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   17865篇
  免费   155篇
  国内免费   122篇
安全科学   427篇
废物处理   681篇
环保管理   2050篇
综合类   5383篇
基础理论   3707篇
环境理论   5篇
污染及防治   4245篇
评价与监测   930篇
社会与环境   645篇
灾害及防治   69篇
  2018年   210篇
  2017年   202篇
  2016年   307篇
  2015年   226篇
  2014年   340篇
  2013年   1245篇
  2012年   385篇
  2011年   547篇
  2010年   513篇
  2009年   578篇
  2008年   595篇
  2007年   632篇
  2006年   549篇
  2005年   486篇
  2004年   519篇
  2003年   479篇
  2002年   458篇
  2001年   623篇
  2000年   427篇
  1999年   291篇
  1998年   208篇
  1997年   199篇
  1996年   201篇
  1995年   239篇
  1994年   256篇
  1993年   209篇
  1992年   231篇
  1991年   237篇
  1990年   257篇
  1989年   232篇
  1988年   185篇
  1987年   186篇
  1986年   185篇
  1985年   187篇
  1984年   208篇
  1983年   192篇
  1982年   202篇
  1981年   217篇
  1980年   175篇
  1979年   185篇
  1978年   151篇
  1977年   142篇
  1976年   141篇
  1974年   150篇
  1973年   147篇
  1968年   157篇
  1967年   184篇
  1966年   154篇
  1965年   148篇
  1964年   151篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
The present paper describes heavy metal contamination of soils and crops resulting from auto traffic, sewage sludge, pig manure and chemical fertilizers, in three separate experiments.The first experiment revealed that although the ADDT (average annual daily traffic) value of the Agricultural Area was lower, higher concentrations of Cu, Cd, Zn, Pb and Mn were obtained in soil when compared with the Commercial-Residential Area. Contaminations of trace metals from various source, e.g., chemical fertilizer, animal manure, night soil and pesticides of the nearby agricultural land were suspected.The second experiment compared the effects of adding a commercial fertilizer and digested sludge which contain substantial amounts of various trace metals to a sandy loam for growing Chinese radish. The results indicated that repeated applications of the fertilizer elevated the contents of various trace metals in the roots of Chinese radish. The phenomenon was further aggravated when digested sludge was also incorporated.The third experiment compared the contents of trace metals in the root and leaf tissues of tree seedlings (Acacia confusa) added with a single dose of the trace metalenriched fertilizer, and different portions of pig manure compost. It was revealed that the fertilizer-treated tree seedlings had a higher content of trace metals in the tissues than those amended with manure compost. Although the metal contents of soil increased as more manure compost was added, the contents in plant tissues did not increase correspondingly.  相似文献   
63.
64.
65.
66.
67.
68.
69.
70.
Mitigation and adaptation synergy in forest sector   总被引:1,自引:1,他引:1  
Mitigation and adaptation are the two main strategies to address climate change. Mitigation and adaptation have been considered separately in the global negotiations as well as literature. There is a realization on the need to explore and promote synergy between mitigation and adaptation while addressing climate change. In this paper, an attempt is made to explore the synergy between mitigation and adaptation by considering forest sector, which on the one hand is projected to be adversely impacted under the projected climate change scenarios and on the other provide opportunities to mitigate climate change. Thus, the potential and need for incorporating adaptation strategies and practices in mitigation projects is presented with a few examples. Firstly, there is a need to ensure that mitigation programs or projects do not increase the vulnerability of forest ecosystems and plantations. Secondly, several adaptation practices could be incorporated into mitigation projects to reduce vulnerability. Further, many of the mitigation projects indeed reduce vulnerability and promote adaptation, for example; forest and biodiversity conservation, protected area management and sustainable forestry. Also, many adaptation options such as urban forestry, soil and water conservation and drought resistant varieties also contribute to mitigation of climate change. Thus, there is need for research and field demonstration of synergy between mitigation and adaptation, so that the cost of addressing climate change impacts can be reduced and co-benefits increased.  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