Issue 8, (2001)
        摘要：The contents of 16 elements, including Ca, Cd, Co, Cr, Fe, Mo, La, Sm, Zn etc., in 47 autopsy liver samples collected from normal subjects who had an accidental death within 24 h in Tianjin, China, were measured with instrumental activation analysis. The differences of elemental contents in livers of male and female were compared by means of t -test, no significant difference was found for most of elements determined, except Cd, Co, Fe, Mo, La and Zn. A comparison between our data and those reported from some other areas in the world was made, no anomalous difference was found. The correlation among different elements in human liver was studied with multi-elements statistics. It was found that there was relatively closer correlation among some elements, and they could be reasonably explained by the similarity of electronic structures of the elements and their physiological functions in human body. Some interesting information on the interrelations of the elements in human body could be obtained from the study of elemental correlation.  
        关键词：Trace elements;Human liver;INAA;Elemental correlation   
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        发布时间：2021-03-12
      • JIA Fang MENG Zhaoxing HU Jiuhua WANG Hua LIU Boli
        Issue 8, (2001)
        摘要：The experimental conditions of 188 Re labeling with antibodies via NHS-MAG 3 as a bifunctional chelating agent were studied by pre-radiolabeling of chelate approach. The conjugation conditions were optimized for the best conjugation performance.The stability of 188 Re-NHS-MAG 3-IgG in vitro and 188 Re-NHS-MAG 3-CL3 in vivo was high.  
        关键词：188Re;Monoclonal antibodies;NHS-MAG 3;Bifunctional chelating agent;Conjugation   
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        发布时间：2021-03-12
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