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   39507篇
  免费   330篇
  国内免费   223篇
安全科学   835篇
废物处理   1856篇
环保管理   5241篇
综合类   5563篇
基础理论   11618篇
环境理论   21篇
污染及防治   9361篇
评价与监测   2748篇
社会与环境   2623篇
灾害及防治   194篇
  2022年   180篇
  2021年   182篇
  2019年   215篇
  2018年   1876篇
  2017年   1760篇
  2016年   1717篇
  2015年   614篇
  2014年   689篇
  2013年   2144篇
  2012年   1318篇
  2011年   2552篇
  2010年   1799篇
  2009年   1654篇
  2008年   2164篇
  2007年   2583篇
  2006年   1191篇
  2005年   1097篇
  2004年   1053篇
  2003年   1060篇
  2002年   1086篇
  2001年   1258篇
  2000年   872篇
  1999年   555篇
  1998年   445篇
  1997年   436篇
  1996年   443篇
  1995年   482篇
  1994年   440篇
  1993年   396篇
  1992年   414篇
  1991年   375篇
  1990年   377篇
  1989年   411篇
  1988年   347篇
  1987年   300篇
  1986年   276篇
  1985年   305篇
  1984年   299篇
  1983年   328篇
  1982年   324篇
  1981年   272篇
  1980年   243篇
  1979年   269篇
  1978年   229篇
  1977年   195篇
  1976年   200篇
  1975年   192篇
  1974年   172篇
  1973年   171篇
  1972年   198篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
The question whether the possibility exists of transmission of HIV by hematophagous insects from infected to uninfected persons is a point of very intensive discussion. The solution of this problem could help to explain the spreading of the disease in human populations and could contribute to an understanding of the evolution of AIDS and the possible transfer from wild primates into human populations. The classical routes of pathogen transmission by blood-sucking arthropods are either "mechanical" or "biological". Both ways are rejected, the latter since no replication of the retro-virus in the vector exists and its survival in the arthropod is very limited. Based on long experimental experience with biting flies as well as with plant-sucking insects a third hitherto neglected way of transmission by regurgitation of gut content can be introduced. Since regurgitation is neither "mechanical" nor "biological", "regurgitative transmission" must be introduced as an additional term.  相似文献   
63.
Wir danken Dr. Kerndorff für die kritische Durchsicht des Manuskripts.  相似文献   
64.
65.
Mitigation and adaptation synergy in forest sector   总被引:1,自引:1,他引:1  
Mitigation and adaptation are the two main strategies to address climate change. Mitigation and adaptation have been considered separately in the global negotiations as well as literature. There is a realization on the need to explore and promote synergy between mitigation and adaptation while addressing climate change. In this paper, an attempt is made to explore the synergy between mitigation and adaptation by considering forest sector, which on the one hand is projected to be adversely impacted under the projected climate change scenarios and on the other provide opportunities to mitigate climate change. Thus, the potential and need for incorporating adaptation strategies and practices in mitigation projects is presented with a few examples. Firstly, there is a need to ensure that mitigation programs or projects do not increase the vulnerability of forest ecosystems and plantations. Secondly, several adaptation practices could be incorporated into mitigation projects to reduce vulnerability. Further, many of the mitigation projects indeed reduce vulnerability and promote adaptation, for example; forest and biodiversity conservation, protected area management and sustainable forestry. Also, many adaptation options such as urban forestry, soil and water conservation and drought resistant varieties also contribute to mitigation of climate change. Thus, there is need for research and field demonstration of synergy between mitigation and adaptation, so that the cost of addressing climate change impacts can be reduced and co-benefits increased.  相似文献   
66.
67.
68.
69.
70.
Ten out of the 12 new EU members, used to belong to the so-called “former eastern block”, with a post WWII environmental policy radically different from the tendencies followed in Western Europe. The lack of conservation regulations has resulted in a rather harmful industrialization, regarding natural resources and environmental quality. While air pollution transfer is a phenomenon of transboundary level, there is a particular interest in examining the contribution of the new EU member states to the environmental pressure faced by the older member states and vice versa. The current study utilises the official data for almost 20 years published by the European Monitoring and Evaluation Program concerning the transboundary transfer of NOx and SO2 in order to analyse the situation and discuss the present and future environmental policy regarding air pollution.  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