首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4578篇
  免费   577篇
  国内免费   1433篇
安全科学   1536篇
废物处理   32篇
环保管理   443篇
综合类   2629篇
基础理论   794篇
环境理论   1篇
污染及防治   200篇
评价与监测   268篇
社会与环境   159篇
灾害及防治   526篇
  2024年   45篇
  2023年   174篇
  2022年   282篇
  2021年   341篇
  2020年   314篇
  2019年   318篇
  2018年   250篇
  2017年   294篇
  2016年   320篇
  2015年   352篇
  2014年   325篇
  2013年   430篇
  2012年   441篇
  2011年   474篇
  2010年   303篇
  2009年   319篇
  2008年   212篇
  2007年   277篇
  2006年   289篇
  2005年   183篇
  2004年   114篇
  2003年   101篇
  2002年   89篇
  2001年   51篇
  2000年   57篇
  1999年   47篇
  1998年   32篇
  1997年   29篇
  1996年   24篇
  1995年   18篇
  1994年   20篇
  1993年   16篇
  1992年   8篇
  1991年   8篇
  1990年   4篇
  1989年   3篇
  1988年   6篇
  1986年   1篇
  1985年   2篇
  1984年   3篇
  1983年   1篇
  1982年   2篇
  1981年   2篇
  1978年   2篇
  1977年   2篇
  1971年   1篇
  1970年   1篇
  1969年   1篇
排序方式: 共有6588条查询结果,搜索用时 814 毫秒
891.
In 2006, Mexico became the first transition country to transfer part of its public-sector natural catastrophe risk to the international reinsurance and capital markets. The Mexican case is of considerable interest to highly exposed transition and developing countries, many of which are considering similar transactions. Risk financing instruments can assure governments of sufficient post-disaster capital to provide emergency response, disaster relief to the affected population and repair public infrastructure. The costs of financial instruments, however, can greatly exceed expected losses, and for this reason it is important to closely examine their benefits and alternatives. This paper analyzes the Mexican case from the perspective of the risk cedent (the Ministry of Finance and Public Credit), which was informed by analyses provided by the International Institute for Applied Systems Analysis (IIASA). The rationale for a government to insure its contingent liabilities is presented along with the fiscal, legal and institutional context of the Mexican transaction. Using publicly available data, the paper scrutinizes the choice the authorities faced between two different risk-transfer instruments: reinsurance and a catastrophe bond. Making use of IIASA's catastrophe simulation model (CATSIM), this financial risk management decision is analyzed within the context of a public investment decision.  相似文献   
892.
The issue of communities and their exposure to bushfire hazard is highly topical internationally. There is a perceived trend of greater exposure to bushfire risk which is exacerbated by increased levels of building in fire-prone areas or peri-urban regions. There is a need to clarify what we understand to be peri-urban regions, and how we conceptualise and describe the communities that reside in them, in order that efficient and effective services are provided. However, more questions arise for us. For example: Where are these communities located? What do we know about the people who live there? What are the implications for bushfire mitigation? Despite being problematic, locality remains important to the understanding of communities, bushfire hazard and delivery of services.  相似文献   
893.
《Environmental Hazards》2013,12(3):213-225
In this paper a large-scale community-based disaster risk-assessment project, undertaken in the Dr Kenneth Kaunda District Municipality in the North-West Province of South Africa, is evaluated. In contrast to other disaster risk management consultancy projects in South Africa, this project included a significant skills transfer component to the at-risk communities and local government officials. In this evaluation, the authors draw on their own experiences in implementing this and similar projects, a review of the project management documents is undertaken, and a focus group interview with facilitators involved in the project is used as a primary source. The discussion is further contextualised in terms of community-based disaster risk assessment theory and the existing literature on disaster risk assessment in South Africa. Logistical and data quality issues as well as staff turnover were found to be concerns during the project. From the findings, it is argued that the common practice of outsourcing disaster risk-management projects is not conducive to effective disaster risk management. Local government entities should take responsibility for disaster risk assessment as a continual activity. This is in contrast to the view currently manifesting in South Africa as a set of bureaucratic actions undertaken by consultants to achieve ‘legislative compliance’ for municipalities.  相似文献   
894.
