最新刊期
      卷 0 ， 期 0 ， 2020
      • Issue 7, (1994)
        摘要：The contents of Pb and Fe in hair of 1308 children and the aged have been determined by XRF. It was found that the contents of both elements were significantly higher in hair of children and the aged than that of adults, and the highest for infants. Furthermore, the contents were decreased with age in childhood and increased with age in the senile, at least for old women. This work suggests that the most attention should be paid to the harmfulness of Ph to children, especially to infants.  
        关键词：Hair;Lead;Iron;XRF;Children;The aged   
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        发布时间：2021-04-09
      • Zhang Weihua
        Issue 7, (1994)
        摘要：A preconcentration neutron activation analysis method has been developed for determination of 14 rare earth elements in soil,sediment and some rock samples. The method involves sample melt together with Na2O2,coprecipitation and ion exchange.Unlike usual INAA, this method can greatly disprove the sensitivity for the REE other than Er, Pr,Tm, Nd and Ho. The absolute detection limit depends on specific elements, the lowest is 8.4ng for Eu and the highest 3.92 μg for Pr.  
        关键词：PNAA;REE;Geological samples   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：RBS/C and ellipsometric spectra were employed to analyse the damage layers of silicon implanted with 26keV As+ ions with the tilt angle of 7°,15°, 30°, 45° and 60°respectively. Some Physical phenomena of low-energy and large-angle tilt ion implantation were discovered.  
        关键词：As￣+;Low- energy ion implantation;Large- angle tilt ion implantation   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：Angular distributions and preferential sputtering for Sn and Al atoms ejectedmom the AlxSn100-x.（x=90,70,50,30,10） alloy system bombarded by 30keV Ar+ ions lave been studied with the collector technique and the RBS analysis.To explain the experimental results, a model considering the influence of surface topography and ocalised element enrichment on the atomic ejection is proposed, and the explanation isquite satisfactory.  
        关键词：Localized element enrichment;Sputtering;Alloys   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：Seeds of maize, rice, wheat, rye etc were implanted by nitrogen or phoshorus ions with energy of 35 to 180keV. The effects on germination percentage,growth speed and plant type were investigated. In the observation of chromosomes,the characters of chromosomes were found normal in mitoses, but abnormal in some meioses. The distributions of implanted ions in seeds were measured by RBS andcalculated with TRIM program. The mechanism of biological effects induced by ion implantation and the prospect for application were discussed.  
        关键词：Ion implantation;Biological effect;Chromosome aberration;RBS analysis   
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        发布时间：2021-04-09
      • Lin Chenglu
        Issue 7, (1994)
        摘要：Al films with a thickness of 700nm（containing 0.85wt% Cu） were deposited on <100> Si substrates. 400keV N or 350keV N ions with doses ranging from 4.3×1017 to 1.5 × 10,18N/cm2 were implanted into the Al films or at the interface between Al and Si, respectively. Automatic spreading resistance, RBS and channelling and Infrared Spectroscopy were used to characterize the formation of AlN and the depth distribution of Cu impurity in the Al films oher ion implantation and post- annealing.The formation of a stoichiometric AlN layer was evident from the ASR, RBS and IR analysis by the Presence of the absorption band at 650cm-1. Segregation of Cuimpurity into the AlN was enhanced during ion implantation by point defects generated by the N+ ion beam.  
        关键词：N￣+ ion implantation;Aluminium nitride;Cu impurity segregation   
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        发布时间：2021-04-09
      • Huang Zhigao
        Issue 7, (1994)
        摘要：Hydrogenation, low temP6rature and magnetic field effects of amorphousFad--.CoxZrlo （x=0,4,10,20） alloys are studied with Mbssbauer spectroscOPy. Theexperimental results show that hydrogenation and low temperature make thehyperfme fields of the amorphous alloys increase, but they have dtherent influenceson magnetic anisotrOPy, i.e. hydrogenation makes the plane anisottopy PY increasewhile low temperature makes it decrease. The hroerfine field distributions of fouramorphous alloys are all bloodal, which means that the coealstence Of fe￣agnoticand antiferromagnetic states, hydrogenation and eXternal magnetic field all make thepercentage of antiferromagnetic slotes decrease. Hydrog6nation and temperatureeffectS become even stronger with decreasing Co content, which is also confirmed bythe difference of the spin--wave excitation and the average hyperhae field as afunction of hydrogenation take.The ed)erimental results are explained with a"3DFM+FS+FSC" magnetic stfuctnye model and a magnetic aaisotrOPy modelresulting from a diPOle-- diPOle interaction.  
