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   423篇
  免费   3篇
  国内免费   2篇
化学   222篇
晶体学   1篇
力学   1篇
数学   52篇
物理学   152篇
  2020年   8篇
  2019年   4篇
  2018年   10篇
  2017年   22篇
  2016年   18篇
  2015年   50篇
  2014年   6篇
  2013年   22篇
  2012年   9篇
  2011年   6篇
  2010年   3篇
  2008年   6篇
  2007年   8篇
  2006年   5篇
  2004年   15篇
  2003年   4篇
  2002年   3篇
  2001年   13篇
  2000年   8篇
  1999年   7篇
  1998年   5篇
  1997年   29篇
  1996年   6篇
  1995年   3篇
  1994年   4篇
  1993年   8篇
  1992年   9篇
  1991年   9篇
  1990年   5篇
  1989年   11篇
  1988年   5篇
  1987年   5篇
  1985年   8篇
  1984年   5篇
  1983年   4篇
  1982年   3篇
  1980年   4篇
  1979年   4篇
  1977年   6篇
  1976年   5篇
  1975年   12篇
  1973年   10篇
  1971年   3篇
  1968年   4篇
  1965年   2篇
  1962年   2篇
  1944年   2篇
  1935年   4篇
  1917年   2篇
  1887年   2篇
排序方式: 共有428条查询结果,搜索用时 515 毫秒
1.
Russian Chemical Bulletin - Terminal disaccharide fragment of phenolic glycolipid from Mycobacterium leprae (PGL-I) was synthesized as a glycoside with 4-(2-aminoethoxy)phenyl aglycon. The obtained...  相似文献   
2.
We formulate the super-KMS condition suggested by Connes and Kastler, in the context of entire cyclic cohomology of quantum algebras. We show that the Chern character of Jaffe, Lesniewski, and Osterwalder — associated by Kastler to a super-KMS functional — satisfies the entire growth condition. Hence, a super-KMS functional defines a cocycle for the entire cyclic cohomology of quantum algebras.Supported in part by the National Science Foundation.  相似文献   
3.
4.
Au sein d'un re´seau de type BaFeF5 des chai?nes d'octae`dres fluore´sa`sommets communs peuvent disparai?tre en donnant naissance a des canaux dont l'occupation partielle ou totale par des files de cations Sr2+ et de couples d'anions F?, conduit respectivement aux phases Sr3(FeF6)2 ou Sr5T3F19 (T = Cr, Co, Ga). Une discussion cristallochimique permet d'expliquer l'existence d'un domaine de solutions solides au sein du diagramme ternaire SrF2BaF2FeF3.  相似文献   
5.
6.
The kinetics of the complexation of NiII by pteroylglutamic acid have been studied in the 545 ∘C range, the ionic strength (0.6 M) being regulated with KNO3, in the 5.5–7.0pH range, using the stopped-flow method. Under the experimental conditions two processes were observed. The faster process was detected in the millisecond range and is associated with the reaction between NiII and the ligand. The slower is observed within a few seconds. Complementary equilibrium studies were made at 25 ∘C. The results are consistent with the formation of a 1:1 complex between the reactants, and a mechanism is proposed to account for the observed behaviour. Equilibrium constants for the NiII plus pteroylglutamic acid system, as well as activation parameters, are reported. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
7.
 Immunoaffinity techniques have been widely used for the determination of different analytes in the medical field. However the use of antibodies immobilized in an appropriate support material to preconcentrate pesticides from environmental samples is only recent. The production of antibodies, election of supports, antibody immobilization procedures, elution of analytes from immunosorbents and the more recent applications in the field of pesticide analysis are reviewed. The present review concludes that immunosorbents have great potential and discusses the present limitations and expected future trends. Received: 29 July 1996 / Accepted: 14 August 1996  相似文献   
8.
 A flow injection system was developed for the sequential determination of total nitrogen and phosphorus in digests of vegetables using potentiometric and spectrophotometric detection systems, respectively. A tubular ammonium selective electrode with a sensor system composed of nonactin/monactin in tris(2-ethylhexyl) phosphate was used. The selectivity limitations of this electrode were overcome by the inclusion of a gas-diffusion unit in the system that separated ammonium from the rest of the sample matrix and allowed the determination of total nitrogen and phosphorus by the partition of the sample plug between two streams. The results obtained with the developed FIA system were in good agreement with those of the reference methods. Sampling rates from 40 to 60 samples per hour and relative standard deviations below 3.5% were achieved. Received: 17 October 1996/Revised: 21 November 1996/Accepted: 27 November 1996  相似文献   
9.
10.
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