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   118篇
  免费   2篇
  国内免费   2篇
安全科学   4篇
废物处理   7篇
环保管理   24篇
综合类   11篇
基础理论   28篇
污染及防治   39篇
评价与监测   8篇
灾害及防治   1篇
  2022年   1篇
  2020年   1篇
  2019年   1篇
  2018年   2篇
  2017年   2篇
  2016年   4篇
  2015年   2篇
  2014年   1篇
  2013年   7篇
  2012年   4篇
  2011年   7篇
  2010年   6篇
  2009年   6篇
  2008年   9篇
  2007年   5篇
  2006年   8篇
  2005年   3篇
  2004年   7篇
  2003年   9篇
  2002年   5篇
  2001年   5篇
  2000年   1篇
  1999年   3篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   2篇
  1994年   1篇
  1993年   5篇
  1992年   1篇
  1988年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1977年   3篇
排序方式: 共有122条查询结果,搜索用时 15 毫秒
121.
The PC revolution continues to produce faster and smarter machines at a stunning pace. Almost forgotten in the rush are the millions of nearly new, but suddenly outdated, computers that are abandoned every year. Can product stewardship offer life‐after‐end‐of‐life for this growing mountain of “attic‐ware,” while averting a costly—and potentially toxic—waste disposal crisis? © 2001 by Cate Gable, Axioun Books. Used with permission.  相似文献   
122.
Pollinator declines have prompted efforts to assess how land-use change affects insect pollinators and pollination services in agricultural landscapes. Yet many tools to measure insect pollination services require substantial landscape-scale data and technical expertise. In expert workshops, 3 straightforward methods (desk-based method, field survey, and empirical manipulation with exclusion experiments) for rapid insect pollination assessment at site scale were developed to provide an adaptable framework that is accessible to nonspecialist with limited resources. These methods were designed for TESSA (Toolkit for Ecosystem Service Site-Based Assessment) and allow comparative assessment of pollination services at a site of conservation interest and in its most plausible alternative state (e.g., converted to agricultural land). We applied the methods at a nature reserve in the United Kingdom to estimate the value of insect pollination services provided by the reserve. The economic value of pollination services provided by the reserve ranged from US$6163 to US$11,546/year. The conversion of the reserve to arable land would provide no insect pollination services and a net annual benefit from insect-pollinated crop production of approximately $1542/year (US$24∙ha–1∙year–1). The methods had wide applicability and were readily adapted to different insect-pollinated crops: rape (Brassica napus) and beans (Vicia faba) crops. All methods were rapidly employed under a low budget. The relatively less robust methods that required fewer resources yielded higher estimates of annual insect pollination benefit.  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