石膏建筑材料放射性检测结果的不确定度评定

根据GB6566-2010《建筑材料放射性核素限量》和JJF1059.1-2012《测量不确定度评定与表示》等标准规定要求,对影响建筑石膏样品放射性检测结果的各相关不确定度分量进行分析、评定和量化,求出合成标准不确定度,最终给出内照射指数和外照射指数的不确定度评定报告。     

一种氡气地表探测覆岩采动裂隙综合试验系统研制与应用

 在概述现有关于覆岩采动裂隙发育特征方面研究现状和总结氡气现有工程应用领域的基础上,首次尝试将氡气的地球物理化学特性应用于采矿工程领域,将放射性测量方法引入到地下煤炭开采覆岩采动裂隙发育过程及其含水性方面的探测,并独立自行研制氡气地表探测覆岩采动裂隙综合试验系统。该综合试验系统具有拆装简便,物理模拟模型铺设方便,在同一物理模拟试验台架上可快速实现二维或三维物理模拟试验等优点。将该综合试验系统应用于神东矿区大柳塔煤矿11203工作面开采二维相似物理模拟试验中,模拟得出覆岩采动裂隙动态演化特征及其与氡气浓度变化二者之间的对应规律。同时,该试验也进一步地验证采用氡气地表探测覆岩采动裂隙的可行性。     

室内墙面干挂玻化砖施工技术探讨

结合工程实例,阐述了室内干挂玻化砖的优点及主要的施工技术措施.     

Tritium Levels in Leachates and Condensates from Domestic Wastes in Landfill Sites

An extensive review study of leachate composition, from landfills which have received mainly domestic wastes in the UK, has been carried out by Aspinwall & Company on behalf of the Department of the Environment. This work has provided detailed information on concentrations of a wide range of determinands. One set of analyses which has produced particularly interesting results comprises the determination of tritium. Tritium is a natural isotope of hydrogen (³H), with a half-life of 12.43 years, which decays radioactively to form stable ³He atoms, releasing beta particles. Although tritium concentrations can be measured accurately as tritium units (TU), these represent extremely low levels of activity, and concentrations of tritium well in excess of 100 000 TU would be needed before acceptable levels of radio-activity in drinking water were exceeded.
Background levels of tritium in UK rainfall rarely now exceed 50 TU although, in the 1960s, values of up to 3000 TU in rainfall were associated with atmospheric testing of atomic weapons. It was somewhat surprising, therefore, to discover that relatively high concentrations of tritium (>10 000 TU) were widespread in leachates from landfills which had received primarily domestic wastes. This paper presents results from samples taken at 30 representative UK sites, and discusses potential sources of tritium.