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   4669篇
  免费   38篇
  国内免费   26篇
安全科学   59篇
废物处理   182篇
环保管理   164篇
综合类   2080篇
基础理论   837篇
环境理论   6篇
污染及防治   976篇
评价与监测   256篇
社会与环境   156篇
灾害及防治   17篇
  2022年   55篇
  2021年   49篇
  2020年   33篇
  2019年   40篇
  2018年   76篇
  2017年   69篇
  2016年   90篇
  2015年   71篇
  2014年   120篇
  2013年   212篇
  2012年   138篇
  2011年   124篇
  2010年   130篇
  2009年   137篇
  2008年   160篇
  2007年   178篇
  2006年   134篇
  2005年   125篇
  2004年   108篇
  2003年   126篇
  2002年   90篇
  2001年   93篇
  2000年   83篇
  1999年   84篇
  1998年   60篇
  1997年   54篇
  1996年   36篇
  1995年   51篇
  1994年   56篇
  1991年   37篇
  1990年   41篇
  1989年   34篇
  1985年   33篇
  1979年   38篇
  1977年   33篇
  1969年   36篇
  1967年   58篇
  1966年   50篇
  1965年   63篇
  1964年   64篇
  1963年   65篇
  1962年   57篇
  1961年   65篇
  1960年   55篇
  1959年   65篇
  1958年   65篇
  1957年   75篇
  1956年   49篇
  1955年   53篇
  1954年   48篇
排序方式: 共有4733条查询结果,搜索用时 46 毫秒
31.
32.
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   
33.
Metasedimentary garnet-mica schists are interlayered with metabasic garnet–omphacite schists and enclose eclogite boudins in the high-pressure metamorphic Maksyutov complex in the Southern Urals, Russia. These three rock types were investigated in one outcrop and compared chemographically and thermobarometrically. The Fe/Mg distributions between garnet rim–omphacite and garnet rim–phengite pairs indicate different equilibration temperatures for the three samples, with the lowest temperature (500°C, >1.5 GPa) for the eclogite boudin, an intermediate temperature (630°C, >1.7 GPa) for the foliated eclogite and the highest temperature (650°C, >1.7 GPa) for the garnet-mica schist. The garnets in garnet-mica schist enclose abundant chloritoid relics and the Fe/Mg distribution between chloritoid and garnet records an earlier high-temperature stage (650°C, >2.0 GPa) before the garnet rim–phengite temperatures were reached. Together with some minimum- and maximum-pressure estimates three different prograde pressure–temperature paths and a common retrograde metamorphic evolution are interpreted from the chemographic and thermobarometric data. The different early metamorphic evolutions and conditions confirm the variability of protoliths, which are also indicated by different U/Pb zircon and rutile ages.  相似文献   
34.
35.
36.
37.
38.
39.
40.
The excellent technical assistance of H. Führer and I. Leib is appreciated. Part of the work was supported by the Bundesministerium für Forschung und Technologie, the Deutsche Forschungsgemeinschaft, the Fonds der Chemischen Industrie, and from the Leitz and Hoechst companies. This paper is part of the M. D. thesis of Ch.L.  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