最新刊期
      期 3 ， 1999
      • XU Yunshu,FU Yibei,HUANG Ruiliang,SUN Ying,HUA Degeng
        Vol. 17, Issue 3, Pages: 129-134(1999)
        摘要：Low molecular weight polybutadiene (LMWPB) was mixed into PCS by solution method,then irradiated in He gas by 9.0MeV electron beam generated by a LINAC. Results showed that just 4.8wt% of LMWPB can drastically lower down the gelling dose from 5 MGy to merely ~0.4 MGy. The chemical structure of irradiated PCS containing LMWPB was similar to that without additives. H2 and CH4 were detected by gas chromatography during irradiation. As detected by TG-FTIR couplet analyzing technique and gas chromatography, there were also CH4 and H2 released during the pyrolysis process. The addition of LMWPB increased PCS'ceramics yield. Metal like pyrolysis product had been obtained by heating the irradiated samples in N2 gas to 1200℃. Element analysis and X-ray diffraction analysis verified the pyrolysis product is semi-crystalline SiC ceramics with high purity.  
        关键词：Polycarbosilane;Curing;Electron beam;Sensitizer;Pyrolysis;Silicon carbide ceramics   
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        发布时间：2023-04-07
      • LI Jun,YI Min,LU Jun,GAO Hongcheng,HA Hongfei
        Vol. 17, Issue 3, Pages: 135-139(1999)
        摘要：Pre-irradiation grafting of poly NIPAAm on silicone rubber was completed successfully. It was found that the graft reaction could be done just at higher temperature and induced by peroxides (mainly hydrogen peroxides) produced during irradiation of samples in air. Production and decomposition of the peroxides were investigated. The active energy of peroxides decomposition equals to 27.2 kJ/mol. The study of grafting kinetics showed that the graft reaction is easy to occur at higher temperature because of the active energy of graft reaction was low,near to 54.7kJ/mol. And the grafting mechanism was discussed deeply.  
        关键词：Silicone rubber;NIPAAm;Pre-irradiation grafting;Thermo-sensitive polymer;Peroxides   
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        发布时间：2023-04-07
      • ZHAI Maolin,LI Jun,LIU Jianqin,YI Min,HA Hongfei
        Vol. 17, Issue 3, Pages: 140-144(1999)
        摘要：Temperature sensitive polymer (poly N-isopropylacrylamide, NIPAAm) was grafted successfully on the surface of cotton cellulose fabric by γ pre-irradiation-induced grafting. The effects of absorbed dose,dose rate,grafting temperature and concentration of monomer on grafting yields were investigated. In order to explain the characteristic of active points and their location in cellulose structure, the generation and decomposition of the peroxides formed during irradiation in air were measured. It was proved that the trapped radicals which made main contribution to grafting copolymerization reaction were mainly located in the third phase between the crystalline and amorphous regions of the samples and the grafted chains,at least part of them, were extended into the crystallinity. It was also found that besides the trapped radicals,the peroxides produced made some contribution to graft reaction even the graft temperature was lower than their decomposition temperature for NIPAAm with special structure. Reaction mechanism was discussed in details.  
        关键词：Cotton cellulose fabric;N-isopropylacrylamide;Pre-irradiation grafting;Trapped radicals;Peroxides   
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        发布时间：2023-04-07
      • XU Yunshu,FU Yibei,SONG Yongcai,HUANG Ruiliang
        Vol. 17, Issue 3, Pages: 145-150(1999)
        摘要：Polycarbosilane (PCS) ceramics precursor fibers were sealed in quartz tubes filled with N2,He,NH3 and air,irradiated to 1~15MGy by γ-ray, then converted to SiC ceramics fibers at 1200 C. Results showed that these filling gases have no significant effect on the FTIR spectra of the irradiated PCS fibers. But serious oxidation of Si-H group was observed in the samples which were irradiated in open air. By using TGA-FTIR coupled analyzing technique and gas chromatography, CH4 and a lot of H2 were detected in the evolved pyrolysis gaseous product. When absorbed dose reached to 13.8MGy the irradiated PCS fibers become infusible fibers,and metal like black SiC fibers were obtained by heating the irradiated fibers to 1200℃ in N2 gas. The oxygen content (1.1wt%) is much lower than conventional SiC fibers by oxidation curing method. No defects were observed in the SEM photos of these SiC fibers.  
