最新刊期
      期 3 ， 1986
      • V. Markovic,A. Safranj
        Vol. 4, Issue 3, Pages: 1-7(1986)
        摘要：Several industrial applications of ionizing radiation are based on radiation crosslinking of polymers: crosslinking of wire and cable insulation, production of heat shrinkable materials, plastic foam, etc. Radiation induced crosslinking has been the subject of many studies, especialy the gel formation and effect of polymer structure and irradiation conditions on the yield of crosslinks. Much less has been done to study crystallization of crosslinked polymers in general and radiation crosslinked polymers in particular. It has been shown for example, that the total crystallinity in irradiated polyethylene is not affected except at very high absorbed doses. On the other hand it is significantly reduced in polypropylene and poly-l-butene already at doses about the gel point. In all cases remelting of irradiated polymers further reduced the total crystallinity.In this work it is shown that not only the total crystallinity, but also the crystallization kinetics are affected by radiation induced crosslinks. The rate of crystallization indicated that the crystallization can be separated in two processes with different growth mechanisms. The rate of cooling is an important factor which determines the crystallization procedure and affects other properties dependent on crystallinity and morphology of crosslinked semicrystaline polymers.  
        关键词：Ionizing radiation;Radiation crosslinking;Yield of crosslinks;Crystallinity   
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        发布时间：2023-04-23
      • Pan Xianming,Liu Kejian,Wu Jilan
        Vol. 4, Issue 3, Pages: 8-17(1986)
        摘要：The trans-stilbene, TOA, TEAand pyridine have been used as positive ion scavengers during γ-radiolysis of TBP. It has been found as the ionization potential of stilbene, TOA and TEA are less than that of TBP, charge transfer mechanism predominates. The experimental results were in agreement with the theoretical calculation of WAS equation. On the other hand, the ionization potential of pyridine is higher than that of TBP, energy of excitation transfer mechanism predominates.  
        关键词：γ-irradiation;TBP;Charge transfer   
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        发布时间：2023-04-23
      • Wang Mingjun,Xu Maojun,Mao Xianqin,Liu Yuming
        Vol. 4, Issue 3, Pages: 18-21(1986)
        摘要：This paper has studied the effect of dose rate on radiation degradation of PTFE by electron beam irradiation. In the case of same dose, if dose rate increases from 1.44×104 to 5.75×104 rad/s, the degradation efficiency of the latter was about 3.3 times of the former. There are linear relationship between the dose rate and the scission parameters (e. g. degree of degradation per unit dose and G(s) etc) . In the case of given degree of degradation, the dose rate will varied oppositely with irradiation dose.  
        关键词：Dose rate;Radiation degradation of PTFE;Degradation parameter   
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        发布时间：2023-04-23
      • Chen Yongming,Li Xingdi,Yuan Longbao,Wang Hongfu
        Vol. 4, Issue 3, Pages: 22-25(1986)
        摘要：In this paper, using the method of turbidimetric technique, changes of rabbit platelet aggregation are observed following γ ray whole-body irradiation with 400 rads. The results indicated that the function of blood platelet aggregation was risen from the first to the fifth day after radiation, but reduced at the seventh day and markedly at the tenth. It is believed that the early elevation of platelet aggregation may result in increase of adherence omd coagulation, and enhance microcirculation disturbances. In addition, a large number of platelets and coagulation factors were consumed, it might be one of the causes of hemorrhage syndrome after exposure. During early therapy of radiation injury, therefore, it is of benefit for improving the repair of radiation injury to inhibit platelet aggregation.  
        关键词：Platelet Aggregation Radiation Injury   
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        发布时间：2023-04-23
      • Feng Ying,Li Shuhua,Zhang Yan,Zhang Yiqun,Zhang Lihua,Zhang Zicheng,Cheng Xinfan,Yen Jiagui
        Vol. 4, Issue 3, Pages: 26-29(1986)
        摘要：Radiation degradation of polyvinyl alcohol (PVA) was shown by-reduced viscosity. Samples were irradiated with. 60Co γ -rays and their viscosity was measured in distilled water at 30℃ to determine the reduced viscosity. The formula used to express the radiation degradstion was the simple relationship between the intrinsio viscosity and the absorbed doseThe method of determination of D0 was described. The α value calculated from experimental data is identical to the value of α in Mark-Houwink equation . By correlating the two equations, the value of p0 (fracture density) and G (main chain fracture) were calculated. The initial number average degree of polymerization , derived from the value of D0 and p0 is approaching to the value of determined by viscometric method.  
        关键词：Polyvinyl alcohol;Radiation degradation;Absorbed dose;Virtual dose;Intrinsic viscosity;Viscosity average molecular weight;Fracture density;Radiation yield of main chain fracture   
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        发布时间：2023-04-23
      • Sun Jiazhen,Zhu Sianglin,Zhang Yuefang
        Vol. 4, Issue 3, Pages: 30-34(1986)
        摘要：Fluoropolymer F-46 may be crosslinked by irradiation under vacuum and a temperature below or near its melting point. It leads to formation of network macromolecules. The presence of network structure of radiation crosslinked F-46 was proved by the following facts: gel formation, appearance of rubbery plateau region and a more closely packing condition of molecular aggregation. The high temperature property of radiation crosslinked F-46 shows beneficial improvement.The radiation crosslinking of F-46 follows the theory of random crosslinking. The dose of gelation is decreased with the increasing of temperature. The radiation crosslinking G value is increased with the increasing of temperature, at 240℃ the G value is 1.16. The mobility of polymer chain is increased with the temperature and it will promote radiation crosslinking of fluoropolymer F-46.  
