最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 3, (2000)
        摘要：This work focuses on the rocking curves of H~+-implanted single silicon crystal detected by Four-Crystal X-ray diffractmeter. The samples were annealed under different temperatures. Lattice defect in H+-implanted silicon crystals was detected by Rutherford Backscattering Spectrometry. It appeared that H-related complex didn’t crush until annealing temperature reached about 400C. At that temperature Hi was formed, deflated in silicon lattice and strained the lattice. But defects didn’t come into being in large quantity. The lattice was undamaged. When annealing temperature reached 500, strain induced by H2 deflation crashed the silicon lattice. A large number of deflects were formed. At the same time bubbles in the crystal and blister/flaking on the surface could be observed.  
        关键词：H~+-implantation;X-ray multi-crystal diffraction;Rutherford backscattering   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：The method of dating a series of 14C samples must suffice high accuracy of dating raised by Project of Xia-Shang-Zhou Chronology. The calibration for series samples using Bayesian statistics is a key work in the method. In order to estimate the applicability and accuracy of the program OxCal. The results calculated by our program and those from OxCal have been put in comparison. The calculation shows that the program OxCal suits the project.  
        关键词：14C dating;A series of samples;Chronological calibration   
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        发布时间：2021-03-12
      • DAI Huiying
        Issue 3, (2000)
        摘要：InP[100] surface was irradiated by monochromatic synchrotron X-rays above (2.153 or 27.98keV) and below (2.140 or 27.85keV) the K-shell binding energy of phosphorus or indium. The experimental results showed that the shapes of XPS P2p. peak changed greatly whether the photon absorption occurred at K-shell of phosphorus or indium atom. The enhancement factors of K-shell absorption for P and In were 4.4 10~-6kg/C and 3.1 10~-5kg/C respectively.  
          
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        发布时间：2021-03-12
      • WANG Chunyan
        Issue 3, (2000)
        摘要：In this paper, the authors brought up a method of using X-rays with varied energy spectra for density distributed imaging, the imaging algorithm, the sources of error, and the mathematical model of error correction were discussed. Finally, some experimental results were given. The results showed that the method was hopefully to be applied in practice.  
        关键词：X-ray;Energy spectrum;Density analytic imaging;Non-linear correction   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：A simple theory, based on a two-zone approximation of the arc column, has been developed to study the properties of arc generated by the air plasma cutting process. Theoretical results of arc radius, arc voltage and the pressure at the nozzle exit as a function of arc current have been obtained for a range of operating conditions, including varying air flow rates, and different nozzle diameters. Some results obtained are in good agreement with the measured values for an air plasma cutting. Also, the dependence of the nozzle diameters and the mass flow rate of plasma gas on plasma power and arc force has been discussed.  
        关键词：Plasma cutting;Arc property;Two-zone approximation;Sonic condition   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：By using very precise, highly sensitive, static accumulated, easily repeated CD- 1 a -cup to survey the migration rule and mechanism of radon and its daughters was studied, and significant results were obtained: (1) Under laboratory conditions, the vertical component of migration of radon and its daughters was much greater than the horizontal component, the former was over 90% and the latter was less than 10%. (2) Despite the very big specific gravity of radon and its daughters, the descending component of migration was less than 45%, while the ascending component was more than 45%. (3) After a -particles (emitted from radon and its daughters) being slowed down, 4He combined with the radon and its daughters to form clusters. When the density of the cluster was less than that of the air the self-ascending would occur.  
          
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：The improvement in the grid-controlled electron gun of the 200MeV linac in the National Synchrotron Radiation Laboratory (NSRL) was discussed. The s and us mode pulser systems were put together, so it was not necessary to change circuit board when work mode was alternated. After the bench tests of the pulser on both p s mode and us mode were done, and some relations between current and grid voltage, filament current, anode voltage, were obtained the combined pulser was installed in the LINAC of HLS (Heifei Synchrotron Radiation Light Sourc).  
        关键词：Grid-controlled gun;Pulser;us pulse;μ s pulse   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：By using radiotracer technique, the sorption and desorption behaviors of iridium in marine sediment-seawater system were studied through the sorption and desorption experiments and visible absorption spectrum analysis. The results indicated that, in the range of very low iridium concentration, the sorption and desorption isotherms were linear, and the sorption-desorption process was irreversible. Iridium in the form of IrCl62- was very easy to be sorbed by the sediments. Once being sorbed by the sediments, Ir was hard to be desorbed. In the sedimentary process, the sediment continuously absorbed the species of IrCl62- from the seawater, which might lead to the Ir accumulation in the sediment. The sorption ability of the Danish K/T Fish Clay was weaker than that of the coastal sediment, which indicated that the excessively high Ir content in the Fish Clay might be caused by the other enrichment mechanisms, such as volcanic or extraterrestrial origin.  
        关键词：Marine sediment;Iridium;Sorption;Desorption;Enrichment   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：Radiosensitivity of tumor cells was studied by the Cytokinesis-Block(CB) micronucleus assay. The results show that radiosensitivity of tumor cells induced by heavy ions and y -rays can be predicted with CB technique, it has the advantages of time saving and higher possibility of success. The dose response for micronuclei per binucleated cells is given by Y= c + kD~n or Y= c + aD+ AD~2 when treated with heavy ions, and given by Y= c + aD in the case ofγ -rays. Under the same dose, effectiveness of heavy ions is stronger than that of γ -rays.  
        关键词：CB micronucleus assay;Tumor cells;Heavy ions;γ -rays;Radiosensitivity   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：The design of the ferrite core and magnetic field of the kicker magnet in the new injection system of HLS is presented. The influences of electromagnetic properties of the ferrite core, including permeability in the range of designed frequencies, spectra, power dissipation and stability to the magnet are also discussed.  
        关键词：Spine safe ferrite;Bump orbit;Kicker magnet;Good field area;Frequency property of ferrite;Power dissipation caused by eddy current;Size resonance   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：intelligent radiation dosimeter, with multiple channel signal collection and data processing, storaging, printing and display, has been developed. It can measure doses at six different positions at one time. The device consists of six microsemicondutors. This dosimeter can be used in irradiation experiments by 6oCo source, radiotherapeutic facilities and radiation processing.  
        关键词：Dosimeter;Microsemiconductor detector;60Co radiation;Multiple channel   
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        发布时间：2021-03-12
      • Issue 3, (2000)
        摘要：Progress in the mechanism research of irradiation-induced DNA single- and double-strand break are reviewed. Researches in recent years show that the yields of DNA strand breaks are related to DNA concentration and scavenging--capacity and are also influenced by DNA structure. a DSBs, induced by the one-hit event of radiation energy deposition, can be formed from both the single free radical transfer mechanism and the LMDS mechanism besides by the direct effect of radiation. For high LET radiation, αDSBs are mainly induced by the LMDS mechanism. In addition, thiol compounds have charges-related radiation protection effects on DNA. Due to the effects of the secondary free radicals of scavengers, the reverse oxygen effect can be observed for DNA strand break. Furthermore, the cylinder model of non-homogeneous kinetics is widely applied to analyze the reaction of ’OH with DNA theoretically.  
          
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        发布时间：2021-03-12
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