共查询到18条相似文献,搜索用时 46 毫秒
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松针中组织自由水氚的测量 总被引:2,自引:0,他引:2
本文用生物样品与有机溶剂共沸蒸馏分离法对秦山核电厂附近秦山上松针中组织自由水氚进行测量。选择甲苯为共沸蒸馏溶剂。松针与甲苯共沸蒸馏,组织自由水回收率达90%。结果表明,松针中组织自由水氚浓度为1.8 Bq/L,与同期大气中氚化水蒸气(HTO)的浓度在同一水平。 相似文献
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本文介绍生的样品有机溶剂共沸蒸馏--液体闪烁计数测定组织自由水氚法,组织自由水回收率松针,大米为90%;青菜,萝卜为95%;牛奶为85%;猪肉(精)为52%。松针(鲜),青菜,萝卜,大米,猪肉(精)与牛奶组织自由水氚活度为分别为1.8,3.2,1.8,2.7,3.3,4.0Bq/L-H2O。 相似文献
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用蒸馏 液闪法和氧化蒸馏 液闪法分别测量了氚污染人员尿中的氚水和总氚(氚水和有机氚)的浓度。根据72个高于本底水平的尿中氚水和总氚浓度分析结果比较,认为在氚内污染工作人员的尿中,有机氚与氚水的浓度比值为(5.4±3.7)%。 相似文献
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土壤样品中氚水的测定 总被引:3,自引:0,他引:3
本文介绍了土壤中氚水的测定方法,主要包括真空解析与冷凝、制样和液闪测量等步骤。当分析120g湿度为20%的土壤时,方法回收率为96.7%,探测下限为0.70Bq/kg。 相似文献
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本文介绍液体闪烁计数测定有机溶剂共沸蒸馏生物样品组织自由水氚的方法。实验测得甲苯共沸蒸馏新鲜松针、青菜、萝卜、、牛奶、猪肉(精)和大米组织自由水的回收率,分别为0.90、0.95、0.95、0.85、0.52和0.90以及组织自由水氚活度.每升样品水中分别为1.8、3.2、1.8、4.0、3.3和2.7Bq。 相似文献
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我国部分地区食品氚的分布规律初探 总被引:1,自引:0,他引:1
调查了我国北京、兰州、上海和成都四个城市的食品氚浓度,其中食品的游离水氚(TFWT)和有机结合氖(OBT)浓度的平均值分别为4.56Bq·L-1和29.51Bq·L-1,食品OBT与TFWT含量的比值(SAR)为6.47.食品OBT浓度由北往南逐渐下降(P<0.05),与纬度呈高度线性关系。植物类食品的OBT浓度较动物类食品高,且地面生长食品的OBT浓度最高,灌溉类食品最低。 相似文献
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N. Baglan;E. Ansoborlo;C. Cossonnet;L. Fouhal;I. Deniau;M. Mokili;A. Henry;E. Fourré;A. Olivier 《Radioprotection》2010,45(3):369-390
The measurement of tritium in its various forms (mainly gas (HT), water (HTO) or solid (hydrides)), is an important key step for evaluating health and environmental risks and finally, dosimetry assessment. In vegetable or animal samples, tritium is often associated with the free water fraction, but may be included in the organic form as organically bound tritium (OBT). In this case, 2 forms exist: (i) a fraction called exchangeable or labile (E-OBT), bound to oxygen and nitrogen atoms, and (ii) a so-called non-exchangeable fraction (NE-OBT) bound to carbon atoms. The main technique for tritium analysis is liquid scintillation, which enables one to measure concentrations in the range of several Bq.L-1. The standards (AFNOR, ISO) published to date relate only to tritium analysis in water. Only one CETAMA method addresses OBT analysis in biological environments. This method has been tested since 2001 through intercomparison circuits on grass samples collected from the environment. Regarding tritium analysis in water, the strengths are reliability of this analysis at low concentrations (order of Bq.L-1), robustness and simplicity, and weaknesses are linked to problems of background, conservation and contamination of samples. Concerning OBT analysis, the analysis is reliable for values around 50 Bq.kg-1 of fresh sample. The weaknesses are problems of contamination, reproducibility, analysis time (2 to 6 days) and lack of reference materials. The difficulty to date is the separation between E-OBT and NE-OBT, that will need experimental validation. 相似文献
