全文获取类型
收费全文 | 10005篇 |
免费 | 543篇 |
国内免费 | 842篇 |
专业分类
化学 | 1339篇 |
晶体学 | 11篇 |
力学 | 513篇 |
综合类 | 88篇 |
数学 | 7875篇 |
物理学 | 1564篇 |
出版年
2023年 | 101篇 |
2022年 | 80篇 |
2021年 | 104篇 |
2020年 | 201篇 |
2019年 | 219篇 |
2018年 | 240篇 |
2017年 | 257篇 |
2016年 | 287篇 |
2015年 | 207篇 |
2014年 | 422篇 |
2013年 | 713篇 |
2012年 | 401篇 |
2011年 | 471篇 |
2010年 | 427篇 |
2009年 | 633篇 |
2008年 | 742篇 |
2007年 | 657篇 |
2006年 | 607篇 |
2005年 | 548篇 |
2004年 | 405篇 |
2003年 | 454篇 |
2002年 | 420篇 |
2001年 | 310篇 |
2000年 | 315篇 |
1999年 | 313篇 |
1998年 | 262篇 |
1997年 | 267篇 |
1996年 | 143篇 |
1995年 | 136篇 |
1994年 | 111篇 |
1993年 | 84篇 |
1992年 | 66篇 |
1991年 | 69篇 |
1990年 | 72篇 |
1989年 | 56篇 |
1988年 | 59篇 |
1987年 | 44篇 |
1986年 | 43篇 |
1985年 | 55篇 |
1984年 | 61篇 |
1983年 | 19篇 |
1982年 | 36篇 |
1981年 | 35篇 |
1980年 | 38篇 |
1979年 | 29篇 |
1978年 | 35篇 |
1977年 | 41篇 |
1976年 | 26篇 |
1974年 | 14篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
41.
对于周期函数f(x)按不同的周期展开对应不同的Fourier级数,这些表面上不同的式子是否一致引起了人们的注意[1],[2].本文应用Parseval等式给出一个关于这种唯一性的简单证明,并把这一种性质推广到高维情况的多重Fourier级数. 相似文献
42.
Manfred Sommer 《Constructive Approximation》2006,23(2):211-227
Hermite interpolation of 2n + k data by spline spaces of order k with n variable knots counting multiplicities is studied.
A characterization of the minimal spline spaces which admit a solution of the interpolation problem is obtained. A sufficient
condition on uniqueness of interpolating spline functions is given. 相似文献
43.
44.
In this paper, we consider questions related to the structure of inverse matrices of linear bounded operators acting in infinite-dimensional complex Banach spaces. We obtain specific estimates of elements of inverse matrices for bounded operators whose matrices have a special structure. Matrices are introduced as special operator-valued functions on an index set. The matrix structure is described by the behavior of the given function on elements of a special partition of the index set. The method used for deriving the estimates is based on an analysis of Fourier series of strongly continuous periodic functions. 相似文献
45.
Robert J. Rubin 《Journal of statistical physics》1991,65(5-6):1207-1216
A one-dimensional lattice random walk in the presence ofm equally spaced traps is considered. The step length distribution is a symmetric exponential. An explicit analytic expression is obtained for the probability that the random walk will be trapped at thejth trapping site. 相似文献
46.
In this paper, we establish two general theorems for equivalence between the Meir–Keeler type contractive conditions and the contractive definitions involving gauge functions. One of these theorems is an extension of a recent result of Lim (On characterization of Meir–Keeler contractive maps, Nonlinear Anal. 46 (2001) 113–120). 相似文献
47.
Characterizations of the containment of a convex set either in an arbitrary convex set or in the complement of a finite union
of convex sets (i.e., the set, described by reverse-convex inequalities) are given. These characterizations provide ways of
verifying the containments either by comparing their corresponding dual cones or by checking the consistency of suitable associated
systems. The convex sets considered in this paper are the solution sets of an arbitrary number of convex inequalities, which
can be either weak or strict inequalities. Particular cases of dual characterizations of set containments have played key
roles in solving large scale knowledge-based data classification problems where they are used to describe the containments
as inequality constraints in optimization problems. The idea of evenly convex set (intersection of open half spaces), which
was introduced by W. Fenchel in 1952, is used to derive the dual conditions, characterizing the set containments. 相似文献
48.
Steen Ryom-Hansen 《Journal of Algebraic Combinatorics》2006,23(1):5-20
We generalize Soergel's tilting algorithm to singular weights and deduce from this the validity of the Lascoux-Leclerc-Thibon
conjecture on the connection between the canonical basis of the basic submodule of the Fock module and the representation
theory of the Hecke-algebras at root of unity.
Supported in part by Programa Reticulados y Ecuaciones and by FONDECYT grant 1051024. 相似文献
49.
T. Nakamura 《The European Physical Journal A - Hadrons and Nuclei》2002,13(1-2):33-37
We present the recent experimental results on the 6He structure studied by the 6Li(t, 3He)6He reaction at 336 MeV. Above the conspicuous peaks for ground and first excited states for 6He, we have observed a broad structures at E
x∼ 5 MeV, and E
x∼ 15 MeV. The angular distribution of this structure exhibits the dominance of a ΔL = 1 transition, indicating the existence of intruder dipole states at low excitation energies in 6He. A slight admixture of positive-parity states in this structure has been indicated as well.
Received: 1 May 2001 / Accepted: 4 December 2001 相似文献
50.
Hui Ping Zhang 《数学学报(英文版)》2006,22(3):945-950
In this paper, we first define a kind of pseudo–distance function and annulus domain on Riemann surfaces, then prove the Hadamard
Theorem and the Borel–Carathéodory Theorem on any Riemann surfaces.
Supported by NSFC 10501052 相似文献