全文获取类型
收费全文 | 586篇 |
免费 | 40篇 |
国内免费 | 59篇 |
专业分类
化学 | 52篇 |
晶体学 | 1篇 |
力学 | 105篇 |
综合类 | 15篇 |
数学 | 347篇 |
物理学 | 165篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 13篇 |
2021年 | 19篇 |
2020年 | 12篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 20篇 |
2016年 | 23篇 |
2015年 | 12篇 |
2014年 | 22篇 |
2013年 | 41篇 |
2012年 | 28篇 |
2011年 | 33篇 |
2010年 | 20篇 |
2009年 | 33篇 |
2008年 | 45篇 |
2007年 | 35篇 |
2006年 | 33篇 |
2005年 | 31篇 |
2004年 | 35篇 |
2003年 | 23篇 |
2002年 | 22篇 |
2001年 | 26篇 |
2000年 | 24篇 |
1999年 | 15篇 |
1998年 | 24篇 |
1997年 | 14篇 |
1996年 | 11篇 |
1995年 | 8篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
排序方式: 共有685条查询结果,搜索用时 31 毫秒
211.
Nicolae Anghel 《Proceedings of the American Mathematical Society》1996,124(11):3555-3561
In this paper we address the problem of generic vanishing for (negative) harmonic spinors of Dirac operators coupled with variable metric connections.
212.
Rui Loja Fernandes 《Advances in Mathematics》2002,170(1):119-179
We extend the notion of connection in order to study singular geometric structures, namely, we consider a notion of connection on a Lie algebroid which is a natural extension of the usual concept of a covariant connection. It allows us to define holonomy of the orbit foliation of a Lie algebroid and prove a Stability Theorem. We also introduce secondary or exotic characteristic classes, thus providing invariants which generalize the modular class of a Lie algebroid. 相似文献
213.
Victor P. Palamodov 《Acta Appl Math》2002,74(1):57-70
The Maxwell system in inhomogeneous medium as well as the elasticity system are considered. We give a sharp form to the conservation laws of geometrical optics in the terms of the distribution theory. We show that the conservation laws keep to hold through any singular point of the wave front. 相似文献
214.
A. M. Matveeva 《Russian Mathematics (Iz VUZ)》2008,52(7):66-70
We study the geometry of affine and normal connections induced by a complete normalization of mutually orthogonal distributions $ \mathcal{M} We study the geometry of affine and normal connections induced by a complete normalization of mutually orthogonal distributions
and in conformal space C
n
, where is a distribution of hyperplane elements, and is a distribution of line elements. We consider invariant fields of pencils that are parallel with respect to the normal
connection along any curve belonging to the distribution .
Original Russian Text ? A.M. Matveeva, 2008, published in Izvestiya Vysshikh Uchebnykh Zavedenii. Matematika, 2008, No. 7,
pp. 79–84. 相似文献
215.
We study the properties of real realizations of holomorphic linear connections over associative commutative algebras \(\mathbb{A}\) m with unity. The following statements are proved.If a holomorphic linear connection ? on M n over \(\mathbb{A}\) m (m ≥ 2) is torsion-free and R ≠ 0, then the dimension over ? of the Lie algebra of all affine vector fields of the space (M mn ? , ??) is no greater than (mn)2 ? 2mn + 5, where m = dim? \(\mathbb{A}\), \(n = dim_\mathbb{A} \) M n , and ?? is the real realization of the connection ?.Let ?? =1 ? ×2 ? be the real realization of a holomorphic linear connection ? over the algebra of double numbers. If the Weyl tensor W = 0 and the components of the curvature tensor 1 R ≠ 0, 2 R ≠ 0, then the Lie algebra of infinitesimal affine transformations of the space (M 2n ? , ??) is isomorphic to the direct sum of the Lie algebras of infinitesimal affine transformations of the spaces ( a M n , a ?) (a = 1, 2). 相似文献
216.
T. N. Glukhova 《Russian Mathematics (Iz VUZ)》2008,52(6):70-74
We find two normal connections induced by the normal framing of a hypersurface V n ? 1 in the conformal space C n , and establish relationship between these connections and a Weyl connection which is also induced by the normal framing of V n ? 1. We study two normal connections induced by a complete framing of a hypersurface V n ? 1 in C n . We establish relationship between geometries of a framed hypersurface V n ? 1 of the conformal space C n and a quadratic hyperband of the projective space P n + 1 associated with V n ? 1. 相似文献
217.
Erkan Nane 《Transactions of the American Mathematical Society》2008,360(5):2681-2692
We introduce a class of stochastic processes based on symmetric -stable processes, for . These are obtained by taking Markov processes and replacing the time parameter with the modulus of a symmetric -stable process. We call them -time processes. They generalize Brownian time processes studied in Allouba and Zheng (2001), Allouba (2002), (2003), and they introduce new interesting examples. We establish the connection of -time processes to some higher order PDE's for rational. We also obtain the PDE connection of subordinate killed Brownian motion in bounded domains of regular boundary.
218.
本文研究了容有半对称度量联络的广义复空间中的子流形上的Chen-Ricci不等式.利用代数技巧,建立了子流形上的Chen-Ricci不等式.这些不等式给出了子流形的外在几何量-关于半对称联络的平均曲率与内在几何量-Ricci曲率及k-Ricci曲率之间的关系,推广了Mihai和Özgür的一些结果. 相似文献
219.
Juan de Dios Pérez 《Mathematische Nachrichten》2016,289(17-18):2263-2272
We consider real hypersurfaces M in complex projective space equipped with both the Levi–Civita and generalized Tanaka–Webster connections and classify them when the covariant derivatives associated with both connections, either in the direction of the structure vector field or any direction of the maximal holomorphic distribution, coincide when applying to the Riemannian curvature tensor of the real hypersurface. 相似文献
220.
《Mathematische Nachrichten》2017,290(14-15):2170-2184
The main goal of this article is to construct some geometric invariants for the topology of the set of flat connections on a principal G‐bundle . Although the characteristic classes of principal bundles are trivial when , their classical Chern–Weil construction can still be exploited to define a homomorphism from the set of homology classes of maps to the cohomology group , where S is null‐cobordant ‐manifold, once a G‐invariant polynomial p of degree r on is fixed. For , this gives a homomorphism . The map is shown to be globally gauge invariant and furthermore it descends to the moduli space of flat connections , modulo cohomology with integer coefficients. The construction is also adapted to complex manifolds. In this case, one works with the set of connections with vanishing (0, 2)‐part of the curvature, and the Dolbeault cohomology. Some examples and applications are presented. 相似文献