最新刊期
      卷 0 ， 期 0 ， 2020
      • WANG Yun1,2 JING Long1 FENG Weiyue1 WANG Bing1 WANG Huajiang1,2 ZHU Motao1,2 WANG Meng1 OUYANG Hong1 ZHAO Yuliang1 CHAI Zhifang1 WU Zhonghua31
        Vol. 32, Issue 1, (2009)
        摘要：A better understanding of biological effects of nanomaterials in organisms requests knowledge of the physicochemical properties of nanomaterials in biological systems. Affected by high concentration salts and proteins in biological medium, nanoparticles are much easy to agglomerate, hence the difficulties in characterizing size distribution of the nanomaterials in biological medium. In this work, synchrotron radiation small angle X-ray scattering (SR-SAXS) was used to determine size distributions of Fe, Fe2O3 and Fe3O4 nanoparticles of various concentrations in PBS and DMEM culture medium. The results show that size distributions of the nanomaterials could perfectly analyzed by SR-SAXS. The SR-SAXS data were not affected by the particle content and types of the dispersion medium. It is concluded that SR-SAXS can be used for size measurement of nanomaterials in unstable dispersion systems.  
        关键词：Small angle X-ray scattering;Nanoparticles;Dispersion system;Particle size distributions   
        19
        |
        13
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231264 false
        发布时间：2021-03-12
      • CHU Kecheng YIN Chongxian LIU Dekang
        Vol. 32, Issue 1, (2009)
        摘要：At Shanghai Synchrotron Radiation Facility (SSRF), timing signals are sent via optic fibers from event generator (EVG) to event receiver (EVR) for all kinds of subsystems and equipments to get precise sequence signal. But the phase drift between output signal sent from EVR and high frequency signal is produced for temperature variation of optic fiber caused by complicated local environment. In order to compensating the phase drift, a phase drift compensation system for the timing system has been developed. In this paper, we report in detail the hardware architecture and the digital phase detecting algorithm, and test results of the compensation system as well.  
        关键词：Phase drift compensation;Timing system;Phase detecting algorithm   
        14
        |
        12
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231287 false
        发布时间：2021-03-12
      • TANG Junlong1 LI Deming2 SHEN Tianjian2 1
        Vol. 32, Issue 1, (2009)
        摘要：A test and control system was designed to evaluate performance of the digital power supplies for SSRF. The software of serial communication (RS-232) and Ethernet interface was developed with LabVIEW. The system can perform functions of instrument and power supply control, data acquisition and display, and store data for 24 h. LAN users can access the system and acquire data conveniently. The data are stored in Excel for analysis and establishment of database of digital PS in the future.  
        关键词：LabVIEW;Digital power supply;Stability   
        16
        |
        11
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231324 false
        发布时间：2021-03-12
      • CAO Lin1 KANG Wu1 XIANG Yongchun1 BIAN Zhishang1 LI Wei1 HAO Fanhua1 Riedmann R A2 Purtschert R2 Loosli H H2 1
        Vol. 32, Issue 1, (2009)
        摘要：As a definitive and unambiguous indicator of a nuclear underground explosion, the noble gas of 37Ar is an important nuclide for on-site inspections under the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization). The Institute of Nuclear Physics and Chemistry has developed the movable 37Ar rapid detection system (MARDS) for on-site inspections, in which low level decay counting method is employed for 37Ar activity measurement. Because no stand is available for 37Ar activity measurement, comparison of the 37Ar activity measurement is necessary. In this paper, comparison measurement between INPC and Division of Climate and Environmental Physics, Physics Institute, University of Berne (KUP) is reported. The results show that the method used in MARDS is of great reliability in 37Ar activity measurement. This work can enhance the trust of CTBTO for MARDS and support the potential application of MARDS in on-site inspections.  
        关键词：37Ar;Activity measurement;Comparison;Proportional counter   
        15
        |
        14
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231307 false
        发布时间：2021-03-12
      • FEI Shunting1 ZHOU Ruimin1 DENG Bangjun1 LIN Xiangfeng1 ZHANG Jianqiang1 ZHOU Fei2 1
        Vol. 32, Issue 1, (2009)
        摘要：Electron beam-irradiation method was used to prepare Cu/Sn alloy nanoparticles using polyvinyl alcohol (PVA) as the surfactant. The products were characterized by X-ray powder diffraction (XRD) and transmission electron microscopy (TEM). The effect of the concentration of surfactant PVA on the particle size was studied by ultraviolet-visible spectrophotometer (UV-vis) and laser scattering particle size distribution analysis (LSPSDA). The average sizes were 172.1, 16.4, 14.1 and 6.4 nm for the copper-tin alloy nanoparticles prepared with the PVA concentrations of 0, 8, 16 and 24 mg/mL, respectively.  
