最新刊期
      期 1 ， 1985
      • Tang Rongbao,Chen Heming,Lyan Shusyan
        Vol. 3, Issue 1, Pages: 1-6(1985)
        摘要：The polarization microscope and scanning electron microscope were used to study the surface structure and the cross section of the grafted copolymer of polytetrafluoroethyene—styrene—fumaric acid in this paper. In the range of the experimental temperatures (19~40℃), when the radiation intensity is higher than the critical radiation intensity, the grafting takes place on the surface of film. On the contrary, the grafting proceeds in the mass. Under the surface grafting conditions, the spheric particles are formed on the surface of grafting copolymer. It was found that the inner layer is the grafted copolymers of polytetrafluoroethyene—styrene—fumaric acid and the outer layer the homopolymer of styrene—fumaric acid. The outer and inner layers are linked by chemical bonds. The main contribution to the adhesive strength is made by outer layer. The grafting process and mechanism and effect of grafting conditions on surface structare have been discussed considering the diffusion and permeation of monomers. In the case of surface grafting, the adhesive strength is found to be above 100 kg/cm2. On the contrary, the adhesive strength is found to be lower 40 kg/cm2, when grafting took place throughout the PTFE substrate.  
        关键词：Polytetrafluoroethylene;Styrene;Fumaric acid;Radiation graft copolymerization;Surface grafting;Bulk grafting;Adhesive strength   
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        发布时间：2023-04-23
      • Zhao Yaojie,Xia Yanchu,Yue Wei
        Vol. 3, Issue 1, Pages: 7-14(1985)
        摘要：This is a work to improve reverse osmosis properties of CTA hollow fibre membrances by liquid mutual radiation grafting.In this paper, the composition of monomer mixture, some parameters of grafting technology, the effect of grafting on R. O. properties of CTA hollow fibre membrances, and the solvent effect of grafting system on CTA hollow fibre membrances are described.  
        关键词：Reverse osmosis;Hollow fibre membrances;Radiation grafting;Cellulose triacetate;Solvent effect   
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        发布时间：2023-04-23
      • Cheng Jiyu,Sun Jiazhen,Chang Zicheng
        Vol. 3, Issue 1, Pages: 15-20(1985)
        摘要：Poly (vinyl acetate)-PVAc and poly (vinyl alcohol)-PVA derived therefrom has been prepared by means of radiation induced emulsion polymerization as well as chemically initiated. The structure and properties of PVAc and PVA obtained by both methods are compared. It was found that PVAc prepared by radiation polymerization has lower 1, 2-diol content, higher degree of crystallinity, lower solubility in water, higher steel-steel adhesive strength, higher glass transition temperature and so on. Results of experiments showed some structure-property relationship of PVAc and PVA. For example, the solubility of PVA is mainly dependent on its crystallinity, which depends on the 1,2-diol content. The Tg and adhesive strength also depend on the degree of branching and molecular weight, respectively.  
        关键词：Polyvinyl acetate;Polyvinyl alcohol;Emulsion polymerization;Radiation induced polymerization;Structure of polymer;Properties of polymer   
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        发布时间：2023-04-23
      • Chen Que,Xing Guoren,Liu Qingmei
        Vol. 3, Issue 1, Pages: 21-27(1985)
        摘要：The DNA excision repair ability of UV-irradiated male germ cells of dog and rat was determined by silver grain counting after 3H-TdR incorporation and autoradiography. The relative content of alkaline-toluidine blue O-stained non-histone nuclear proteins (NHP) in situ of the normal germ cells was measured by microspectrophotometry. Among the germ cells the primary spermatocytes contain the most NHP, they have revealed the highest repair ability; the spermatogonia contain less NHP, a lower repair ability (but that of dog spermatogonia was only a slightly lower average value); the round spermatids contain even less NHP, they, as well as the spermatozoa, no repair ability. A significant statistical correlation coefficient between the repair ability and the nuclear NHP content had been obtained in dog germ cells; while that in the rat germ cells has not yet been obtained, merely owing to the technical difficulty in measuring the NHP content in the irregular-shaped spermatozoan nuclei. By the microscopical observation or together with the microspectrophotometry, two groups of spermatozoa had been identified in dog and rat testes: the one's nuclei contain a little amount of NHP and the other's don't. No NHP was found in the nuclei of dog spermatozoa taken from ejaculated semen.  
        关键词：Male germ cell;UV-irradiation;DNA excision repair;Non-histone nuclear protein;UDS   
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        发布时间：2023-04-23
      • Zheng Xiulong,Zhao Fang,Ding Zhenying,Gao Jiangguo
        Vol. 3, Issue 1, Pages: 28-34(1985)
        摘要：A sensitive simple and rapid hydroxyapatite centrifugation-fluorometric method for detection of DNA strand breaks and its rejoining in nondividing cells was used and modified The circulating blood lymphocytes of rat were proved to be proficient in their ability to rejoin γ induced strand breaks at 37℃. However, incomplete repairing was observed after irradiation with dosage of 30 Gy. If incubation was continued up to 8 hours, the rejoined DNA molecules were broken again and cell-death also increased at the same time. It was confirmed that the break of rejoined DNA molecules is an irreversible biochemical change which predicts the cell-death. This suggestion has been proposed in our foregoing paper.  
        关键词：Hydroxyapatite centrifugation-fluorometric method;Rat blood lymp-hocytes;DNA strand break;DNA rapair;Rejoined DNA break again   
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        发布时间：2023-04-23
      • Li Busen,Zhu Xinfang
        Vol. 3, Issue 1, Pages: 35-39(1985)
        摘要：A new GC stationary phase with good performance is acquired when choosed monomer is bonded to the surface of PTFE micro-particles by radiation-induced graft copolymerization.In this paper, the features of the process of graft copolymerization in monomer vapor for the preparation of PTFE-VAC stationary phase have been described. Mechanism of GC effect on the copolymer has been discussed generally.  
