全文获取类型
收费全文 | 6646篇 |
免费 | 419篇 |
国内免费 | 694篇 |
专业分类
化学 | 300篇 |
力学 | 151篇 |
综合类 | 122篇 |
数学 | 5694篇 |
物理学 | 1492篇 |
出版年
2024年 | 12篇 |
2023年 | 74篇 |
2022年 | 104篇 |
2021年 | 114篇 |
2020年 | 117篇 |
2019年 | 184篇 |
2018年 | 191篇 |
2017年 | 219篇 |
2016年 | 172篇 |
2015年 | 134篇 |
2014年 | 227篇 |
2013年 | 977篇 |
2012年 | 222篇 |
2011年 | 297篇 |
2010年 | 275篇 |
2009年 | 356篇 |
2008年 | 457篇 |
2007年 | 429篇 |
2006年 | 403篇 |
2005年 | 332篇 |
2004年 | 332篇 |
2003年 | 316篇 |
2002年 | 308篇 |
2001年 | 222篇 |
2000年 | 226篇 |
1999年 | 186篇 |
1998年 | 165篇 |
1997年 | 194篇 |
1996年 | 106篇 |
1995年 | 78篇 |
1994年 | 47篇 |
1993年 | 40篇 |
1992年 | 36篇 |
1991年 | 31篇 |
1990年 | 21篇 |
1989年 | 29篇 |
1988年 | 18篇 |
1987年 | 11篇 |
1986年 | 19篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 4篇 |
1982年 | 11篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 5篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1936年 | 5篇 |
排序方式: 共有7759条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
《Discrete Mathematics》2020,343(2):111679
A path in an edge-colored graph is called monochromatic if any two edges on the path have the same color. For , an edge-colored graph is said to be monochromatic -edge-connected if every two distinct vertices of are connected by at least edge-disjoint monochromatic paths, and is said to be uniformly monochromatic -edge-connected if every two distinct vertices are connected by at least edge-disjoint monochromatic paths such that all edges of these paths are colored with a same color. We use and to denote the maximum number of colors that ensures to be monochromatic -edge-connected and, respectively, to be uniformly monochromatic -edge-connected. In this paper, we first conjecture that for any -edge-connected graph , , where is a minimum -edge-connected spanning subgraph of . We verify the conjecture for . We also prove the conjecture for and with . When is a minimal -edge-connected graph, we give an upper bound of , i.e., . For the uniformly monochromatic -edge-connectivity, we prove that for all , , where is a minimum -edge-connected spanning subgraph of . 相似文献
5.
In this paper, the deformation of the Heisenberg algebra, consistent with both the generalized uncertainty principle and doubly special relativity, has been analyzed. It has been observed that, though this algebra can give rise to fractional derivative terms in the corresponding quantum mechanical Hamiltonian, a formal meaning can be given to them by using the theory of harmonic extensions of function. Depending on this argument, the expression of the propagator of the path integral corresponding to the deformed Heisenberg algebra, has been obtained. In particular, the consistent expression of the one dimensional free particle propagator has been evaluated explicitly. With this propagator in hand, it has been shown that, even in free particle case, normal generalized uncertainty principle and doubly special relativity show very much different result. 相似文献
6.
Paul S. Wesson 《General Relativity and Gravitation》2003,35(1):111-119
Results from 5D induced-matter and membrane theory with null paths are extended to show that a particle obeys the 4D Klein-Gordon equation but with a variable mass. The Dirac equation also follows, but raises concerns about 4D quantization in the two natural 5D gauges, and reopens the question of a Regge-like trajectory for the spin angular momenta and squared masses of gravitationally-dominated systems. 相似文献
7.
Summary This paper is concerned with the problem of developing numerical integration algorithms for differential equations that, when
viewed as equations in some Euclidean space, naturally evolve on some embedded submanifold. It is desired to construct algorithms
whose iterates also evolve on the same manifold. These algorithms can therefore be viewed as integrating ordinary differential
equations on manifolds. The basic method “decouples” the computation of flows on the submanifold from the numerical integration
process. It is shown that two classes of single-step and multistep algorithms can be posed and analyzed theoretically, using
the concept of “freezing” the coefficients of differential operators obtained from the defining vector field. Explicit third-order
algorithms are derived, with additional equations augmenting those of their classical counterparts, obtained from “obstructions”
defined by nonvanishing Lie brackets. 相似文献
8.
Regis Guyonnet 《Journal of statistical physics》1991,65(1-2):269-289
The NMR properties of nuclei linked to long linear polymer molecules are sensitive to the influence of hard walls. In this context, the residual energy of tensorial spin-spin interactions is calculated using a path integral approach. Several thermodynamic quantities of the polymer system (free energy, equation of state,...) are also expressed, taking chain stiffness effects and the presence of two repulsive walls into consideration. 相似文献
9.
Algebra matrix and similarity classification of operators 总被引:1,自引:0,他引:1
ZHANG Zilong & LI Yucheng Department of Mathematics Hebei Normal University Shijiazhuang China 《中国科学A辑(英文版)》2006,49(3):398-409
In this paper, by the Gelfand representation theory and the Silov idempotents theorem, we first obtain a central decomposition theorem related to a unital semi-simple n-homogeneous Banach algebra, and then give a similarity classification of two strongly irreducible Cowen-Douglas operators using this theorem. 相似文献
10.
We give a coring version for the duality theorem for actions and coactions of a finitely generated projective Hopf algebra.
We also provide a coring analogue for a theorem of H.-J. Schneider, which generalizes and unifies the duality theorem for
finite Hopf algebras and its refinements.
This paper was written while the first author visited the Mathematics Departments of Syracuse University and California State
University Dominguez Hills. He would like to thank both departments for their hospitality. 相似文献