全文获取类型
收费全文 | 348篇 |
免费 | 26篇 |
专业分类
化学 | 332篇 |
晶体学 | 3篇 |
力学 | 1篇 |
数学 | 9篇 |
物理学 | 29篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 16篇 |
2019年 | 13篇 |
2018年 | 6篇 |
2017年 | 2篇 |
2016年 | 12篇 |
2015年 | 16篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 41篇 |
2011年 | 36篇 |
2010年 | 16篇 |
2009年 | 9篇 |
2008年 | 32篇 |
2007年 | 18篇 |
2006年 | 16篇 |
2005年 | 24篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1997年 | 5篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 5篇 |
1984年 | 2篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有374条查询结果,搜索用时 0 毫秒
371.
Xue‐Fang Yu Shohei Yamazaki Tetsuya Taketsugu 《Journal of computational chemistry》2012,33(20):1701-1708
Excited‐state double proton transfer (ESDPT) in the (3‐methyl‐7‐azaindole)‐(7‐azaindole) heterodimer is theoretically investigated by the long‐range corrected time‐dependent density functional theory method and the complete‐active‐space second‐order perturbation theory method. The calculated potential energy profiles exhibit a lower barrier for the concerted mechanism in the locally excited state than for the stepwise mechanism through the charge‐transfer state. This result suggests that the ESDPT in the isolated heterodimer is likely to follow the former mechanism, as has been exhibited for the ESDPT in the homodimer of 7‐azaindole. © 2012 Wiley Periodicals, Inc. 相似文献
372.
α-Alkylation of ketones with styrene derivatives was developed using a mesitylcopper-dppp complex as a soft Brønsted base catalyst. No waste derived from the alkylating reagent was produced in this catalytic alkylation reaction. The bisphosphine ligand structure, as well as the reaction solvent, had profound effects on catalyst activity. The reaction proceeded under mild conditions from a range of ketones and styrene derivatives. The present catalysis is especially useful for the selective mono-alkylation of ketones. 相似文献
373.
Shohei Inoue Takuzo Aida Hiroshi Sugimoto Chikara Kawamura Masakatsu Kuroki 《Macromolecular Symposia》1994,88(1):117-122
An organoaluminum compound with bulky phenoxide groups as a Lewis acid can accelerate much the living polymerization of alkylene oxide initiated with aluminum porphyrin by the coordinative activation of the monomer. This concept can be extented to the polymerization initiated with aluminum Schiff base and tetraazaannulene complexes. 相似文献
374.
Shohei Inoue Takuzo Aida Masashi Kinugawa Masanori Isoda Daisuke Takeuchi 《Macromolecular Symposia》1995,98(1):163-170
Metalloporphyrin initiator coupled with an appropriate organometallic Lewis acid catalyst could make possible the first example of living anionic polymerization of oxetane. Lewis acid built-in metalloporphyrins were designed as a new highly active catalyst/initiator system. The concept of monomer activation by Lewis acid was extended to the use of appropriate protonic acid. 相似文献