全文获取类型
收费全文 | 346篇 |
免费 | 20篇 |
专业分类
化学 | 230篇 |
晶体学 | 1篇 |
力学 | 4篇 |
数学 | 47篇 |
物理学 | 84篇 |
出版年
2023年 | 10篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 10篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 5篇 |
2016年 | 14篇 |
2015年 | 14篇 |
2014年 | 7篇 |
2013年 | 5篇 |
2012年 | 11篇 |
2011年 | 19篇 |
2010年 | 21篇 |
2009年 | 14篇 |
2008年 | 22篇 |
2007年 | 22篇 |
2006年 | 10篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 19篇 |
2002年 | 17篇 |
2001年 | 16篇 |
2000年 | 8篇 |
1999年 | 2篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 4篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1986年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 2篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1913年 | 1篇 |
排序方式: 共有366条查询结果,搜索用时 18 毫秒
31.
Uwe Klingebiel Stefan Schmatz Eike Gellermann Christian Drost Mathias Noltemeyer 《Monatshefte für Chemie / Chemical Monthly》2001,40(5):1105-1124
This review describes the synthesis and isomerization reactions of cyclic silylhydrazines. Topics of discussion are the ring
expansion of the three-membered Si(SiN2) to the four-membered (SiN)2 ring by lithiation of the (SiN2) ring and by thermal silyl group insertion into the N*N bond, the ring expansion of a three-membered (SiN2) to a five-membered (CSi2N2) ring by SiCH2 insertion into the Si*N bond, the formation of isomeric four- and six-membered (SiN2)2 rings, the synthesis of five- and six-membered silylhydrazine rings, and the expansion of a five-membered (N2Si2N)N ring to the isomeric six-membered (SiNN)2 ring. The mechanisms of the isomerizations are explained by quantum chemical calculations, and the results are verified by
crystal structure determinations. 相似文献
32.
33.
Eike Lau 《Inventiones Mathematicae》2008,171(3):617-628
Over p-adic Nagata rings, formal p-divisible groups are classified by nilpotent displays according to T. Zink. We extend this result to arbitrary p-adic rings. The proof uses the Grothendieck–Illusie deformation theory of truncated p-divisible groups. 相似文献
34.
35.
Based on continuous methodical advances and developments, solid-state NMR spectroscopy has become a powerful tool for the
investigation of various materials, including polymers, glasses, zeolites, fullerenes, and many others. During the past decade,
solid-state NMR spectroscopy also found increasing interest for the study of biomolecules. For example, membrane proteins
reconstituted into lipid environments such as bilayers or vesicles, protein aggregates such as amyloid fibrils, as well as
carbohydrates can now be studied by solid-state NMR spectroscopy. This review briefly introduces the principles of solid-state
NMR spectroscopy and highlights novel methodical trends. Selected applications demonstrate the possibilities of solid-state
NMR spectroscopy as a valuable bioanalytical tool. 相似文献
36.
Reaction of imidazole derivatives with 2,3-di(bromomethyl)pyrazine results in the formation of the new pyrazine-bridged diimidazolium salts 1-8. These salts proved to be valuable precursors for dinuclear complexes with mixed NHC/pyrazine ligands. Two of the pyrazine-bridged diimidazolium salts 3·H2O and 8·2H2O have been characterized by X-ray diffraction. Furthermore, the first catalytic studies with mixtures of palladium acetate and the imidazolium salts have been carried out. The in situ prepared palladium complexes derived from the diimidazolium salts 1-8 exhibit a modest catalytic activity in Heck-type coupling reactions between 4-bromo benzaldehyde and styrene or n-butyl acrylate. 相似文献
37.
Recent theoretical and experimental progress on nanolasers is reviewed with a focus on the emission properties of devices operating with a few or even an individual semiconductor quantum dot as a gain medium. Concepts underlying the design and operation of these devices, microscopic models describing light‐matter interaction and semiconductor effects, as well as recent experimental results and lasing signatures are discussed. In particular, a critical review of the “self‐tuned gain” mechanism which gives rise to quantum‐dot mode coupling in the off‐resonant case is provided. Furthermore recent advances in the modeling of single quantum dot lasers beyond the artificial atom model are presented with a focus on the exploration of similarities and differences between the atomic and semiconductor systems. 相似文献
38.
39.
40.
Kleinert J. Hannemann S. Eike B. Eisenbarth U. Grieser M. Grimm R. Gwinner G. Karpuk S. Saathoff G. Schramm U. Schwalm D. Weidemüller M. 《Hyperfine Interactions》2003,146(1-4):189-195
Hyperfine Interactions - We review recent experiments at the Heidelberg Test Storage Ring which apply advanced laser cooling techniques to stored ion beams. Very high phase-space densities are... 相似文献