        关键词：Copper-tin alloy nanoparticles;EB-irradiation;Surfactant;Size distribution   
        15
        |
        12
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231483 false
        发布时间：2021-03-12
      • DU Liang DAN Guiping ZENG Junhui
        Vol. 32, Issue 1, (2009)
        摘要：SiC films on stainless steel prepared by ion beam mixing were irradiated to 1×1018 ions/cm2 by 5 kV H+ beam. Secondary ion mass spectrometry (SIMS) was used for depth profiling of H+ and mass spectra of positive species in the samples. The property of SiC films’ hydrogen resistance and the mechanism were studied. The permeability coefficient was measured to confirm the capability of tritium resistance. It was found that the SiC films on stainless steel show good retarding effects on the permeation of hydrogen isotopes. The tritium permeability is reduced by 4~5 orders of magnitude, and the hydrogen resistance of SiC films is the result of C-H, C-H2, C-H3, Si-H, Si-H2 and Si-H3 in the films.  
        关键词：SiC films;Tritium infiltration;Tritium resistance;Stainless steel   
        13
        |
        11
        |
        2
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231296 false
        发布时间：2021-03-12
      • YANG Kang MA Mingwang CHEN Xiliang ZHU Zhiyong
        Vol. 32, Issue 1, (2009)
        摘要：The irradiation of solids by energetic particles may cause extensive displacement cascades and point defects (vacancies and interstitials), and can be widely used for material modification. In order to repair an electrical breakdown photoconductive antenna (PCA), we irradiated the (100)-oriented, low-temperature (LT) grown GaAs substrate with 1016/cm2 of 2 MeV helium ions. After being implanted, electric resistance of the PCA has increased from 800 ? to 60 M?. The irradiated PCA exhibits improvements in the output power in comparison with the electrical breakdown PCA and its signal intensity has increased from 2 nA to 8 nA. Accordingly, its output power has become more than one order of magnitude higher than that before irradiation. The frequency range of PCA has obviously improvement.  
        关键词：Ion irradiation;THz spectra;Photoconductive antenna   
        14
        |
        11
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231343 false
        发布时间：2021-03-12
      • LI Shaoqing1 SHEN Lianguan2 1
        Vol. 32, Issue 1, (2009)
        摘要：The thermostat system for a low-power accelerating tube was designed with the help of numerical simulation on temperature. The results revealed that the primary role of thermostat system was not cooling but uniforming the temperature and reducing the environmental impact.  
        关键词：Accelerator;Cooling system;Numerical simulation   
        17
        |
        13
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231334 false
        发布时间：2021-03-12
      • LI Zhe TUO Xianguo MU Keliang WANG Honghui ZHONG Hongmei
        Vol. 32, Issue 1, (2009)
        摘要：Matrix effect always affects EDXRF (Energy Dispersive X-ray Fluorescence) analysis of mineral samples. In this work, characteristic X-ray peaks of Ti and Fe in different ore samples were fitted by Gaussian fitting function and analyzed in an attempt to solve nonlinear relation between the counting rate and elemental contents, Classification and forecast methods were used in the analysis. Core samples (80 groups) were classified by the SOFM self-adapt neural net and the identification rate of concentrated iron ore and concentrated titanium ore samples is 100%. The RBF net was used to forecast the contents of Ti and Fe. Comparing the forecast results with chemical analysis results, relative errors of 65.4% samples were less than ±1%, and the others were less than ±3%, whereas less than 5% is demanded by the industry production. The results show that it is an effective method to use ANN technique to classify and forecast element content in core samples.  
        关键词：EDXRF;Matrix effect;SOFM net;RBF net;Content forecast   
        16
        |
        11
        |
        11
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231393 false
        发布时间：2021-03-12
      • ZHANG Yuan WANG Shiheng ZHANG Shifeng
        Vol. 32, Issue 1, (2009)
        摘要：Grease stain thickness in pipeline detected by 137Cs γ-ray was simulated by Monte-Carlo method. The simulation results agree with the experimented results. The weighted method was used to improve the variance. The response relationship was found between transition rate of the γ-ray and grease stain thickness. These provide basis for the nondestructive transmission method and the development of measuring instrumentation.  
        关键词：γ-ray;Ray transmission method;Thickness detection;Monte-Carlo method   
        16
        |
        15
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231531 false
        发布时间：2021-03-12
      • LIANG Lizhen HU Chundong LIU Zhimin LI Jun
        Vol. 32, Issue 1, (2009)
        摘要：The structure and principle of Diagnostic Neutral Beam in HT-7 tokamak is introduced. The factors affecting the ratio of temperature rise, shutoff effect of sample hole and beam focus are analyzed, and experiment results could be explained by analysis. According to ratio of average of temperature rise, the focus of beam was calculated. The result revealed that error was no larger than 0.05, which is required by the system design.  
        关键词：Diagnostic neutral beam;Beam estimation system;Target plate;Ratio of temperature rise   
        16
        |
        20
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231410 false
        发布时间：2021-03-12
      • LI Mian1 YANG Jianfeng1 HOU Jiancai2 SHEN Zhenzhou1 1
        Vol. 32, Issue 1, (2009)
        摘要：Based on analysis of 137Cs activities in soil profiles on hill slope of different slope lengths in the Loess Hilly Area in China, the spatial variance of erosion was studied. The results show that the slope length has great impact on the spatial distribution of the soil erosion intensity, and the soil erosion intensity on loess hill slope was in a fluctuating tendency. In the influx process of runoff in a small watershed, net soil loss intensity increased first and then decreased with flow distance.  
