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   1841篇
  免费   19篇
  国内免费   15篇
安全科学   53篇
废物处理   67篇
环保管理   311篇
综合类   306篇
基础理论   440篇
环境理论   4篇
污染及防治   472篇
评价与监测   134篇
社会与环境   83篇
灾害及防治   5篇
  2024年   7篇
  2023年   27篇
  2022年   21篇
  2021年   27篇
  2020年   29篇
  2019年   26篇
  2018年   39篇
  2017年   47篇
  2016年   45篇
  2015年   46篇
  2014年   50篇
  2013年   127篇
  2012年   73篇
  2011年   108篇
  2010年   77篇
  2009年   92篇
  2008年   95篇
  2007年   115篇
  2006年   84篇
  2005年   73篇
  2004年   72篇
  2003年   67篇
  2002年   78篇
  2001年   33篇
  2000年   26篇
  1999年   18篇
  1998年   19篇
  1997年   23篇
  1996年   18篇
  1995年   23篇
  1994年   25篇
  1993年   13篇
  1992年   16篇
  1991年   15篇
  1990年   12篇
  1989年   12篇
  1988年   17篇
  1987年   12篇
  1986年   15篇
  1984年   8篇
  1983年   10篇
  1982年   11篇
  1981年   9篇
  1980年   7篇
  1979年   10篇
  1978年   7篇
  1976年   6篇
  1974年   6篇
  1955年   5篇
  1954年   8篇
排序方式: 共有1875条查询结果,搜索用时 0 毫秒
301.
302.
Filling and emptying normal FIBC (flexible intermediate bulk containers) in hazardous areas represents a high electrostatic ignition hazard. Manufacturers of FIBC have therefore designed different measures to reduce the ignition risks from static electricity. Depending on the measures applied FIBC are categorized into types A, B, C and D. End of 2005 a new international standard for testing type D FIBC has been published. Type D FIBC have now to be certified according to this standard. Since this standard requires comprehensive ignition testing on a test rig especially designed for this purpose, industry is looking for a simpler test method, which can be used for the development of new FIBC fabric and in production quality control. In the present paper it is attempted to apply the method of charge transfer measurement to assess the ignition probability of static discharged from FIBC during filling and emptying and to correlate the results with the ignition tests performed on the standard test rig.  相似文献   
303.
304.
305.
Australian governments have sought to invest in irrigation infrastructure to improve the efficiency of water delivery to rural properties and improve water supply and on-farm efficiency. A programme of rationalising irrigation infrastructure has attracted criticism and doubts about its likely success. Attitude theory in the form of the Reasoned Action Model was applied to understand the intentions of landowners to connect to a ‘modernised’ irrigation system. Attitudes towards connecting to the system, social norms and perceptions of control over the behaviour provided an explanation of intentions to connect. Actual financial capability and other variables were important in discriminating a group of landowners who had already connected to the modernised system from farmers who had not.  相似文献   
306.
Atlantic mollies (Poecilia mexicana) inhabit a variety of surface habitats, but they also occur in a sulfur cave in southern Mexico. We examined male mate choice relative to female body size in the cave population and in the most closely related surface-dwelling population from a nearby river. Males from both populations were either light- or dark-reared and could choose between two differently sized females either on the basis of visual cues in light or on the basis of solely nonvisual cues in darkness. Sexual preferences were estimated from the degree of association. Cave molly males always showed a preference for the larger female, both in light and in darkness. Among the surface males, only light-reared males showed a preference in the visual cues test, but not in darkness. In a control experiment, we demonstrated that male association preferences directly translate into actual mating preferences. Apparently, using visual cues for mate choice is the ancestral state in this system, and using nonvisual cues has evolved as a novel trait in the cave population. We discuss the evolution of nonvisual male mate choice in the context of changed environmental conditions, namely the absence of light, hypoxia, and toxic hydrogen sulfide in the cave.  相似文献   
307.
308.
309.
310.
The planning system is significant because of its capacity to determine the quality of the built environment as well as the health, well-being and quality of life of the individuals and communities therein. Development planning is especially important because of the long-term impact of the decisions. This paper was developed in response to increasing recognition amongst HIA practitioners in Scotland of the importance of planning for health. It focuses on the relationship between the planning system in Scotland, specifically the Development Planning element of it, and population health and considers how the health impact assessment (HIA) approach can facilitate and support joint working with planners. In particular, consideration is given to the potential impact of the introduction of Strategic Environmental Assessment (SEA) on the linkages between health, HIA and planning.  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