全文获取类型
收费全文 | 2228篇 |
免费 | 210篇 |
国内免费 | 213篇 |
专业分类
化学 | 280篇 |
晶体学 | 2篇 |
力学 | 111篇 |
综合类 | 75篇 |
数学 | 1838篇 |
物理学 | 345篇 |
出版年
2024年 | 6篇 |
2023年 | 22篇 |
2022年 | 39篇 |
2021年 | 39篇 |
2020年 | 51篇 |
2019年 | 60篇 |
2018年 | 76篇 |
2017年 | 52篇 |
2016年 | 68篇 |
2015年 | 53篇 |
2014年 | 84篇 |
2013年 | 163篇 |
2012年 | 85篇 |
2011年 | 99篇 |
2010年 | 105篇 |
2009年 | 121篇 |
2008年 | 137篇 |
2007年 | 155篇 |
2006年 | 149篇 |
2005年 | 147篇 |
2004年 | 124篇 |
2003年 | 119篇 |
2002年 | 115篇 |
2001年 | 80篇 |
2000年 | 80篇 |
1999年 | 85篇 |
1998年 | 75篇 |
1997年 | 61篇 |
1996年 | 34篇 |
1995年 | 23篇 |
1994年 | 22篇 |
1993年 | 18篇 |
1992年 | 15篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 12篇 |
1988年 | 7篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1959年 | 1篇 |
排序方式: 共有2651条查询结果,搜索用时 15 毫秒
91.
In a Hilbert space, there exists a natural correspondence between continuous projections and particular pairs of closed subspaces.
In this paper, we generalize this situation and associate to a symmetric lattice L a subset P(L) of L× L, called its projection poset. If L is the lattice of closed subspaces of a topological vector space then elements of P(L) correspond to continuous projections and we prove that automorphisms of P(L) are determined by automorphisms of the lattice L when this lattice satisfies some basic properties of lattices of closed subspaces.
Primary: 06C15, Secondary: 03G12 81P10. 相似文献
92.
The Doss trick is employed to find solutions of Schrüdinger equations on symmetric spaces of compact type. The potentials and initial conditions are taken from an algebra of functions which admit an holomorphic extension to the complexification of the considered symmetric spaces. 相似文献
93.
Energy conservation of numerical integrators is well understood for symplectic one-step methods. This article provides new insight into energy conservation with non-symplectic methods. Sufficient conditions and counter-examples are presented.
AMS subject classification (2000) 65L06, 65P10, 37J99.Submitted June 2004. Accepted October 2004. Communicated by Syvert Nørsett. 相似文献
94.
We have constructed a class of plane symmetric macro models in Barber's second self-creation theory, when the source of the gravitational field is a macro matter field representing perfect fluid and satisfying the gamma-law equation of state p=(-1), where =4/3 and 3/2. The solutions of the field equations are derived and their physical aspects are studied. 相似文献
95.
Yu. B. Orochko 《Functional Analysis and Its Applications》2004,38(2):125-132
Let H be the minimal symmetric operator in L
2() generated by the differential expression (-1)
n
(c(x)f
(n))(n), n 1, with a real coefficient c(x) that has countably many zeros without finite accumulation points and is infinitely smooth at all points x with c(x) 0. We study the value Def H of the deficiency indices of H. It is shown that DefH=+ if infinitely many zeros of c(x) have multiplicities p satisfying the inequality n – 1/2 < p < 2n – 1/2. Our second result pertains to the case in which the set of zeros of c(x) is bounded neither above nor below. Under this condition, Def H = 0 provided that the multiplicity of each zero is greater than or equal to 2n – 1/2. The multiplicities of zeros of c(x) are understood in the paper in a broader sense than in the standard definition. 相似文献
96.
New classes of domains with explicit Bergman kernel 总被引:9,自引:1,他引:8
Roos GUY 《中国科学A辑(英文版)》2004,47(3):352-371
We introduce two classes of egg type domains, built on general bounded sym-metric domains, for which we obtain the Bergman kernel in explicit formulas. As an aux-iliary tool, we compute the integral of complex powers of the generic norm on a boundedsymmetric domains using the well-known integral of Selberg. This generalizes matrix in-tegrals of Hua and leads to a special polynomial with integer or half-integer coefficientsattached to each irreducible bounded symmetric domain. 相似文献
97.
Two-Parametric Compound Binomial Approximations 总被引:1,自引:0,他引:1
We consider two-parametric compound binomial approximation of the generalized Poisson binomial distribution. We show that the accuracy of approximation essentially depends on the symmetry or shifting of distributions and construct asymptotic expansions. For the proofs, we combine the properties of norms with the results for convolutions of symmetric and shifted distributions. In the lattice case, we use the characteristic function method. In the case of almost binomial approximation, we apply Steins method.__________Published in Lietuvos Matematikos Rinkinys, Vol. 44, No. 4, pp. 443–466, October–December, 2004. 相似文献
98.
99.
Enrico Leuzinger 《Proceedings of the American Mathematical Society》2004,132(3):919-927
Let be a noncompact semisimple Lie group and an arbitrary discrete, torsion-free subgroup of . Let be the bottom of the spectrum of the Laplace-Beltrami operator on the locally symmetric space , and let be the exponent of growth of . If has rank , then these quantities are related by a well-known formula due to Elstrodt, Patterson, Sullivan and Corlette. In this note we generalize that relation to the higher rank case by estimating from above and below by quadratic polynomials in . As an application we prove a rigiditiy property of lattices.
100.
L. Ya. Vulakh 《Transactions of the American Mathematical Society》2004,356(6):2325-2348
Multi-dimensional continued fractions associated with are introduced and applied to find systems of fundamental units in some families of totally real fields and fields with signature (2,1).