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   59篇
  免费   1篇
安全科学   2篇
环保管理   8篇
综合类   36篇
基础理论   11篇
污染及防治   2篇
灾害及防治   1篇
  2023年   2篇
  2021年   2篇
  2019年   1篇
  2017年   4篇
  2016年   2篇
  2015年   2篇
  2014年   3篇
  2013年   4篇
  2012年   2篇
  2011年   6篇
  2010年   1篇
  2009年   3篇
  2008年   2篇
  2007年   2篇
  2005年   1篇
  2004年   2篇
  2003年   1篇
  2002年   4篇
  2001年   3篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1990年   1篇
  1985年   1篇
  1984年   1篇
  1981年   1篇
排序方式: 共有60条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
ABSTRACT: Lakes, marshes and wet meadows occur in the broad, flat, interdune valleys of the Nebraska Sandhills, a vegetation-stabilized dune field underlain by sediments containing an enormous supply of groundwater. Hydrologic, geologic and possibly climatologic factors influence the chemical quality of lake water. Central and eastern lakes generally are in connection with the groundwater reservoir. The hydrologic nature of western lakes and the cause of their high alkalinity is not fully understood. Lakes in close proximity may vary in both their chemical characteristics and in the degree to which they change in size and depth over time. Climatic, hydrogeologic and natural lake-aging processes of accumulation of organics appear to be primarily responsible for lake-size variations.  相似文献   
5.
6.
7.
8.
9.
Obstetric complications, such as severe pre-eclampsia, fetal growth restriction, abruptio placentae, or stillbirth are associated with abnormally elevated second-trimester maternal serum alpha-fetoprotein (MSAFP) and β subunit of human chorionic gonadotrophin (βhCG). This has been attributed to placental abnormalities. Women with thrombophilias have been shown to have abnormalities of the placenta resulting in adverse pregnancy outcome in these patients. The purpose of the present study was to evaluate whether women with pregnancy complications and inherited thrombophilias have abnormally elevated second-trimester MSAFP or βhCG. Sixty-two women with pregnancy complications were tested for inherited thrombophilias several months after delivery. The thrombophilia group included 29 women with pregnancy complications and an inherited thrombophilia and the control group included 33 other patients without thrombophilia. Patients in the thrombophilia group had a higher median MoM MSAFP compared to the controls (1.337 vs 1.086, p=0.0516). The incidence of abnormally elevated MSAFP (>2.5 MoM) was also significantly higher in the thrombophilia group compared to controls (21% vs 3%, p=0.04). Neither the median MoM βhCG nor the incidence of abnormally elevated βhCG were significantly different between the groups. We conclude that second trimester MSAFP, but not βhCG, is abnormally elevated in patients with thrombophilia and obstetric complications. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
10.
High rise housing is characterized by two major factors—height and number of people—each of which play a role in the image created and each of which are associated with advantages and disadvantages. The purpose of this study was to compare the image of high rise housing which emerges from the literature with the image and experience of high rise living as reported within a particular physical, social and cultural context—that of Israel. Three hundred and forty four individual, structured interviews were conducted with middle-class women living in buildings from four to 20 storeys high. Data are presented on their image of high rise housing; their experience of specific aspects: such as crowding, neighbor relations, childrens' outdoor play; and their general satisfaction with the building. On the whole the results indicate that these Israeli respondents' experience does not correspond to the image of high rise housing as portrayed in much of the literature. Their image is a function of their experience, which in turn is a function of the interaction between their own personal characteristics (particularly stage in the life cycle) and the height of the building—within a particular socio-cultural context.  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