全文获取类型
收费全文 | 1508篇 |
免费 | 37篇 |
国内免费 | 12篇 |
专业分类
化学 | 914篇 |
晶体学 | 6篇 |
力学 | 43篇 |
数学 | 246篇 |
物理学 | 348篇 |
出版年
2023年 | 9篇 |
2022年 | 13篇 |
2021年 | 13篇 |
2020年 | 27篇 |
2019年 | 29篇 |
2018年 | 18篇 |
2017年 | 10篇 |
2016年 | 27篇 |
2015年 | 25篇 |
2014年 | 29篇 |
2013年 | 67篇 |
2012年 | 57篇 |
2011年 | 76篇 |
2010年 | 50篇 |
2009年 | 44篇 |
2008年 | 67篇 |
2007年 | 66篇 |
2006年 | 72篇 |
2005年 | 76篇 |
2004年 | 63篇 |
2003年 | 62篇 |
2002年 | 42篇 |
2001年 | 20篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 15篇 |
1997年 | 8篇 |
1996年 | 14篇 |
1995年 | 8篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 13篇 |
1989年 | 8篇 |
1985年 | 27篇 |
1984年 | 21篇 |
1983年 | 19篇 |
1982年 | 35篇 |
1981年 | 33篇 |
1980年 | 20篇 |
1979年 | 11篇 |
1978年 | 18篇 |
1977年 | 9篇 |
1976年 | 16篇 |
1975年 | 15篇 |
1974年 | 15篇 |
1973年 | 13篇 |
1971年 | 8篇 |
1965年 | 9篇 |
排序方式: 共有1557条查询结果,搜索用时 15 毫秒
1.
Leo Liebermann 《Fresenius' Journal of Analytical Chemistry》1883,22(1):232-233
Ohne Zusammenfassung 相似文献
2.
Stefano De Leo 《International Journal of Theoretical Physics》1996,35(9):1821-1837
We derive an appropriate definition of transpose for quaternionic matrices and give a new panoramic review of the quaternionic groups. We aim to analyze possible quaternionic groups for GUTs. 相似文献
3.
4.
B. Savo P. Romano A. Nigro R. Di Leo 《Physica C: Superconductivity and its Applications》2002,370(4):275-280
The flat voltage noise component of current biased, high-transparency Nb/AlOx/Nb superconducting tunnel junctions has been investigated at frequencies up to 70 kHz. Several aspects of the analyzed phenomena suggest the presence of current noise effects induced by the discreteness of the charge carriers. At subgap voltages, where excess currents occur, a behavior coherent with a multiple Andreev reflection-assisted transport through the tunnel barrier has been found. However, the measured charge values exceed any theoretical prediction. 相似文献
5.
Monica-Gabriela Cojocaru Leo B. Jonker 《Proceedings of the American Mathematical Society》2004,132(1):183-193
We prove existence and uniqueness of integral curves to the (discontinuous) vector field that results when a Lipschitz continuous vector field on a Hilbert space of any dimension is projected on a non-empty, closed and convex subset.
6.
An approach called Schramm–Loewner evolution (SLE) provides a new method for dealing with a wide variety of scale-invariant problems in two dimensions. This approach is based upon an older method called Loewner Evolution (LE), which connects analytic and geometrical constructions in the complex plane. In this paper, the bases of LE and SLE are described and some simple applications are discussed in relatively non-technical form. A bibliography of the subject is presented. 相似文献
7.
8.
Leo Brewin 《General Relativity and Gravitation》2007,39(4):521-528
We show by an almost elementary calculation that the ADM mass of an asymptotically flat space can be computed as a limit involving
a rate of change of area of a closed 2-surface. The result is essentially the same as that given by David Brown and York (Phys.
Rev. D 55, 1977–1984 1997; Phys. Rev. D 47, 1407–1419 1993). We will prove this result in two ways, first by direct calculation from the original formula as given by
Arnowitt, Deser and Misner and second as a corollary of an earlier result by Brewin for the case of simplicial spaces. 相似文献
9.
10.
2,6- and 2,7-Dimethylanthracenes were reduced seriatim with lithium in liquid ammonia and lithium in methylamine to their 1,4,5,8,9,10-hexahydro derivatives. Two-fold epoxidation of these tetraenes provided the cis and trans diepoxides resulting from electrophilic attack at the inner double bonds. Trans diepoxide 1 has the very unusual characteristic of lacking a σ plane of symmetry but possessing an inversion center. As a consequence, the 1H NMR spectrum of C1-symmetric 1 is simplified relative to those of its isomers 5, 9, and 10. 相似文献