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   28376篇
  免费   230篇
  国内免费   169篇
安全科学   553篇
废物处理   1467篇
环保管理   3943篇
综合类   3901篇
基础理论   8095篇
环境理论   13篇
污染及防治   6680篇
评价与监测   2143篇
社会与环境   1828篇
灾害及防治   152篇
  2022年   126篇
  2021年   163篇
  2020年   124篇
  2019年   176篇
  2018年   1683篇
  2017年   1591篇
  2016年   1552篇
  2015年   434篇
  2014年   464篇
  2013年   1500篇
  2012年   1018篇
  2011年   2054篇
  2010年   1311篇
  2009年   1208篇
  2008年   1641篇
  2007年   1990篇
  2006年   848篇
  2005年   662篇
  2004年   715篇
  2003年   677篇
  2002年   681篇
  2001年   777篇
  2000年   538篇
  1999年   333篇
  1998年   299篇
  1997年   276篇
  1996年   273篇
  1995年   305篇
  1994年   315篇
  1993年   247篇
  1992年   278篇
  1991年   243篇
  1990年   273篇
  1989年   249篇
  1988年   205篇
  1987年   187篇
  1986年   172篇
  1985年   184篇
  1984年   219篇
  1983年   208篇
  1982年   202篇
  1981年   193篇
  1980年   154篇
  1979年   172篇
  1978年   142篇
  1977年   126篇
  1975年   121篇
  1974年   122篇
  1973年   115篇
  1972年   138篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
Progress in the greening of UK local government has been hampered by uncertainty about the relationship between resource use and environmental protection. Ecological modernizationmay offer the most appropriateparadigm to reconcile economic, social and environmentalinterpretationsof sustainability. The transition from corporate to strategic environmental management currently being attempted by some 'green' authorities can be construed as an attempt to promote ecological modernization in the form of institutional learning. Fife Council in Scotland provides an interesting case study. Progress with corporate environmental management has become bound up with a radical devolution of decision making. Efforts to link the authority's Sustainable Development Policy to a Local Agenda 21 programme have been initiated with the piloting of sustainability indicators.  相似文献   
42.
43.
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   
44.
Peregrine falcons (Falco peregrinus) have been recorded nesting in Big Bend National Park, Texas, USA and other areas of the Chihuahuan Desert since the early 1900s. From 1993 to 1996, peregrine falcon productivity rates were very low and coincided with periods of low rainfall. However, low productivity also was suspected to be caused by environmental contaminants. To evaluate potential impacts of contaminants on peregrine falcon populations, likely avian and bat prey species were collected during 1994 and 1997 breeding seasons in selected regions of western Texas, primarily in Big Bend National Park. Tissues of three peregrine falcons found injured or dead and feathers of one live fledgling also were analyzed. Overall, mean concentrations of DDE [1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene], a metabolite of DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane], were low in all prey species except for northern rough-winged swallows (Stelgidopteryx serripennis, mean = 5.1 microg/g ww). Concentrations of mercury and selenium were elevated in some species, up to 2.5 microg/g dw, and 15 microg/g dw, respectively, which upon consumption could seriously affect reproduction of top predators. DDE levels near 5 microg/g ww were detected in carcass of one peregrine falcon found dead but the cause of death was unknown. Mercury, selenium, and DDE to some extent, may be contributing to low reproductive rates of peregrine falcons in the Big Bend region.  相似文献   
45.
46.
47.
48.
49.
50.
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