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   657篇
  免费   67篇
  国内免费   45篇
安全科学   64篇
废物处理   8篇
环保管理   251篇
综合类   179篇
基础理论   80篇
环境理论   4篇
污染及防治   10篇
评价与监测   15篇
社会与环境   95篇
灾害及防治   63篇
  2024年   3篇
  2023年   11篇
  2022年   15篇
  2021年   26篇
  2020年   29篇
  2019年   21篇
  2018年   27篇
  2017年   43篇
  2016年   61篇
  2015年   34篇
  2014年   22篇
  2013年   92篇
  2012年   38篇
  2011年   36篇
  2010年   26篇
  2009年   35篇
  2008年   20篇
  2007年   36篇
  2006年   31篇
  2005年   25篇
  2004年   19篇
  2003年   18篇
  2002年   15篇
  2001年   11篇
  2000年   13篇
  1999年   17篇
  1998年   4篇
  1997年   5篇
  1996年   4篇
  1995年   4篇
  1994年   2篇
  1992年   1篇
  1991年   1篇
  1990年   3篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   2篇
  1984年   2篇
  1982年   1篇
  1981年   2篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
  1973年   2篇
  1972年   3篇
排序方式: 共有769条查询结果,搜索用时 15 毫秒
131.
李娟  孟瑾 《环境科学导刊》2008,27(1):15-16,39
以获得2004年澳大利亚国家奖励的地方政府有关项目为典型,对澳大利亚地方政府如何进行环保宣传教育进行分析。澳大利亚地方政府重视并积极开展环保教育,教育对象有儿童、学生、政府机构和社区以及企业各行各业的人群,内容有环保知识、技能和情报信息等,教育宣传方式、渠道及组织形式多样,并发动多方参与、广泛合作,为推进环保和可持续发展奠定了基础。  相似文献   
132.
Abstract

There is an obvious departure from the regional equilibrium of developments between the upper and lower reaches of the Pearl River in Guangdong, which resulted in “the effects of contra-geography-grads development”. It is mainly because the upriver mountainous areas have been deeply stuck in industrialization delay and marginalization plights, so that nearly 40 million local people have conceived a dream to get rid of “the vicious circle of poverty” by speeding up industrial development. But the problem is that such industrialization efforts on a large scale in mountainous areas are encountering the bottleneck of environmental capacity that strictly limits industrial emissions along the upper reaches of any water system. As a solution, an institutional arrangement called “the Local Area Quotas for Industrial Emis-sions along the Pearl River” is put forward supposed to give corresponding compensation to the rights of industrial development yielded by some areas with lower environmental capacity through the distribution and trading of IDQs.  相似文献   
133.
Abstract

This paper examines the role and effectiveness of local institutions in the management of forest biodiversity in New Dabaga-Ulongambi Forest Reserve, Tanzania. Data were obtained through questionnaires, interviews, focus group discussions, participatory rural appraisal and field observations. The study revealed that the most remarkable local institutions connected to forest biodiversity management include: Village Natural Resources Management Committee (92%), tree nursery group (79.4%), beekeeping groups (61.1%), fish farming (43.3%), livestock rearing group (33.9%). Main activities carried out by local institutions which directly contribute to the sustainability of forest reserve include: forest patrols, fire extinguish, preparation of fire breaks, planting of trees along the forest boundaries, creation of awareness, arresting of forest defaulters, participation in income generation activities. For the purpose of realization that local communities are capable of managing forest biodiversity through their traditional institutions, the policy should provide tangible opportunity for local communities to meet their needs as they manage the forests.  相似文献   
134.
针对现有行业规范中的排烟口结构参数尚不明确的问题,依托过海瓦贵区间隧道,搭建隧道通风排烟模型实验系统。设定11种排烟口面积工况,结合实验与数值模拟,得到排烟口上、下游的静压值和风速。引入动能修正系数,推导出基于上下游能量差的排烟口局部阻力表达式,绘制出无量纲面积比与局部阻力系数曲线族。研究结果表明:排烟口长宽比值较大时,不利于排烟口下方风流流动;在同一风机组合工况下,当排烟口面积缩小时,局部阻力系数会呈现出先减后增的趋势;提出排烟口最优结构长宽比为1.06。研究结果可为相关规范制定提供参考,并为防灾救灾提供理论支持。  相似文献   
135.
