全文获取类型
收费全文 | 16095篇 |
免费 | 1231篇 |
国内免费 | 1513篇 |
学科分类
数理化 | 18839篇 |
出版年
2024年 | 20篇 |
2023年 | 136篇 |
2022年 | 174篇 |
2021年 | 200篇 |
2020年 | 329篇 |
2019年 | 369篇 |
2018年 | 348篇 |
2017年 | 448篇 |
2016年 | 467篇 |
2015年 | 367篇 |
2014年 | 696篇 |
2013年 | 1323篇 |
2012年 | 722篇 |
2011年 | 872篇 |
2010年 | 812篇 |
2009年 | 1058篇 |
2008年 | 1126篇 |
2007年 | 1137篇 |
2006年 | 953篇 |
2005年 | 886篇 |
2004年 | 760篇 |
2003年 | 774篇 |
2002年 | 628篇 |
2001年 | 506篇 |
2000年 | 495篇 |
1999年 | 477篇 |
1998年 | 438篇 |
1997年 | 411篇 |
1996年 | 307篇 |
1995年 | 199篇 |
1994年 | 186篇 |
1993年 | 150篇 |
1992年 | 133篇 |
1991年 | 120篇 |
1990年 | 88篇 |
1989年 | 72篇 |
1988年 | 63篇 |
1987年 | 50篇 |
1986年 | 44篇 |
1985年 | 77篇 |
1984年 | 54篇 |
1983年 | 41篇 |
1982年 | 54篇 |
1981年 | 59篇 |
1980年 | 35篇 |
1979年 | 42篇 |
1978年 | 47篇 |
1977年 | 28篇 |
1976年 | 23篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
利用Liapunov函数方法,结合积分不等式技巧,分析了时滞细胞神经网络的平衡点存在的唯一性和全局指数稳定性,保证时滞细胞神经网络全局指数稳定的一个新的充分判据被得到.所得判据比已有文献具有更少的限制,为实际应用提供了方便. 相似文献
92.
Dirichlet boundary value problems for perturbed second-order differential equations on a half line are investigated in this paper. The methods mainly depend on the calculus of variations to the classical functionals. Sufficient conditions are obtained for the existence of the solutions. 相似文献
93.
Anatoliy Malyarenko 《Journal of Theoretical Probability》2006,19(2):263-288
We prove a general functional limit theorem for multiparameter fractional Brownian motion. The functional law of the iterated
logarithm, functional Lévy’s modulus of continuity and many other results are its particular cases. Applications to approximation
theory are discussed.
相似文献
94.
The understanding of mesoscopic transport has now attained an ultimate simplicity. Indeed, orthodox quantum kinetics would seem to say little about mesoscopics that has not been revealed — nearly effortlessly — by more popular means. Such is far from the case, however. The fact that kinetic theory remains very much in charge is best appreciated through the physics of a quantum point contact. While discretization of its conductance is viewed as the exclusive result of coherent, single-electron-wave transmission, this does not begin to address the paramount feature of all metallic conduction: dissipation. A perfect quantum point contact still has finite resistance, so its ballistic carriers must dissipate the energy gained from the applied field. How do they manage that? The key is in standard many-body quantum theory, and its conservation principles. 相似文献
95.
Liang-gen Hu 《应用数学学报(英文版)》2007,23(2):281-288
In this paper,we will establish several strong convergence theorems for the approximation ofcommon fixed points of r-strictly asymptotically pseudocontractive mappings in uniformly convex Banachspaces using the modiied implicit iteration sequence with errors,and prove the necessary and sufficient conditionsfor the convergence of the sequence.Our results generalize,extend and improve the recent work,in thistopic. 相似文献
96.
In this paper we prove existence results for semilinear neutral functional differential inclusions with finite or infinite
delay in Banach spaces. Our theory makes use of analytic semigroups and fractional powers of closed operators, integrated
semigroups and cosine families.
相似文献
97.
We prove that, for any given vertex ν* in a series-parallel graph G, its edge set can be partitioned into κ = min{κ′(G) + 1, δ(G)} subsets such that each subset covers all the vertices of G possibly except for ν*, where δ(G) is the minimum degree of G and κ′(G) is the edge-connectivity of G. In addition, we show that the results in this paper are best possible and a polynomial time algorithm can be obtained for
actually finding such a partition by our proof. 相似文献
98.
LI Cun YANG Bai-Feng CAI Hao HUANG Nian-Ning 《理论物理通讯》2006,46(2):244-248
One of the basic problems about the inverse scattering transform for solving a completely integrable nonlinear evolutions equation is to demonstrate that the Jost solutions obtained from the inverse scattering equations of Cauchy integral satisfy the Lax equations. Such a basic problem still exists in the procedure of deriving the dark soliton solutions of the NLS equation in normal dispersion with non-vanishing boundary conditions through the inverse scattering transform. In this paper, a pair of Jost solutions with same analytic properties are composed to be a 2 × 2 matrix and then another pair are introduced to be its right inverse confirmed by the Liouville theorem. As they are both 2 × 2 matrices, the right inverse should be the left inverse too, based upon which it is not difficult to show that these Jost solutions satisfy both the first and second Lax equations. As a result of compatibility condition, the dark soliton solutions definitely satisfy the NLS equation in normal dispersion with non-vanishing boundary conditions. 相似文献
99.
John A. Ryan 《Discrete Applied Mathematics》2006,154(2):399-412
We consider irreducible Goppa codes over Fq of length qn defined by polynomials of degree r, where q is a prime power and n,r are arbitrary positive integers. We obtain an upper bound on the number of such codes. 相似文献
100.
Heinz H. Bauschke 《Proceedings of the American Mathematical Society》2007,135(1):135-139
Recently, S. Reich and S. Simons provided a novel proof of the Kirszbraun-Valentine extension theorem using Fenchel duality and Fitzpatrick functions. In the same spirit, we provide a new proof of an extension result for firmly nonexpansive mappings with an optimally localized range.