全文获取类型
收费全文 | 3776篇 |
免费 | 137篇 |
国内免费 | 331篇 |
专业分类
化学 | 277篇 |
力学 | 124篇 |
综合类 | 31篇 |
数学 | 3327篇 |
物理学 | 485篇 |
出版年
2024年 | 3篇 |
2023年 | 54篇 |
2022年 | 51篇 |
2021年 | 51篇 |
2020年 | 100篇 |
2019年 | 99篇 |
2018年 | 98篇 |
2017年 | 85篇 |
2016年 | 113篇 |
2015年 | 72篇 |
2014年 | 167篇 |
2013年 | 359篇 |
2012年 | 109篇 |
2011年 | 227篇 |
2010年 | 185篇 |
2009年 | 261篇 |
2008年 | 253篇 |
2007年 | 248篇 |
2006年 | 212篇 |
2005年 | 191篇 |
2004年 | 151篇 |
2003年 | 173篇 |
2002年 | 144篇 |
2001年 | 126篇 |
2000年 | 129篇 |
1999年 | 129篇 |
1998年 | 100篇 |
1997年 | 90篇 |
1996年 | 65篇 |
1995年 | 45篇 |
1994年 | 28篇 |
1993年 | 18篇 |
1992年 | 11篇 |
1991年 | 10篇 |
1990年 | 9篇 |
1989年 | 14篇 |
1988年 | 5篇 |
1987年 | 11篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1936年 | 2篇 |
排序方式: 共有4244条查询结果,搜索用时 437 毫秒
21.
In this paper, space adaptivity is introduced to control the error in the numerical solution of hyperbolic systems of conservation laws. The reference numerical scheme is a new version of the discontinuous Galerkin method, which uses an implicit diffusive term in the direction of the streamlines, for stability purposes. The decision whether to refine or to unrefine the grid in a certain location is taken according to the magnitude of wavelet coefficients, which are indicators of local smoothness of the numerical solution. Numerical solutions of the nonlinear Euler equations illustrate the efficiency of the method. 相似文献
22.
混合位级正交试验设计的极差分析方法 总被引:3,自引:0,他引:3
本文指出,在混合位级的正交试验设计中,以往的极差分析方法存在着不足。本文给出了极差的修正方法,并用大量实例做了数值验证,说明这个修正确实很有效 相似文献
23.
A generalization of strong regularity around a vertex subset C of a graph Γ, which makes sense even if Γis non-regular, is studied. Such a structure appears, together with a kind of distance-regularity around C , when an spectral bound concerning the so-called predistance polynomial of C is attained. As a main consequence of these results, it is shown that a regular (connected) graph Γwith d + 1 distinct eigenvalues is distance-regular, and its distance- d graph Γ d is strongly regular with parameters a = c , if and only if the number of vertices at distance d from each vertex satisfies an expression which depends only on the order of Γand the different eigenvalues of Γ. 相似文献
24.
S. V. Tyshkevich 《Mathematical Notes》2007,81(5-6):851-853
25.
Let P(G,λ) be the chromatic polynomial of a graph G with n vertices, independence number α and clique number ω. We show that for every λ≥n, ()α≤≤ ()
n
−ω. We characterize the graphs that yield the lower bound or the upper bound.?These results give new bounds on the mean colour
number μ(G) of G: n− (n−ω)()
n
−ω≤μ(G)≤n−α() α.
Received: December 12, 2000 / Accepted: October 18, 2001?Published online February 14, 2002 相似文献
26.
Yafang Gong 《分析论及其应用》2006,22(4):329-338
Based on Bernstein's Theorem, Kalandia's Lemma describes the error estimate and the smoothness of the remainder under the second part of Hoelder norm when a HSlder function is approximated by its best polynomial approximation. In this paper, Kalandia's Lemma is generalized to the cases that the best polynomial is replaced by one of its four kinds of Chebyshev polynomial expansions, the error estimates of the remainder are given out under Hoeder norm or the weighted HSlder norms. 相似文献
27.
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
28.
Linear complexity and linear complexity profile are important characteristics of a sequence for applications in cryptography
and Monte-Carlo methods.
The nonlinear congruential method is an attractive alternative to the classical linear congruential method for pseudorandom
number generation.
Recently, a weak lower bound on the linear complexity profile of a general nonlinear congruential pseudorandom number generator
was proven by Gutierrez, Shparlinski and the first author. For most nonlinear generators a much stronger lower bound is expected.
Here, we obtain a much stronger lower bound on the linear complexity profile of nonlinear congruential pseudorandom number
generators with Dickson polynomials. 相似文献
29.
On interpolatory divergence-free wavelets 总被引:1,自引:0,他引:1
We construct interpolating divergence-free multiwavelets based on cubic Hermite splines. We give characterizations of the relevant function spaces and indicate their use for analyzing experimental data of incompressible flow fields. We also show that the standard interpolatory wavelets, based on the Deslauriers-Dubuc interpolatory scheme or on interpolatory splines, cannot be used to construct compactly supported divergence-free interpolatory wavelets.
30.