        关键词：PTFE;VAC;Stationary phase of GC;Mutual irradiation in monomer vapor   
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        发布时间：2023-04-23
      • Zhang Yuefang,Ge Xuewu,Sun Jiazhen
        Vol. 3, Issue 1, Pages: 40-47(1985)
        摘要：Radiation crosslinking of the multiple-phase system for PDMVS and EVA have been studied. The results obtained from the optical microscope and the mechanical properties show that the proless of phase-turnover ocuured between and PDMVS-to-EVA ratio. PDMVS acts as sensitizer of the radiation crosslinking of EVA. The radiation dose of gelation for the multiple-phase system increased with the reduce of PDMVS content. In the neighbourhood of turnover point, G value of radiation crosslinking has a minimium. The crystallinity and crystal melting point decreased with the increasing of dose in the process of radiation crosslinking. Radiation-crosslinked multiple-phase system have good heat-Shrinkage properities.  
        关键词：Multiple system;Radiation crosslinking;Polydimethylvinylsiloxane(PDMVS);Copolymer of ethylene-yinylacetate (EVA);Charlesby relationship;Chen-Liu-Tang relationship   
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        发布时间：2023-04-23
      • Zhang Shiyu,Luo Lasheng,Zhang Shimei
        Vol. 3, Issue 1, Pages: 48-53(1985)
        摘要：The effects of γ-radiation on the properties and structures of isotactic polypropylene have been investigated in different medium and at different temperature.The results showed that the intrinsic viscosity of polypropylene decreased with the increase of dose, and initial decrease in the intrinsic, viscosity is considerable. When the polypropylene irrradiated in air at room temperature, the degradation of polypropylene is predominate. The efficiency of cross-linking of polypropylene increased by irradiation in vacuum. When the temperature increased during irradiation, the gel point of polypropylene moved up to higher dose. Polypropylene irradiated in vacuum at 180℃ does not produce gel.It was found by the X-analysis and infrared spectrum measurement that the degree of crystallinity and tacticity of polypropylene decreased remarkably with increasing temperature during irradiation.  
        关键词：Isotactic polypropylene;Cross-linking;Degradation;Properties and structures of polypropylene;γ-Irradiation   
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        发布时间：2023-04-23
      • Gu Ruiqi
        Vol. 3, Issue 1, Pages: 54-56(1985)
        摘要：The radiation protective effect of sinapine, which is widely distributed in Cruciferae, on wheat and barley was reported by my foregoing article. The hydrolysis products of sinapine are sinapic acid and choline. For searching the effective parts of sinapine in radiation protection, the germinating wheat seeds were treated with choline chloride before irradiation, then they were irradiated with X ray. The growth of wheat(6 days after irradiation) showed that choline chloride had not protective effect on germinating wheat seeds.  
        关键词：Radiation protective effect;Sinapine;Choline chloride;Wheat   
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        发布时间：2023-04-23
      • Tu Tiecheng,Lin Nianyun,Li Xuepeng
        Vol. 3, Issue 1, Pages: 57-60(1985)
        摘要：Since the preliminary proposal of "free radical repair" via H-transfer process was suggested, a series of ESR studies, such as by Ormerod and Alexander, Pullman and Milvy et al.[1] have been performed to clarify the repair mechanism exerted by the sulfhydryl compounds such as octyl mercaptan, cysteine, but only cysteamine was studied in detail in binary system containing DNA or dTMP and cysteamine. As for cysteine it was failed to be confirmed in binary system containing cysteine •HCl and DNA or dTMP.In our previous work cysteine paramethyl benzenesulfonate was used to instead of its hydrochloride, thus ESR spectrum from dTMP-cysteine paramethyl benzenesulfonate irradiated and recorded at 77K revealed predominately characteristic from dTMP, but after a long range vaiable temperature from 189 to 323K accompanying the decay of ESR spectrum from dTMP the signal from cysteine grew gradually and a stable state assigned to secondary organosulfur radical RCH2SS• or RCHS•-SH2CR) attained at higher temperature (323K) or long time (~20 hrs) annealing at room temperature.Recently, the ESR spectrum from DNA-cysteine paramethyl benzenesulfonate irradiated and recorded at 77K revealed the charcteristic similar to that from cysteine alone. After annealing at room temperature ESR pattern also changed into that from cysteine alone, no trace signal from 5-thymyl radical can be found.  
        关键词：Free radical repair mechanism;Sulfhydryl protectors;DNA   
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        发布时间：2023-04-23
      • Lin Nianyun,Gu Ruiqi
        Vol. 3, Issue 1, Pages: 61-62(1985)
        摘要：The radiation inhibition of bareley and wheat growth was decreased by pre-irradiation treatment with the extracts from the seedings of B. napus L., B. Chinensis L., B. Juncea coss., B. Oleracea L. etc. The radioprotective substance, sinapine, was separated and identified from the extracts. The ESR spectra from sinapine-thymine and sinapine-dTMP all with molar ratio 1:10 also sinapic acid-dTMP with molar ratio 1:10 irradiated and recorded at 77 K confirmed the long range eletron transfer from thymine of dTMP- to sinapine or sinapic acid,guite similar to that by caffeic acid protectors[(Lin Nianyun et al. J. Radiat. Res. Radiat, Process. 1(1), 1(1983)]. Both the radioprotective and anticarcinogenic abilities of sinapine or sinapic acid may be some what better than caffeic acid or ferulic acid.  
          
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        发布时间：2023-04-23
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