住房室内氡的危害及其控制措施

首先概述了室内氡的危害、特性和其主要来源,然后介绍了国家对住房室内氡浓度达到的控制标准,最后根据氡的来源和国家标准,探讨了住房室内氡的相应控制措施。     

南宁市某新建高层住宅楼室内辐射水平测量分析

对于室内空气辐射水平,人们最关心的是氡浓度及γ辐射。文章通过对南宁市某新建高层住宅楼室内氡浓度及γ辐射水平的监测,探讨室内空气辐射水平的测量方法及结果分析,以及值得注意的一些问题。     

气溶胶和氡浓度变化对氡子体影响的探讨

为了得到气溶胶变化后对氡子体产生的影响,实验通过气溶胶粒径谱仪SMPS测试氡室内不同浓度气溶胶,分析气溶胶的变化情况,根据AlphaGUARD测氡仪以及AlphaPM子体仪测试变化的氡浓度不同气溶胶下子体变化情况。实验结果表明:在两个NaCl浓度的气溶胶条件下,气溶胶的总量随着气溶胶发生器中的NaCl浓度的增大而变大,由于氡子体结合态随气溶胶浓度改变,氡子体浓度也随气溶胶浓度的增大而增大。并且在相同气溶胶浓度情况下,氡子体的浓度随着氡浓度的增大而增大。     

乌鲁木齐市土壤氡浓度分布水平初探

为初步了解乌鲁木齐市土壤氡的污染分布情况,采用RAD7电子测氡仪,于2008年6月～2009年11月期间对乌鲁木齐市土壤氡浓度进行了调查。通过多测点、大范围的调查研究,初步揭示了乌鲁木齐市土壤氡污染状况的分布特征,为正确认识乌鲁木齐市氡污染水平及研究土壤氡与室内氡关联性提供了科学依据。     

室内放射性气体~(222)Rn的防治方法

随着社会的发展,室内放射性气体氡的污染已经成为人们关注的焦点。采取有效的方法和措施来降低其污染,已经成为一个重要的研究方向。对室内氡的来源及现有的防治方法进行了总结,并提出了一些建议。     

蚊香对空调房内氡子体浓度影响的初步研究

本文采用专业氡测量仪AlphaGUARD PQ2000PRO及其子体附件AlphaPM监测空调房内普通盘式蚊香及电热蚊香产生的气溶胶颗粒对氡子体浓度变化的影响。通过对比测量,可以看出普通盘式蚊香和电热蚊香产生的亚微米级气溶胶均会使得空调房内氡子体浓度增高,且前者导致的增加趋势更明显。建议开空调时室内使用电热蚊香,并且应定时开窗通风十几分钟,以降低室内氡子体浓度,减少其对人体的危害。     

室内氡子体浓度调查

目的:调查了某办公室24小时室内氡子体α潜能浓度的变化范围。方法:按照国家标准方法。结果:24小时室内α潜能浓度的变化范围为(531.08~746.28)nJ/m3。     

新装修居室内放射性污染物及氡的现场调查研究

阐述了新装修的室内不同功能居室、不同地面材料、不同大理石材料及不同电器所释放的放射性污染物。同时也监测了11间新装修的居室内和1间已装修多年的居室内氡浓度,最后提出减轻放射性及氡污染的一些有效措施。     

除氡新品——“苍穹”空气净化器

<正>2014年12月22日,上海苍穹环保技术有限公司的除氡新品——"苍穹"空气净化器在北京举行产品发布会。该公司研发的"室内氡控制技术"曾在中国发明协会主办的第八届国际发明展览会上荣获"发明创业奖·项目奖"金奖。随着科学的发展,人们对危害人体健康的空气中的污染物的认识越来越深刻。如今,一个陌生的名字——"氡"已开始引起人们的高度重视。氡是由镭衰变产生的一种天然放射性惰性气体,无色无味,又无处不在。建筑物内的氡主要来     

某校园室内氡浓度水平调查

随着经济的发展,人们对生活环境要求也越来越高,室内氡放射性对健康的影响也越来越被更多的人所关注。本文以连云港市某高校为例,为了解其校园室内氡浓度水平,选取了该校园三个典型建筑物,对其部分房屋的室内氡浓度进行了测量,监测结果显示该校室内氡水平在国家标准范围内正常水平。     

累积法测氡析出率方法以及数据修正研究

本文研究了在出现泄漏情况和反扩散作用对累积法测量氡析出率造成的影响,通过两种不同的处理方法得到不同的结果,对结果进行分析表明等时间间隔法适用的范围更广、实验结果更准确。     

用双滤膜法测定氡析出率的实验研究

用双滤膜方法对居室和建材的氡析出率进行了可行性测定及探讨，数个测点实测结果表明：与常规的活性炭方法相比，双滤膜方法原理可行，操作简单，结果可比，是一种更加灵敏、高效、快速的氡析出率测定方法。     

一种新的复杂背景下快速车牌定位方法

针对实际应用中具有复杂背景的高分辨率数码图像下车辆牌照定位问题，提出了一种综合利用了车牌纹理特征、几何特征以及色彩特征的快速车牌定位方法。该方法按顺序分为图像预处理、牌照区域粗定位、牌照精确定位三个步骤对牌照由粗到细准确定位出车辆牌照位置所在。实验结果表明．对于场景大，背景复杂的车辆图像，该方法运行速度快，定位准确率高，具较强抗干扰能力。     

调和NA群上几种新的Hardy不确定原理

介绍了调和NA群上的Radon变换,以及这个变换和Helgason-Fourier变换之间的关系。基于这些变换,将实直线R上Morgan形式的Hardy不确定原理和Cowling-Price形式的Hardy不确定原理推广到调和NA群。     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.