最新刊期
      期 2 ， 1984
      • Zhang Zicheng,Li Shuhua,Zhang Lihua,Li Qian,Zhao Xing
        Vol. 2, Issue 2, Pages: 1-5(1984)
        摘要：Polyacrylamide hydrogel Ⅰ (PAM-HG Ⅰ) which retains distilled water) 350 g/g) has been obtained by radiation crosslinking of polyacrylamide (Mw 9.8×106). Polyacrylamide hydrogel Ⅱ (PAM-HG Ⅱ) was prepared by alkaline hydrolysis of PAM-HG I to enhance its hydrophilic character. In contact with water PAM-HG Ⅱ forms a "superabsorbent" gel which retains very large amount of water (up to 958 g/g). But the water retention is stronly reduced in NaCl and CaCl2 aqueous solutions when pH<4 and > 10.  
        关键词：Radiation crosslinking;Suspension hydrolysis;Polyacrylamide hydrogels;Superabsorbent of water   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361501 false
        发布时间：2023-04-23
      • Qin Guoliang,Zhang Wenlong,Zhang Jiashan
        Vol. 2, Issue 2, Pages: 6-11(1984)
        摘要：In this paper, we have investigated the effect of the radical and cation-anion scavenges on the dimerization of thymine in frozen aqueous solution induced by r-rays. It was proved that the indirect effect of OH radical produced by water rediolysis is not the cause of forming the thymine dimer linked by the cyclobutane ring. The cation-anion recombination is not the way of forming the dimer too. From the research of excitation transfer we have obtained the evidence that thymine dimer linked by the cyclobutane ring is caused by the excited state of thymine. At the same time, We have found that the thymine dimer A can also be formed at 268 K.  
        关键词：Scavenger;Dimerization of thymine;Frozen aqueous solution;Excitation transfer   
        3
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361498 false
        发布时间：2023-04-23
      • Li Qian,Li Donghui,Quan Shouyi,Zhang Zicheng,Li Meirong
        Vol. 2, Issue 2, Pages: 12-16(1984)
        摘要：Preparation of hydrogels by radiation copolymerization of acrylamide and sodium acrylate was investigated. Monomer concentration of mentioned system may be increased from 20 wt.% to 50 wt.% by adding small amount of non-ionic surfactant. The polymerization conversion and intrinsic viscosity of copolymers in high monomer concentration are greater than that in low monomer concentration to a certain extent. Radiation crosslinking of copolymer gives hydrogels having swelling ratio in water above 1,000, The swelling ratio of the copolymer-hydrogels depends not only on the crosslinking density, but also on the amount of -COONa groups in macromoleculer chains.  
        关键词：Radiation copolymerization of acrylamide with sodium acrylate;Polyacrylamide hydrogels;High water absorbents;Swelling ratio   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361500 false
        发布时间：2023-04-23
      • Li Xuepeng,Lin Nianyun,Tu Tiecheng,Xie Jidong
        Vol. 2, Issue 2, Pages: 17-22(1984)
        摘要：In this paper the mechanisms of radiation protection exerted by histidine and arginine on thymine were studied. By means of ESR and molecular orbital calculations the radiation protection mechanism via electron transfer from thymine anion to the basic amino acids has heen confirmed. The electrophilic property of the amino acids varies with thier degree of protonation. Under PH7 condition, the mechanism of radiation protection by histidine on thymine may be a coordinated process of electron and hydrogen transfer.  
        关键词：Basic amino acid;Charge transfer protection;Hydrogen transfer;ESR;Thymine;Histidine;Arginine   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361502 false
        发布时间：2023-04-23
      • Zhang Manwei,Zhang Zhicheng
        Vol. 2, Issue 2, Pages: 23-28(1984)
        摘要：The probability of positronium (Ps) formation in molecular substances is investigated from the viewpoint of radiation chemistry. A new conception so called as "radiation protective function" (F) is proposed. A correlative equation with both the probability of Psformation (I3) and radiation protective function was derived in "ideal binary systems" according to the competitive reaction mechanism in the spur:where α0, β0 are the parameters indicating the relative rate of competitive reactions between e+ and A+ or B+ with e- in the spur, K=α0+β0. Furthermore, on the authority of this correlative equation, it is made a quantitative fittings with the I3 values for systems of n-heptane-positive hole scavenger (dioxane, trimethylamine, pyrrolidine) and for aqueous solutions of some anions(I-, Br-, Cl-, S2-, SCN- and F-). It is found that in systems containing positive hole scavenger pyrrolidine possesses a larger radiation protection comparing with dioxane and trimethylamine to n-heptane, and that for anion aqueous solutions the order of radiation protection of the anions to water is I->SCN->S2->Br->Cl->F-. In fact, F- have nothing of the protection for water.  
