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      • Weicheng Zhang
        Vol. 10, Issue 8, (1987)
        关键词：Mössbauer sources;in beam implantation technique;Synchrotron radiation   
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        发布时间：2022-09-13
      • Yuanfu Xia,Rongchuan Liu,Jing J.F.,H. Engelmann,U. Gonser
        Vol. 10, Issue 8, (1987)
        摘要：In earlier Mössbauer investigations of oxide glasses the spectra were usually fitted using simple Lorentzians. However in glasses a considerable line-broadening is caused by distribution of electric field gradients EFG. For a more detailed analysis of the measured spectra, in the present work the total quadrupole splitting distribution was calculated using the method of He se and Rubartsch. In addition the resulting distribution curves were fitted by Gaussian sub-distributions in order to separate the contributions of Fe ions in tetra and octahedral coordinations. The calculated mean quadrupole splitting and the distribution widths σΔ characterize the symmetry and the similarity of Fe ion surroundings respectively and hence can be used as a measure of short range order in glasses. From the quadrupole splitting distributions, according to the model developed by Brodbeck and Bukrey, distributions of distortion parameters have been derived, which can provide more detailed information about the short range order in glasses.  
        关键词：Mossbauer spectroscopy;glass   
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        发布时间：2022-09-13
      • Yuesheng Chao,Shouguo Zhang,Junshi Han,Qingman Shi,Shi Li
        Vol. 10, Issue 8, (1987)
        摘要：The structural relaxation process of amorphous alloys Fe79Si7B14 and Fe83Si4B10C3 have been investigated by differential thermal analysis and Mössbauer technique. The experimental results obtained show that the structural relaxation associates with topographical short range ordering, chemical short range ordering and nucleation growth of base metal phase, relatively, in different temperature region.  
        关键词：structural relaxation;model of dence random packing of hard spheres;Mossbauer spectroscopy;differential thermal analysis (DTA);the relaxation associated with topographical short range ordering;the relaxation associated with chemical short range   
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        发布时间：2022-09-13
      • Youtong Wang
        Vol. 10, Issue 8, (1987)
        摘要：Mössbauer spectra of nitrogen model compounds with monocubane configration [(Et4N)MoFe3S4 (Et2dtc)5] • CH3CN have been measured for the first time. The data have been fitted successfully with a least-squares fitting computer program The Mössbauer parameters measured at 15.5℃ are as follows: For Fe1, δ=0.406±0.04mm/s, ΔEQ=1.107±0.04 mm/s, the line width is 0.296±0.04 mm/s;For FeII, δ=0.266±0.04 mm/s, ΔEQ=0.395 ±0.04 mm/s, the line width is 0.0462±0.04 mm/s. The isomer shift is relative to α-Fe. The ratio of quadrupole split area for FeI and FeII is about 2:1. With these parameters we found that FeII is in+3 high spin state. Using the empirical formula of the isomer shift δ and the mean oxidation state S of Fe atoms in tetrahedron FeS4: δ=1.44-0.43S, we have obtained the result that FeI is in +2.5 high spin state.  
        关键词：monocubane;nitrogen fixation model compounds;Mossbauer spectroscopy   
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        发布时间：2022-09-13
      • Qingqian Lu,Shuxuan Zhou,Yonghua Tang,Xiaolei Sun,Xusheng Hu,Deyi Li,Liqiang Yin
        Vol. 10, Issue 8, (1987)
        摘要：The instrument introduced provides a means for leak detection of long buried pipelines based on the radioactive tracer technique. The principle, block diagram and performances for the instrument are described The leak-detecting method and the determination of some related parameters are also presented.Leak-detection sensitivity of the instrument is 185 kBq (5µCi). Accuracy for leak localization is within 2.5m (per km). It is suitable for the buried light oil (gasoline, kerosene, diesel oil) and industrial water pipelines with a diameter of 15 or 20cm.The detection length for a single operation reaches up to 50 km.  
        关键词：buried pipeline;leak detection;industrial application of tracer   
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        发布时间：2022-09-13
      • Zhenqiang Qiu,Huiyin Tian,Mingli Meng
        Vol. 10, Issue 8, (1987)
        摘要：Based on an apple-Ⅱ microcomputer, an automatic X-ray analysis system has been developed. The automatic data acquisition, sample changing and spectrum data processing are its main features.  
        关键词：microcomputer;X-ray analysis;Data acquisition;automatically changing sample   
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        发布时间：2022-09-13
      • Weixi Yi,Ziyuan Ouyang,G. Heusser,D. Kaether,E. Pernicka,W. Hampel,T. Kirsten
        Vol. 10, Issue 8, (1987)
        摘要：An intense radiochemical neutron activation analysis method (RNAA) for the cosmogenic 53Mn in meteorites was described and the 53Mn depth profile of Jilin thondrite core A was shown schematically.  
        关键词：radiochemical neutron activation analysis;Meteorite;cosmogenic nuclide   
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        发布时间：2022-09-13
      • Jianpu Chen,Xinghua Ma,Renquan Zhu,Juling Qian,Chuanyu Shu
        Vol. 10, Issue 8, (1987)
        摘要：The accelerating tube in 750 kV pre-injector is of open-structure high-gradient type. The whole tube consists of two sections, and each section structures consist of alternate metal (stainless steel) and ceramic rings bonded together with vinyl acetate. This is one of the largest tubes ever built in the world, the inner diameter of ceramic rings reaches 600 mm.The design aspects for improving the quality of the bonded joints in such large tubes are described. Several new techniques are adopted in cleaning process and in preparing resin films.All joints proved to be vacuum tight and passed a series of strength tests. The tube has been working satisfactorily for more than 3 years.  
