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本文建立了在稳定氡源的情况下，氡室中氡量变化规律的数学模型，并导出了氡室中氡量控制参数的三个计算公式。该数学模型为氡室的研制和氡量控制提供了理论依据。对环境的辐射监测与评价也有指导意义。 相似文献
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本文从战略角度出发考虑了社会生活用房中氡的测量和减少氡对人体作用的问题；讨论了住宅中氡的测量，氡的来源，以及氡浓度变化的原因和若干防氡措施等。 相似文献
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本文建立了在稳定氡源的情况下，氡室中氡量变化规律的数学模型，并导出了氡室中氡量控制参数的三个计算公式．该数学模型为氡室的研制和氡量控制提供了理论依据，对环境的辐射监测与评价也有指导意义． 相似文献
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本文通过试验，测定了多种材料的阻氡效果。数据表明，即使采用薄铜片阻氡，也难以达到较好地阻氡外逸的目的。文中指出了阻氡的具体途径和最佳的阻氡材料。 相似文献
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加拿大卫生福利部希望对全加拿大本国人住宅中的氡的潜在危害进行评价。根据航空伽玛测量数据。地质和地球化学，选择了４１个潜在氡高的居民区的１６个潜在氡低的居民区进行取样，在潜在氡低的居民区中没有一个住宅氡的水平超过４００Ｂｑ／ｍ＾３，而在潜在氡高的居民区中很多住宅超过加拿大的标准８００Ｂｑ／ｍ＾３。根据这一研究结果，加拿大卫生和福利部开始了一项追踪计划，测量住宅中氡浓度可能超过加拿大标准８００Ｂｑ／ｍ 相似文献
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在居民所受到的天然辐射作用的总剂量中，氡及其子体的吸入占有主要部分。在进行综合生态测量时，在俄罗斯的不同地区进行了氡及其子体的测量；这些地区是：圣彼得堡地区、俄中部地区和阿尔泰地区。使用了以径迹蚀刻和活性炭探测器为基础的剂量计，对环境氡浓度进行了测量；这是两种适用的低成本方法。以０．５的平衡系数和推荐的０．０６１ｍＳｖ／（Ｂｑ／ｍ＾３）有效测量当量系数计算了氡子体活度和有效剂量当量。在２１个村镇对 相似文献
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洞穴氡来源、分布、测定及旅游评价 总被引：4，自引：3，他引：1
洞穴氡来源于岩石中含铀以及洞穴壁裂隙中渗析出来氢的累积和地下水溶解氡的释放。洞穴氡值与地区、洞穴围岩,以及距洞口深度有关,与洞内的地质条件有关。在洞穴氡值的测定中,目前国际上最新采用的是SSN TD方法。本文不仅介绍了该方法的基本原理,还应用它对我国部分洞穴的氡值进行了测定。 相似文献
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喀斯特洞穴氡研究综述 总被引：2，自引：0，他引：2
氡对人体健康的影响向来是医学、化学、核物理学等学科的研究热点。近年来学术界虽然对喀斯特洞穴氡的来源(岩石、地下水)、氡浓度的影响因素(地质因素、洞体结构、洞内外气象参数)、氡浓度的测量(测量对象、测量仪器及方法)、氡的危害、氡的防治(隔离氡气渗入途径、排风通氡、控制洞穴内停留时间减少吸入量、加强监测)等方面开展了研究并取得了不少的成果,但对于喀斯特洞穴氡的形成机理、喀斯特洞穴氡测量标准的制定及有效剂量的估算、喀斯特洞穴氡的防治技术及员工的健康管理等方面的研究还比较薄弱,有待加强。 相似文献
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经过10年对3个不同测点氡季节性变化的调查，以及幼儿园，学校，防空掩蔽所和地窖氡浓度的测量后，对奥西耶克（东克罗地亚，130000户居民）的住宅（住宅建筑）进行了系统的室内氡测量，用LR－115固态径迹探测器在城镇48个测点上测量了室内氡，给出了算术平均值为71．6Bq.m^-3,标准偏差为44．0Bq,m^-3,和几何平均值为60．1Bq.m6-3，其冬浓度范围从22．7到186．5Bq.m^-3,由Radhome硅探测器进行的氡测量差异并不大，氡浓度的经验频率分布（分组宽度20Bq.m^-3)与x^2检验示出的理论对数正态分布相一致，氡图指指出了由地质土壤构造造成的氡浓度较高的区域（该城镇的中部）。上述提及住宅中氡及其子体的平衡因子为0．44，有些氡模型的有效剂量当量估计数接近2mSv.a^-1. 相似文献
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环境中氡及其子体的危害与控制 总被引：5，自引：1，他引：4
简要回顾氡致肺癌的长时间认识过程和研究历史,简述了当年铀矿工人和矿工吸入氡及其子体与肺癌发病率的关系,指出环境中氡的危害。重点讨论了国内外室内氡和地下建筑物中氡浓度分布及其来源,从而启发人们研究环境中氡的地质来源以及控制室内氡水平的基本措施;进一步阐述了我国室内氡研究的成果和需要进一步研究的问题。 相似文献
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Pressure of natural gas in its rock reservoir determines the final radon concentration in this gas after its decompression to normal conditions. In this investigation, radon contents of 62 natural gas samples were measured and a simple physical model of the gas reservoir was applied. The model takes into account an additional dependence of radon concentration on the natural gas pressure and on the porosity of the rock reservoir. The influence of the gas pressure on the value of the radon emanating power is discussed. The mean
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Ra content in the source rock needed for generation of
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Rn concentrations observed in gas is also calculated. The calculations are made with the help of regression analysis. 相似文献
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Increasing concern about possible links between emissions of radon and certain types of malignant disease has led to local and regional surveys to measure radon concentrations in the soil and in dwellings. The spatial scale at which radon varies is largely unknown, and so efficient sampling schemes and methods of mapping cannot be selected. To determine the spatial scale of radon variation in the English Midlands we measured radon in the soil using solid-state nuclear track detection in three areas of different geological complexity. In two of them we used an unbalanced multistage sampling scheme with seven stages of nesting: the Hereford survey covered distances from 10 m to 7.5 km, and the Buxton survey distances from 1 m to 3.75 km. The results from the nested surveys suggested that geology exerts a strong control on the variation. Finally radon was measured every 20 m along a 2-km long transect which crossed several lithologies close to Nottingham. The soil radon values changed in an erratic way along the transect. The sample variogram of radon has a substantial nugget variance, suggesting that much of the variation occurred for distances less than the sampling interval. The structure at the longer scale seems to be controlled by the underlying geology. These results have implications for designing further surveys and for selecting a method of mapping. Stratification based on lithology might be the only feasible solution to sampling, estimating and mapping radon concentrations over large areas. Where the locally erratic component of variation is large, estimation by kriging, for example, would confer little additional benefit compared with that by classification. 相似文献