        关键词：Cesium-137;Soil erosion;Slope length;Loess Hilly Area   
        15
        |
        19
        |
        4
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231464 false
        发布时间：2021-03-12
      • LIU Qingcheng WU Xinmin LIU Yujuan YANG Yaxin ZHANG Ye
        Vol. 32, Issue 1, (2009)
        摘要：According to elemental geochemistry in Beijing, the uranium content in the area was measured, and distribution of radon concentration was predicted. Based on the uranium-radium equilibrium coefficient, porosity and diffusion coefficient, which were either measured or calculated, the radon geological potential of Beijing city was studied using γ-ray spectroscopy or mass spectroscopy and certain models were used to calculate the relation between radon geological potential and lithology and geological structure. The results showed that radon geological potential of Beijing city could be divided into four zones, tend of every zone coincides with the main structure, and the potential values nearly relate with geological factors.  
        关键词：Beijing city;Radon;Radon exhalation rate;Radon geological potential   
        16
        |
        17
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231439 false
        发布时间：2021-03-12
      • XIE Quanxin LI Dayong WU Jianjun
        Vol. 32, Issue 1, (2009)
        摘要：The reuse of recycled uranium form the spent fuel can save the resource of natural uranium. The enrichment of 235U, dilution of 232U and compensation of burning-up depth caused by 236U must be synthetically considered in the separation of recycled uranium form LWR. Based on the cascade theory of multi-component isotope separation, several different cascade schemes for the separation of recycled uranium were presented. Theoretic calculations were conducted for different cascade schemes. The result of calculation shows that the double cascade scheme with a carrier gas is optimum one.  
        关键词：Spent fuel;Recycled uranium;Multi-component cascade;Isotope;Separation   
        16
        |
        21
        |
        6
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231382 false
        发布时间：2021-03-12
      • XU Hongkun1 FANG Fang1 CUI Junliang2 WANG Pan1 DING Weicheng1 1
        Vol. 32, Issue 1, (2009)
        摘要：Energy spectral analysis is an important method for applications in earth science, environmental science, and other fields of research. In this paper, we introduce a new spectral analysis system based on LabVIEW. By wavelet analysis and Gaussian fitting, functions are realized to smooth, identify and scale the peaks of an α- or γ-ray spectrum. Concentrations of the radon gas, and the uranium, thorium and potassium radionuclides, are calculated. By the virtual instrument technology based on LabVIEW, one is able to make full use of computer hardware resource and improve the processing capacity of the system with reduced costs. The system, with a user-friendly interface, can be widely used in applications of mineral analysis, building material analysis, environmental assessment of the radiation, and many other occasions.  
        关键词：Energy spectral analysis;LabVIEW;Wavelet reconstruction   
        14
        |
        13
        |
        1
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231354 false
        发布时间：2021-03-12
      • TANG Yuelin1 WEI Biao1 REN Yong2 MI Deling1 FENG Peng1 PAN Yingjun1 1
        Vol. 32, Issue 1, (2009)
        摘要：According to key problem of real-time calculation of FFT in nuclear signal frequency spectrum analysis, the special structure feature of "0" and "1" series is used in neutron pulse signal. Neutron pulse series Fourier translation algorithm is proposed with addition and address instruction by new rotation-table. The algorithm is optimized by SSE, and a PC-based real-time frequency spectrum analysis algorithm is implemented at 1 GHz sampling rates. Numerical experiments demonstrate that the presented algorithm is about 517% faster than FFTW, and is enhanced performance about 209% by SSE at the count rate of 3×106 s-1. The algorithm meets the demand of real-time frequency spectrum analysis.  
        关键词：Signal processing;Neutron pulse series (NPS);Spectrum analysis;SSE   
        12
        |
        13
        |
        5
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231422 false
        发布时间：2021-03-12
      • YANG Shumin1,2 XIE Qiaoling1,2 ZHOU Xingtai1 ZHU Dezhang1 GONG Jinlong1 1
        Vol. 32, Issue 1, (2009)
        摘要：In this paper, effect of pressure on deposition temperature for hot filament chemical vapor deposition of diamond thin films was investigated. SEM images show that diamond film of small grain size can be deposited at 500°C by decreasing the pressure from 5.32 kPa to 0.67 kPa. Raman spectra show that the quality of the film deposited at 0.67 kPa and 500°C was as good as that of the film deposited at 5.32 kPa and 700°C. We believe that the deposition of diamond film at low temperature and low pressure is due to the effect of pressure on the concentrations and kinetic energy of the active species near the substrate surface. Compared to the situations with higher pressure, the active species at 0.67 kPa arrive at the substrate surface with higher concentration, which makes it possible for the high-quality diamond films of small grain size can be deposited at very low temperature (500°C).  
        关键词：Diamond film;System pressure;Hot filament chemical vapor deposition   
        13
        |
        12
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 7231367 false
        发布时间：2021-03-12
      0