《Environmental Hazards》2013,12(2):148-165
While the listeriosis outbreak of 2008 brought attention to food safety decision making in Canada, little of that attention was placed on public involvement and risk communication. With a primary focus on Health Canada (HC) and the Canadian Food Inspection Agency (CFIA), this article describes the state of microbial-related public involvement and risk communication undertakings and suggests ways in which improvements can be made. The findings show that public involvement and risk communication activities have been strengthened since the outbreak, but they have become neither dialogical nor highly participatory. HC engages with experts to a far greater extent than with the lay public and it has fallen short in fulfilling its stated commitment to openness and transparency. Furthermore, both HC's and the CFIA's approach to risk communication has been overly general, has failed to provide opportunities for dialogue with vulnerable and more general groups with whom it is communicating and is not rooted in foodborne surveillance data. Public involvement in food safety governance would be improved if HC provided the lay public with a seat on advisory committees and improved its public involvement reporting methods. HC and the CFIA could also make risk communication improvements by creating opportunities for dialogue between officials and the general public, and by exploring alternative risk communication vehicles, such as food labels.  相似文献   
895.
北京山区泥石流灾害保险的风险评判方法研究   总被引:4,自引:0,他引:4  
泥石流是北京山区主要的自然灾害,在1989-1999年期间,泥石流灾害造成的经济损失高达3.09亿元.对泥石流灾害保险风险的评判是首先按北京山区各区县的泥石流危险度分区划分风险区,然后对各风险区进行灾害危险性和灾害易损性评判.在危险性评判中,按各风险区的泥石流危险度等级赋予危险度评判指标值.在易损性评判中,选择国内生产总值、固定资产、人口密度和人口自然增长率等4个因素作为评判指标,并分为两个层次进行评判.第一层次是经济易损性与社会易损性评判,第二层次是泥石流灾害易损性评判.最后用泥石流灾害保险风险分析数学模型,计算出各风险区的泥石流灾害保险风险度,并由此绘制了北京山区泥石流灾害保险风险区划图.  相似文献   
896.
沿海和内陆地区居民汞暴露量对比   总被引:1,自引:0,他引:1  
牛小丽  张瑛  周集体 《环境化学》2012,31(12):1942-1947
通过对沿海和内陆居民食用水产品消费情况调查以及居民头发汞含量的分析,对不同地区普通居民的汞暴露水平进行了对比研究.居民水产品的消费情况采用调查问卷的形式,对沿海地区大连和内陆地区河南两地普通居民进行了随机调查,并同时采集被调查者的头发作为汞暴露情况的生物样本.本次研究共收集到有效调查问卷及头发样本213份(大连112份;河南101份),两地居民水产品消费量分别为:大连104 g.d-1,河南74 g.d-1;收集到的头发样本采用DMA-80测汞仪(按美国EPA-7473的方法)进行总汞含量的测定.头发总汞含量分析结果显示,大连为(0.363±0.256)μg.g-1,河南地区为(0.192±0.167)μg.g-1.两地区对同一年龄段居民发汞水平比较发现,大连地区居民发汞水平明显高于河南地区.以美国环境保护署(EPA)参考剂量1μg.g-1作为发汞基准,大连地区的超出比例为3%,河南地区的超出比例为1%.该研究结果为了解我国普通居民的汞暴露情况以及后续的汞暴露风险的定量计算提供了基础数据.  相似文献   
897.
珠江八大入海口表层沉积物中DDTs和HCHs残留调查   总被引:2,自引:0,他引:2  
于2010年8月-2011年5月4次采集珠江八大人海口表层沉积物,采用气相色谱-电子捕获(GC—ECD)法分析沉积物中DDTs(p,P’-DDE、P,P’-DDD、0,P’-DDT、P,P-DDT)和HCHs(α-HCH、β-HCH、γ-HCH、δ-HCH)的污染现状。结果显示,珠江8大人海口表层沉积物中DDTs总含量介于1.02—3.08μg·kg-1之间(以干质量计,下同),平均值为1.91μg·kg-1;HCHs总含量介于0.21—0.41μg·kg-1之间,平均值为0.31μg·kg-1。DDTs平均含量大于HCHs,其中P,P。DDT对污染的贡献最大,含量范围为ND~7.66μg·kg-1,平均值为2.12μg·kg-1。大部分样点伽(α-HCH)/w(γ-HCH)比值小于3,说明研究区α-HCH大都被降解,或者林丹正取代工业HCHs成为珠江口水环境中HCHs输入的主要来源;甜(DDT)/w(DDD+DDE)比值大于2,表明沉积物中除早期农药残留外,仍然有新的DDTs类农药输入。  相似文献   
898.
