最新刊期
      期 3 ， 2005
      • HU Yucai,LIN Jie,LI Min,LU Jubo,LIU Shufen
        Vol. 23, Issue 3, Pages: 129-134(2005)
        摘要：The application of microwave irradiation as a new kind of energy source for activation of reactions has become a popular and useful technology in organic chemistry. The high heating efficiency of microwaves brings, in many cases, marked increase of the reaction rate and dramatic reduction of the reaction time. Many studies in the past decade on organic synthesis by microwave irradiations showed that this was because of dielectric heating effects of microwaves, while some other studies suggested that non-thermal effects of microwaves could change the reaction dynamics and decrease activation energy of organic reactions. The paper reviews recent progresses in the enhancement of microwave to organic reactions and the reaction mechanisms.  
        关键词：Microwave chemistry;Organic synthesis;Microwave catalysis   
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        发布时间：2023-03-30
      • HU Jun,WANG Jianlong
        Vol. 23, Issue 3, Pages: 135-139(2005)
        摘要：Radiation processing is a promising technology for applications in environmental protection, which includes wastewater treatment, micro-polluted drinking water treatment and the treatment of industrial wastewater containing various toxic and nonbiodegradable pollutants, municipal sewage and sludge disinfection, and flue gas desulfuration, etc. The paper reviews mainly the recent progresses in radiolysis of chlorinated phenols in aqueous solution. Advantages and existing problems of the method in this particular applicatrion are discussed . Mechanisms of radiation-induced degradation of chlorophenols, and the factors affecting the degradation efficiency, are discussed, too. It is concluded that combined approaches, such ozone oxidation and other methods, are of great help to the radiation processing application, in terms of lowering down the dose and increasing the efficient of pollutant removal.  
        关键词：Chlorophenols(CPs);Radiation technology;Radiolysis;Environmental protection;Persistent organic pollutans   
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        发布时间：2023-03-30
      • ZHANG Yiqing,LU Zhaoxin,ZOU Xiaokui
        Vol. 23, Issue 3, Pages: 140-144(2005)
        摘要：Protopectinase will be of potential use in industry. The strain of protopectinase-producing Aspergillus sp. XZ-131 was mutagenized by 15keV N+ ion implantation, with a dose range of 0.52×1015 ion/cm2 to 4.68×1015 ion/cm2. From the ion implanted Aspergillus sp. XZ-131, the Strain Z-25, which yields high activity protopectinase, was screened out. The protopectinase activity increased by 179% and the protopectinase (U/g dry cell) increased by 84%. In addition, the exponential phase of Aspergillus sp. Z-25 was 24 hours shorter than the Strain XZ-131. The Aspergillus sp. Z-25 yielded high protopectinase activity during stationary phase, the highest protopectinase activity was achieved after 72 h fermentation.  
        关键词：Ion implantation;Protopectinase;Mutation;Screening;Breeding;Fermentation process   
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        发布时间：2023-03-30
      • LI Junqing,HUANG Yudong,WANG Zhuo
        Vol. 23, Issue 3, Pages: 145-150(2005)
        摘要：Radiation processing is a high efficient, energy-saving and environment-friendly technology, and has been widely used to modify material interfaces. In this paper, simultaneous γ-ray radiation graft copolymerization was used to improve surface property of carbon fibers (CF) with phenolic aldehyde/ethyl alcohol solutions of different concentrations. The CF samples treated with the solutions were irradiated by 60Co γ-rays to 30kGy at a dose rate of 4.8kGy/h. The grafted samples were characterized with atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). And interlaminar shear strength (ILSS) of the composite reinforced by the grafted CFs was compared to the control (composites reinforced by the virgin CFs). The AFM measurement revealed obvious morphology changes of the grafted CF. The XPS spectra showed that the oxygen/carbon ratio and quantity of oxygen functional groups were enhanced efficiently by the radiation graft copolymerization. And interfacial performance of the composite reinforced by the grafted CFs was enhanced significantly.  
