最新刊期
      卷 0 ， 期 0 ， 2020
      • Liu Changshi
        Issue 3, (1994)
        摘要：he point defects of Pb and E’in two kinds of Si-SiO2 formed by different techllological process,before and after irradistion with different dosage and bias field, have been examined using election spin resonance （ESR）. The experimental results show that there are Pb defects in both kinds of Si-SiO2 no matter whether they are irradiated, and the radiation of 60Co can generate more Pb defects in the Si-SiO2 systems. In the first kind of Si-SiO2 the E’ defects can be observed after irradiation with positive bias field, while with free field these defects appear only when the irradiation dosage is as high as 50 kGy（Si）. But there are not any E’ in the second kind of Si-SiO2 even if they are irradiated. Besides, the ΔH（peak to peak） of Ph and E’ in the ESR spectya indicates that Ph is referred to a slow relaxation defect but E’ to a fast relaxation defect. Finally, the experimental results are qualitatively explained.  
        关键词：Pb defect;E’defect;Si-SiO2;ESR   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：y implanting 2.0MeV（φ= 1.0×1015/cm2）+2.9MeV（φ= 1.1 ×1015/cm2） oxygen ions into semi-insulating GaAs crystal, the sample has an almost homogeneous oxygen concentration in the range of 1.5 μm to 2.5 μm. The implanted samples were annealed respectively for 15 minutes at temperatures ranging from 400-800℃. The samples annealed at 500℃and 600℃ have high resistivity （108Ω·cm）, but those annealed at temperatures higher than 600℃ have lower resistivity and become p-type. The 2.0MeV RBS/channeling analysis shows that the crystal is almost totally recovered when annealed at temperature higher than 700℃.  
        关键词：High energy implantation;GaAs;Oxygen;Resistivity;Damage Profile   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：The concentration of 12 elements in 414 hair samples of male adults from esophageal cancer group（ECG）, serious esophagus epithelial cell hyperplasia group（SEECHG）and normal control group （NCG） were determined by PIXE. By a t-test it is found that significant differences exist for 10 elements（St, S, Ca, Cr, Mn, Fe, Ni,Cu, Pb and Sr） between ECG and NCG and for 9 elements （St, P, S, Ca, Cr, Mn, Fe,Ni and Zn） between SEECHG and NCG. The three types of persons mentioned above were classified by Mahalanobis distance discriminatory analysis （one of thecomputerized pattern recognition methods）.The results show that the ratio of correct classification is around 72%,suggesting that this may become a promising method for the early diagnosis of esophageal cancer.  
          
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：The radiation hardness of scintillator tile/fiber calorhoeters with different structure and materials is described. Five calorimeter modules were irradiated up to 10 or 60 kGy using 1 GeV electron beam from BEPC. Radiation damage and annealing were quantified by the measurement of light yield at various integrated doses and in various locations within the calorimeter modules.  
        关键词：Scintillator;Fiber;Calorimeter;Radiation damage   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：sing a CR-39 solid track detector the Bragg peak location for 239Pu α-particles （5.15MeV） passing through an air gap of 3 or 4cm and a collimater of φ1mm aperture is determined according to the distribution rule of radiation damage density along charged particle tracks. For a-particles of about 1.2MeV, the Bragg peaks in CR-39 are located at about 7 μm, and the calculated value in this case is 6.14 μm. The experimental result is in good agreement with the theoretical value.  
        关键词：Solid track detectors;Heavy ion;Bragg peak;Localized induced mutation   
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        发布时间：2021-04-09
      • Jiang Rangrong
        Issue 3, (1994)
        摘要：he monthly 7Be monitoring results at 3 positions near Hangzhou are reported.The annual average 7Be concentration in the air above ground is 4.6±2.0mBq·m-3,about 50%-80% more than the value of UNSCEAR report. It reachs the amximum in October to December, the minimum in February and June to July, and approaches the mean value in April to May. These changes evidently relate to seasonal raining and do not follow UNSCEAR report, which indicates that the maximum occurs in spring and the minimum in late autumn caused by the subsidence from stratosphere.The 7Be radiation dose is also evaluated, which is much less than 222Rn and can be ignored.  
