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   303篇
  免费   6篇
  国内免费   4篇
安全科学   12篇
废物处理   4篇
环保管理   74篇
综合类   40篇
基础理论   86篇
污染及防治   58篇
评价与监测   23篇
社会与环境   10篇
灾害及防治   6篇
  2024年   2篇
  2023年   6篇
  2022年   10篇
  2021年   4篇
  2020年   3篇
  2019年   10篇
  2018年   13篇
  2017年   12篇
  2016年   18篇
  2015年   16篇
  2014年   8篇
  2013年   16篇
  2012年   18篇
  2011年   18篇
  2010年   8篇
  2009年   12篇
  2008年   13篇
  2007年   20篇
  2006年   15篇
  2005年   13篇
  2004年   5篇
  2003年   7篇
  2002年   11篇
  2001年   10篇
  2000年   8篇
  1999年   3篇
  1998年   1篇
  1997年   4篇
  1996年   1篇
  1994年   3篇
  1993年   1篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   2篇
  1987年   2篇
  1986年   1篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1971年   1篇
  1966年   1篇
  1963年   1篇
  1934年   1篇
排序方式: 共有313条查询结果,搜索用时 15 毫秒
61.
62.
    
Summary This paper reviews the status of the flue gas desulphurisation (FGD) programme in the United Kingdom up to the end of 1989, with particular regard to siting and systems choices. Environmental issues associated with the on-going retrofit at Drax power station are analysed and extrapolated to a retrofit at Fiddler's Ferry power station. The emission reductions required of the UK by the European Community Large Combustion Plant Directive are assessed. The impact of privatisation of the electricity supply industry on the flue gas desulphurisation programme is discussed with particular reference to the new electricity generating companies for England and Wales.Ron' Reid is a recent Environmental Studies graduate of Manchester Polytechnic who completed his dissertation on the environmental impacts of FGD installation at Fiddler's Ferry power station. Dr Jim Longhurst is Director of the Acid Rain Information Centre at Manchester Polytechnic.The Acid Rain Information Centre is supported by Tameside Metropolitan Borough Council on behalf of the Association of Greater Manchester Authorities and the Department of the Environment.  相似文献   
63.
64.
    
Riprap, consisting of large boulders or concrete blocks, is extensively used to stabilize streambanks and to inhibit lateral erosion of rivers, yet its effect on river morphology and its ecological consequences have been relatively little studied. In this paper, we review the available information, most of it culled from the “grey” literature. We use a simple one‐dimensional morphodynamic model as a conceptual tool to illustrate potential morphological effects of riprap placement in a gravel‐bed river, which include inhibition of local sediment supply to the channel and consequent channel bed scour and substrate coarsening, and downstream erosion. Riprap placement also tends to sever organic material input from the riparian zone, with loss of shade, wood input, and input of finer organic material. Available information on the consequences for the aquatic ecosystem mainly concerns effects on commercially and recreationally important fishes. The preponderance of studies report unfavorable effects on local numbers, but habitat niches created by openings in riprap can favorably affect invertebrates and some small fishes. There is a need for much more research on both morphological and ecosystem effects of riprap placement.  相似文献   
65.
66.
67.
68.
    
Interventions of the host–pathogen dynamics provide strong tests of relationships, yet they are still rarely applied across multiple populations. After American bullfrogs (Rana catesbeiana) invaded a wildlife refuge where federally threatened Chiricahua leopard frogs (R. chiricahuensis) were reintroduced 12 years prior, managers launched a landscape-scale eradication effort to help ensure continued recovery of the native species. We used a before-after-control-impact design and environmental DNA sampling of 19 eradication sites and 18 control sites between fall 2016 and winter 2020–2021 to measure community-level responses to bullfrog eradication, including for two pathogens. Dynamic occupancy models revealed successful eradication from 94% of treatment sites. Native amphibians did not respond to bullfrog eradication, but the pathogens amphibian chytrid fungus (Batrachochytrium dendrobatidis) and ranaviruses were coextirpated with bullfrogs. Our spatially replicated experimental approach provides strong evidence that management of invasive species can simultaneously reduce predation and disease risk for imperiled species.  相似文献   
69.
Sediment budgets describe the production, transport, deposition and export of sediment in a catchment, and thus provide information useful for planning soil conservation, restoration and monitoring programmes and for evaluating existing and future environmental impacts. Five examples from New Zealand illustrate a variety of sediment budgeting approaches and their use in achieving goals relevant to land-use planning and management. Appropriate sediment budgeting strategies can be selected for a particular application only through careful consideration of the kinds of decisions that will follow from budgeting results. Sediment budget projects can be designed to incorporate the close co-operation between technical experts and clients that results in the most useful sediment budgets.  相似文献   
70.
Illegitimate tasks, a recently introduced occupational stressor, are tasks that violate norms about what an employee can reasonably be expected to do. Because they are considered a threat to one's professional identity, we expected that the daily experience of illegitimate tasks would be linked to a drop in self‐esteem and to impaired well‐being. We report results of two daily diary studies, one in which 57 Swiss employees were assessed twice/day and one in which 90 Americans were assessed three times/day. Both studies showed that illegitimate tasks were associated with lowered state self‐esteem. Study 1 demonstrated that high trait self‐esteem mitigated that relationship. Study 2 showed that illegitimate tasks were associated with not only lowered state self‐esteem but also lower job satisfaction and higher anger and depressive mood, but not anger or job satisfaction remained elevated until the following morning. Copyright © 2015 John Wiley & Sons, Ltd.  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