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   5111篇
  免费   33篇
  国内免费   14篇
安全科学   75篇
废物处理   185篇
环保管理   238篇
综合类   2005篇
基础理论   1045篇
环境理论   9篇
污染及防治   1185篇
评价与监测   207篇
社会与环境   200篇
灾害及防治   9篇
  2019年   51篇
  2018年   96篇
  2017年   96篇
  2016年   124篇
  2015年   106篇
  2014年   123篇
  2013年   226篇
  2012年   130篇
  2011年   213篇
  2010年   148篇
  2009年   154篇
  2008年   223篇
  2007年   204篇
  2006年   172篇
  2005年   135篇
  2004年   125篇
  2003年   113篇
  2002年   150篇
  2001年   98篇
  2000年   93篇
  1999年   74篇
  1998年   53篇
  1997年   45篇
  1996年   55篇
  1995年   64篇
  1994年   63篇
  1993年   42篇
  1992年   53篇
  1991年   50篇
  1990年   43篇
  1989年   40篇
  1988年   38篇
  1985年   40篇
  1981年   36篇
  1976年   40篇
  1968年   36篇
  1967年   54篇
  1966年   44篇
  1965年   56篇
  1964年   50篇
  1963年   46篇
  1962年   45篇
  1961年   55篇
  1960年   46篇
  1959年   48篇
  1958年   57篇
  1957年   49篇
  1956年   46篇
  1955年   46篇
  1954年   44篇
排序方式: 共有5158条查询结果,搜索用时 203 毫秒
31.
32.
33.
34.
35.
36.
37.
38.
39.
Counselling in connection with prenatal diagnosis (PND) is a common task for the obstetrician and the midwife. However, the decision making processes of pregnant women are not completely known, for instance, the questions of women's autonomy, the decision on how to act in the case of an abnormal test, and the partner's participation in the decision. A questionnaire and interview study was carried out among 211 women undergoing PND by amniocentesis or chorionic villus biopsy. Most women in the sample indicated that PND was completely voluntary. However, at the same time almost every woman reported that it was difficult to decline from PND when offered. Even before the visit to register at the antenatal clinic, most of the women (83 per cent) had made up their minds to have PND. At the time of the test, many of the participants (62 per cent) had decided in favour of a legal abortion if the test indicated an abnormality in the fetus. At the same time, however, the data indicate a need for reflection and ambivalence, which the medical staff have to accept. In the questionnaire most of the women stated that they and their partners had similar attitudes towards PND, but when interviewed 38 per cent of the women admitted some differences between their own attitudes and their partners'. Although some women reported considerable deliberation and ambivalence, most of them said that they would undergo PND in another pregnancy.  相似文献   
40.
A family with two siblings, 10 and 8 years old, both with clinical and ultrastructural evidence of juvenile neuronal ceroid lipofuscinosis is described. The family was found to be informative for the restriction fragment length polymorphisms (RFLPs) detected by the probes pCJ52–95Ml (locus D16S148) and pCJ52-94Tl (locus D16S159) flanking the juvenile neuronal ceroid lipofuscinosis locus, CLN3. The parents were both heterozygous using these probes, while their two children with juvenile neuronal ceroid lipofuscinosis were both homozygous. Chorionic villi analysis showed that the fetus was heterozygous and had inherited the one allele of the mother which was not found in the two siblings. This suggested that the fetus had derived one healthy allele from the mother, the risk for a double crossing-over being less than 1 per cent. Electron microscopy showed no fingerprint inclusions in chorionic villi. The child was investigated at 6 months of age and found to be healthy, as new fingerprint inclusions were found at electron microscopy and no vacuolated lymphocytes were found in the blood smear. Due to the risk of heterogeneity, both DNA-based analysis and electron microscopy on chorionic villi are recommended for prenatal examination for juvenile neuronal ceroid lipofuscinosis.  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