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   1306篇
  免费   32篇
  国内免费   20篇
安全科学   55篇
废物处理   68篇
环保管理   129篇
综合类   285篇
基础理论   228篇
环境理论   1篇
污染及防治   349篇
评价与监测   144篇
社会与环境   79篇
灾害及防治   20篇
  2023年   10篇
  2022年   16篇
  2021年   30篇
  2020年   17篇
  2019年   17篇
  2018年   38篇
  2017年   49篇
  2016年   43篇
  2015年   31篇
  2014年   62篇
  2013年   93篇
  2012年   45篇
  2011年   80篇
  2010年   54篇
  2009年   65篇
  2008年   73篇
  2007年   69篇
  2006年   50篇
  2005年   54篇
  2004年   60篇
  2003年   72篇
  2002年   49篇
  2001年   53篇
  2000年   31篇
  1999年   25篇
  1998年   16篇
  1997年   12篇
  1996年   5篇
  1995年   12篇
  1994年   11篇
  1993年   14篇
  1992年   16篇
  1991年   3篇
  1990年   4篇
  1989年   7篇
  1988年   6篇
  1987年   2篇
  1986年   5篇
  1985年   8篇
  1984年   4篇
  1983年   8篇
  1982年   8篇
  1981年   4篇
  1980年   2篇
  1979年   2篇
  1976年   2篇
  1970年   2篇
  1962年   5篇
  1961年   2篇
  1938年   1篇
排序方式: 共有1358条查询结果,搜索用时 15 毫秒
351.
Although teaching sustainability issues is considered a difficult task, teachers are at the centre of curriculum renewal when directing it more towards sustainability. This article presents a teacher's manual and method for the integration of SD in curricula of higher education as well as an evaluation of their use. The manual is a powerful tool that combines a focus on teacher's capacities for SD integration within their discipline with student-activating teaching methods. Even in institutions where management support is low, it is a valuable means. Because of its generality and flexibility, the method appears to be of great potential as a framework for SD integration.  相似文献   
352.
353.
354.
355.
356.
357.
Cell length of the diatom Cylindrotheca closterium (Ehr.) Reimann & Lewin was investigated on a fortnightly basis from January to April 2000 in a hyperhaline pond (Sardinia, Mediterranean Sea) and relationships, with changes in temperature, salinity, and nitrite concentrations were assessed using single and multiple regression analyses. Results of our study indicate that C. closterium cell size was inversely related to temperature changes, but that salinity and nitrite concentrations may have a major idiosyncratic effect on cell size variability.  相似文献   
358.
359.
In order to find out an alternative to traditional environmental policies in the State of São Paulo (Brazil), which have been mainly focused on legal standard compliance for air and water emissions, as well as in soil contamination, the Environmental Agency of São Paulo State — CETESB — launched a research project entitled Industrial Toxic Substances Use Reduction Programme. The project was launched in 2006 with funding from the United States Trade and Development Agency. Its aim was to propose new policies and strategies to reduce industrial releases of toxic compounds to the environment. Its general steps were the identification of an initial toxic chemical targets list; a review of successful programmes in the United States; the development of key elements and the establishment of alternative combinations of those elements for the implementation of an indigenous programme. Since project completion, CETESB has been discussing the possibility of implementing the results through a pilot project being developed jointly with industry representatives. This pilot project will serve as a model for a broader industrial toxic substances reduction programme to be implemented in São Paulo State.  相似文献   
360.
In Flanders, the northern part of Belgium, about 31% of the produced amount of MSWI bottom ash is recycled as secondary raw material. In view of recycling a higher percentage of bottom ash, a particular bottom ash fraction (Ø 0.1–2 mm) was studied. As the leaching of this bottom ash fraction exceeds some of the Flemish limit values for heavy metals (with Cu being the most critical), treatment is required.Natural weathering and accelerated carbonation resulted in a significant decrease of the Cu leaching. Natural weathering during 3 months caused a decrease of Cu leaching to <50% of its original value, whereas accelerated carbonation resulted in an even larger decrease (to ca. 13% of its initial value) after 2 weeks, with the main decrease taking place within the first 48 h.Total organic carbon decreased to ca. 70% and 55% of the initial concentration in the solid phase, and to 40% and 25% in the leachate after natural weathering and after accelerated carbonation, respectively. In the solid material the decrease of the Hy fraction was the largest, the FA concentration remained essentially constant. The decrease of FA in the leachate can be attributed partly to an enhanced adsorption of FA to Fe/Al (hydr)oxides, due to the combined effect of a pH decrease and the neoformation of Al (hydr)oxides (both due to carbonation). A detailed study of adsorption of FA to Fe/Al (hydr)oxides showed that significant adsorption of FA occurs, that it increases with decreasing pH and started above pH 12 for Fe (hydr)oxides and around 10 for Al (hydr)oxides. Depending whether FA or Hy are considered the controlling factor in enhanced Cu leaching, the decreasing FA or Hy in the leachate explains the decrease in the Cu leaching during carbonation.  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