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   23篇
  免费   0篇
系统科学   1篇
现状及发展   3篇
研究方法   1篇
综合类   18篇
  2015年   1篇
  2013年   1篇
  2012年   1篇
  2011年   2篇
  2007年   2篇
  2006年   1篇
  2005年   1篇
  2004年   2篇
  2003年   3篇
  2002年   1篇
  2001年   2篇
  1993年   1篇
  1988年   1篇
  1985年   1篇
  1978年   1篇
  1972年   1篇
  1969年   1篇
排序方式: 共有23条查询结果,搜索用时 93 毫秒
21.
Zusammenfassung Die Präsenz einer charakteristischen Na+–K+-aktivierbaren ATPase (E.C. 3.6.1.3) wurde erstmals in einer mikrosomalen Fraktion des Enddarmes und der malpighischen Gefässe bei der WüstenschreckeScistocerca gregaria und der LaubheuschreckeJamaicana flava nachgewiesen.  相似文献   
22.
High interannual variability of sea ice thickness in the Arctic region   总被引:9,自引:0,他引:9  
Laxon S  Peacock N  Smith D 《Nature》2003,425(6961):947-950
Possible future changes in Arctic sea ice cover and thickness, and consequent changes in the ice-albedo feedback, represent one of the largest uncertainties in the prediction of future temperature rise. Knowledge of the natural variability of sea ice thickness is therefore critical for its representation in global climate models. Numerical simulations suggest that Arctic ice thickness varies primarily on decadal timescales owing to changes in wind and ocean stresses on the ice, but observations have been unable to provide a synoptic view of sea ice thickness, which is required to validate the model results. Here we use an eight-year time-series of Arctic ice thickness, derived from satellite altimeter measurements of ice freeboard, to determine the mean thickness field and its variability from 65 degrees N to 81.5 degrees N. Our data reveal a high-frequency interannual variability in mean Arctic ice thickness that is dominated by changes in the amount of summer melt, rather than by changes in circulation. Our results suggest that a continued increase in melt season length would lead to further thinning of Arctic sea ice.  相似文献   
23.
Leishmania parasites cause a broad spectrum of clinical disease. Here we report the sequencing of the genomes of two species of Leishmania: Leishmania infantum and Leishmania braziliensis. The comparison of these sequences with the published genome of Leishmania major reveals marked conservation of synteny and identifies only approximately 200 genes with a differential distribution between the three species. L. braziliensis, contrary to Leishmania species examined so far, possesses components of a putative RNA-mediated interference pathway, telomere-associated transposable elements and spliced leader-associated SLACS retrotransposons. We show that pseudogene formation and gene loss are the principal forces shaping the different genomes. Genes that are differentially distributed between the species encode proteins implicated in host-pathogen interactions and parasite survival in the macrophage.  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