全文获取类型
收费全文 | 419篇 |
免费 | 13篇 |
专业分类
化学 | 276篇 |
晶体学 | 2篇 |
力学 | 7篇 |
数学 | 27篇 |
物理学 | 120篇 |
出版年
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 12篇 |
2011年 | 18篇 |
2010年 | 11篇 |
2009年 | 5篇 |
2008年 | 19篇 |
2007年 | 10篇 |
2006年 | 9篇 |
2005年 | 18篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 15篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1997年 | 5篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1993年 | 7篇 |
1992年 | 10篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 10篇 |
1981年 | 4篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 14篇 |
1977年 | 5篇 |
1976年 | 11篇 |
1975年 | 8篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1972年 | 4篇 |
1971年 | 5篇 |
1968年 | 7篇 |
1967年 | 4篇 |
1966年 | 4篇 |
1965年 | 6篇 |
1962年 | 6篇 |
排序方式: 共有432条查询结果,搜索用时 15 毫秒
431.
Peter A. Macdonald Dr. Sumanta Banerjee Dr. Alan R. Kennedy Dr. Alexander van Teijlingen Dr. Stuart D. Robertson Prof. Tell Tuttle Prof. Robert E. Mulvey 《Angewandte Chemie (International ed. in English)》2023,62(27):e202304966
Catalytic reduction of a representative set of imines, both aldimines and ketimines, to amines has been studied using transfer hydrogenation from 1,4-dicyclohexadiene. Unusually, this has been achieved using s-block pre-catalysts, namely 1-metallo-2-tert-butyl-1,2-dihydropyridines, 2-tBuC5H5NM, M(tBuDHP), where M=Li–Cs. Reactions have been monitored in C6D6 and tetrahydrofuran-d8 (THF-d8). A definite trend is observed in catalyst efficiency with the heavier alkali metal tBuDHPs outperforming the lighter congeners. In general, Cs(tBuDHP) is the optimal pre-catalyst with, in the best cases, reactions producing quantitative yields of amines in minutes at room temperature using 5 mol % catalyst. Supporting the experimental study, Density Functional Theory (DFT) calculations have also been carried out which reveal that Cs has a pathway with a significantly lower rate determining step than the Li congener. In the postulated initiation pathways DHP can act as either a base or as a surrogate hydride. 相似文献
432.
Dr. Luis Lanzetta Thomas Webb Dr. Jose Manuel Marin-Beloqui Dr. Thomas J. Macdonald Prof. Saif A. Haque 《Angewandte Chemie (International ed. in English)》2023,62(8):e202213966
Tin halide perovskites (Sn HaPs) are the top lead-free choice for perovskite optoelectronics, but the oxidation of perovskite Sn2+ to Sn4+ remains a key challenge. However, the role of inconspicuous chemical processes remains underexplored. Specifically, the halide component in Sn HaPs (typically iodide) has been shown to play a key role in dictating device performance and stability due to its high reactivity. Here we describe the impact of native halide chemistry on Sn HaPs. Specifically, molecular halogen formation in Sn HaPs and its influence on degradation is reviewed, emphasising the benefits of iodide substitution for improving stability. Next, the ecological impact of halide products of Sn HaP degradation and its mitigation are considered. The development of visible Sn HaP emitters via halide tuning is also summarised. Lastly, halide defect management and interfacial engineering for Sn HaP devices are discussed. These insights will inspire efficient and robust Sn HaP optoelectronics. 相似文献