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   173篇
  免费   11篇
  国内免费   1篇
化学   84篇
晶体学   1篇
力学   27篇
数学   22篇
物理学   51篇
  2023年   1篇
  2022年   6篇
  2021年   16篇
  2020年   14篇
  2019年   11篇
  2018年   11篇
  2017年   7篇
  2016年   18篇
  2015年   15篇
  2014年   13篇
  2013年   12篇
  2012年   6篇
  2011年   16篇
  2010年   8篇
  2009年   3篇
  2008年   4篇
  2007年   1篇
  2006年   4篇
  2005年   4篇
  2004年   3篇
  2003年   3篇
  2000年   1篇
  1994年   1篇
  1993年   1篇
  1981年   2篇
  1979年   1篇
  1977年   1篇
  1976年   1篇
  1972年   1篇
排序方式: 共有185条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
Research on Chemical Intermediates - Chitosan functionalized by triacid imide has been applied as an effective catalyst for the synthesis of benzodiazepines by one-pot reactions of...  相似文献   
45.
Journal of Thermal Analysis and Calorimetry - In this paper, artificial neural networks (ANNs) are developed to predict the thermal conductivity ( $$k_{\text{nf}}$$ ) of multi-walled carbon...  相似文献   
46.
Neutral and cationic cyclopentadienone (CpO) N‐heterocyclic carbene (NHC) bis‐carbonyl iron(0) complexes bearing, appended to the NHC ligand, either a terminal amino group on the lateral chain, [Fe(η4‐CpO)(CO)2C‐NHC(CH2)nNH2)] with n = 2 ( 2a ) and 3 ( 2b ), or a cationic NMe3+ fragment, [Fe(η4‐CpO)(CO)2C‐NHC(CH2)2NMe3)](I) ( 3 ), were prepared and characterized in terms of their structure, stability and reactivity. The photochemical properties of 2a and 2b were examined both in organic solvents and in water, revealing the photoactivated release of one CO ligand followed by the formation of the chelated complex [Fe(η4‐CpO)(CO)(κ2C,N‐NHC(CH2)2NH2)] ( 4 ), whose molecular structure was confirmed by single crystal X‐ray diffraction studies. This metallacyclization occurs only in the case of 2a , with the ethylene spacer between NHC ring and NH2 group in the lateral chain, allowing the formation of a stable 6‐membered ring. On the other hand, 2b undergoes decomposition upon irradiation. The reactivity in aqueous solutions revealed the chemical speciation of the complexes at different pH and especially under physiological conditions (phosphate buffer solution at pH 7.4 and 37 °C). The lack of data on the biological properties of iron(0) complexes prompted us to preliminarily investigate their cytotoxicity against model cancer cells (AsPC‐1 and HPAF‐II), along with a determination of their lipophilicity.  相似文献   
47.
48.
KCC‐1/IL/Pd NPs can used as an excellent support for the synthesis of highly sparse homogeneous catalyst. KCC‐1 has high surface area that was functionalized with ionic liquid phase acting as the strong performers so that the Pd catalyst was well‐dispersed without aggregation on the framework of the KCC‐1/IL. This nano catalyst was specified by TGA, XRD, TEM, SEM, FT‐IR, and ICP. For reduction of 2‐nitroaniline and 4‐nitrophenol used from the KCC‐1/IL/Pd NPs as a green catalyst that showed excellent catalytic activities. Compared with the traditional substrate, KCC‐1 substantially increases protection and the accessibility of the nanoparticle sites due to its three dimensional hierarchical structure.  相似文献   
49.
50.
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