最新刊期
      卷 0 ， 期 0 ， 2020
      • WANG Xiangqi HE Ning FENG Deren
        Issue 4, (2006)
        摘要：A kind of solid state modulator trigger control system based on CPLD, microprocessor and network is in- troduced. The trigger signal is generated by EPM7128S, and both frequency and width of the trigger signal are con- trolled by AT89C51 which is connected to the network through RTL8019AS. The details of hardware and software are also given in this paper.  
        关键词：CPLD;Microprocessor;RTL8019AS;Modulator   
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        发布时间：2021-03-12
      • LIU Yi
        Issue 4, (2006)
        摘要：A synchrotron radiation small angle X-ray scattering beamline and station is designed, which has energy range of 5—20 keV, energy resolution better than 1×10-3 and photon flux greater than 1x1011 s-1. The sagittally bent crystal monochromator is used to monochromize the synchrotron radiation, as well as to focus the X-ray beam hori- zontally. The distance from the detector to the sample is adjustable to achieve desired small angle resolution. The sample environments with controllable temperature and pressure are suitable for the time resolution experiment. The fast shutter system will make the time resolution reaching to the millisecond region.  
        关键词：SSRF;Synchrotron radiation;Small angle X-ray scattering;Beamline and station   
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        发布时间：2021-03-12
      • CHEN Yeqing WU Yichu WANG Zhu
        Issue 4, (2006)
        摘要：Interaction between hydrogen and defects in AISI 304 stainless steel was investigated by positron annihi- lation lifetime and coincidence Doppler broadening (CDB) measurements. Hydrogen was electrochemically charged into the annealed stainless steel samples in 0.5 mol/L H2SO4 solution for 1h at different current density. Experimental results show that mean lifetime τ, second lifetime component τ2 and its intensity I2 increase with current density. This means that hydrogen-induced defects are created in the annealed stainless steel samples. Furthermore, the CDB ratio curves (ratio to annealed sample) show that the enhancement in the low-momentum region (less than 5×10-3 m0c) af- ter hydrogen-charging denotes that the positrons are trapped in hydrogen-induced defects, which is consistent with the result of positron lifetime. It is interestingly found that an obvious peak appears in the high-momentum region after hydrogen-charging, and the peak site doesn’t vary with current density. This suggests that hydrogen might interact with vacancy and become the center of vacancy accumulation, leading to the formation of vacancy-hydrogen com- plexes, which results in the change of chemical environment of defects.  
        关键词：Positron annihilation;Coincidence Doppler broadening (CDB);Hydrogen;Defect;Steel   
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        发布时间：2021-03-12
      • HUANG Yanjun LIN Jun LI Shuzhen LI Shimin XIA Yuanfu
        Issue 4, (2006)
        摘要：M?ssbauer effect has become a necessary tool in the study of hyperfine interactions since it was discovered. But the application of this technique was restricted by several factors such as the recoil-free factor and the lifetime of the M?ssbauer precursor isotope. With the development of the radioactive nuclear beam techniques, dozens of short life M?ssbauer precursor isotopes were discovered. After educed from the Isotope Separator On-Line (ISOL) facility, the M?ssbauer precursor isotopes were implanted into the samples, and then the M?ssbauer spectra were recorded on-line. The on-line M?ssbauer spectrometers have been established on many ISOL-type radioactive facilities (such as CERN, RIKEN) all over the world. In this paper a test bench of on-line M?ssauber spectrometer is introduced.  
        关键词：On-line Mssbauer spectroscopy;Radioactive nuclear beam;Isotope separator on-line;Parallel plate avalanche counter   
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        发布时间：2021-03-12
      • WANG Siguang1 MAO Yajun1 TANG Peijia2 1
        Issue 4, (2006)
        摘要：A multi-channel spectrum of plutonium samples measured by HPGe detector includes 22 γ or X-ray lines in the 94—104 keV energy range, which can be used to provide information on the abundances of plutonium isotopes. A code named as CMGA (China Multi-Group Analyzer, Version 1.0), developed to unfold this region, is introduced in this paper. One and only one plutonium sample we can obtain was measured 19 times and the results of 240Pu/(239Pu+240Pu) given by CMGA are presented. The ratio of the mean 240Pu/(239Pu+240Pu) value from repeated measurements given by CMGA to that given by mass spectrum analysis is 1.004 with a relative standard deviation around ±1.4%.  
