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   4807篇
  免费   96篇
  国内免费   75篇
安全科学   215篇
废物处理   242篇
环保管理   1288篇
综合类   404篇
基础理论   1110篇
环境理论   5篇
污染及防治   1154篇
评价与监测   338篇
社会与环境   173篇
灾害及防治   49篇
  2023年   23篇
  2022年   22篇
  2021年   48篇
  2020年   30篇
  2019年   61篇
  2018年   70篇
  2017年   89篇
  2016年   111篇
  2015年   109篇
  2014年   105篇
  2013年   546篇
  2012年   176篇
  2011年   254篇
  2010年   190篇
  2009年   187篇
  2008年   257篇
  2007年   258篇
  2006年   239篇
  2005年   165篇
  2004年   182篇
  2003年   190篇
  2002年   170篇
  2001年   82篇
  2000年   106篇
  1999年   99篇
  1998年   73篇
  1997年   66篇
  1996年   77篇
  1995年   77篇
  1994年   65篇
  1993年   65篇
  1992年   74篇
  1991年   46篇
  1990年   55篇
  1989年   42篇
  1988年   35篇
  1987年   43篇
  1986年   47篇
  1985年   40篇
  1984年   45篇
  1983年   50篇
  1982年   38篇
  1981年   56篇
  1980年   46篇
  1979年   23篇
  1978年   26篇
  1977年   18篇
  1976年   12篇
  1975年   20篇
  1971年   15篇
排序方式: 共有4978条查询结果,搜索用时 265 毫秒
951.
952.
Environment as the Stage for Economic Actors   总被引:6,自引:0,他引:6  
The relative importance of economics and environment in debate may soon be reversed due to the influence of three fac- tors. Firstly, in the global economy it is hard to hide the unwanted products of economic processes. Secondly, huge advances in sci- ence will reduce the imperfect knowledge of markets, making some monitoring and analyzing tools show the design of sensible and equitable livelihood in communities, which is more important than the motivation of maximising profits for some individuals or firms. Thirdly, China, as the last major player on the planet to take on economic growth, comes from traditions fundamentally differ- ent from those economies that have experienced the Industrial Revolution previously. Its challenges with sustainability and en- vironmental conservation predate Western economics by millennia, and it is implementing policies domestically and starting to work on the world stage that acknowledges that the surroundings are the host for any economic and socio-political system.  相似文献   
953.
The important role that non-motorised transport plays in urban sustainability is discussed with particular reference to the developing world and to the links between environmental and poverty issues. The significance of non-motorised transport in terms of reduced pollution, income maintenance for the poor and providing transport for vulnerable groups is stressed and placed within the general context of sustainable development. More specifically, evidence is presented for rickshaws in Calcutta, which demonstrates the vital role that non-motorised transport must play if sustainable development objectives are to be met. This evidence indicates that if rickshaws were to disappear from Calcutta's streets there would not only be significant increases in air pollution but also a substantial increase in the numbers of people living in poverty.  相似文献   
954.
955.
956.
We used genotypic data from three highly polymorphic microsatellite loci (two autosomal and one sex-linked) to examine micro-spatial and temporal arrangements of genetic paternity for more than 1,500 embryos housed along 12 egg-case strings of the knobbed whelk, Busycon carica. Multiple paternity proved to be the norm in these single-dam families, with genetic contributions of several sires (at least 3.5 on average) being represented among embryos within individual egg capsules as well as along the string. Two strings were studied in much greater detail; five and seven fathers were identified, none of which was among the several males found in consort with the female at her time of egg-laying. Each deduced sire had fathered roughly constant proportions of embryos along most of the string, but those proportions differed consistently among fathers. A few significant paternity shifts at specifiable positions along an egg-case string were also observed. Although the precise physical mechanisms inside a female whelk’s reproductive tract remain unknown, our genetic findings indicate that successive fertilization events (and/or depositions of zygotes into egg capsules) normally occur as near-random draws from a well-but-not-perfectly blended pool of gametes (or zygotes) stemming from stored ejaculates, perhaps in different titers, of a dam’s several mates.  相似文献   
957.
958.
The White House Conference on Environmental Technology, held December 12–14, 1994, is the most recent of many events building toward a national environmental technology strategy, which President Clinton will announce on April 22, 1995, the 25th anniversary of Earth Day. Promoting innovation and eliminating barriers to new environmental technologies are important issues in developing this strategy. Anticipating these developments, EPA launched its own Technology Innovation Strategy in early 1994. EPA's strategy explicitly calls for strengthening incentives for technology innovation within regulatory, policy, and enforcement programs. In this light, it is worthwhile to look at a recent case study showing how regulations impact innovative environmental technologies, particularly because there appears to be a gathering political sentiment for deeper regulatory reform.  相似文献   
959.
Although groundwater is widely and increasingly exploited for potable water-supply in developing countries the threat of groundwater pollution has, as yet, received little attention. Activities currently producing the principal risks are described in some detail. A basis for rapid assessment of the degree of groundwater pollution risk is proposed, based on the evaluation of, and the interaction between, pollutant loading and aquifer vulnerability. Protection zones around individual groundwater supply sources can generally play, at most, only a minor role in overall policy. The strategy proposed is aquifer-oriented and activity-related. The evaluation of aquifer pollution vulnerability, made in the rapid risk assessment and based on three semi-independent criteria, could be used to select the required protection measures in relation to specific land-use activities.  相似文献   
960.
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