最新刊期
      期 4 ， 1994
      • Fang Xingwang,Wei Genshuan,Wu Jilan
        Vol. 12, Issue 4, Pages: 193-198(1994)
        摘要：Effects of O2 and dose rate on the radiolysis of rabbit hepatic metallothionein-I(MT-I) in phosphate buffer solution at pH 8.0 have been studied. Active species (OH and H2O2) formed under irradiation principally attack the Zn-S bonds in the β-domain of MT-I and as a result, give birth to disulfide bonds, and the formation of disulfide bonds mainly occurs intramolecularly. The radiolysis of N2- or N2O-saturated MT-I solutions resulted in sulfhydryl-group-decrease with G_SH_=4.2 and 7.2 respectively, whereas G values of dimer were only 0.32 and 0.67.A short chain-reaction exists in the decrease of sulfhydryl groups when O2-saturated MT-I was irradiated, but it contributed little to . However, the damaged MT-I can be repaired completely by reduced glutathione. The reaction between H2O2 and MT-I also was investigated, and k2a=10 mol•dm-3•s-1 for RS-(MT-I)+H2O2→RSOH+OH- was abtained. Furthermore, the radiolysis mechanism of MT-I was disscussed on the basis of above mentioned results and good material balances were achieved.  
        关键词：Metallothionein;Radiolysis;Disulfide bond;Radiation effects   
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        发布时间：2023-04-23
      • Lin Weizhen,Tu Tiecheng,Dong Jirong
        Vol. 12, Issue 4, Pages: 199-203(1994)
        摘要：The mechanism of radiation induced electron transfer within a series of binary molecular aggregates, which were composed of myosin and caffeic acid with varied molar ratios (r) of amino acid residues in myosin to caffeic acid, has been studied by resolution of composite ESR spectra recorded at 77 K. A series of spin transfer ratios (RST) defined as the spin concentration ratios of caffeic acid anion radical arising from transfer of captured electron by peptide chain of myosin to that from directly trapping of secondary electrons by caffeic acid were obtained . A series of RST were plotted against r varied from 1:1 to 100:1. A linear relationship between RsT and r demonstrates that RsT increase linearly with decrease of caffeic acid content. The capture of radiation induced secondary electrons depend on the electron affinities of components including electron affinitive amino acid residues and peptide carbonyl of myosin and caffeic acid. The process of electron transfer along peptide chain and trapping on caffeic acid finally has been elucidated based on the comparison of the energies of lowest empty molecular orbital(ELUMO) of the electron affinitive components and reaction rate constants of with these components respectively using pulse radiolysis techniques.  
        关键词：Electron transfer;Myosiu;Caffeic acid;Resolution composite ESR spectra   
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        发布时间：2023-04-23
      • Zhao Shanqi,Li Tianwang,Jia Lin,Zheng Jingchun,Xia Jifu,Song Zeling
        Vol. 12, Issue 4, Pages: 204-208(1994)
        摘要：A 200 A triac was irradiated by electrons beams with 12 MeV in three different ways, and the major parameters of the triac were measured before and after irradiation, The experimental results show that the commutating capability of the triac can be effectively improved by the method. Further more, we can make the electronic parameters of the triac more perfect by using different ways of irradiation. In order to ensure working steadiness of the triac for a long time,an annealing time should be prolonged for 2 to 4 hours at 200℃ after irradiation.  
        关键词：Electron beam irradiation;Triac;Commutating capability;Electronic parameter   
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        发布时间：2023-04-23
      • Wang Chuanshan,Luo Wenyun,Xu Mengjie,Zhou Shuxin,Feng Yongxiang,Zhang Limin,Gu Jiqing
        Vol. 12, Issue 4, Pages: 209-213(1994)
        摘要：A semiempirical code ED 510 which can simulate depth-dose distribution of the energy deposition of electron beam in multilayer absorbers is described in this paper.The absorbed dose of electron beam computed by ED 510 code is compared with the experimental result that measured by graphite absorbed-dose calorimeter, and their deviation is between 3%.  
        关键词：ED 510 code;Graphite calorimeter;Radiation processing;Depth-dose distribution   
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        发布时间：2023-04-23
      • Xu Honglin,Zhang Wenhui
        Vol. 12, Issue 4, Pages: 214-219(1994)
        摘要：The free radicals in wood induced by γ-radiation were studied by electron spin resonance. the fine structure of the ESR signal from sawdust samples irradiated could be resolved into various radicals. These free radicals have a very long lifetime. The major spectrum for the free radicals will exponentially increased along with the radiation dose according to Y=1 - Exp(-αaD). The intensity of radiation radicals is dependent on tree species. The stronger the intensity of mechanic free radicals is the stronger the intensity of radiation free radicals is.  
        关键词：Wood Sawdust;γ-irradiation;Free radical   
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        发布时间：2023-04-23
      • Zhang Zhengguo,Ha Hongfei
        Vol. 12, Issue 4, Pages: 220-223(1994)
        摘要：In this work grafting copolymerization of acrylic acid to cotton cellulose by using preirradiating method was investigated. At lower concentration of monomer (10%) the relationship between grafting yield and total dose, dose rate, reaction time and reaction temperature was measured. It was found that in the temperature range of 294 K to 323 K the grafting yield decreased with increasing of grafting reaction temperature. The grafting yields as a function of above reaction conditions were given by the expression., where R=8.314×10-3kj•K-1•mol-1,D=irradiation dose, T=reaction temperature, and t= reaction time.  