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为提高硅胶吸附法监测环境空气中氚的样品前处理效率,采用铸铝加热方式结合温度自动控制技术,研制了一种用于环境硅胶样品自动化氚水蒸馏的装置。经实验验证,该装置选择250℃的加热温度,15 min的蒸馏冷凝收集时间为硅胶吸附氚化水的最佳解析条件,此时对硅胶中氚化水的平均回收率大于99%,氚记忆效应小于0.2‰,100 g饱和硅胶样品能解析水7~10 ml,满足液闪测量要求,研制的氚水蒸馏装置较以往装置蒸馏效率提高了近3倍,能耗减少约77%。 相似文献
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氚是环境中的主要放射性核素之一,对氚进行准确高效的监测是十分有必要的。目前常用的液体闪烁计数法所需的样品量较大,测量时间较长,不能对微量样品进行高精度测量。加速器质谱具有测量样品小、测量精度高和测量时间短的特点,能够更好地满足环境氚监测的需求,可以广泛应用于地球与环境科学、生物医学和辐射监测等方面。文中介绍了加速器质谱测氚的基本原理和发展历史、制样方法,对加速器质谱测氚的已有研究成果和主要应用进行了总结和展望。 相似文献
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Activities regarding tritium safety technology in the Tritium Process Laboratory (TPL) at Tokai Establishment of Japan Atomic Energy Research Institute are reviewed. Research and development of a new tritium removal system is being carried out by using a gas separation membrane which enable to make the ITER atmosphere detritiation system more compact and cost-effective. Techniques of gas flowing calorimetry and laser Raman spectroscopy are applied to develop new tritium accountancy methods. Studies of tritium-material interaction, such as plasma material interactions, radiochemical reaction of tritium in gas phase, radiolysis of tritiated water, and waste processing are being carried out under ITER/EDA and U.S.-Japan collaboration. Tritium release experiments for research of tritium behavior in confinements and environment and demonstration of safety related components are planned. 相似文献
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介绍了一种可甄别空气中惰性气体氡的高灵敏度氚实时连续监测仪,其一体化的平行板型丝壁测氚电离室和镀铝聚酯膜窗平行板型测氡密闭电离室,实现了空气中氚监测过程中氡干扰的实时、同步测量与补偿。该氡甄别型氚监测仪不仅在一般使用环境条件下减少了环境氡的影响.提高了氚监测仪的探测灵敏度,而且可在氡浓度比环境高100倍的场所探测到100Bq/L的氚浓度。对于监测环境中其他8放射性惰性气体.这种新型的氚监测仪预期将会有更好的甄别补偿性能。 相似文献
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《核技术(英文版)》2016,(2):26-34
La_((1-x))Mg_xNi_(4.25)Al_(0.75)(x = 0.0, 0.1, 0.2, 0.3)alloys for tritium storage were prepared by a method of electromagnetic induction melting. The crystal structure and hydrogen storage performance of the as-cast alloys were investigated. The results showed that a single phase of La Ni_4Al was in the alloys with x = 0.0 and 0.1 and that LaNi_4Al and second phase of(La,Mg)Ni)_3 and AlNi_3 were in the alloys with x = 0.2 and 0.3. On the other hand, the plateau pressures of P–C isotherms of the alloys were increased with the rise of the x value from 0.2 to 0.3 and the hydrogen storage capacity was obviously degraded simultaneously. It was found that the alloy had faster absorption kinetics as the proportion of Mg increased from 0.1 to 0.3. 相似文献