        关键词：Amorphous alloys;Mossbauer spectroscopy;Magnetic anisotropy   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：A Phoswich detector consisting of a 1mm thick PILOT-U and a 40mm thick NE115 is used to measure the particles emitted in 4oAr+ 197Au reaction with beam energy of 25 MeV/u. By measuring the fast and slow composition of the Phoswich aclear Z identification is obtained. For Z= 1 particles, p,d and t can be separated.  
        关键词：Phoswich detector;Heavy ion reaction;Particle identification   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：Carbon cluster ion beams were extractrd from a Cs sputtering negative ion source with a graphite sputtering cathode. A few kinds of ions with relatively weak electron affinity were observed. From the same ion source, negative cluster ion beams of C60,C70 and their dissociated products were also obtained with a cathode containing the mixture of C6o and C70.Some characteristics of the cluster ion mass spectra for both cathodes were described, and the dependence of the C60 beam current intensity on the operation parameters was also given.  
        关键词：Cluster;C60;Cs sputtering negative ion source   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：Computer simulations of the moderator structure for 14MeV neutron source have been made by using TAMAKER- ANISN Program and 46 groups （25 neutron groups and 21 Photon groups） UW cross-section data with an IBM/PC AT computer.Polythene was chosen as the moderation material and lead as the intensifying msterial. In the calculation the （n,2n） reaction of lead was acted as a fission source introduced into the source term of the transport equation. The calculation results have been justified by the experiments and the optimum structural combination ofpolythene and lead has been found. In principle, the intensifying factor for the peak thermal neutron may be larger than 3.0 when using lead as the intensifying material in polyethene moderator.  
        关键词：MeV neutron source;Moderator structure;Intensifying material;Intensifying factor   
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        发布时间：2021-04-09
      • Issue 7, (1994)
        摘要：Relative intensities of secondary X-rays excited by 241Am and 238Pu sources in Fe and Cu foils with different thickness have been measured by a Si（Li） detector in the incidence direction. The experimental results indicate that:1) intensity of secondary X-rays is raised with the increase of the foil’s thickness which is ranged from 5 to 100 μm; 2) there are more characteristic X-rays excited in the higher Z materials; and 3) intensity of secondary X-rays is related to activity,and energy of the exciting source and the way of the foil’s formation. Finally, the mechanism for the experimental results are briefly discussed.  
        关键词：Second X- rays;Low energy photon sources;Foils   
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        发布时间：2021-04-09
      • Weng Sihao
        Issue 7, (1994)
        摘要：The selective dielectric heating with microwave energy to convert a portion of pyrite particles to moderately magnetic pyrrhotic has been suggestedto enhance the magnetic separation of inorganic sulfur from coal. The results of Mossbaueranalysis show that a considerable amount of pyrrhotite produced during microwave irradiation, carrying with some of non- magnetic pyrite（unconverted）, ferrous sulfate,and troilite, is completely removed from coal after magnetic separation. The optimum desulfurization efficiency can be obtained by appropriately controlling the irradiation time to maximize the amount of pyrrhotite formed during pyrite decomposition.Excessive irradiation would be unfavorable for approving magnetic separation due to further decomposition of pyrrhotite to antiferromagnetic troilite.  
        关键词：Coal desulfurization;Microwave irradiation;Magnetic separation;Mossbauer spectroscopy   
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        发布时间：2021-04-09
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