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   88篇
  免费   0篇
安全科学   1篇
废物处理   5篇
环保管理   2篇
综合类   37篇
基础理论   15篇
环境理论   2篇
污染及防治   23篇
评价与监测   1篇
社会与环境   2篇
  2022年   1篇
  2021年   2篇
  2019年   1篇
  2018年   3篇
  2016年   3篇
  2015年   2篇
  2014年   3篇
  2013年   2篇
  2012年   5篇
  2011年   3篇
  2010年   3篇
  2009年   7篇
  2008年   2篇
  2007年   2篇
  2006年   4篇
  2005年   2篇
  2004年   5篇
  2003年   1篇
  2002年   1篇
  2001年   4篇
  1999年   1篇
  1995年   2篇
  1993年   1篇
  1991年   1篇
  1989年   1篇
  1985年   1篇
  1984年   1篇
  1982年   2篇
  1981年   2篇
  1977年   3篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1968年   1篇
  1962年   1篇
  1961年   1篇
  1957年   1篇
  1955年   3篇
  1954年   2篇
  1953年   1篇
  1952年   1篇
  1951年   1篇
  1938年   1篇
  1934年   1篇
排序方式: 共有88条查询结果,搜索用时 260 毫秒
1.

Naturwissenschaften Aktuell

Konzept für konzentrierte Meeresforschung an fünf Orten  相似文献   
2.
3.
4.
5.
Production facilities serve to transform raw materials into products, usually with the goal of achieving a designated output, in terms of quantity and quality, with the minimum of cost and labour. With the aid of production planning and controlling (PPC) systems, raw material inputs, and labour can be planned to achieve a determined output of products. In general, the role of environmental and social aspects is neglected in production planning processes. Because of the growing pressure from politics and customers, sustainable production of products is becoming more important. One possibility for supporting sustainable manufacturing is, to integrate sustainable aspects in the production planning process. This paper presents input and output information for current PPC systems and discusses the need for additional information necessary for sustainable PPC. For this approach, a text review of cooperate social responsibility (CSR) reporting indicators provided by the GRI was performed. Based on the text review, an input-output model has been developed for conventional and another one for sustainable PPC systems. Through the comparison of the two input-output models, challenges and requirements for sustainable PPC systems have been defined as a basis for future work and analyses.  相似文献   
6.
We modelled the combined effects of past and expected future changes in climate and nitrogen deposition on tree carbon sequestration by European forests for the period 1900-2050. Two scenarios for deposition (current legislation and maximum technically feasible reductions) and two climate scenarios (no change and SRES A1 scenario) were used. Furthermore, the possible limitation of forest growth by calcium, magnesium, potassium and phosphorus is investigated. The area and age structure of the forests was assumed to stay constant to observations during the period 1970-1990. Under these assumptions, the simulations show that the change in forest growth and carbon sequestration in the past is dominated by changes in nitrogen deposition, while climate change is the major driver for future carbon sequestration. However, its impact is reduced by nitrogen availability. Furthermore, limitations in base cations, especially magnesium, and in phosphorus may significantly affect predicted growth in the future.  相似文献   
7.
The dynamic soil chemistry model SMART was applied to 121 intensive forest monitoring plots (mainly located in western and northern Europe) for which both element input (deposition) and element concentrations in the soil solution were available. After calibration of poorly known parameters, the model accurately simulated soil solution concentrations for most plots as indicated by goodness-of-fit measures, although some of the intra-annual variation especially in nitrate and aluminium concentrations could not be reproduced. Model evaluations of two emission-deposition scenarios (current legislation and maximum feasible reductions) for the period 1970-2030 show a strong reduction in sulphate concentrations between 1980 and 2000 in the soil due to the high reductions in sulphur emissions. However, current legislation hardly reduces future nitrogen concentrations, whereas maximum feasible reductions reduces them by more than half. Maximum feasible reductions are also more effective in increasing pH and reducing aluminium concentrations, mostly below ‘critical’ values.  相似文献   
8.
9.
10.
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