聚合物的基本辐射效应辐射向聚合物的能量转移

聚合物的辐射交联、降解和接枝改性都是由辐射向聚合物的能量转移引发的.任何一种辐射源的辐射,都可以引发聚合物分子的活化或电离,生成发生化学反应所需的活性粒子.能量转移的主要形式是射线通过电离与聚合物分子发生作用,而碰撞的贡献比较小.X射线或γ射线等电磁波的辐射会产生高能二次电子,高能二次电子可以使聚合物分子发生电离.电子束、γ射线和离子束作为辐射源,其穿透聚合物材料过程中能量损失方式的宏观机理大相径庭.本文从宏观和微观两方面的机理分别对由电子、γ射线、离子和中子引发的单一辐射效应事件进行描述.     

Approach to reducing the effect of bone—coal power station on radiation environment

The effect of two bone-coal power stations(6MWe) on environment was investigated within the scope of the dose contribution caused by various radionucildes in different ways.It is found that the best measures to reduce the effect of bone-coal power station on radiation environment include to select a fine boiler system and a comprehensive utilization of the bone-coal cinder(BCC),soot and ash in the catchers.     

长期低剂量电离辐射对工作人员心电图影响的Meta分析

通过搜索有关文献,按照预先设定的纳入排除标准严格筛选后,以放射组和对照组心电图检查总人数、心电图异常人数为基本数据,研究其异质性检验,用OR(OR即比值比,表示暴露者的疾病危险性与非暴露者疾病危险性的比值)作为效应值,然后使用固定效应模型或随机效应模型进行Meta分析。结果显示,符合纳入标准的文献共计15篇;放射组与对照组之间异常率有统计学意义[OR=1.63,95%CI(1.32,2.02),p0.000 01]。结果提示,长期暴露于低剂量电离辐射环境下会对工作人员心电图异常有显著影响。     

Ionizing radiation effect on 10-bit bipolar A/D converter

<正>In this article,radiation effects and annealing characteristics of a bipolar analog-to-digital converter(ADC) are investigated in different biases and dose rates.The results show that ADC is sensitive to both the bias and dose rate. Under high-dose-rate irradiation,the ADC functions well,while under low-dose-rate irradiation,the parameters of ADC change obviously at low dose level,and the damage is significant at zero bias.Combining the fringing field with the space charge model,the underlying mechanism for this response is discussed.     

甘氨酸辐射效应的谱学研究

用固体高分辨核磁共振~(13)C谱、电子自旋共振谱以及X衍射光谱研究了多晶甘氨酸的γ辐射稳定性。结果表明甘氨酸在0—140kGy辐照剂量范围内是稳定的,而~(13)C共振谱线则随着辐照剂量的增加而线性地增宽。     

The effect of radiation on the properties of silicone rubber

As a result of -radiation, silicone rubber undergoes a series of changes due to radiation cross-linking. The modulus of elasticity increases linearily with a dose up to 150–200 megarads. The vitrification temperature (– 120 to- 125 ° C) hardly changes up to 100 megarads and at 270 megarads it is –110 to –115 ° C. With cross-linking, the rate of crystallization and degree of crystallinity decrease. The melting point falls from – 35 ° C for the initial material to – 55 ° C for rubber Irradiated with a dose of 40 megarads. A dose of 100 megarads practically completely eliminates crystallization. This dose produces rigid rubbers with a modulus of 200– 250 kg/cm² and a high degree of frost resistance, (Tg –125 ° C), but with a very small breaking stretch (15–20%) with a strength of 30–40 kg/cm².     

The effect of radiation on the anaerobic corrosion of steel

To ensure the safe encapsulation of spent nuclear fuel elements for geological disposal, SKB of Sweden are considering using a canister, which consists of an outer copper canister and a cast iron insert. Previous work has investigated the rate of gas generation due to the anaerobic corrosion of ferrous materials over a range of conditions. This paper examines the effect of radiation on the corrosion of steel in repository environments. Tests were carried out at two temperatures (30 °C and 50 °C), two dose rates (11 Gray h⁻¹ and 300 Gray h⁻¹) and in two different artificial groundwaters, for exposure periods of several months. Radiation was found to enhance the corrosion rate at both dose rates but the greatest enhancement occurred at the higher dose rate. The corrosion products were predominantly magnetite, with some indications of unidentified higher oxidation state corrosion products being formed at the higher dose rates.     

Effect of the composition of radiation on the radiation damage to graphite

A statistical analysis is performed of the results on the determination of the critical neutron fluence in MR, SM-2, and BOR-60 with different irradiation temperature. It is shown that the critical neutron fluence depends not only on the irradiation temperature but also, and to an even greater extent, on the radiation composition factor (ratio of the neutron and γ-ray flux densities). Thus the critical neutron fluence for irradiation at 600°C in MR (radiation composition factor 0.13) is 17·10²¹ cm⁻² and in SM-2 (radiation composition factor 0.1) 11·10²¹ cm⁻² at the same temperature. When the same graphite is irradiated in the region of the outer corner of a working block of RBMK, where the radiation composition factor is 0.55, it is expected that the critical neutron fluence will be 31.7·10²¹ cm⁻². In summary, taking account of the effect of γ-radiation introduces substantial corrections: the experimental results obtained in research reactors are found to be at least a factor of 2 too low. This gives hope of substantiating the substantial increase in the service life of the RBMK graphite masonry. 3 figures, 8 references. Scientific-Research and Design Power-Engineering Institute. State Science Center—Scientific-Research Institute of Nuclear Reactors. Translated from Atomnaya énergiya, Vol. 87, No. 1, pp. 24–28, July, 1999.     

A systematic approach to the radiation damage problem

To assess the suitability of a material for use as a core component in a fast reactor or for the first wall in a fusion reactor, it is necessary to know the irradiation damage behaviour of the material outside the usual materials testing data domain. In the present paper we propose a strategy based on a closely co-ordinated programme of experimental and theoretical research. The aim of this strategy is the systematic construction of a physically based model of the evolving damage structures. This would then allow both the necessary extrapolations of the data to the desired conditions to be achieved in a reliable fashion and provide a rational basis for the development of low-swelling alloys for the two nuclear systems.     

核电站放射性环境调查的气溶胶采样方法

介绍了秦山核电站二三期放射性环境调查气溶胶采样的方法、滤膜的检查、采样体积的修正和质量保证措施,并对采样中经常存在和值得注意的问题展开了讨论,提出了一些解决的方法,为今后进一步做好气溶胶采样工作提供了有益的参考。     

空间低剂量率效应模拟方法研究

一方面介绍了利用线性响应理论能够预估MOS器件空间低剂量率的辐射响应,并得出在相同偏压下,高剂量率辐照加室温退火所引起的阈值电压漂移量在误差允许的范围内等于低剂量率辐照的漂移量,两者总的时间相等;另一方面对美军标1019．4实验程序进行了重新评估,对氧化物陷阱电荷和界面态效应的评估方面给出了一些建议。