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   11490篇
  免费   160篇
  国内免费   112篇
安全科学   369篇
废物处理   526篇
环保管理   1614篇
综合类   1353篇
基础理论   3120篇
环境理论   7篇
污染及防治   3168篇
评价与监测   813篇
社会与环境   719篇
灾害及防治   73篇
  2023年   58篇
  2022年   136篇
  2021年   121篇
  2020年   88篇
  2019年   111篇
  2018年   197篇
  2017年   192篇
  2016年   298篇
  2015年   209篇
  2014年   293篇
  2013年   886篇
  2012年   372篇
  2011年   559篇
  2010年   438篇
  2009年   483篇
  2008年   567篇
  2007年   569篇
  2006年   513篇
  2005年   419篇
  2004年   366篇
  2003年   429篇
  2002年   364篇
  2001年   526篇
  2000年   369篇
  1999年   209篇
  1998年   155篇
  1997年   141篇
  1996年   158篇
  1995年   180篇
  1994年   143篇
  1993年   111篇
  1992年   133篇
  1991年   127篇
  1990年   138篇
  1989年   140篇
  1988年   104篇
  1987年   97篇
  1986年   74篇
  1985年   99篇
  1984年   94篇
  1983年   95篇
  1982年   94篇
  1981年   86篇
  1980年   63篇
  1979年   72篇
  1977年   57篇
  1976年   49篇
  1975年   57篇
  1974年   52篇
  1973年   53篇
排序方式: 共有10000条查询结果,搜索用时 375 毫秒
151.
There was a widespread misconception about the causes of vegetation and land fires in Indonesia. At a certain point, the public perceived that fires and the associated haze pollution were primarily caused by smallholders' agricultural activities. In fact, there was a variety of land-use activities including large-scale land clearing following deforestation for further land development. El Niño events and the associated dry weather were sometimes quoted by officials and the media as the cause of fires. The fire episodes from 1980 to 2000 were analysed in connection with climate anomalies and the implementation of land-use policies related to forest conversions. The analysis employs long-term climatic and sea surface temperature data to reconstruct climate distributions and anomalies including Southern Oscillation Index (SOI), Sea Surface Temperature (SST) and Outgoing Long-wave Radiation (OLR). In this study, the terrestrial carbon emissions from vegetation fires were estimated based on official statistical data on area burnt. The possible incentives for sustainable land management were discussed in the light of fire prevention. The underlying cause neglected in the discussion of Indonesian vegetation fires was forest and land development policy. Legitimated in the early 1980s, it drove massive forest conversions and the use of fires for land clearing. El Niño Southern Oscillation (ENSO) provided dry weather suitable for biomass burning and widespread fire, but it was hardly the cause of fires. The estimate of area burnt in the big fires in 1997 was about 11.6 Mha, resulting in carbon release of 1.45 Gt, equivalent to 0.73 ppmv of CO2, or almost half the annual global atmospheric CO2 growth. Based on the current carbon market price such emissions by the 1997 fire episode were worth around US$ 3.6 billion.  相似文献   
152.
Mitigation and Adaptation Strategies for Global Change - Guidelines of the Intergovernmental Panel on Climate Change (IPCC) were used to assess a greenhouse gas inventory for land use change and...  相似文献   
153.
154.
155.
156.
157.
A syncytiotrophoblast-associated antigen identified by the monoclonal antibody (McAb) H315 is detectable on the surface of a low proportion of peripheral blood cells in pregnant women, raising the possibility of a new approach to prenatal diagnosis of genetic disorders. We aimed at verifying the trophoblastic origin of H315+ cells and their use for prenatal diagnosis of β-thalassaemia. H315 + cells were separated from the peripheral blood of pregnant women: the DNA obtained from these cells in two selected cases was shown to have genetic markers indistinguishable from those of the mother and definitely different from the fetus. Our results suggest that H315 antigen is expressed by maternal cells and that prenatal diagnosis on peripheral blood of the mother using H315 McAb is not feasible.  相似文献   
158.
159.
160.
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