全文获取类型
收费全文 | 237篇 |
免费 | 23篇 |
国内免费 | 1篇 |
专业分类
化学 | 212篇 |
晶体学 | 13篇 |
力学 | 2篇 |
数学 | 6篇 |
物理学 | 28篇 |
出版年
2024年 | 1篇 |
2023年 | 5篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 23篇 |
2018年 | 16篇 |
2017年 | 6篇 |
2016年 | 16篇 |
2015年 | 13篇 |
2014年 | 7篇 |
2013年 | 6篇 |
2012年 | 15篇 |
2011年 | 22篇 |
2010年 | 13篇 |
2009年 | 7篇 |
2008年 | 15篇 |
2007年 | 6篇 |
2006年 | 7篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 12篇 |
2000年 | 3篇 |
1999年 | 10篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 2篇 |
1994年 | 1篇 |
排序方式: 共有261条查询结果,搜索用时 0 毫秒
21.
The heme peroxidase-catalyzed iodination of human angiotensins I and II is described. It is observed that lactoperoxidase (LPO) can effectively and selectively iodinate the tyrosyl residues in angiotensin peptides. The thiourea/thiouracil-based peroxidase inhibitors effectively inhibit the iodination reactions, indicating that iodination is an enzymatic reaction and the mechanism of iodination is similar to that of peroxidase-catalyzed iodination of thyroglobulin. This study also shows that the monoiodo Ang I is a better substrate for the angiotensin converting enzyme than the native peptide. 相似文献
22.
A series of optically active cyclic trans-β-amido alcohols were obtained by the non-enzymatic kinetic resolution of the corresponding racemic amido alcohols using commercially available (S)-BINAP and NCS by SN2 halogenation of the hydroxy group. The product, cis-β-amido chloride, was also obtained in optically active form with an inversion of stereochemistry. 相似文献
23.
24.
25.
26.
27.
28.
The electronic structure of silicon carbide with increasing germanium content have been examined using first principles calculations based on density functional theory. The structural stability is analysed between two different phases, namely, cubic zinc blende and hexagonal phases. The zinc blende structure is found to be the stable one for all the Si1-xGexC semiconducting carbides at normal pressure. Effect of substitution of Ge for Si in SiC on electronic and mechanical properties is studied. It is observed that cubic SiC is a semiconductor with the band gap value 1.243?eV. The band gap value of SiC is increased due to the substitution of Ge and the band gap values of Si 0.75 Ge 0.25 C, Si 0.50 Ge 0.50 C, Si 0.25 Ge 0.75 C and GeC are 1.322 eV, 1.413 eV, 1.574 eV and 1.657?eV respectively. As the pressure is increased, it is found that the energy gap gets decreased for Si1-x GexC (X?=?0, 0.25, 0.50, 0.75, 1). The elastic constants satisfy the Born – Huang elastic stability criteria. The bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio are also calculated and compared with the other available results. 相似文献
29.
Journal of Solid State Electrochemistry - Nanostructured electrode materials for supercapacitors have attracted research interest due to their high power density and long cycle life. Herein, porous... 相似文献
30.
A series of optically active cyclic trans-β-aryloxy alcohols have been obtained by non-enzymatic kinetic resolution of the corresponding racemic aryloxy cyclic alcohols using commercially available (S)-BINAP and NCS by SN2 halogenation of a hydroxy group. The product, cis-β-aryloxy chlorides, was also obtained in optically active form with inversion of the stereochemistry. 相似文献