最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 4, (2000)
        摘要：In order to study how impurities effect the parameters of positron spectroscopy, a series of Si crystals with different impurity concentrations have been investigated by using slow positron beam. The results show that doping does not effect the open volume of the defects but the mobility of positron does decrease with increasing doping concentration.  
        关键词：Positron mobility;Defect;Slow positron;Parameter S   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：The structural changes of aspartic acid （Asp） and phenylalanine （Phe） implanted with N+ ions of 30keV were studied using Fourier transform infrared （FTLR） spectroscopy. Implanted at the same fluence of 1×1016/cm2, similar phenomena were observed in both Asp and Phe, i.e., the relative intensities of NH3+ vibration decreased and those of COO- stretching vibration increased. The changes of absorption intensities in Phe were more obvious than those in Asp. It was also observed that the intensities of COOH, COO- and NH3+ groups of Asp changed regularly with increasing implantation fluences. The possible reasons responsible for these results were studied. The radiolysis products of Asp implanted at a higher fiuence of 6×1016/cm2 were analyzed.  
        关键词：Low energy ion implantation;Radiation effects;FTIR;Aspartic acid;Phenylalanine   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：The depth distribution of vanadium in the embroys sunflower after V ion implantation were studied by SEM and TEM. The longitudinal depth of vanadium was 18 μm in seed coat while it was not found in embryo. And the TEM results indicated that the microstructure of embryo cells after implantation was not obviously changed.  
        关键词：Low energy ion implantation;Vanadium;Microstructure   
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        <引用本文> <批量引用> 7205111 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：A high-T_c YBaCuO superconductor lens was used to focus intense relativistic electron beams. The superconductor lens(Tc≥90K, Jc≥150A/cm~2) was developed into taper-shape with a length of 100mm and a thickness of 4mm. The inner diameters of both ends were 60mmm and 40mm respectively. The experimental results indicate that the superconductor lens possesses obvious focusing characteristic and can be used to effectively control the beam intensity distribution with a flated top in the beam transverse-section.  
        关键词：High-T_c superconductor;Lens;Intense relativistic electron beams;Focusing   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：A positron lifetime spectrometer consisting of a thin scintillator that detects positrons penetrating through it, has been established on the basis of β~+ -γ coincidence. The spectrometer has been used in the measurement of a Si sample with a time resolution FWHM = 255ps.  
        关键词：Positron lifetime;β~+-γ coincidence;Time resolution   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：The contents of chromium in the DNA, RNA and protein fractions separated from chromium-rich and normal brewer’s yeast were determined with the neutron activation analysis in order to study the combination of Cr with DNA, RNA and protein in chromium-rich brewer’s yeast. Our results showed that the extracting rats and concentrations of DNA, RNA and protein had no significant difference in two types of yeast, but the chromium contents of DNA, RNA and protein in the chromium-rich yeast were significantly higher than those in the normal. In addition, the content of chromium in DNA was much higher than that in RNA and protein, which indicated that the inorganic chromium compounds entered into the yeast cell, during the yeast cultivation in the culture medium containing chromium were converted into organic chromium compounds combined with DNA, RNA and protein.  
        关键词：Chromium;Chromium-rich brewer’s yeast;DNA;RNA;Protein;Neutron activation analysis   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：The decay of 70As to levels in 70Ge has been studied using a NaI-HpGe Compton-suppression spectrometer and a three-parameter（γ-- γ-T） coincidence system of HpGe-HpGe detectors. From the single γ-ray spectra, the energies and relative intensities of 65 gamma rays were determined. Gamma-rays of 1036.99, 1196.66, 1539.29 and 2531.7keV were observed for the first take. From the coincidence data, the decay scheme was constructed. Five new levels of 3570.53, 3744.23, 4243.10, 4554.25 and 5265.81keV and some previoualy unknown transitions （corresponding to 496.74, 685.50, 1295.24, 1417.24, 1507.80, 1881.67, 2219.34, 2325.42 and 2424.41keV γ-rays） have been found. The intensities of β+ and electron capture feeding corresponding levels and lgft values were calculated.  
        关键词：Decay;γ-rays;Coincidence;Levels   
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        <引用本文> <批量引用> 7204622 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：Microorganisms were used to release 14C-chlorsulfuron bound residues from soil. It was revealed that 34.40%-40.55% of total bound residues became extractable after incubation for 5 days, and the amounts of these residues changed slightly thereafter. It was also showed that those residues which existed in fulvic acid（FA） fraction of soil organic matter would be preferentially released by microorganisms. Compared with the control, two bacteria, Bacillus me gaterium and Arthrobacter sp., did not demonstrate a strong ability to release bound residues.  
