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   33136篇
  免费   369篇
  国内免费   469篇
安全科学   983篇
废物处理   1612篇
环保管理   3848篇
综合类   5548篇
基础理论   8548篇
环境理论   22篇
污染及防治   8952篇
评价与监测   2342篇
社会与环境   1935篇
灾害及防治   184篇
  2023年   172篇
  2022年   422篇
  2021年   406篇
  2020年   281篇
  2019年   321篇
  2018年   592篇
  2017年   562篇
  2016年   891篇
  2015年   651篇
  2014年   1054篇
  2013年   2694篇
  2012年   1235篇
  2011年   1600篇
  2010年   1300篇
  2009年   1292篇
  2008年   1590篇
  2007年   1631篇
  2006年   1399篇
  2005年   1171篇
  2004年   1059篇
  2003年   1143篇
  2002年   1005篇
  2001年   1268篇
  2000年   884篇
  1999年   536篇
  1998年   354篇
  1997年   364篇
  1996年   359篇
  1995年   442篇
  1994年   457篇
  1993年   360篇
  1992年   376篇
  1991年   355篇
  1990年   390篇
  1989年   348篇
  1988年   298篇
  1987年   282篇
  1986年   225篇
  1985年   252篇
  1984年   265篇
  1983年   257篇
  1982年   245篇
  1981年   222篇
  1980年   176篇
  1979年   196篇
  1978年   176篇
  1975年   143篇
  1974年   118篇
  1972年   131篇
  1971年   132篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
231.
Abstract:  The Society for Conservation Biology (SCB) can enhance conservation of biodiversity in North America by increasing its engagement in public policy. Toward this end, the North America Section of SCB is establishing partnerships with other professional organizations in order to speak more powerfully to decision makers and taking other actions—such as increasing interaction with chapters—geared to engage members more substantively in science-policy issues. Additionally, the section is developing a North American Biodiversity Blueprint, which spans the continental United States and Canada and is informed by natural and social science. This blueprint is intended to clarify the policy challenges for protecting continental biodiversity, to foster bilateral collaboration to resolve common problems, and to suggest rational alternative policies and practices that are more likely than current practices to sustain North America's natural heritage. Conservation scientists and practitioners can play a key role by drawing policy makers' attention to ultimate, as well as proximate, causes of biodiversity decline and to the ecological and economic consequences of not addressing these threats.  相似文献   
232.
Abstract: Indigenous people inhabit approximately 85% of areas designated for biodiversity conservation worldwide. They also continue to struggle for recognition and preservation of cultural identities, lifestyles, and livelihoods—a struggle contingent on control and protection of traditional lands and associated natural resources (hereafter, self‐determination). Indigenous lands and the biodiversity they support are increasingly threatened because of human population growth and per capita consumption. Application of the Endangered Species Act (ESA) to tribal lands in the United States provides a rich example of the articulation between biodiversity conservation and indigenous peoples' struggle for self‐determination. We found a paradoxical relationship whereby tribal governments are simultaneously and contradictorily sovereign nations; yet their communities depend on the U.S. government for protection through the federal‐trust doctrine. The unique legal status of tribal lands, their importance for conserving federally protected species, and federal environmental regulations' failure to define applicability to tribal lands creates conflict between tribal sovereignty, self‐determination, and constitutional authority. We reviewed Secretarial Order 3206, the U.S. policy on “American Indian tribal rights, federal–tribal trust responsibilities, and the ESA,” and evaluated how it influences ESA implementation on tribal lands. We found improved biodiversity conservation and tribal self‐determination requires revision of the fiduciary relationship between the federal government and the tribes to establish clear, legal definitions regarding land rights, applicability of environmental laws, and financial responsibilities. Such actions will allow provision of adequate funding and training to tribal leaders and resource managers, government agency personnel responsible for biodiversity conservation and land management, and environmental policy makers. Increased capacity, cooperation, and knowledge transfer among tribes and conservationists will improve biodiversity conservation and indigenous self‐determination.  相似文献   
233.
Abstract: We reviewed the evidence on the extent and efficacy of conservation of tropical forest biodiversity for each of the classes of conservation action defined by the new International Union for Conservation of Nature (IUCN) classification. Protected areas are the most tested conservation approach, and a number of studies show they are generally effective in slowing deforestation. There is some documentation of the extent of sustainable timber management in tropical forest, but little information on other landscape‐conservation tactics. The extent and effectiveness of ex situ species conservation is quite well known. Forty‐one tropical‐forest species now survive only in captivity. Other single‐species conservation actions are not as well documented. The potential of policy mechanisms, such as international conventions and provision of funds, to slow extinctions in tropical forests is considerable, but the effects of policy are difficult to measure. Finally, interventions to promote tropical conservation by supporting education and livelihoods, providing incentives, and furthering capacity building are all thought to be important, but their extent and effectiveness remain poorly known. For birds, the best studied taxon, the sum of such conservation actions has averted one‐fifth of the extinctions that would otherwise have occurred over the last century. Clearly, tropical forest conservation works, but more is needed, as is critical assessment of what works in what circumstances, if mass extinction is to be averted.  相似文献   
234.
235.
236.
237.
238.
239.
240.
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