        关键词：bonding;vinyl acetate;High-gradient accelerating tube   
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        发布时间：2022-09-13
      • Xiaogang Zhou,Xiuwei Chen,Xiaolin Tu,Yangfang Sun,Naisen Zhang
        Vol. 10, Issue 8, (1987)
        摘要：An on-line single photon counting system has been developed for the time resolved experiments by using synchrotron radiation. The time resolved of single photon is 1 ns for the spectrometer.  
        关键词：Single photon;time resolved;ps;fluorescence lifetime;Synchrotron radiation   
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        发布时间：2022-09-13
      • Liming Zhang
        Vol. 10, Issue 8, (1987)
        摘要：The combined action of relexation reagent, chromium acetyl acetonate, with inversion gated control technique was studied and used to get a quantitative 13C NMR spectra using microsample technique in the range of 3—5 mg. This method may be used as an alternative for obtaining 13C labelled palmitic acid, which is a tracer for heart muscle studies. A good results have been obtained, in which, the enriched factor reached to 48 between C=O group at 175 ppm and - (CH)10 at 29.7 ppm.This means that 13C isotope was enriched on C=0 group thus the same procedure may be applied to prepare 13C labelled compounds.  
        关键词：13C NMR;13C labelled compounds;palmitic acid   
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        发布时间：2022-09-13
      • Chengdu Cooperations Group of Investigation and Sterilization on the Paper Currency Pollution
        Vol. 10, Issue 8, (1987)
        摘要：A irradiation installation and irradiation technology for irradiation sterilization of circulating paper currency is discribed.  
        关键词：paper money;technology of irradiation sterilization   
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        发布时间：2022-09-13
      • Zongqin Xia,Tengchang Dai,Jianhua Zhang,Yaer Hu,Bingyao Yu,Xingrong Xu,Guanlu Huang,Gengrong Shen,Yaqiu Zhou,Hong Yu,Hanming Lu,Xunhai Li
        Vol. 10, Issue 8, (1987)
        摘要：In order to study the mechanism of the imbalance of amino acid metabolism during hepatic failure, a stable isotope tracer method for observing simultaneously the metabolic kinetics of several amino acids has been established. 15N-L-Ala, (2,3-D3)-Leu and (2,3-D3)-Phe were chosen as nonessential, branched chain and aromatic amino acids. A single iv injection of 40 mg N-Ala, 20 mg deuterated Leu and 20 mg deuterated Phe was given to each human subject. Blood samples were taken just before and at different times (up to 60 min) after the injection. Total free amino acids were isolated from the plasma with a small dowex 50×8 column and converted to trifluoroacetyl derivatives. Their abundances were then analyzed with a GC-MS system and typical double exponential time course curves were found for all the three labelled amino acids. A two-pool model was designed and applied for compartmental analysis.Significant changes were found in the kinetic parameters of Phe and Leu in patients with fulminant hepatitis or heptic cirrhosis. The half-lives of both Phe pools were longer and the pool sizes were larger than normal subjects, while the half-lives and pool sizes of Leu changes in the opposite direction. No marked change was found in Ala. The significance of intracellular imbalance of Phe and Leu metabolism was discussed. It is evident that the combination of GCMS technique and multiple-tracers labelled with stable isotopes is of great potential for similar purposes.  
        关键词：gas chromatography-mass spectrometry;amino acids;hepatic failure;stable isotope tracer   
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        发布时间：2022-09-13
      • Shiqiang Weng,Weijia Tian,Chengmo Zhu
        Vol. 10, Issue 8, (1987)
        摘要：In this paper the computer method for evaluation of LV regional ejection fraction (REF) is described. Gated radionuclide angiocardiograms are obtained using gamma camera computer system. The computer (DJS-131) was made in ChinaWe define Gp (x, y) as the background corrected image, thenGp (x, y)=Fp (x, y)-BpWhere Fp (x, y) is the image before background corrections, Bp is the background correction factor generated by the background ROI. The subscript p refers to image phase and p=0 (at ED) or p=1 (at ES). The LV ROI is subdivided in to i equiangular sections around its center of gravity (i>2). Sector 1 is marked by the long axis in opposite to the apex. REF is computed according to equation:Where Spi (p=0 or1) is the number of pixels within the sector of interest (i). If we define i=8, then we can quantitatively evaluate the LV contraction functions in the following sections: posterior lateral (superior, medium, inferior), apical, septal (superior, medium inferior).This method has been successfully used to determine REF in 51 cases with either CAD or MI and 11 cases without heart disease.  
        关键词：regional ejection fraction;quantitative method by computer   
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        发布时间：2022-09-13
      • Qinglong Fang,Jiancong Song,Mingguang Yi
        Vol. 10, Issue 8, (1987)
        摘要：This paper describes a method of radioactive intensity measurement for two radioactive nuclides of double labelled pharmaceuticals studies.This method is easy to proceed and highly sensitive.  
        关键词：double labelled medicines;Pharmacokinetics;radioactivity;sulfatodiaminocyclohexaneplatinum (Ⅱ)   
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        发布时间：2022-09-13
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