        关键词：Polycarbosilane;Gamma ray;Pyrolysis;Silicon carbide fiber   
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        发布时间：2023-04-07
      • CAI Xichen,WEI Zengquan,LI Wenjian,LIANG Jianping,LI Qiang
        Vol. 17, Issue 3, Pages: 151-155(1999)
        摘要：In this paper thymine (T) irradiated by 18O8+ ion beam in N2O saturated aqueous solution was studied. The apparatus of Ultraviolet (UV) ,High Performance Liquid Chromatography (HPLC) ,Gas Chromatography (GC) ,Gas Chromatography - Mass Spectrometry (GC-MS) and Gas Chromatography - Fourier Transformation - Infrared (GC-FT-IR) were used to analyze the products. The hydroxy and hydro adducts and dimers were determined. The G values of products were calculated. The damage of the irradiation of heavy ion beam was more serious than that of γ ray. The mechanism of the irradiation of heavy ion beam on materials was discussed at the end of this paper.  
        关键词：Thymine;The irradiation of heavy ion beam;UV;GC-MS;GC-FT-IR   
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        发布时间：2023-04-07
      • ZHANG Huaming,YANG Kebing,XIONG Ruilin,CHEN Chuan,XU Jiajing,LI Xiourong
        Vol. 17, Issue 3, Pages: 156-158(1999)
        摘要：Study was made on crystallinity change of PA610 in which copper halogenide was added and then irradiated by EB. The analyses of X-ray diffraction and DSC show that copper halogenide can improve the radiation crosslinking effectiveness of PA610.  
        关键词：Polyamide 610;Copper halogenide;Radiation effect   
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        发布时间：2023-04-07
      • JU Guizhi,LUO Can,FU Haiqing,SU Xu,Fu Shibo,LIU Shuzheng
        Vol. 17, Issue 3, Pages: 159-162(1999)
        摘要：To investigate whether adaptive response of [Ca2+]i and CD71 expression in splenic lymphocytes could be induced by low dose WBI with X-ray. Fluorecent indicator fura-2 was used to measure [Ca2+]i concentration in splenic lymphocytes. And flow cytometry was used to analyze CD71 expression of splenic lymphocytes for their immunofluorescence stained with monoclonal antibodies. It was found that the suppressive effect of [Ca2+]i and CD71 in lymphocytes be 2.0Gy was reduced by 0.075 Gy low dose pre-irradiation. Adaptive response of [Ca2+]i and CD71 expression of splenic lymphocytes could be incudced by low dose radiation. This finding might be one of the important mechamisms of immunological adaptive response fo T lymphocytes induced by low dose radiation.  
        关键词：Low dose radiation;Adaptive response;[Ca2+]i;CD71   
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        发布时间：2023-04-07
      • XIAO Bin,LI Sunao,ZHOU Youyi,ZHOU Yong,ZHAO Pengji
        Vol. 17, Issue 3, Pages: 163-169(1999)
        摘要：The electron beam radiation curing was carried out in the air by using phosphorus and nitrogen active monomer,which was firstly synthesized in our laboratory. Some factors of influencing curing were studied,such as the resistance of oxygen inhibition effect of phosphours and nitrogen compound, and the effects of various concentration of active monomer and different doses in radiation curing. The optimum concentration of phosphorus and nitrogan active monomer and influencing regularity of radiation dose in EB curing were obtained. At the Same time,resisting oxygen inhibition mechanism of compound containing phosphorus in EB curing was gave. By examining the quality of coating layer,a possibility which phosphorus and nitrogen conpounds were applied to industry of EB curing in the air was put forward.  
