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   15245篇
  免费   49篇
  国内免费   27篇
安全科学   107篇
废物处理   1123篇
环保管理   1610篇
综合类   1756篇
基础理论   4221篇
环境理论   5篇
污染及防治   3704篇
评价与监测   1527篇
社会与环境   1253篇
灾害及防治   15篇
  2023年   63篇
  2022年   172篇
  2021年   173篇
  2020年   75篇
  2019年   88篇
  2018年   1564篇
  2017年   1467篇
  2016年   1407篇
  2015年   290篇
  2014年   335篇
  2013年   569篇
  2012年   793篇
  2011年   1669篇
  2010年   942篇
  2009年   818篇
  2008年   1184篇
  2007年   1540篇
  2006年   297篇
  2005年   250篇
  2004年   220篇
  2003年   218篇
  2002年   252篇
  2001年   132篇
  2000年   87篇
  1999年   56篇
  1998年   36篇
  1997年   25篇
  1996年   16篇
  1995年   44篇
  1994年   32篇
  1993年   22篇
  1992年   22篇
  1991年   15篇
  1990年   18篇
  1989年   14篇
  1988年   14篇
  1983年   14篇
  1967年   12篇
  1966年   15篇
  1965年   16篇
  1964年   35篇
  1963年   18篇
  1962年   23篇
  1961年   14篇
  1960年   14篇
  1959年   28篇
  1958年   35篇
  1957年   19篇
  1956年   15篇
  1955年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Gamergates (i.e. mated reproductive workers) are mostly known from ant species within the Ponerinae. We report here the discovery of gamergates in two species of the subfamily Myrmicinae. Until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. However, in two species of the myrmicine Metapone (Metapone madagascarica and a newly discovered, not yet described Metapone species) all workers have six ovarioles and a spermatheca; and some of them are mated. There are no morphological differences between mated and non-mated workers. Field observations and laboratory studies indicate that colonies of the Metapone species can reproduce with gamergates only.  相似文献   
82.
Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x.  相似文献   
83.
In this study, an inventory of air pollutant emission estimates from major air polluting sources in Turkey for period between 1985 and 2005 with 5-year intervals were estimated. Inventory covers anthropogenic sources of five major air pollutants of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides and non-methane volatile organic compounds. Their break-down with respect to main activity sectors were shown and their distribution by the largest industrial source categories were worked out as annual estimates. This inventory and its analysis point to serious environmental implications of air pollutants and a need to develop a policy plan for reducing these emissions.  相似文献   
84.
Foreword     
Mitigation and Adaptation Strategies for Global Change -  相似文献   
85.
86.
87.
88.
89.
90.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach.  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