        关键词：Plutonium isotopes abundances;Multi-channel γ ray spectrum;Non-destructive assay   
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        发布时间：2021-03-12
      • WU Huailong HAO Fanhua GONG Jian XIANG Yongchun HUANG Ruiliang
        Issue 4, (2006)
        摘要：Other than obtaining the quantity of gas fission products by a deduced formula, the dynamic calculation is derived on the basis of the probability decay law. The differential of the time variable is considered and the change trend of the quantity of the nuclei is understood by calculating the variation in every tiny time fraction. Thus a calcu- lation method of fission quantity is developed by simulating chemical sampling and physical measurement.  
        关键词：Gas fission products;Numerical calculation;γ-spectrum   
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        发布时间：2021-03-12
      • YANG Tianyou1 CHEN Linhai1 QIN Guangyong1 LI Zongwei1 SU Mingjie1 WANG Yanping1 CHANG Shenghe1 LI Zongyi2 HUO Yuping1 1
        Issue 4, (2006)
        摘要：The effects of non-implantation factors, such as drying, vacuum and the staying time of the E.coli LE392 culture, on survival rate of E.coli LE392 were studied when E.coli LE392 was irradiated by the low-energy N+. The results show that the survival rate of E.coli LE392 does not reduce steadily all the time but rapidly drops sometime during drying. The survival rate of E.coli LE392 declines sharply as the samples are placed in vacuum, then falls in- distinctively with increasing of time. The tolerance of E.coli LE392 towards vacuum increasingly strengthens when the E.coli LE392 culture is placed at room temperature. Preparing the culture in batchs can ensure the consistency of the irradiated samples and avoid errors caused by the inconsistent samples. When the non-implantation factors are controlled, E.coli is implanted by 30 keV N+ of 1×1014 cm-2 and 3×1015 cm-2, respectively. And the results show no difference in the E.coli’s survival rates between batchs at the same dose.  
        关键词：Non-implantation factors;Survival rate;Drying;Vacuum;N+ implantation   
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        发布时间：2021-03-12
      • LIU Yunhong1,2 WANG Rong1,3 SUN Xufang2 YANG Jingbo2 DUAN Liying2 1
        Issue 4, (2006)
        摘要：For simulating space environmental radiation a 2×1.7 MV tandem accelerator was used. GaAs solar cells with and without MQW were irradiated using 2 MeV protons with fluences of 1×109—2×1013 cm-2, and the I-V char- acteristics and the spectral response of GaAs solar cells were measured. The results show that the degradation of Isc, Voc and Pmax of the two kinds of solar cells increases as the irradiation fluence rises. But the degradation for the GaAs solar cells with MQW is more serious than that for the GaAs solar cells without MQW at the same irradiation fluence. After irradiation with a fluence of 2×1013 cm-2, the spectral response of GaAs solar cells with MQW drops in the whole wavelengths (400—1000 nm), and the quantum well characteristics in the long wavelengths (900—1000 nm) disappear. Thus, the addition of MQW structure to GaAs solar cells results in the degradation of its radiation tolerance.  
        关键词：GaAs;Solar cells;MQW;Proton irradiation   
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        发布时间：2021-03-12
      • WANG Jianqing SONG Yuntao WU Songtao ZHANG Yuanbin
        Issue 4, (2006)
        摘要：International Thermonuclear Experimental Reactor (ITER) is an unprecedented international collaboration program. Magnet cryostat feedthroughs are the channels that ensure the normal operation of magnet. The structures of cryostat feedthrough (CF) components have been designed, analyzed and optimized by means of the FEM software in this paper. The results show that the structures satisfy the design requirement and the optimized methods are reason- able.  