为探讨不同模型对污染场地健康风险评估结果的影响,以苯并[a]芘为例,采用RBCA、CLEA和CalTOX模型对某工业污染场地表层土壤进行健康风险评估,分析了评估结果的差异和原因,同时对模型的主要暴露参数进行了敏感性分析,并推导出基于风险概率分布的土壤修复限值。结果表明,RBCA、CLEA和CalTOX模型计算的苯并[a]芘致癌总风险分别为2.40×10-4、6.32×10-4和7.04×10-6,且经口摄入和皮肤接触2个途径对人体健康造成的危害最大。降解作用是影响CalTOX模型风险评估结果不同于RBCA和CLEA模型的重要因素,3个模型间参数取值及方法学的差异也会导致风险评估结果不同。各模型暴露参数的敏感性排序也有差异。采用基于风险概率分布的方法推导土壤修复限值,RBCA、CLEA和CalTOX模型所得结果分别为0.18、0.08、0.13(不考虑降解作用CalTOX模型)和10.74(考虑降解作用CalTOX模型)mg·kg-1,为各模型直接推导值的1.5~2.6倍。基于风险概率分布的方法可有效降低风险评估过程中参数不确定性的影响,为工业污染场地土壤修复值的制定提供参考。  相似文献   
899.
中国不断发生的重大环境突发事故使得环境风险管理提上了政府的议事日程,建立有效和实用的环境风险管理体系势在必行。近年来,风险地图已成为环境风险管理中迅速崛起的新领域。风险地图不但可以探讨污染物效应的空间特征,而且可作为风险可视化的重要工具。通过调研和分析大量文献,在描述了环境风险地图的功能、重要的风险地图类型基础上,以一个城市为例展示了风险图制作流程,最后,对环境风险地图在中国的应用和发展提出了建议。  相似文献   
900.
住宅室内降尘中邻苯二甲酸酯污染特征及暴露评价   总被引:3,自引:0,他引:3       下载免费PDF全文
利用CH2Cl2和超声对天津市13户家庭住宅冬季和夏季26个室内降尘样品中6种邻苯二甲酸酯(DMP、DEP、DBP、BBP、DEHP、DOP)进行提取分离,并采用气相色谱-质谱定量分析,研究了邻苯二甲酸酯污染变化特征和暴露风险.结果表明,冬夏两季,室内降尘样品均以DEHP 浓度最大,DBP第二,且DBP 和DEHP之和占ΣPAEs 的比例达到80.0%以上;冬季,各采样点6种邻苯二甲酸酯总含量(∑PAEs)浓度在1.498~32.587μg/g之间,平均浓度为(6.772±8.154)μg/g;夏季,∑PAEs浓度在1.981~40.041μg/g之间,平均浓度为(13.406±12.911) μg/g;PAEs浓度季节变化差异显著,夏季降尘样品中PAEs浓度高于冬季.暴露评价显示儿童和成人的夏季邻苯二甲酸酯总暴露量均大于冬季;经口暴露水平大于皮肤;平均儿童的暴露水平是成人的10倍左右;成人和儿童对4种物质(DBP、DEHP、DEP、BBP)的总暴露量最大值均出现在夏季;天津室内降尘暴露量与我国6城市室内降尘总暴露水平相当(除DEHP外),与德国和美国的暴露水平相比,天津儿童和成人的暴露量偏小.但是,室内环境中PAEs污染对人体健康的影响仍要引起重视,尤其是对低龄儿童的健康危害.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号