        关键词：γ-rays;Radiation graft copolymerization;Carbon fiber;Composite;Interface   
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        发布时间：2023-03-30
      • LEI Zhongli,FAN Youhua
        Vol. 23, Issue 3, Pages: 151-154(2005)
        摘要：The chelating fiber containing amidoxime group has been synthesized by graft copolymerization of acryloonitrile (AN) and acrylic acid (AA) onto polypropylene (PP) and amidoximation after electro-beam (EB) preirradiation. The article systematically studies the influence factors of grafting rate. Such as preirradiation dose, reaction time and temperature and monomer concentration. Optimum grafting results could be achieved by irradiating the PP non-woven material to 200 kGy and reacting for 4 hours at 75℃ with 50% monomer concentration of AN/AA = 40/60, while adding 0.05mol/L H2SO4 and Mohr’s of 0.08% in concentration.Inhibiting effect of [(NH4)2Fe(SO4)2] was also studied. The results of FT-IR revealed the total grafting rate which varied with the monomer concentration. The effect of the monomer ratio on the total grafting rate was associated to the stability of the monomers. For the monomer concentration range under investigation, the total grafting rate increased with the monomer concentration.  
        关键词：Electro-beam irradiation;Grafting;Polypropylene cloth;AN/AA   
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        发布时间：2023-03-30
      • GUO Jinxue,LI Yuguo,WU Shengwei,LI Wenxin
        Vol. 23, Issue 3, Pages: 155-158(2005)
        摘要：Multi-wall carbon nanotubes (MWNTs) irradiated with γ-rays were subjected to chemical modification. Products from each chemical treatment were characterized by FTIR and Raman spectroscopy. Elemental and TGA analyses of the modified MWNTs indicated that the concentration of functional groups bound on MWNTs increased with increasing doses, due to defects created on the MWNTs by γ-ray irradiation. Solubility in acetone and DMF of the irradiated and chemically modified MWNTs enhanced considerably in comparison with the control (without irradiation). The study will be of help for exploring novel applications of functional carbon nanotubes.  
        关键词：MWNTs;γ-ray irradiation;Chemical modification   
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        发布时间：2023-03-30
      • LI Linfan,XIE Leidong,YU Ming,FU Haiying,SHENG Kanglong
        Vol. 23, Issue 3, Pages: 159-163(2005)
        摘要：This paper introduces mainly experimental results of graft copolymerization of styrene-butadiene-styrene (SBS) with methyl methacrylate (MMA) in solution by γ-ray irradiation. Effects of irradiation dose and monomer concentration on mass increment and graft yield onto two types of SBS have been discussed. FTIR characterization of the irradiated samples showed that the monomer had been grated to the SBS molecular chains, while thermal performance of the graft products, SBS-g-MMA, was measured by DSC.  
        关键词：Styrene-butadiene block copolymer;Irradiation;Graft copolymerization;Methyl methacrylate   
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        发布时间：2023-03-30
      • ZHANG Wenyi,JIAO Ling,PAN Zhihong,ZENG Hongyu,ZHANG Liangan
        Vol. 23, Issue 3, Pages: 164-168(2005)
        摘要：The work is to study influences of sample preparations on dentine ESR (electron spin resonance) signals, in order to use dentine samples for dose reconstruction, which has been performed with enamel samples. The dentine and enamel samples were collected from non-irradiated adult teeth and prepared by mechanical or mechanical plus chemical methods. The samples were scanned by an ESR spectrometer before and after their irradiation by 60Co γ-rays. The sensitivities of ESR signals of dentine and enamel samples to irradiation dose differed significantly among different sample preparation methods. The results show that dentine samples mechanically and chemically prepared have good enough ESR response to low dose γ-ray irradiations, and it is possible to use the dentine samples for dose reconstruction, as a substitution to enamel samples when they are short of supply.  
        关键词：Electron spin resonance;Dentine;Sample preparation   
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        发布时间：2023-03-30
      • YU Chunhui,ZU Jianhua,WU Minghong,ZHANG Jianqiu,LIU Zhaomin,LIU Xinwen
        Vol. 23, Issue 3, Pages: 169-173(2005)
        摘要：High-density polyethylene (HDPE) films were irradiated by electron beams and then acrylic acid (AA) and sodium styrene sulfonate (SSS) were grafted onto the films, in an attempt to prepare bifunctional cation exchange membranes with the grated film. The grafting yield were studied with different experimental conditions of the monomer concentration, irradiation dose and reaction temperature. The activation energy for the grafting was calculated to be 22.2kJ/mol. Infrared spectroscopy analysis of the grafted membrane confirmed the existence of sulfonate and carboxylic acid groups.  
