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   1426篇
  免费   18篇
  国内免费   11篇
安全科学   43篇
废物处理   47篇
环保管理   167篇
综合类   449篇
基础理论   256篇
环境理论   3篇
污染及防治   359篇
评价与监测   74篇
社会与环境   54篇
灾害及防治   3篇
  2023年   11篇
  2022年   18篇
  2021年   25篇
  2020年   16篇
  2019年   15篇
  2018年   40篇
  2017年   41篇
  2016年   44篇
  2015年   36篇
  2014年   42篇
  2013年   65篇
  2012年   53篇
  2011年   84篇
  2010年   64篇
  2009年   67篇
  2008年   78篇
  2007年   71篇
  2006年   40篇
  2005年   58篇
  2004年   35篇
  2003年   42篇
  2002年   40篇
  2001年   23篇
  2000年   19篇
  1999年   11篇
  1998年   18篇
  1997年   8篇
  1996年   14篇
  1995年   25篇
  1994年   15篇
  1993年   10篇
  1992年   12篇
  1991年   7篇
  1990年   8篇
  1989年   8篇
  1988年   8篇
  1987年   7篇
  1986年   9篇
  1984年   9篇
  1978年   7篇
  1977年   7篇
  1963年   8篇
  1961年   11篇
  1960年   7篇
  1959年   8篇
  1958年   14篇
  1957年   8篇
  1955年   7篇
  1923年   6篇
  1914年   6篇
排序方式: 共有1455条查询结果,搜索用时 515 毫秒
21.
22.
23.
The printed circuit board (PCB) manufacturers face several problems regarding the waste they generate. In Austria, a detailed study for waste minimization was carried out with three PCB manufacturers and one electroplating company. In this project a lot of ecologically and economically effective options were found and implemented. The ecological evaluation of processes is still an unsolved problem. Several evaluation models are tested on selected processes of the project.  相似文献   
24.
A case is presented in which percutaneous umbilical sampling (PUBS) was utilized in the second and third trimesters for the diagnosis and management of a pregnancy at risk for neonatal alloimmune thrombocytopenia (NAIT).  相似文献   
25.
26.
The observation that thyroid disease is frequent in mothers of children with Down syndrome (DS) has suggested that maternal thyroid antibodies could be a factor predisposing to trisomy 21 in their offspring. In this study, the incidences of thyroglobulin (Tg) and thyroid peroxidase (TPO) antibodies were analysed with a sensitive solid-phase immunosorbent radioassay in sera from 29 mothers giving birth to children with trisomy 21 and 87 control mothers. The serum samples were collected at delivery. There was no statistical difference regarding the proportion of thyroid antibodies (against Tg and/or TPO) in the two groups. Thyroid antibodies were detected in 6/29 (20.7 per cent) of the DS mothers and in 23/87 (26.4 per cent) of the control mothers. Among the women with thyroid antibodies, 4/6 (66.7 per cent) of the DS mothers and 12/23 (52 per cent) of the control mothers had antibodies against both Tg and TPO. There was no increase in the relative risk of having a child with DS if the titre of either Tg or TPO antibodies or both were positive, i.e. ≥ 1/5. The results indicate that the presence of thyroid antibodies in the serum of a pregnant woman has no prognostic value for the birth of an infant with DS.  相似文献   
27.
Disaggregation of sectoral energy use and greenhouse gas emissions trends reveals striking differences between sectors and regions of the world. Understanding key driving forces in the energy end-use sectors provides insights for development of projections of future greenhouse gas emissions. This paper examines global and regional historical trends in energy use and carbon emissions in the industrial, buildings, transport, and agriculture sectors. Activity and economic drivers as well as trends in energy and carbon intensity are evaluated. We show that macro-economic indicators, such as GDP, are insufficient for comprehending trends and driving forces at the sectoral level. These indicators need to be supplemented with sector-specific information for a more complete understanding of future energy use and greenhouse gas emissions.  相似文献   
28.
29.
30.
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