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1.
环保型防氡、防辐射建筑材料研究进展   总被引:1,自引:1,他引:1  
综合国内外文献介绍了氡和原子辐射的危害、致癌机理,部分建筑材料的氡和放射性情况以及防氡、防辐射的机理,并重点介绍了当前国内外防氡、防辐射建筑材料的研究进展,提出了可利用我国丰富的矿产资源如重晶石、石膏、沸石、以及各种工业废渣开发各种具有防氡、防辐射的功能微集料作为基元材料,制备能够吸收和屏蔽建筑材料所释放的氡气和辐射的环保型建筑涂料、砌筑水泥、各种瓷砖胶结剂以及墙体腻子等的建设性意见.  相似文献   

2.
针对一种新型适合地下工程高湿度、不透气特殊环境的防氡涂层的性能进行了研究。局部静态法和RAD-7型α能谱氡气检测仪对防氡效率的测试结果表明,随涂覆厚度的增加防氡效率上升,当涂覆厚度为0.8mm时,新型防氡涂层的防氡效率为92.92%,涂覆厚度为2.0和2.4mm时,防氡效率分别为98.91%和99.02%。实干时间测试发现,温度为23.7℃、相对湿度RH为95%时,涂覆厚度为2.0mm的新型防氡涂层经12.1h完全干燥;耐老化性能研究显示,新型防氡涂层具有优异的耐高浓度氡辐射、耐湿热以及耐霉菌老化的性能。因此,这种新型防氡涂层可以很好地满足地下工程苛刻的应用要求。  相似文献   

3.
本文介绍了常用的氡测量方法和测氡仪器,对氡测量技术进行了较详细分析,为选择适宜的方法进行氡浓度监测提供了参考。标准氡室的研制为各种测氡仪器的刻度和量值溯源性提供了技术支撑,保证了测量结果的准确可靠,文章简要介绍了国内外标准氡室的发展状况。  相似文献   

4.
标准氡室在氡浓度量值溯源和传递中起着重要作用。为了保证测氡仪量值统一、准确可靠,建立了测氡仪检定装置。针对在建立标准过程中出现的流气式氡源泄漏、氡室实验累积氡浓度值与理论值不一致和液体镭源结晶等问题,重点研究多重密封、改造洗气管路、优化洗气模式及多重过滤等技术方法,并建立氡室累积氡浓度经验曲线和质量管理措施等。按照新建立的实验方法和实验流程,氡室实验调节氡浓度和理论累积氡浓度相对偏差在±3.8%以内,液体镭源长期稳定性在0.7%以内,符合氡室建标的计量性能要求。  相似文献   

5.
为建立氡测量的计量标准,研制以多功能的标准氡室为核心的氡测量仪检定/校准装置。采用氡浓度动态稳定技术以实现氡浓度的自动调控;设计用夹胶钢化玻璃制作氡室以减少箱体对氡的吸附,并具有良好的保温效果;设计制作温湿度调控系统和气溶胶发生与采集装置,实现氡子体放射性气溶胶的检测功能。装置氡室体积为4m3,氡浓度测量范围为370~20000Bq/m3,氡浓度值测量结果的相对扩展不确定度不超过5.8%,可用于测氡仪器的检定校准和氡子体放射性气溶胶的实验研究。  相似文献   

6.
标准氡室内氡气的体积活度值是刻度与校准测氡仪的约定真值,通常由仪器准确测量获得.通过对标准氡室氡体积活度理论计算方法及相关参数实验测定方法的探讨,并对标准氡室氡体积活度进行实验测量,验证了理论计算方法及实验测定参数的可行性.  相似文献   

7.
室内空气中氡的防护   总被引:1,自引:0,他引:1  
介绍了氡的产生和特性,阐述了室内氡的来源,介绍了室内氡浓度的测量方法,由此总结了降低室内氡浓度的一些控制措施,以期创造健康的室内环境.  相似文献   

8.
基于液体闪烁计数原理和滤膜采样技术,建立了一种氡(222Rn)子体体积活度和α潜能浓度的测量方法。应用该方法对氡室中处于放射性平衡状态的氡子体体积活度进行了取样测量,氡子体α潜能浓度测量结果的扩展不确定度小于1.5%(k=2);用α能谱法对氡子体液体闪烁计数测量方法进行了旁证,两种方法的测量结果在不确定度范围内一致。  相似文献   

9.
在重庆,存在大量的地下工程,如人防工程,地下商场等,但至今没有发现对其中氡浓度进行检测的报道.本文介绍了地下工程中氡的来源,综述了当前使用的氡的检测方法,认为现在广泛使用于普通室内氡检测的方法需进一步改进才能应用于地下工程中氡的检测.  相似文献   

10.
建筑石膏外加剂研究进展   总被引:13,自引:0,他引:13  
石膏是国际上推崇使用的绿色建材.我国是石膏资源大国,具备发展石膏建材的资源和政策优势.使用外加剂是提升石膏基材料技术经济水平,推动石膏行业科技进步的最有效途径,也是高性能石膏基材料的核心技术.本文综述了国内外建筑石膏减水剂、缓凝剂、保水剂研究的现状,并对国内石膏外加剂研究与应用中存在的问题进行了分析.  相似文献   