        关键词：Active monomer;Radiation curing;Resistance of oxygen inhibition   
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        发布时间：2023-04-07
      • LIANG Mingzhi,LUO Chengji,GUO Zhaohua,ZHOU Yanhong
        Vol. 17, Issue 3, Pages: 170-173(1999)
        摘要：Effects of rhGM-CSF on reconstruction of hemopoietic function in mice exposed to total body gamma irradiation with a dose of 6.0Gy combined with 15% TBSA full thickness burn were further investigated. The result showed that hemopoietic function was damaged severely after the combined injury. There was a significant decrease of peripheral blood white cells, bone marrow mononuclear cells and CFU-GM. The lowest values occured at the initial period after injury. After administrating rhGM-CSF at 10µg/kg•d-1 constinuously for 10 d,the significant increase of peripheral blood white cells was obsverved from day 11 to day 20 postinjury. The highest values could restored to pre-injury levels. Bone marrow mononuclear cells and CFU-GM also show a remarkable increase at day 10 and day 15 postinjury. All of these indicated that rhGM-CSF could stimulate hematopoietic progenitor cell to proliferate and differentiate,give support to recovery of hemopoietic function after combined radiation-burn injury at different levels.  
        关键词：GM-CSF;Combined radiation burn injury;Hematopoietic progenitor cell;Treatment of radiation injury   
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        发布时间：2023-04-07
      • CHEN Haiwen,Takashi Sasaki,Fumio Yoshii,Keizo Makuuchi
        Vol. 17, Issue 3, Pages: 174-179(1999)
        摘要：A new vulcanization processes of CR has been studied radiation vulcanization. It has been found that CR containing 4phr PFM 4G, 30phr carbon black and 4phr MgO can be vulcanizede at 30~50kGy. And in that case radiation vulcanized CR rubbers have better physical properties comparing to those of tradiational chemical vulcanized CR rubbers. Soinsome case,CR can be vulcanized by radiation instand of chemical methods.  
        关键词：Electron beam radiation vulcanization;Polyfunctional monomers;Chemical vulcanization;Chloropren rubbers(CR)   
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        发布时间：2023-04-07
      • XU Fenxiang,HU Xiujin,YANG Chengzhi,LI Chaodong,ZENG Huiling,ZOU Linxing
        Vol. 17, Issue 3, Pages: 180-184(1999)
        摘要：This paper described the graft polymerization of methyl methacrylate (MMA) on chloroprene rubber (CR) under irradiation of 60Co γ-rays. The influence of radiation dose,dose rate,and weight ratio of MMA to CR on grafted CR were studied in this paper. Experimental result showed that the grafted CR have superior graft ratio.  
        关键词：Chloroprene rubber;Graft modification;Irradiation graft polymerization;Methyl methacrylate   
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        发布时间：2023-04-07
      • JIA Shu,XU Huiqun,MA Zhaoxiang,LI Guohua,DONG Min
        Vol. 17, Issue 3, Pages: 185-189(1999)
        摘要：In this work the flake-materials (thickness=4mm and 1.2mm) of lower density PE are selected as samples. By putting them in aqueous solution of acrylic acid,the graft copolymerization is completed by 60Co γ-irradiation. So on the surfaces of flake-samples the monomer of acrylic acid is grafted, and the samples surfaces are transformed from non-polar ones to the ones with polar groups. Thus the surface-adhesiveness of PE flake-material is modified much better. With different adhesives,the adhere-links of modified and primary flake-samples are accomplished respectively,then the surfaces adhesive strength of them is measured. The measured results show that the surface-adhesiveness of modified flake-samples is much better than that of primary samples.  
        关键词：PE flake-materials;Modification;Surface-adhesiveness;Radiation-graft;Adhered-surface;Anti-tensile-shearing strength   
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        发布时间：2023-04-07
      • HE Jing,LI Wenjian,ZHOU Guangming,WANG Jufang,LI Qiang,XIE Hongmei,DANG Bingrong,WEI Zengquan,GAO Qingxiang
        Vol. 17, Issue 3, Pages: 190-192(1999)
        摘要：Most melanin tumour B16 cells cultured in hypoxic (gas flow) enviorment were irradiated with 50 MeV 12C6+ in the extended Bragg peak region of ion ranges. Average OER (oxygen enhancement ratio of 1.25 Were deduced from survival curves,This comparatively low OER value indicates that the oxygen effects are net so remarkable referring to the cel killing efficiencey of carbon ions of this energy, i.e. carbon ions of this energy are efficient for killing both aerobic and hypoxic celees.  
        关键词：12C6+ ions;B16 cell;Oxygen effect;Colony forming method   
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        发布时间：2023-04-07
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