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   697篇
  免费   27篇
  国内免费   1篇
化学   502篇
晶体学   4篇
力学   21篇
数学   62篇
物理学   136篇
  2023年   6篇
  2022年   5篇
  2021年   27篇
  2020年   14篇
  2019年   22篇
  2018年   13篇
  2017年   15篇
  2016年   37篇
  2015年   25篇
  2014年   25篇
  2013年   52篇
  2012年   31篇
  2011年   41篇
  2010年   30篇
  2009年   34篇
  2008年   54篇
  2007年   35篇
  2006年   39篇
  2005年   23篇
  2004年   23篇
  2003年   16篇
  2002年   16篇
  2001年   8篇
  2000年   5篇
  1999年   9篇
  1998年   4篇
  1997年   12篇
  1996年   4篇
  1995年   6篇
  1994年   5篇
  1993年   4篇
  1992年   3篇
  1990年   5篇
  1989年   3篇
  1988年   4篇
  1984年   2篇
  1982年   2篇
  1981年   4篇
  1980年   4篇
  1978年   4篇
  1977年   6篇
  1976年   7篇
  1975年   6篇
  1974年   4篇
  1973年   5篇
  1972年   3篇
  1971年   4篇
  1970年   2篇
  1969年   3篇
  1967年   2篇
排序方式: 共有725条查询结果,搜索用时 156 毫秒
721.
722.
2‐(3‐Methyl‐1,3‐diazabuten‐1‐yl)‐3‐ethoxycarbonylthiophenes are phosphorylated with phosphorus(III) halides in basic media at position 5 of the thiophene ring. Up to three heteroaromatic substituents can be introduced one by one at the same phosphorus atom. On this basis, mono‐, bis‐, and trishetaryl substituted P(III) and P(V) derivatives have been obtained. Phosphorylated 2‐(N,N‐dimethylformamidino)‐3‐ethoxycarbonylthiophenes provide a synthetic access to phosphorylated thienopyrimidines. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:641–651, 2001  相似文献   
723.
The reaction of phosphorus tribromide with phenylhydrazones of heterocyclic aldehydes leads to formation of a new phosphorus‐containing heterocyclic system—heterocondensed 1,2,3‐diazaphosphorines. Properties of the phosphorus‐containing heterocyclic compounds that have been synthesized are described. © 2001 John Wiley & Sons, Inc. Heteroatom Chem 12:658–664, 2001  相似文献   
724.
Interest in Cd complexes has been growing in recent years. Cd complexes are considered a potential solution in the search for novel antibiotics that can fight antimicrobial resistance. In addition, Cd complexes draw attention to material chemistry. The main objective of this work was to prepare the first Cd(II) complexes with anionic forms of pyridine-based thiazolyl hydrazone (THs) ligands HLS2 [(E)-4-(4-methoxyphenyl)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)thiazole] and HLS3 [(E)-2-(2-[pyridine-2-ylmethylene]hydrazinyl)-4-(p-tolyl)thiazole] and perform their structural and spectroscopic characterization, as well as stability in solution and upon heating. Studies related to their biological activities and possible electrochromic applications are also being conducted. Complexes [Cd(HLS2)2] ( 1 ) and [Cd(HLS3)2] ( 2 ) have been characterized by a single-crystal X-ray diffraction and computational analysis of intermolecular interactions responsible for their solid-state structures was performed. Thermal stability of 1 and 2 in the solid-state was analyzed by TGA/MS, where as their solution stability was determined by the spectrophotometric titration method. Electrochemical and in situ UV–Vis spectroelectrochemical analyses of 1 and 2 were carried out to determine redox mechanisms and the influence of the substituents and electrolytes on their redox responses. The antioxidant capacity of both complexes was tested in antioxidant assays, while their antimicrobial activity was tested against five Gram-positive and four Gram-negative bacteria, as well as against three fungi. The obtained results indicate their potent antioxidant capacity. The antimicrobial activity of investigated compounds on almost all tested bacterial strains was stronger than that of the standard antibiotic erythromycin. The results of docking studies indicate that the minor groove DNA is the possible biological target of 1 and 2 .  相似文献   
725.
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