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   40355篇
  免费   414篇
  国内免费   482篇
安全科学   1142篇
废物处理   1978篇
环保管理   5250篇
综合类   6051篇
基础理论   10874篇
环境理论   9篇
污染及防治   9647篇
评价与监测   2943篇
社会与环境   3132篇
灾害及防治   225篇
  2023年   185篇
  2022年   404篇
  2021年   444篇
  2020年   262篇
  2019年   352篇
  2018年   947篇
  2017年   964篇
  2016年   1257篇
  2015年   728篇
  2014年   1092篇
  2013年   3101篇
  2012年   1452篇
  2011年   2245篇
  2010年   1649篇
  2009年   1726篇
  2008年   2162篇
  2007年   2245篇
  2006年   1497篇
  2005年   1356篇
  2004年   1282篇
  2003年   1278篇
  2002年   1251篇
  2001年   1358篇
  2000年   941篇
  1999年   578篇
  1998年   440篇
  1997年   451篇
  1996年   482篇
  1995年   557篇
  1994年   466篇
  1993年   415篇
  1992年   442篇
  1991年   422篇
  1990年   393篇
  1989年   375篇
  1988年   344篇
  1987年   295篇
  1986年   284篇
  1985年   297篇
  1984年   322篇
  1983年   308篇
  1982年   312篇
  1981年   267篇
  1980年   204篇
  1979年   221篇
  1978年   188篇
  1977年   161篇
  1975年   167篇
  1973年   198篇
  1972年   183篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Cultural heritage is being addressed by a number of charters and conventions and it is clear that its consideration within decision-making processes is progressively becoming a real challenge, both for developers and public authorities. Against this background, this paper reviews the environmental assessment framework developed by the European Community, as this should increasingly influence decision making about cultural heritage in an urban setting. The legislative framework for access to environmental information is also reviewed because of its relevance to the decision-making process.The Directives on Environmental Impact Assessment and Strategic Environmental Assessment both require a consideration of cultural heritage in decision making. This requirement can go some way to addressing the paradox in the European Community's position whereby the community wishes to conserve and enhance its own cultural identity whilst, at the same time, cultural heritage is usually defined at a local level. The present paper suggests that, given their flexibility, the two European Community directives on environmental assessment constitute a promising opportunity to address this seeming paradox, but that there is a significant gap between legal obligations and the methodological tools to meet them.  相似文献   
62.
A site contaminated by mercury serves as an example for evaluating the environmental medicine aspects of mercury emissions on individuals living in the surroundings. Based on defined, conventional scenarios, estimations of internal exposure were made for seven different age groups and with regard to such contact media as soil, air and food. Using human monitoring methods, an attempt was made to compare the epidemiological results. The site-specific and pathway-specific estimation of exposure is based on a multitude of various samples as well as on measurements of concentrations in the compartments relevant for intake. As based upon rigid guideline values, both these calculations and the epidemiological investigations reveal a slight increase in the mercury exposure.  相似文献   
63.
64.
The effect of industrial air pollution on natural small mammal populations has been studied in the northern taiga subzone of the boreal forest zone. The results of long-term monitoring have been used to demonstrate the possibility of predicting changes in the main population and community characteristics of the animal species studied as dependent on the degree of anthropogenic impact.  相似文献   
65.
66.
67.
68.
69.
This work, carried out within the framework of the PRISMA II project, aims at evaluating the effects of the Po River flow on primary productivity, measured by C with in situ sample incubations. A total of four cruises was carried out in late winter and early summer (1996-1998) along transects from the coast offshore. In both seasons, the highest primary productivity was found in the most oligohaline stations. The effects of the Po River inputs were therefore clearly evident in the westernmost area, both in high productivity values and in the shape of productivity profiles. In late winter, extensive blooms of Skeletonema costatum and Pseudo-nitzschia delicatissima resulted in productivity values that were sometimes higher than in early summer. In early summer 1996, greatly reduced river flow clearly influenced productivity which was much lower than in 1997.  相似文献   
70.
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