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   94993篇
  免费   1237篇
  国内免费   1312篇
安全科学   3838篇
废物处理   3589篇
环保管理   14399篇
综合类   21501篇
基础理论   26850篇
环境理论   73篇
污染及防治   16830篇
评价与监测   5741篇
社会与环境   4146篇
灾害及防治   575篇
  2022年   844篇
  2021年   854篇
  2020年   677篇
  2019年   902篇
  2018年   1270篇
  2017年   1263篇
  2016年   2260篇
  2015年   1868篇
  2014年   2601篇
  2013年   9276篇
  2012年   2437篇
  2011年   2862篇
  2010年   3381篇
  2009年   3523篇
  2008年   2471篇
  2007年   2362篇
  2006年   2581篇
  2005年   2521篇
  2004年   2778篇
  2003年   2685篇
  2002年   2179篇
  2001年   2608篇
  2000年   2183篇
  1999年   1590篇
  1998年   1386篇
  1997年   1383篇
  1996年   1518篇
  1995年   1599篇
  1994年   1494篇
  1993年   1347篇
  1992年   1347篇
  1991年   1303篇
  1990年   1269篇
  1989年   1222篇
  1988年   1051篇
  1987年   1001篇
  1986年   993篇
  1985年   1074篇
  1984年   1161篇
  1983年   1174篇
  1982年   1172篇
  1981年   1095篇
  1980年   953篇
  1979年   922篇
  1978年   826篇
  1977年   712篇
  1976年   639篇
  1975年   607篇
  1973年   630篇
  1972年   643篇
排序方式: 共有10000条查询结果,搜索用时 1 毫秒
71.
72.
   Global change, i.e. the mega-process radically transforming the relationship between nature and human civilization since the end of World War II, is investigated from the point of view of systems analysis. It is argued that this unbridled process should rather be domesticated by planetary control strategies transpiring from a new science called “geocybernetics”. The formal aspects of geocybernetic theory are sketched and illustrated in a tutorial theatre world reflecting the overall environment and development problematic. Within this setting a straightforward operationalization of the sweeping “sustainable development” ideal through a set of concise paradigms can be achieved. Evidence is provided that geocybernetics is actually feasible on the basis of earth system modelling and fuzzy-control techniques.  相似文献   
73.
74.
This paper examines the relationship between survivor reactions to a downsizing and retention subsequent to a downsizing. We hypothesize that survivors who experience the downsizing as distributively, procedurally, and interactionally just and who see top management as trustworthy will feel more attached to the organization because each reduces the threat inherent in downsizing. In addition, we hypothesize that survivors who feel empowered will also feel more attached to the organization because they feel better able to cope with the downsizing. We further hypothesize that those survivors who feel more attached to the organization following the downsizing will be more likely to remain with the organization in the coming year. The theoretical model is tested on a sample of aerospace employees who survived an organizational downsizing. The trustworthiness of management, distributive justice, procedural justice, and three dimensions of empowerment are found to facilitate more organizational attachment. Higher levels of attachment are found, in turn, to facilitate less voluntary turnover in the year following the downsizing. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   
75.
76.
77.
78.
79.
80.
Material suppliers and industrial metabolism   总被引:1,自引:1,他引:0  
Life Cycle Assessment (LCA) is not sufficiently tailored to the analysis of strategic environmental problems of material suppliers. Sustainable development calls for a reduction by a factor of 10 to 20 in the material intensity of the economy, a situation which leads to dramatic shifts in markets for raw materials. Furthermore, a material supplier might have major improvement options in the material’s numerous downstream uses. LCAs, however, can’t cover these two aspects. An adapted form of Substance Flow Analysis (SFA) may be an answer. This approach defines a system in relation to the flow of a specific material through society. All environmental interventions related to the material are inventoried. An emission evaluation indicates the dominant environmental bottlenecks, given the current market volume of each application of the material. This helps to identify improvement options and strategic choices in market portfolios. Scenario analysis on potential measures can further indicate changes of material flows — and thus markets — in the system. The approach is illustrated with a case study on chlorine.  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