最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 4, (1995)
        摘要：Based on a portable radioisotope XRF instrument the XRF analysis method for light elementS in bauxite has been developed for the first time in China.It can be used to measure simultaneously elements, such as Al,P,S,K,Ca, Ti,Fe,and the Al/Si ratio.The confidence levels for analyzing Al2O3, SiO2 and Fe2O3 in bauxite are 100%, 93% and 97% respectively. Technical difficulties in the analysis of bauxite are indicated and basic concepts and some main test measures for tackling them are put forward.At last, the measurement results are given, and the selection of calibration samples and the asssy model are discussed.  
        关键词：XRF analysis;Bauxite;Quantitative assay model   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：Synthesis of [13C] urea is reported. The yield of [13C] urea from [13C] barium carbonate was 75%. The product was used for the breath test of helicobacter pylori.  
        关键词：Helicobacter pylori;[￣（13）C] labelled urea;Breath test   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：The existing forms of adsorbed Cr and the effect of PH value and Cr（Ⅵ） concentration on the forms were studied using sequential extraction and isotopic tracer technique. It was shown that the order of Cr adsorbed in different phases was Fe/Mn oxide>organic, and carbonate>residual>exchangeable. Adsorption of Cr in sediment was controlled by Cr（Ⅵ） concentration and pH value, but the distribution of Cr adsorbed in various phases was independent of these factors.Fe/Mn oxide and organic matter were the main adsorbent of Cr in sediment.  
        关键词：Sediment;￣（51）Cr;Adsorbed Cr;Sequential extraction   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：The influence of several factors on 186Re-BLM formation is investigated by means of Sn（II） reducing method. The results show that the labelling yield is mainly dependent on the pH value in reaction medium, and that sodium gluconate is a suitable protecting agent to avoid Re-oxidation of the reduced Re. The method for preparing 186-BLM is described with labelling yield up to 98% in the pH range from 3 to 4.5.  
        关键词：?186)Re-bleomycin;Tumor therapeutic agent;Sn（Ⅱ） reducing method;Sodium gluconate   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：In this paper a theoretical study of diffusion of positrons to the surface of semiconductors with an internal electric field was reported. For the semi-infinite medium, by using a radiative boundary condition and δ-function method, the fraction of positrons diffusing back to the surface was calculated. The results are of universal significance. For the film with a thickness d, the fractions of positrons diffusing to the surfaces at x=0 and x=d under an absorbing boundary condition were also calculated with the same method. As d approaches infinity, in both cases of implantation profiles, solutions of the positron diffusion equation for the semi-infinite medium can be obtained. The results can be used to the analysis of experimental data for the overlayer/substrate system which contains one film or leveral films and a semi-infinite medium.  
        关键词：Semiconductor;Positron;Semi-infinite medium;Film   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：A set of apparatus used for measuring a decays of mother-daughter nuclei is described. With this equipment a decays of mother and daughter nuclei produced in the nuclear reaction can be measured, respectively, and a time sequential α-spectrum can be obtained. This apparatus can be widely used in identification of new nuclides. Its properties and performance have been tested in experiments.  
        关键词：Mother-daughter detector;Mother-daughter nuclei;α-decay;Collecting chamber;Genetic relation;New nuclide identification   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：The high temperature oxidation resistance property of Y+ implanted H13 steel has been studied by 5.8 MeV proton backscattering. The measured oxygen area density of H13 steel after implanted with Y+ and oxidized at 800℃ for 45min shows that the oxidation speed is decreased by a factor of 25. The experimental results also show that for Y+ implanted H13 steel an enriched Cr layer was created and the behaviour of oxygen diffusion is apparently different from that of unimplanted samples.  
        关键词：Yttrium;Ion implantation;H13 steel;Oxidation resistance;High energy ion backscattering   
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        发布时间：2021-04-09
      • Sun Guanqing
        Issue 4, (1995)
        摘要：Envelopes of ion beam for different energies, masses and initial entrance conditions in the high-gradient accelerating tube were calculated. Space-charge effect of ion beam was also considered. Some important factors directly influencing the focusing properties of the accelerating tube were discussed. The calculated results are in agreement with the practical situation.  