        关键词：Fluoropolymer F-46;Radiation crosslinking;Theory of random crosslinking;Charlesby-Pinner relationship;Characterization of crosslinked polymer   
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        发布时间：2023-04-23
      • Zhang Wanxi,Zhang Yuefang,Qi Chuizhen,Sun Jiazhen
        Vol. 4, Issue 3, Pages: 35-38(1986)
        摘要：In the present work, the effect of flexibility of fluoropolymers on their radiation crosslinking behavior have been studied and the validity of the relationship between sol fraction and radiation dose[1] to the fluoropolymers have been assured.  
        关键词：Fluoropolymers;Radiation crosslinking;Structure of polymers;Glass transition temperature   
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        发布时间：2023-04-23
      • Huang Zhentong,Wang Likang,Dong Xin,Lin Nianyun
        Vol. 4, Issue 3, Pages: 39-44(1986)
        摘要：In order to find more effective radioprotector, an improved new method to synthesis sinapic acid and its amine salt derivatives has been reported, and the study of ESR spectra from sinapic acid-dTMP with molar ratio 1:10 irradiated and recorded at 77 K has confirmed the long range electron transfer from thymine of dTMP to sinapic acid:also, the radioprotective effect of sinapic acid amine salt derivatives on irradiated mice(500 rad.) has been shown in increasing peripheral platelet count with significance of statistics. The I. R and NMR spectra of sinapic acid derivatives also have been reported.  
        关键词：Radioprotector;Synthesis of Sinapic Acid;Charge transfer;ESR;Platelet Increasing   
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        发布时间：2023-04-23
      • Zhao Xin,Liu Junchen,Chen Zhiping
        Vol. 4, Issue 3, Pages: 45-48(1986)
        摘要：The state of macromolecular aggregation of hydrolyzed product of graft copolymers of acrylonitrile onto starches prepared by γ-ray and Ce(Ⅳ) initiator respectively was investigated with elemental analysis, IR spectrum, X-ray diffraction and SEM. The results indicate that in a spite of different initiating, by "bridging" of graft side chains there are the various sizes of cavities and random crosslinking in the state of aggragation, and the macromolecular chains include -COONa and -CO-NH2 groups, which show stronger infrared absorption 1400 cm-1 and 1652 cm-1 bands respectively. The structure characterization is associated with water retention.  
        关键词：Hydrolyzed product of graft copolymers of acrylonitrile onto starches;γ radiation initiation;State of macromolecular aggregation;Water absorbing starch resins   
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        发布时间：2023-04-23
      • Wan Fuyuan
        Vol. 4, Issue 3, Pages: 49-53(1986)
        摘要：Using electronic beam radiation, the procedure for extraction and seperation of cytochrome b5 reductase and the mechanism of reduction and oxidation reactions of this enzyme were described. Hydro-electron was produced when the solution was subjected to the action of electronic beam. From the spectrum of oxidized form of cytochrome b5 reductase after reducing with hydro-electron, we discovered a new spectrum neither oxidized form nor reduced form, so we considered that it will be the existance of a middle form besides both oxidized and reduced form of this enzyme.  
        关键词：Oxidized spectrum;Reduced spectrum;Differential spectrum;Hydro-electron   
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        发布时间：2023-04-23
      • Chen yuan,Zhou Mei,Ti Fengju,Hong Hua
        Vol. 4, Issue 3, Pages: 54-57(1986)
        摘要：The Contents of the fluorescent products and the Se-GSHPx activities of Liver, spleen and testis of mice irradiated with 100rads were determined. There were no changes in the contents of the fluorescent products of liver in our test; there was significantly increased in spleen on the 7 th and 15th days post irraditaon (p<0.01) ; except for decrase on the 3rd day (p<0.05) , the contents of the fluorescent products in testis didn't show any changes in all times tested. The seGsHPX activities were incerased in liver from the 1st to the 5th days after irradiation(P<0.05) , and had a tendency to restore on the 7th day; the enzyme activities were increased murkedly in spleen on the 3rd day post exposure (P<0.01) , then turned to decrease on the 5th and the 7th days (P<0.05) .  
        关键词：Radiation-induced lipoperoxidation;pluorescent Product;Sedependent gtutathione peroxidase   
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        发布时间：2023-04-23
      • Liu Yuming
        Vol. 4, Issue 3, Pages: 58-62(1986)
        摘要：The three systems of dilatometer on kinetic study of radiation induced polymerization are presented.(1) The atmospheric dilatometer. It is suited to determine the homogeneous polymerization and copolymerization process under atmospheric polymerization.(2) The pressure dilatometer of bulk polymerization. It is suited to determine the bulk homogeneous polymerization and copolymerization process under 10 kg/cm2 such as radiation induced bulk polymerization of some fluoro-alkene monomers.(3) The pressure dilatometer of solvent polymerization.It is suited to determine the solvent polymerization and copolymerization process under 10 Kg/cm2 such as radiationinduced copolymerization of Chlorotrifluoroethylene(CTFE) and ethylene(E) in trifluorotrichloroethane (FC-113) .All of the above-mentioned delatometers are made of hard glass, and they are simple in construction, easy to handle, measuring at long-distance and recording by automatic recorder. In addition, the abovementioned dilatometers not can only measure the initial polymerization process, but can also measure the autocatalytis reaction after gel effect.  
        关键词：Atmospheric dilatometer;Pressure dilatometer;Dilatometer bulb;Preirradiation polymerization;Polymerization kinetic   
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        发布时间：2023-04-23
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