        关键词：ITER;Cryostat feedthrough;Finite Element Analysis (FEA);Optimization   
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        发布时间：2021-03-12
      • CHENG Muhua PAN Zhiheng LING Yunbiao ZHANG Feng CHEN Weizhen
        Issue 4, (2006)
        摘要：The purpose of this paper is to study the quantitative method of evaluating hepatic function of patients with hepatocirrhosis. The 37 cases of hepatocirrhosis and the 12 controls were arranged to perform the hepatobiliary dynamic imaging with 99mTc-labelled ethylene hepatobiliary iminodiacetic acid (99mTc-EHIDA). Based on the three compartmental model, we acquired the radioactivity-time curves of the liver cell, and calculated the function indexes of liver cell’s uptake and excretion. The peak time and mean residue index for the hepatocirrhosis group were higher than those for the normal controls, P< 0.01. Compared to normal controls, the peak value, index of uptake, uptake slope and excretion slope of the time–activity curves for the hepatocirrhosis group were all lower, P<0.05. Hence the quantitative evaluation of hepatobiliary imaging was a better method for evaluating the change of liver cell functions of hepatocirrhosis.  
        关键词：Hepatocirrhosis;Hepatic function;Radionuclide scintigraphy   
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        发布时间：2021-03-12
      • ZAN Liangbiao LIU Ning YANG Yuanyou JIN Jiannan
        Issue 4, (2006)
        摘要：α-emitting nuclides are considered as very attractive in cancer therapy due to their strong radiobiological characteristics and cytotoxicity, especially for disseminated and micrometastatic tumors. In this paper, progress of the targeted tumor therapy with α-emitting nuclides are reviewed with 65 references. In addition, its present situation, problems and prospect are also discussed.  
        关键词：α-emitting nuclides;Radiopharmaceutical compound;Tumor;Targeted therapy   
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        发布时间：2021-03-12
      • WANG Jianlong CHEN Can
        Issue 4, (2006)
        摘要：The microbial reduction of radionuclides has received increasing attention recently because these trans- formations can play important roles for the remediation of environment contaminated by radionuclides. This review focuses on the research progress in the reduction of radionuclides including U(VI), Np(V) and Tc(VII). The mecha- nisms of microbial reduction are discussed, the environmental impact of such transformations as well as the possible applications of these activities in the bioremediation are also evaluated.  
        关键词：Microbial reduction;Radionuclide;Bioremediation;Environmental biotechnology   
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        发布时间：2021-03-12
      • HUANG Biao1,2 TAO Wenyi1 ZHANG Lianfen1 SHI Jin1 ZHAO Xiaolian1 JIN Jian1 1
        Issue 4, (2006)
        摘要：The aim of this work is to provide a rapid, selective and very high sensitive method for the determination of aflatoxins B1(AFB1) using the indirect competitive time-resolved fluoroimmunoassay (TRFIA). On the indirect competitive assay, aflatoxins B1-horseradish peroxidase (AFB1-HRP) is bound on the surface of a microtiter plate. AFB1 containing samples or standards and a rabbit anti- AFB1 antibody are given in the wells of the microtiter plate. Solid-phase bound and free AFB1 compete for the antibody binding sites, the secondary antibody, labelled with Eu3+ is used to enable detection. The luminescent enhancement solution contained mainly 2-naphthoyltrifluoroacetone. Results showed the AFB1 detection limit to be 0.01 μg /L for indirect competitive TRFIA formats. The 80%, 50%, 20% inhibition binding effect dose (ED80, ED50, ED20) of AFB1 were (0.07±0.01) μg/L, (0.63±0.02) μg/L and (12.5±0.47) μg/L, respectively. The assay range was 0.01—100 μg /L. The cross reactivity with aflatoxins B2 was 10% and antibodies did not react with aflatoxins G2, ochratoxin A, ochratoxin B and HRP. The within-run and be- tween-run CVs of the AFB1- TRFIA were 4.1% and 6.8%, respectively. The mean recoveries of samples were 97.2%. Both TRFIA and ELISA tests were applied to the quantitative measurement of AFB1 in the same samples, and the co- efficient of correlation was 0.917. The present studies clearly show that the newly developed TRFIA could be applied to detect the AFB1 contamination in samples. The AFB1-TRFIA provides very high sensitivity and optimal range, and it will be useful to screen AFB1 contamination easily, simply and economically when the number of samples is large.  