        关键词：High-gradient accelerating tube;Beam transportation;Space charge effect   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：The concentration of impurity Ge on the cross section of silicon crystal was determined by synchrotron radiation-excited X-ray fluorescence analysis using a fundamental parameter method. The accuracy of the program was ascertained by analyzing standard samples. The relative error is less than 12%.  
        关键词：Fundamental parameter method;Synchrotron radiation;X-ray fluorescence analysis   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：As one of the experimental terminal facilities of the heavy ion accelerator in Lanzhou, a large cylindrical scattering chamber for general purpose has been built up and put in use. In this paper described is its structure and function. The total length of the chamber, the diameter of the cylinder, the maximun flight distance in forward angle and flight distance in periphery angle are 6.4, 2.4, 4.5 and 1.0m respectively. The spherical detector carriage, movable detector carriages and carriage for supporting the plastic scintillator detector wall are arranged around the target, in the middle and in the front of the chamber respectively. Samples can be placed in the Faraday-cup for radiation. Eight turbopumps with pumping rate of 1500L/s each are used to obtain high vacuum. The working vacuum is 4mPa and the up-limit vacuum can reach up to 0.8mPa.  
        关键词：Flight distance;Detector carriage;Scattering chamber   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：In this article studied was the temporal development of radiation damage in the first wall by fusion α-particles. By means of computer simulation program MARLOWE-13 with the time-ordered binary approximation, the radiation damage in amorphous iron materials caused by fusion α-particles with energies in the order of ten’s keV has been investigated. The time evolution of the distributions of vacancies, energy deposition and stopped α-particles in the materials have been calculated. The results based on the time-ordered and velocity-ordered collision cascade simulations has also been compared.  
        关键词：Radiation damage;Collision cascade;Velocity-order;Time-order   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：The design and experiments of an absorbed dose calorimeter in quasi-adiabatic mode of operation and its measuring system are described. The absoption disk and outer shell of the calorimeter are made of anisotropic pyrolytic graphite. The graphite itself is used as heating resistor of the electrical heating unit, for the purpose of check and simulation. The ratio of calculated value and experimental value for temperature rising is 1.008. The standard deviation is less than 0.6%. The total uncertainty of absorbed dose determination. with the graphite calorimeter approximetes to 2.7% （K=2） for the 0.5-3.0MeV electron beam in the dose range of 1-5×102kGy. The powder alanine/ESR dosimeter and plastic thin-film dosimeter can, be calibrated by the calorimeter. The passivation of temperature rising curve,heat equilibrium, measurement of calorimetric ratio and its error are also discussed in this paper.  
        关键词：Pyrolytic graphite calorimeter;High dose dosimetry;Radiation processing;Electron beam;Absorbed dose standard;Calibration   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：A dual ion beam technique was adopted to produce the Zr-O films, of which the composition was studied with RBS and XPS.The results show that all the films consist of three portions: a carbon contamination layer on the uppermost surface, the film bulk where N（O）/N（Zr）=const, and the transition layer between the deposited Zr-O film and the substrate. N（O）/N（Zr） is found to be changed from zero to 2.3 with the increase of oxygen ion beam density. But thicknesses of both carbon contamination layer and transition layer are unchanged for different oxygen ion beam densities. The formation of zirconium oxides in the film bulk was examined by Zr3d chemical shifts.  
        关键词：Dual ion beam technique;Zr-O films;Composition characterization   
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        发布时间：2021-04-09
      • Issue 4, (1995)
        摘要：The structure and performance of a silicon absorbed dose calorimeter are reported. The experimental results for flash X-ray radiation doses are presented.  
        关键词：Silicon;Absorbed dose;Calorimeter;Flash X-ray   
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        发布时间：2021-04-09
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