        关键词：Ortho-positronium;Probability of positronium formation;Radiation protective function;Ideal binary system   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361499 false
        发布时间：2023-04-23
      • Ma Yizheng,Zhang Luya
        Vol. 2, Issue 2, Pages: 29-33(1984)
        摘要：The Properties of polypropylene film and nonwoven, such as the viscosity average molecuar weight, degree of tacticity and mechanical strength have been ivestigated by irradiation in vacuum, in nitrogen. and in air at room temperature.The gases evoluted during irradiation have been analyzed and meas measured, so that the G values were calculated as foollows: 2.52~3.56 for H2 0.11~0.12 for CH4, 0.01~0.02 for C2 H4 0.13~0.20 for C3 H6, and 0.24~0.26 for C4H8.The results showed that the physical and mechanical prorerties of polypropylene were not changed, when the dose of radiation was lower than 5×105 rad, but decreased with fourther increasing doses (up to 5×106 rad) and a large quantity of low molecular hydro-carbon compounds were produced, When the dose exceeded 3×107 rad, the polypropylene sample could be dameged extremely and even changed into powder.It was found by the ESR measurement that trapped free radical of polypropylene, irradiation in vacuum at room temperature, was converted into peroxy radical rapidly as the samples were exposed in air, obviously, this may cause auto-oxidation degradation of polypropylene,The authors suggest that in order to improve the radiation stability of polypropylene it is necessary to add some anti-oxidents or to prepare polypropylene in the form of multi-component copolymers.  
        关键词：Polypropylene;γ-Irradiation;G volues;Physical and mechanical properties of polyoropylene;ESR spectroscopy   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361572 false
        发布时间：2023-04-23
      • Wang Ying,Liu Tai Fu
        Vol. 2, Issue 2, Pages: 34-38(1984)
        摘要：Ultrasonic Heating (1MHz, 0.5~1.0 W/cm2)for 30 minutes before irradiation euhanced the effect of radiotherapy, the inhibition rate of the combined treatment on S 180 in mice is 99.5%, whereas, for radiation alone, it is 68.4% and ultrasonic heating alone 89.9%.Radiation or ultrasonic heating alone had no curative effect on the tumor when compared to the combined treatment, as seen in day 30 observation on tumor regrawth.  
        关键词：Tumor radiotherapy;Ultrasonic heating;The growth of S 180   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361571 false
        发布时间：2023-04-23
      • Zhou Jiwen,Wang Jixian,Deng Bifang,Wang Sulan
        Vol. 2, Issue 2, Pages: 39-44(1984)
        摘要：The early and late effects of a single radiation dose or fractional doses on the mice during the period of organogenesis were studied.In the early effect group, a variety of congenital defects and a great number of death in fetus were produced by γ-irradiation.All the animals in the late effect group have been observed for two years. It was shown that the incidence of leukemia in the treated group was 2.5 times higher than that in the control group, and the average weight of the irradiated fetus decreased significantly.  
        关键词：Radiation;Carcinogensis;Malformation;Embryo effect   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361575 false
        发布时间：2023-04-23
      • Wang Tianyu,Yang Lijun
        Vol. 2, Issue 2, Pages: 45-51(1984)
        摘要：The dependence of 60Co γ-ray induced irregularities (chromosome aberrations and micronuclei) in human peripheral blood lymphocytes in vitro on radiation doses has been studied. All blood samples were irradiated with lower doses (0-60 rads) of 60Co γ-ray (dose rate 70.05 rad/min) at 37±0.5℃, cultured for 50 hrs by microtechnique; and observed in the same smears.The obtained data concerning chromosome aberrations and micronuclei were fitted to the model Y=a+bD by least square regression analysis using Poisson variance and weights. And, a=a0=0, the regression was constrained to pass through the origin. We found a close relation (r=1.000)between the index of chromosome aberration and that of micronucleus obtained in different radiation doses existed. These experimental results indicated that the biological indexes of chromosome aberration and micronucleus, in the diagnosis of radiation dose, were iso-effective for "Biological Dosimeter", they were equally significant and valuable. Considering both the chromosome aberration and micronucleus, the level of lower dose diagnosis, was ranged from 60 to 5 rad.  
        关键词：Chromosome aberration;Micronucleus;Diagnosis of radiation dose;Close relation;Iso-effect;Biological dosimeter   
        4
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361574 false
        发布时间：2023-04-23
      • Zhang Zhonglun,Li Fengzhang
        Vol. 2, Issue 2, Pages: 52-58(1984)
        摘要：The model BPS TE spherical chambers have been constructed. The basic performances of the chambers have been determined. The chambers are three terminal devices with gas inlet and outlet During operating the chamber at 250 V and 500 V, the saturation correction factors are 1.003 and 1.0007, respectively. The relative change of the response for the chamber is less than 0.5 per cent when the angles of the incident radiation are changed in the range of 0°~120° for the 60Co gamma rays. The stem effect and the energy response of the chamber have been studied. The results of measurement show that the variation of the composition of TE-gas will cause noticeable error  
        关键词：Spherical ionization chamber;Saturation characteristics;Stem effect;Tissue equivalent gas;Energy response curve   
        3
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361573 false
        发布时间：2023-04-23
      • Wu Weibin,Xu Moujun,Du Cong,Zhu Zhenkang,Zhou Jichun
        Vol. 2, Issue 2, Pages: 59-62(1984)
        摘要：Polyurethane acrylate coating was prepared by diluting the reation products of hydroxypropyl acrylate, polypropylene glycol and toluene diisocynate with some acrylates. The varnish was applied to the surface of wood and was irradiated by electron beam under nitrogen atmosphere with total dose 3 Mrad. Properties of this coating were examined and proved to be excellent.  
        关键词：Electron beam processing;Radiation curing;Acrylate coating;Wood surface;Varnish;Oligomer   
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361597 false
        发布时间：2023-04-23
      • Vol. 2, Issue 2, (1984)
          
        2
        |
        0
        |
        0
        <HTML>
        <L-PDF><Meta-XML>
        <引用本文> <批量引用> 36361578 false
        发布时间：2023-04-23
      0