11.
This paper gives the technical characteristics of the Italian Committee for Research and Development of Nuclear Energy and Alternative Energy (ENEA) radon chamber and the operational procedures developed for testing radon and daughters measuring equipment. Runs were carried out under different experimental conditions defined in terms of radon and daughter concentrations, equilibrium ratio (F-factor), and aerosol concentration and size distribution. Stable radon reference atmospheres with known equilibrium factors were obtained using standard aerosols.  相似文献   

12.
Results from closed-can radon exhalation experiments must be interpreted bearing the time-dependent radon diffusion theory in mind. A rapid change from the free to final steady-state exhalation rate will take place for all samples that are thin compared with the radon diffusion length. The radon gas accumulating in a closed can corresponds to a free exhalation rate only if the outer volume of air is much larger than the pore volume of the enclosed sample, or the thickness of the sample is much larger than the radon diffusion length.  相似文献   

13.
研究了利用氡活度绝对测量装置制备高准确度标准氡源的方法,得到了活度扩展不确定度为0.8%(k=2)的量传用氡源。依据计算标准氡体积活度的基本原理,对用于氡源活度量传所配套的小氡室的有效体积进行了校准,其有效体积的扩展不确定度为0.46%(k=2),对一般氡标准装置(标准氡室)所用的参考仪器(AlphaGUARD型标准测氡仪)进行校准,得到其平均体积活度响应为1.01,体积活度响应的扩展不确定度为3.2%(k=2)。  相似文献   

14.
One important requirement for accurate monitoring of radon in working environments, dwellings, and outdoors is to ensure that the measurement instrumentation is properly calibrated against a recognized standard. To achieve this goal, the U.S. Department of Interior Bureau of Mines (BoM) Radiation Laboratory has participated since 1983 in a program to establish international radon measurement standards. Originally sponsored by the Organization for Economic Cooperation and Development (OECD), the program is also sponsored by the International Atomic Energy Agency. While the National Institute of Standards and Technology (NIST) radium solution ampules are acceptable to all participating laboratories as a primary standard, a method of transferring radon from the NIST source into each laboratory’s primary counting apparatus is a critical problem. The Bureau’s method transfers radon from the primary solution by bubbling 3 L of air through it into a steel cylinder. After homogenizing the radon concentrations in the cylinder, eight alpha-scintillation cells are filled consecutively and measured in a standard counting system. The resulting efficiency is 81.7±1.2%.  相似文献   

15.
The ideal facility for assessing the quality of radon measurements at environmental levels consists of: (1) an instrument whose response to radon and its progeny is determined from measurements of a certified or standard 226Ra source, and (2) a calibration room with a known radon concentration.The linkage between these two elements and additional quality control requirements are discussed here for some Environmental Measurements Laboratory radon measurements programs.  相似文献   

16.
A procedure for the calibration of instruments for the detection of 222Rn in air is described. The method is based on the alpha-spectrometric determination of the concentration in air of 218Po in the calibration chamber. The calibration chamber is described, together with the method of maintaining a high aerosol concentration. The 218Po concentration at steady state in the chamber is found to be 98% of the 222Rn concentration typically. An assessment of the sources of uncertainty in the method presented indicate that the 222Rn concentration in the chamber can be determined with an overall uncertainty of about 7% at the 95% confidence level.  相似文献   

17.
基于中国计量科学研究院建立的小立体角氡绝对测量装置,研究了冷凝氡源的α能谱随冷凝室内真空压力和冷指温度的变化特性,介绍了在少量杂质气体不可避免地被引入冷凝室、导致氡源能谱分辨率变化的情况下,如何计算冷凝氡源活度的方法.实验结果表明:氡源冷凝之后,杂质气体随时间逐渐增加会导致能谱分辨力变差,根据氡与子体衰变特性所建立的计算方法计算氡活度,得到连续5h的重复测量结果的一致性在0.45%以内,这对氡源活度的国际比对及量值传递具有重要意义.  相似文献   

18.
Zinc sulfide coated scintillation cells are the primary method for measuring radon-222 at the U.S. Environmental Protection Agency (EPA), Office of Radiation Programs (ORP), Eastern Environmental Radiation Facility (EERF). These cells are used to measure concentrations of radon in exposure chambers that are used to calibrate or test other devices or instruments. Individual cells are calibrated by analyzing samples of air with known concentrations of radon produced by emanation of radon from standard radium-226 solutions obtained from the National Institute of Standards and Technology. The calibration procedure includes ingrowth of radon-222 into equilibrium with the radium in the standard solution, transfer from the solution into an evacuated container, and dilution with a measured volume of air. Samples of the radon in air mixture are transferred to evacuated scintillation cells and sealed for 4 h prior to counting, which allows secular equilibrium to be established between the radon and its decay products.Calibration factors for each individual cell are computed by decay correcting the radon to the time of collection and calculating the ratio of count rate (cpm), corrected for background, to radon activity (Bq) for the specific volume of the cell. Four or more calibration factors are determined for each cell and aver-aged to provide the calibration factor used for measurements. Calibrations are repeated at 6-mo intervals, and the results of each calibration are compared to the previous averages. When calibration factors fall outside the 95% confidence interval, they are rejected and the cell is checked for defects prior to recalibration.  相似文献   

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