        关键词：Cotton cellulose;Acrylic acid;Preirradiation grafting;Energy of activity;Radiation modification   
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        发布时间：2023-04-23
      • Du Kairu,Lu Zhongliang,Gu Fang,Qian Zhilin,Guo ling,Yu Fengying,Yu Yunzhen
        Vol. 12, Issue 4, Pages: 224-227(1994)
        摘要：The investigation result on radiation level in certain uranium mine was given in this paper. The radon concentration and α potential energe of radon progene in mine were 6.87×103Bq•m-3 and 1415.27×10-8J•m-3 respectively. The γ exposure rate in mine was 6.72 C/kg•h. The concentration of radon and its progene and γ exposure rate in mine surface, living area and its surroundings were 15.40 Bq•m-3, 8.95×10-8J•m-3 and 0.45 C/kg•h respectively.  
        关键词：Radon concentration;Radon progene α potential energe;γ exposure rate;Uranium mine   
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        发布时间：2023-04-23
      • Li Wenjian,Wei Zengquan,Xie Hongmei,Han Guangwu,Zhang Jinlian,Hu Yue
        Vol. 12, Issue 4, Pages: 228-231(1994)
        摘要：Free radicals were studied at room temperature using ESR spectroscopic method after wheat embryos were irradiated with argon ion beams with medium energy (20.7 MeV/u). The stability of the radicals was observed. Experimental results show that the radical concentration in seeds linely increases with moisture content of seeds: the radical concentration increases with irradiation dose and gradually reaches a saturation state. The relatioship of the radicals and damage to seeds was discussed. According to experimental data and radical diffusion theory the diffusion distance of the radicals in wheat embryos was estimated.  
        关键词：Argon ion;Ion beams;Wheat;ESR spectroscopy;Free radical;Irradiation dose   
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        发布时间：2023-04-23
      • Jiang Bin,Luo Zhengming
        Vol. 12, Issue 4, Pages: 232-238,213(1994)
        摘要：In this paper, a Gaussian distribution for electron energy is deduced by Fokker-Planck approximation to the Boltzmann equation for high-energy electrons penetrating in multi-constituents media, then a recursion-iteration algorithm for the mean energy calculation of high-energy electron beam is obtained after introducing the modified CSDA mean energy and using Yang's multiple scattering theory. Some calculational results of this algorithm are also given in the article, and compared with corresponding data of Monte Carlo simulations and experimental measurements. The comparison shows that the algorithm can precisely predict the mean energy of high-energy electron beam penetrating in light media. Furthermore, two common formulae for electron beam mean energy calculation in radiotherapy dose algorithms. i. e., the Harder formula and Brahme formula, are discussed, and a more accurate semi-empirical formula is recommended in this paper as well.  
        关键词：Mean energy of electron beam;Radiotherapy;Radiation doses;Electron beam dosimetry   
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        发布时间：2023-04-23
      • Wang Shunbao,Feng Ningyuan,Niu Wenzhe,Yang Yuhui,Guo Lei
        Vol. 12, Issue 4, Pages: 239-241,227(1994)
        摘要：Biological elfect of the 192Ir high activity source on LA795 tumor of mice and HCT-8 cells have been investigated when decay of the source power from 340.4 GBq to 81.4 GBq No marked difference was found between the two cell survival curves of HCT-8 cells and both of them compared with that of the X-ray irradiation the value of relative biological effect (0.1 survival) was 0.43. On the experiment of tumor LA795 of mice, when the source power was 293.3 GBq and 96.2 GBq,no different biological effect can be seen between the two series of figures The relative biological effect was 0.55—0.60 (tumor growth delay) when compared with those of X-ray irradiation.  
        关键词：192Ir Radiation;Relative biological effect;HCT-8 cells;LA795 tumor;Biological radiation effects   
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        发布时间：2023-04-23
      • Luo Jiquan,Gu Chongde,Liu Wei,Zhang Yuming,Shang Binglan,Liu Kebo,Chen Haijun,Xie Xiushen
        Vol. 12, Issue 4, Pages: 242-246(1994)
        摘要：Irradiation preservation is an effective method for storage of the intact cooked Huanghe carp at room temperature. The experiments have shown that for the Huanghe carp irradiated with 6—8 kGy 60Co γ-rays, their microbiological index conformed to the National Food-Health Standard and nutritional composition and contents of amino acids were comparable to those of the carp unirradiated. No effect on growth and development of animals feeded with irradiated carp was observed within 90 days animal feeding experiment. No obvious change in micronucleus and chromosome aberration were found and Ames tests were all negative. Also there was no abnormal alteration found in blood assay, internal organ observation and pathological examination.  
        关键词：Radiation preservation;Huanghe carp;Irradiated feeds   
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        发布时间：2023-04-23
      • Du Zeji,Su Liaoyuan,Liu Fenju
        Vol. 12, Issue 4, Pages: 247-250(1994)
        摘要：Monoclonal antibodies of anti CD4, anti CD8 and anti B wereused to separate CD4+, CD8+ and B lymphocyte subsets respectively. After low dose X-rays radiation, the regulatory functions of CD4+ and CD8+ on B cell were studied by using 3H-TdR incorporation. The results indicated that CD4+ cell could increase the 3H-TdR incorporation of B cell, CD8+ could decrease the 3H-TdR incorporation of B cell. Low dose radiation could enhance the helping effect of CD4+ and inhibitive effect of CD8+ on B cell at a dose range of 0.02—0.20 Gy, especially at the dose of 0.10 Gy X-rays radiation.  
        关键词：Low dose radiation;Lymphocyte subsets;Inter-regulation;Biologi cal radiation effects   
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        发布时间：2023-04-23
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