        关键词：Pre-irradiation grafting;Acrylic acid;Sodium styrene sulfonate;Kinetic equation   
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        发布时间：2023-03-30
      • ZU Jianhua,LIU Xinwen,ZHOU Ruimin,TU Tiecheng,QIU Shilong
        Vol. 23, Issue 3, Pages: 174-178(2005)
        摘要：Electron spin resonance (ESR) method was used for studying radicals generated in low and high density polyethylene (LDPE and HDPE) by gamma ray irradiation. Decay rate of the radicals were determined as a function of storage time at different temperatures, according to which, appropriate storage time and temperature could be chosed for the irradiated polyethylene. Identification and quantitative analysis of radicals originated from different types of polyethylene was done with the PE samples irradiated under ambient or N2 atmosphere. For the relationship between radical concentration and irradiation dose, the results showed a nearly linear increasing of R·, (relative concentration of radicals) with doses in the range of 10-100 kGy. Under the same dose, R· of the HDPE samples was higher than LDPE, and HDPE was chosen for pre-irradiation grafting. In the case of irradiation HDPE under ambient atmosphere, decay rate of R· was dominated by quantity of oxygen diffusing into the HDPE matrix.  
        关键词：Polyethylene;Irradiation;Electron spin resonance   
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        发布时间：2023-03-30
      • FU Haiying,XIE Leidong,YU Ming,LI Linfan,YAO Side
        Vol. 23, Issue 3, Pages: 179-184(2005)
        摘要：Graft copolymerization of methacrylic acid (MAA) onto SBS powder was studied by 60Co γ-ray irradiation. Effects of the irradiation dose, MAA concentration, and irradiation conditions on the graft yield were studied. The graft copolymer, SBS-g-MAA, was characterized by means of Fourier-transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and dynamic shear rheological (DSR). The -C=O- absorption peak at 1705cm-1 of the FT-IR spectra, and the wilder molecule number distribution of SBS-g-MAA by GPC analysis indicated that the MAA monomer had been grafted onto SBS molecular chains. The DSC analysis revealed an increased glass transition temperature of PS phase of the grafted SBS, while the DSR showed of the MAA monomer affected the PS phase of SBS more easily.  
        关键词：Styrene-Butadiene-Styrene;Graft copolymer;Methacrylic acid;Radiation graft   
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        发布时间：2023-03-30
      • TU Yu,ZHOU Juying,WANG Lili
        Vol. 23, Issue 3, Pages: 185-188(2005)
        摘要：The work is to study possible mechanisms of radiation injuries to brain by observing Ca2+ and Mg2+ contents in electron beam irradiated rat brain. Sprague-Dawley rats were irradiated with a single dose of 10Gy, 20Gy or 30Gy by 6MeV electrons. On different days after the irradiation, Ca2+ and Mg2+ contents in whole brain of the rats were measured by direct-reading plasma spectrography, and the brain water content was calculated with wet-dry weight formula. In comparison to the control groups, the total tissue water and Ca2+ content in brain of all the irradiated rats increased, while the Mg2+ content in brain decreased. The of Ca2+ content increased markedly (p<0.05) 24h after the irradiation, and the Mg2+ content decreased significantly (p<0.05) 7d after the irradiation. The content changes became severe with increasing dose. Discusions are made on mechanisms of radiation induced brain injuries based on observations of the Ca2+ and Mg2+ contents changes in the rat brain.  
        关键词：Radiation-induced brain Injuries;Calcium;Magnesium;Rat   
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        发布时间：2023-03-30
      • FU Yankun,DUAN Shujun,WANG Jingfeng,YANG Yu
        Vol. 23, Issue 3, Pages: 189-192(2005)
        摘要：Powder samples of naturally dried and spray processed spriulina polysacchrides were irradiated to different doses from 1.2 to 13.5 kGy by 60Co γ-rays. Microbial tests were performed and the nutritional compositions were measured. The results showed that for decontamination down to 1.0×104cfu/g of total number of bacteria and 25cfu/g of fungi, the minimum doses were 10.1kGy and 2.9kGy for the naturally dried powder and spray processed powder, respectively. However, 10.1kGy irradiation caused over 40% loss of carotene in the naturally dried powder, whereas 2.9kGy irradiation caused just 15% loss of .carotene in the spray processed powder.  
        关键词：Spriulina polysacchrides;Food irradiation;Nutritional losses   
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        发布时间：2023-03-30
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