        关键词：?Be;Air above ground;Seasonal raining   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：Some topics on trace elements in the field of basic medical science were studied by means of Scanning Proton Microprobe（SPM） and Synchrotron Radiation X-ray Fluorescence Microprobe（SR-XMF） techniques.The preliminary results indicate that these methods, with high sensitivity, high resolution and being non- destructive,are particularly fit for the basic medical science research. They are very useful tools in microscopic study of cellular physiology to probe the biological functions of trace elements and to demonstrate pathogenic mechanism of some diseases.  
        关键词：Scanning Proton Microprobe（SPM）;Synchrotron Radiation X-rayFluorescence Microprobe（SR-XMF）;Lipoperoxidation   
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        发布时间：2021-04-09
      • Yang Ruiying
        Issue 3, (1994)
        摘要：The cenozoic volcanic rocks in eastern part of Liaoning-Jinn district consist mainly of basaltS which contain abundant mantle-derived xenoliths. The rocks of ultramafic inclusions are composed mostly of spinel lherzolites and a small amount of websterites. It order to study the origin of xenoliths, the concentrations of several trace elements （REE, Rb,Sr, Ba, Th, U, Hf, Sc, Cr, Fe, Co and Ni） have been studied by NAA. According to geochemical characteristics of REE and other trace elements,there are two types of spinel lherzolite inclusions. The first type is refractory residues left after partial melting of the upper mantle and the second type is metasomatizing refractory residues. It applies that even within a small volume beneath the area studied the upper mantle is inhomogeneous. But websterites inclusions are formed by segregation of basaltic melt derived from high degree of melting of mantle source rocks.  
        关键词：Ultyamafic inclusions;Primitive mantle;Residual mantle;Mantlemetasomatism;Spinel lherzolite;Websterite   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：The instrumental neutron activation analysis （INAA） has been performed on 27pairs of scalp hair samples for mothers and their new-born babies living in Haidian District, Beijing. The transfer of mercury in pregnant women and its accumulation in new-born babies were studied. The results showed that a significant positive correlation exists between the mercury contents in maternal and infant hair（r=+0.856, P<0.001）, and the infant level exceeded the maternal level by 12%.It was found that the concentration of mercury in maternal hair was gradually decreased during pregnancy.  
        关键词：INAA;Lying-in women;New- born baby;Hair;Mercury   
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        发布时间：2021-04-09
      • Guo Jingru
        Issue 3, (1994)
        摘要：During the past decade, China has made notsble progress in all areas of radioanalytical chemistry.The Progress in methodology and typical applications are reviewed in this article.  
        关键词：Radioanalytical chemistry;Progress;China   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：The application of DBN-arsenazo in determination of trace thorium was described. In aqueous solution,the thorium DBN-arsenazo complex exhibited maximum absorbance at 630nm. Molar absorptivity in 1 mol/L HCl was calculated（εmax=8.6×104L·mol-1 cm-1）.The uranium interference can be tole rated even if its intensity is 90 tabes higher than thorium itself. Beer’s law is obeyed in the concentration range of 0-13μg Th/10ml with correlation coefficient r=0.9991. In 30% TBP-kerosene solution,trace thorium can be directly determined by DBN-arsenazo using ethylene glycol monobutyl ether as intersolvent.The thorium DBN- arsenazo complex exhibited maximum absorbance at 620nm in the intersoluble system.Molar absorptivity was calculated（εmax = 4.9×104L·mol-1·cm-1）. Beer’s law is obeyed in the concentration range of 0- 14μg Th/10ml.  
        关键词：DBN-arsenazo;Trace thorium;Spectrophotometric determination   
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        发布时间：2021-04-09
      • Issue 3, (1994)
        摘要：A new-type double gridded ionization chamber（GIC） with a multi-parameters data acquisition and processing system has been established for the study of fast-neutron-induced（n,p）and（n,α） reactions. The system has been applied to measurements of angular distribution, energy spectra and integral cross section of the 40Ca（n, α）37 Ar reaction.  
        关键词：Double gridded ionization chamber;Angular distribution;Differential cross section;Fast neutron(n;p) and (n;α) reactions   
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        发布时间：2021-04-09
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