        关键词：Chlorsulfuron;Bound residues;Microbiological release   
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        <引用本文> <批量引用> 7204881 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：(s)-BZM { （s）- （-）-2-hydroxy-3-6-methoxy-N- [（1-ethyl-2-pyrrodinyl） methyl] benzamide} was labelled with radio-iodine by low concentration hydrogen peroxide plus acetic acid （LCHPPAA） as oxidant, The radio-iodinated IBZM was separated by Sep-Pak C18 cartridge. The results showed that the LCHPPAA was a superior oxidant for preparation of radio-iodinated IBZM. This process had no by-products and its labelling yield was ≥90%. The radiochemical purity of purified products was 96.8% ±1.4% （n= 5）. The overall yield of the radio-iodinated IBZM prepared by this method was 81.9%±2.8% （n=5）. Therefore, the LCHPPAA labelling technique and the Sep-Pak C18 cartridge purification method was very useful for the preparation of radio-iodinated IBZM in clinical application.  
        关键词：Radio-iodinated labelling;Receptors of dopamine;Receptor imaging   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：This paper briefly describes the new injection system of Hefei synchrotron radiation Light Source (HLS). The perturbed bump orbit caused by the kicker magnets’ error and its effect on the injection process are analyzed. Simulations of 3 kinds of operation modes have been performed to find out the allowance of the kicker magnets’ error.  
        关键词：Kicker magnet;Close orbit;β function;Bump orbit   
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        <引用本文> <批量引用> 7205022 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：Since the very small cross section and the high background in the experiments induced by neutrons, it is very difficult to study the double differential cross section of (n, charged particles) reactions. Besides some special techniques relating to structure of the detector, methodology of mesurement and offline calibration, the event selection techniques should also be considered in the readout and data acquisition sections of measuring system. In this paper an event selection system for the measurement of the double differential cross section of (n, charged partilce) reactions is described in detail.  
        关键词：Neutron;Charged particle;Event selection;Background   
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        <引用本文> <批量引用> 7205060 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：The trace elemental contents in normal male (20-40 years old) scalp hair collected in 1994 and 1996, respectively, at the Shijing Shan district of Beijing have been determined with the instrumental neutron activation analysis. The comparison of the elemental contents between these two batchs of samples has been made by means of statistical t-test in order to evaluate the alteration trend of the environment situation in this area and the changes of nutrition state of the studied group. It has also been compared with the published data in literature of the elemental contents of scalp hair to indicate its functions on the study of environmental bioindicating.  
        关键词：Human hair;Trace elements;Environmental bioindicator   
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        <引用本文> <批量引用> 7204608 false
        发布时间：2021-03-12
      • ZHANG Yongming
        Issue 4, (2000)
        摘要：An important question in particle physics, astrophysics and cosmology is whether or not the rest mass of neutrino is exactly zero. Chooz experiment is a long-baseline search for the neutrino oscillations, which utilize a gadolinium-loaded liquid scintillation detector 300m underground and one kilometer from a large nuclear power station. It can probe Δm2 values down to 1×10-3eV2 for large sin22θ values. Its total detection efficiency comes to 81% and the total error is about 3.7%-5.1%.  
        关键词：Neutrino oscillation;Liquid scintillator;Pressurized light water reactor   
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        <引用本文> <批量引用> 7204672 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：A method of density-thickness joint compensation was developed to make the on-line measurement of moisture for moving irregular mineral materials. At the same take, the materials’ thickness, as a weighted factor, was chosen to modify the prompt moisture in a fixed time and improve the accuracy of measuring moisture. The result is in accord with the data of Reference [5]. The experimental data show that the measurement accuracy is better than 5% for a thickness of >2cm and a moisture of >6%. The system has been running on the spot for about three months, with a result accorded with that by the stoving-weighing method.  
        关键词：Neutron moisture gauge;Density-thickness joint compensation;Irregular moving materials flow   
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        <引用本文> <批量引用> 7204856 false
        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：Three new extratants, N-octanoylpyrrolidine(OPOD), N-decanoylpyrrolidine (DPOD) and N-dodecanoylpyrrolidine(DOPOD) have been synthesized and their structure has been identified by means of FT-IR and ~1H-NMR spectra. Their extracting properties with U(Ⅵ) have been studied.  
        关键词：N-acylpyrrolydine;Extractants;Synthesis;Uranium(Ⅵ)   
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        发布时间：2021-03-12
      • Issue 4, (2000)
        摘要：A new method of fixed soil core Eu tracer associated with INAA technique for studies on erosion of red soil in sloping fields is described. Principles for selection and amount calculation of the tracer, the tracing and INAA procedures, the calculation of the erosion results, as well as its application in bamboo fields at sloping area are introduced. The results show that this new method is suitabls for investigating the sheet or rill erosions of red soil in sloping fields.  
        关键词：INAA;Soil erosion;Red soil slope field;Fixed soil core Eu trace technique   
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        发布时间：2021-03-12
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