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   108篇
  免费   9篇
  国内免费   1篇
  2022年   1篇
  2021年   2篇
  2018年   2篇
  2017年   4篇
  2016年   3篇
  2015年   2篇
  2014年   7篇
  2013年   8篇
  2012年   11篇
  2011年   4篇
  2010年   10篇
  2009年   6篇
  2008年   7篇
  2007年   3篇
  2006年   7篇
  2005年   3篇
  2004年   2篇
  2003年   5篇
  2002年   3篇
  2001年   4篇
  2000年   1篇
  1999年   3篇
  1998年   4篇
  1997年   3篇
  1996年   2篇
  1995年   1篇
  1994年   3篇
  1990年   1篇
  1988年   1篇
  1983年   1篇
  1982年   1篇
  1979年   2篇
  1977年   1篇
排序方式: 共有118条查询结果,搜索用时 15 毫秒
111.
112.
113.
Despite concerted surveys, the Maloti minnow Pseudobarbus quathlambae (Barnard 1938) had not been recorded in South African waters for almost eighty years since the original collections were made at the type locality in the upper uMkhomazana River in 1938. The species was therefore declared extinct in South Africa, whereas extant populations were considered confined to various rivers in the Lesotho highlands. In April 2017, however, this species was rediscovered in the Mzimkhulu River system in KwaZulu-Natal. The rediscovery of a species that was considered locally extinct supports the need for extensive surveys to determine its distribution range, estimate population sizes, assess conservation status and implement effective strategies to ensure its continued existence in KwaZulu-Natal.  相似文献   
114.
115.
Failure of articular cartilage has been investigated experimentally and theoretically, but there is only partial agreement between observed failure and predicted regions of peak stresses. Since trauma and repetitive stress are implicated in the etiopathogenesis of osteoarthritis, it is important to develop cartilage models which correctly predict sites of high stresses. Cartilage is anisotropic and inhomogeneous, though it has been difficult to incorporate these complexities into engineering analyses. The objectives of this study are to demonstrate that a transversely isotropic, biphasic model of cartilage can provide agreement between predicted regions of high stresses and observed regions of cartilage failure and that with transverse isotropy cartilage stresses are more sensitive to convexity and concavity of the surfaces than with isotropy. These objectives are achieved by solving problems of diarthrodial joint contact by the finite-element method. Results demonstrate that transversely isotropic models predict peak stresses at the cartilage surface and the cartilage-bone interface, in agreement with sites of fissures following impact loading; isotropic models predict peak stresses only at the cartilage-bone interface. Also, when convex cartilage layers contacted concave layers in this study, the highest tensile stresses occur in the convex layer for transversely isotropic models; no such differences are found with isotropic models. The significance of this study is that it establishes a threshold of modeling complexity for articular cartilage that provides good agreement with experimental observations under impact loading and that surface curvatures significantly affect stress and strain within cartilage when using a biphasic transversely isotropic model.  相似文献   
116.
117.

Background  

Guanosine triphosphate (GTP)-binding proteins play an important role in regulation of G-protein. Thus prediction of GTP interacting residues in a protein is one of the major challenges in the field of the computational biology. In this study, an attempt has been made to develop a computational method for predicting GTP interacting residues in a protein with high accuracy (Acc), precision (Prec) and recall (Rc).  相似文献   
118.
Atomic absorption spectrophotometry was employed in an evaluation of zinc, copper and iron as trace elements in serum and erythrocytes from 56 children with protein-calorie malnutrition at different stages (early kwashiorkor, kwashiorkor and marasma). Iron and zinc concentrations showed a decreasing pattern through the various stages of the P.C.M. Significant changes are present in zinc values. The role of these trace elements in the P.C.M. is shortly discussed.  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