        关键词：Aflatoxins B1;Time-resolved fluoroimmunoassay (TRFIA);Mycotoxin;Antibodies   
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        发布时间：2021-03-12
      • DU Yan GU Chenglin
        Issue 4, (2006)
        摘要：A pulsed magnet with 10 mm in bore diameter and a pulsed duration of 10 ms is designed, which can generate the magnetic flux density of 60 T. The behavior simulation of this magnet supplied by different pulsed power modules is also presented.  
        关键词：Magnets;Pulsed magnets;Magnet design;Simulation   
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        发布时间：2021-03-12
      • LI Chengbo1 YUAN Jian1 MENG Qiuying1 ZHOU Shuhua1 ZHANG Lu2 ZHANG Taiping2 NING Baojun2 TIAN Dayu2 1
        Issue 4, (2006)
        摘要：The silicon PIN photodiode is an important part of the PbWO4 detector read-out system that will be used in the Photon Spectrometer (PHOS) in the CERN/ALICE experiment. High specific resistivity n-type silicon material is used for the first time in our R&D of PIN, and special techniques are employed in the production process to ensure low dark current, high quantum efficiency, and low noise. The PIN diode has a sensitive area of 16 mm×17 mm. The leak current is lower than 5 nA at room temperature, the quantum efficiency in the wavelength range of 400—500 nm is about 82%, and the junction capacity is about 110—120 pF. The noise level (ENC) of PIN+PreAmp system is lower than 600 e at –25℃. The PIN diodes have passed the long-term stability test. The performance of our R&D PIN photo-diodes has overall met the ALICE/PHOS requirement.  
        关键词：PIN;Junction capacity;Leakage current;Quantum efficiency;ENC   
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        发布时间：2021-03-12
      • YANG Quanjiu ZHANG Dawei MA Bing LV Zongfang ZHAO Shujun LV Yunpeng
        Issue 4, (2006)
        摘要：A muliti-channel nuclear data acquisition system composed of many detecting channels is introduced, with which radiation from the 4 MeV electrostatic accelerator can be monitored in time. Every channel adopts AVR chip microprocessor ATmega128 as host controller and transfers data through USB interface based on CH375. With great acquisition speed, short dead time and high counting rate, this system can detect and analyze many kinds of ra- diation, such as γ, X, fast-neutrons and so on. If some detecting sensors are changed and some parameters are adjusted, the system can be applied to radiation monitoring for facilities other than accelerators.  
        关键词：Muliti-channel nuclear data acquisition;Electrostatic accelerator;AVR chip microprocessor;USB con- troller   
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        发布时间：2021-03-12
      • SHEN Ji1 CHEN Ziyu1 YE Yunxiu1 CUI Xiangzong2 LI Jiacai2 1
        Issue 4, (2006)
        摘要：This paper describes the research on the energy and position resolution of the MWPC used in the e/π Test Beam on BEPC (Beijing Electron Positron Collider), which localizes the particles of e/π by the readout method of gravity center of the induced charges on the cathode strips. The spatial resolution of about 0.24 mm and energy reso- lution of 17% for 5.9 keV γ photons are attained at the 3700 V anode voltage. For the 1.1 GeV electrons, the spatial resolution of 0.3 mm is obtained. The contributions of various factors to energy resolution are analysed. It is found that energy resolution is changed with the anode voltage and there exists a least energy resolution. The reasons for these are discussed.  
        关键词：Multiwire Proportional Chamber (MWPC);BEPC;Test beam;Cathode induction;Position resolution;Energy resolution   
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        发布时间：2021-03-12
      • HOU Xinsheng1 SHAO Li2 QU Yong2 XU Shuxi2 1
        Issue 4, (2006)
        摘要：Rn concentration is an important factor in the indoor air quality survey. In order to decrease Rn concentration in lower residence, Rn concentration in the soil of groundwork has to be surveyed to avoid high Rn concentration in the residence to be built. The variation rules of Rn concentration in the soil of the groundwork in Chengdu area is discussed from different angles.  
        关键词：Groundwork;Lower residence;Rn concentration;National standard   
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        发布时间：2021-03-12
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