全文获取类型
收费全文 | 2902篇 |
免费 | 248篇 |
国内免费 | 270篇 |
专业分类
化学 | 96篇 |
晶体学 | 1篇 |
力学 | 145篇 |
综合类 | 19篇 |
数学 | 2398篇 |
物理学 | 761篇 |
出版年
2024年 | 1篇 |
2023年 | 32篇 |
2022年 | 20篇 |
2021年 | 43篇 |
2020年 | 75篇 |
2019年 | 81篇 |
2018年 | 85篇 |
2017年 | 84篇 |
2016年 | 70篇 |
2015年 | 72篇 |
2014年 | 119篇 |
2013年 | 432篇 |
2012年 | 94篇 |
2011年 | 124篇 |
2010年 | 124篇 |
2009年 | 181篇 |
2008年 | 230篇 |
2007年 | 182篇 |
2006年 | 159篇 |
2005年 | 156篇 |
2004年 | 149篇 |
2003年 | 147篇 |
2002年 | 140篇 |
2001年 | 88篇 |
2000年 | 126篇 |
1999年 | 66篇 |
1998年 | 90篇 |
1997年 | 73篇 |
1996年 | 36篇 |
1995年 | 30篇 |
1994年 | 15篇 |
1993年 | 21篇 |
1992年 | 13篇 |
1991年 | 2篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 11篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1974年 | 2篇 |
1936年 | 3篇 |
排序方式: 共有3420条查询结果,搜索用时 187 毫秒
1.
2.
3.
4.
6.
We study locally conformal symplectic (LCS) structures of the second kind on a Lie algebra. We show a method to construct new examples of Lie algebras admitting LCS structures of the second kind starting with a lower dimensional Lie algebra endowed with a LCS structure and a suitable extension. Moreover, we characterize all LCS Lie algebras obtained with our construction. Finally, we study the existence of lattices in the associated simply connected Lie groups in order to obtain compact examples of manifolds admitting this kind of structure. 相似文献
7.
《Physics letters. A》2020,384(17):126349
We consider the quantization procedure and investigate the application of the quantizer–dequantizer method and star-product technique to construct associative products and the associative algebras formed by the quantizer–dequantizer operators and their symbols. The corresponding Lie algebras are also constructed. We study the case where the quantizer–dequantizer operators form a self-dual system and show that the structure constants of the Lie algebras satisfy some identity, in addition to the Jacobi identity. Using tomographic quantizer–dequantizer operators and their symbols, we construct the continuous associative algebra and the corresponding Lie algebra. 相似文献
8.
9.
We classify all Leibniz conformal algebras of rank two. 相似文献
10.
Victor García Jesús Sánchez-Márquez Estefanía Torres David Zorrilla Manuel Fernández 《International journal of quantum chemistry》2020,120(6):e26129
As part of previous studies, we introduced a new type of basis function named Simplified Box Orbitals (SBOs) that belong to a class of spatially restricted functions which allow the zero differential overlap (ZDO) approximation to be applied with complete accuracy. The original SBOs and their Gaussian expansions SBO-3G form a minimal basis set, which was compared to the standard Slater-type orbital basis set (STO-3G). In the present paper, we have developed the SBO basis functions at double-zeta (DZ) level, and we have assessed the option of expanding the SBO-DZ as a combination of Gaussian functions. Finally, we have determined the quality of the new basis set by comparing the molecular properties calculated with SBO-nG with those achieved with some standard basis sets. 相似文献