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   100篇
  免费   1篇
化学   62篇
力学   3篇
数学   24篇
物理学   12篇
  2023年   2篇
  2022年   3篇
  2021年   3篇
  2020年   1篇
  2019年   2篇
  2018年   2篇
  2017年   2篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   3篇
  2012年   6篇
  2011年   7篇
  2010年   2篇
  2009年   5篇
  2008年   6篇
  2007年   5篇
  2006年   5篇
  2005年   9篇
  2004年   2篇
  2003年   4篇
  2002年   5篇
  2001年   1篇
  2000年   4篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1988年   1篇
  1985年   1篇
  1984年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1968年   1篇
排序方式: 共有101条查询结果,搜索用时 15 毫秒
61.
Different organotin phenoxides react at room temperature with diethyl acetylenedicarboxylate in diethyl ether, in the presence of lithium perchlorate to give a mixture of corresponding phenyl vinyl ethers and ring ethenylated phenols. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
62.
Summary.  Experimental solubility data for metals and non-metallic substances in liquid alkali metals have been collected from literature, critically evaluated, and selected for recommendation. Sometimes results for a selected system at a selected temperature vary over more than an order of magnitude. This is not uniquely connected with a poor precision of the measurements. Some impurities may spectacularly modify the solubilities and, moreover, definition of a saturating solute phase is not always a simple task. Based on supplementary experiments one may explain several phenomena which often accompany dissolution processes. These accompanying processes are essentially the same as those frequently observed in solution chemistry. Received February 3, 2000. Accepted (revised) May 8, 2000  相似文献   
63.
An efficient silylative coupling of trisubstituted vinylsilanes with dialkoxy(vinyl)boranes is described. Under optimum conditions the reaction offers a selective route to 1-(silyl)-1-(boryl)ethenes, which are potentially attractive intermediates in organic synthesis  相似文献   
64.
65.
In this survey paper we present some recent results in the iteration theory. Mainly, we focus on the problems concerning real iteration groups (flows) and semigroups (semiflows) such as existence, regularity and embeddability. We also discuss some issues associated to the problem of embedddability, i.e. iterative roots and approximate iterability. The topics of this paper are: (1) measurable iteration semigroups; (2) embedding of diffeomorphisms in regular iteration semigroups in \({{\mathbb{R}}^n}\) space; (3) iteration groups of fixed point free homeomorphisms on the plane; (4) embedding of interval homeomorphisms with two fixed points in a regular iteration group; (5) commuting functions and embeddability; (6) iterative roots; (7) the structure of iteration groups on an interval; (8) iteration groups of homeomorphisms of the circle; (9) approximately iterable functions; (10) set-valued iteration semigroups; (11) iterations of mean-type mappings; (12) Hayers–Ulam stability of the translation equation. Most of the results presented here was obtained by the means of functional equations. We indicate the relations between the iteration theory and functional equations.  相似文献   
66.
67.
68.
69.
Construction and classification of two-dimensional (2D) superintegrable systems (i.e. systems admitting, in addition to two global integrals of motion guaranteeing the Liouville integrability, the third global and independent one) defined on 2D spaces of constant curvature and separable in the so-called geodesic polar coordinates are presented. The method proposed is applicable to any value of curvature including the case of Euclidean plane, sphere and hyperbolic plane. The main result is a generalization of Bertrand’s theorem on 2D spaces of constant curvature and covers most of the known separable and superintegrable models on such spaces (in particular, the so-called Tremblay–Turbiner–Winternitz (TTW) and Post–Winternitz (PW) models which have recently attracted some interest).  相似文献   
70.
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