国内外不同尺度的旱灾风险评价研究进展   总被引:2,自引:0,他引:2  
作为旱灾风险管理实践的科学基础,旱灾风险评价愈来愈受到社会各界的广泛关注。在阅读大量文献的基础上,从4个不同的区域尺度对国内外旱灾风险评价研究进展作了综述。结果表明:(1)目前所有区域尺度研究中,农业旱灾风险评价研究较多;(2)地区尺度的旱灾风险评价是研究其他尺度的切入点,可为实现空间尺度上推(全球和国家尺度)和下推(县乡农户尺度)旱灾风险评价结果的转换提供依据;(3)随空间尺度从全球和大洲→国家→地区→地方尺度,旱灾风险评价的文献量逐渐增多,内容逐渐深入;(4)旱灾风险对饥荒和粮食安全的影响、农业系统和农作物承灾体的旱灾风险评价是目前研究的热点。在此基础上,指出旱灾发生频率较低但生态环境敏感区的旱灾风险评价需加强;从干旱灾害链的角度以及综合旱灾风险与脆弱性、恢复性、适应性的关系来研究旱灾风险是今后的重点。  相似文献   
136.
In the presence of local (sulfur) and global (carbon) pollutants, we examine the pollution haven hypothesis and free riding behavior. Under domestic emissions trading, poorer Southern countries become pollution havens when free trade opens up whenever sulfur damage functions are linear or when sulfur levels in equilibrium are not higher in the South. With global trading of carbon permits, the pollution haven effect emerges in equilibrium whenever the convex sulfur damage functions are nonlinear. Countries that do not participate in a Global Protocol designed to reduce carbon emissions enjoy double benefits, stemming from free riding and cleaner local environments.  相似文献   
137.
The aim of this paper is to provide an investigation, using large eddy simulation, into plume dispersion behind an aircraft in co-flowing take-off conditions. Validation studies of the computational model were presented by Aloysius and Wrobel (Environ Model Softw 24:929–937, 2009) and a study of the flow and dispersion properties of a double-engine aircraft jet was presented by Aloysius et al. (EEC/SEE/2007/001, EUROCONTROL Experimental Centre, ), in which only the engine was modelled. In this paper, the complete geometry of a Boeing 737 is modelled and investigated. The current work represents a contribution towards a better understanding of the source dynamics behind an airplane jet engine during the take-off and landing phases. The information provided from these simulations will be useful for future improvements of existing dispersion models.  相似文献   
138.
发展地方环保产业的思考   总被引:1,自引:0,他引:1  
本文论述了发展地方环保产业的六大要素:优势、科技、龙头、基地、环境、创新。抓住了这六大要素,地方环保产业就可成为地方经济新的增长点。  相似文献   
139.
The involvement of local communities, as well as the private sector and the government in forest management is now an important principle of tropical forestry policy and practice and a major component of most international forestry aid programmes. This paper present an analysis on the Joint Forest Management Project initiated by two timber companies (Ghana Primewood Products Ltd and Dalhoff Larsen & Horneman) in collaboration with local people in Gwira-Banso of Ghana. Conditions required for enhancing responsibility for and commitment to local forest management, and for an effective local participatory process were also analysed. The study began with the premise that incentives and good communication will enhance participation in joint forest management.The assumption was valid and the results from the survey showed that five broad issues prioritised by respondents to be essential for co-partnership in forest management are communication, financial support, tree planting, multiple land use and benefit sharing. The Project enjoys a great deal of support from the local community, but a number of factors make the continued support of local people a challenging task, including questions of immediate livelihood sources and tenure arrangements. Although this participatory forest management has been implemented over a relatively short period, there is evidence that government and private sectors can successfully involve local people in sustainable management of the forests.  相似文献   
140.
The minister of Agriculture, Nature Management andFisheries of the Netherlands reflects on the question``Is agriculture in need of ethics?'' Changingnorms and values in society, the influence of newtechnologies (such as biotechnology) and theinternational trade liberalisation (WTO) providearguments for a positive answer on this question.  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