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为了保证我国氡填图方法研究中关键参数土壤氡浓度测量结果的准确性和可靠性,笔者所在的实验室作为首次参加氡国际比对的中国组织,参加了2010年在捷克举行的3个氡参考点Cetyně、Bohostice和Buk现场测量国际比对。经T-学生分布检验,当显著性水平α=1%时,本实验室在氡参考点上45个测点的实测土壤氡浓度值cA与全部比对测量参加者的CA(2000年以来该参考点全部组织的平均值)数据有很好的一致性;3个参考点的平均氡浓度与自2000年以来在这些氡参考点进行试验的所有成功组织(N=180)提交数据形成的数据库中的数据高度一致,总相对误差小于6%。该成果表明本实验室的土壤氡测量技术已达国际相应水平。通过本次氡国际比对,发现了我国土壤氡测量中仪器校准、土壤气体采样技术等方面存在的问题,建议系统开展土壤氡测量方法及其技术规范等研究。 相似文献
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本文探讨了矿物热释氡找矿中氡的来源问题。我们对七五二花岗岩中铀矿床的无矿及含矿花岗岩用闪烁射气法进行了各种温度间的矿物热释氡量的测定;用包裹体爆裂法进行了爆裂温度及相对爆裂次数的测定。通过实验发现,加热样品在包裹体爆裂以前,能释放出大部分氡,在包裹体大量爆裂的温度区间热释氧量反而很少。磨破包裹体放出氡后,再加热仍然有氡气释放出来。用包裹体中的铀含量计算出的氡量低于测定方法的灵敏度,无法测出,说明矿物热释氡量与包裹体无关。样品又做了化学铀分析和放射化学镭分析。明显看出热释氡量与铀、氡含量成正相关关系。各种实验均证明氧气不是来自包裹体,而是来源于整个矿物。 相似文献
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D. K. Talbot J. D. Appleton T. K. Ball M. H. Strutt 《Journal of Geochemical Exploration》1998,65(1):79-90
Soil-gas radon measurements provide a valuable tool in assessing probable indoor radon levels on a regional basis. However, in Great Britain, seasonal weather changes can cause large changes in soil-gas radon concentration. Although this does not significantly constrain systematic radon potential mapping programmes, it does cause difficulties in responding to ad-hoc requests for site-specific radon investigations. The relationship between soil-gas radon and gamma spectrometry measurements made in the field with radon released from a representative sample of soil in the laboratory has been investigated as part of a program to develop a method of radon potential mapping and site investigation which can be used at any time of the year. Multiple soil and soil-gas samples were collected from sites underlain by bedrocks with widely varying radon potentials. For each geological unit, sites both free of and covered by glacial drift deposits were sampled. Soil and soil-gas samples were taken at the same depth of 60–100 cm. The effectiveness of these radon site investigation procedures has been evaluated by studying the relationship between the soil-gas radon, gamma spectrometry and radon emanation data with an independent estimate of the radon risk. The geologic radon potential (GEORP), which is the proportion of existing dwellings which exceed the UK radon Action Level (200 Bq m−3) for a particular combination of solid and drift geology within a defined geographic area, has been used for this study as the independent estimate of radon risk. Soil-gas radon, radon emanation and eU (equivalent uranium by field γ spectrometry) are all good geochemical indicators of radon risk (GEORP) in Derbyshire but only soil-gas radon correlates significantly with GEORP in Northamptonshire. Radon in soil gas discriminates more effectively between sites with different radon potential in Northamptonshire if soil permeability is also taken into account. In general, measurement of soil-gas radon in the field provides the most universally applicable indicator of radon potential. If soil-gas radon concentrations cannot be determined because of climatic factors, for example when the soil profile is waterlogged, measurement of radon emanation in the laboratory or measurement of eU can be used as radon potential indicators in some geological environments. This applies particularly in areas where the soil composition rather than the composition and permeability of the underlying rock or superficial deposits are the dominant controls of radon potential. It appears, therefore, that it may be necessary to use different radon site investigation methods according to the specific factors controlling radon emanation from the ground. In some cases no method will provide a reliable indicator of radon risk under unfavourable climatic conditions. 相似文献