全文获取类型
收费全文 | 4513篇 |
免费 | 248篇 |
国内免费 | 583篇 |
专业分类
化学 | 33篇 |
力学 | 63篇 |
综合类 | 67篇 |
数学 | 4993篇 |
物理学 | 188篇 |
出版年
2024年 | 7篇 |
2023年 | 88篇 |
2022年 | 39篇 |
2021年 | 63篇 |
2020年 | 90篇 |
2019年 | 130篇 |
2018年 | 142篇 |
2017年 | 141篇 |
2016年 | 135篇 |
2015年 | 102篇 |
2014年 | 189篇 |
2013年 | 373篇 |
2012年 | 132篇 |
2011年 | 215篇 |
2010年 | 206篇 |
2009年 | 303篇 |
2008年 | 331篇 |
2007年 | 337篇 |
2006年 | 313篇 |
2005年 | 278篇 |
2004年 | 227篇 |
2003年 | 208篇 |
2002年 | 198篇 |
2001年 | 150篇 |
2000年 | 147篇 |
1999年 | 148篇 |
1998年 | 129篇 |
1997年 | 132篇 |
1996年 | 86篇 |
1995年 | 50篇 |
1994年 | 39篇 |
1993年 | 17篇 |
1992年 | 17篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 11篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 15篇 |
1984年 | 10篇 |
1983年 | 9篇 |
1982年 | 14篇 |
1981年 | 10篇 |
1980年 | 19篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1977年 | 8篇 |
1976年 | 5篇 |
1936年 | 3篇 |
排序方式: 共有5344条查询结果,搜索用时 234 毫秒
51.
Wengu Chen Yixin Lai 《分析论及其应用》2006,22(2):195-200
Let μ be a Borel measure on Rd which may be non doubling. The only condition that μ must satisfy is μ(Q) ≤ col(Q)n for any cube Q () Rd with sides parallel to the coordinate axes and for some fixed n with 0 < n ≤ d. The purpose of this paper is to obtain a boundedness property of fractional integrals in Hardy spaces H1 (μ). 相似文献
52.
A number of generalized metric spaces have been defined or characterized in terms of g-functions. Symmetric g-functions are discussed by C. Good, D. Jennings and A. M. Mohamad. In this paper, some questions about symmetric g-functions are answered, particularly it is shown that every sym-wg-space is expandable.
The project is supported by the NNSF (10571151) and NSF (2006J0397) of Fujian Province of China. 相似文献
53.
The generalized Morrey spaces are introduced under the hypothesis that Rn is endowed with the general parabolic metric , and the boundedness properties are established in generalized Morrey spaces for a class of singular integral operators, which include Calderon-Zygmund singular integrals and their commutators with BMO. 相似文献
54.
Antonio Jimé nez-Melado Claudio H. Morales 《Proceedings of the American Mathematical Society》2006,134(2):501-507
We show a fixed point theorem for condensing mappings under a new condition of the Leray-Schauder type. We call it the Interior Condition. We also discuss examples that demonstrate the independence of these two conditions.
55.
The aim of this article is to derive stable generalized sampling in a shift-invariant space by using some special dual frames in L2(0,1). These sampling formulas involve samples of filtered versions of the functions in the shift-invariant space. The involved samples are expressed as the frame coefficients of an appropriate function in L2(0,1) with respect to some particular frame in L2(0,1). Since any shift-invariant space with stable generator is the image of L2(0,1) by means of a bounded invertible operator, our generalized sampling is derived from some dual frame expansions in L2(0,1). 相似文献
56.
57.
58.
In this paper, we discuss the classical ill-posed problem of numerical differentiation, assuming that the smoothness of the function to be differentiated is unknown. Using recent results on adaptive regularization of general ill-posed problems, we propose new rules for the choice of the stepsize in the finite-difference methods, and for the regularization parameter choice in numerical differentiation regularized by the iterated Tikhonov method. These methods are shown to be effective for the differentiation of noisy functions, and the order-optimal convergence results for them are proved.
59.
Bin Han 《Advances in Computational Mathematics》2006,24(1-4):375-403
In this paper, we present a necessary and sufficient condition for the existence of solutions in a Sobolev space Wpk(ℝs) (1≤p≤∞) to a vector refinement equation with a general dilation matrix. The criterion is constructive and can be implemented.
Rate of convergence of vector cascade algorithms in a Sobolev space Wpk(ℝs) will be investigated. When the dilation matrix is isotropic, a characterization will be given for the Lp (1≤p≤∞) critical smoothness exponent of a refinable function vector without the assumption of stability on the refinable function
vector. As a consequence, we show that if a compactly supported function vector φ∈Lp(ℝs) (φ∈C(ℝs) when p=∞) satisfies a refinement equation with a finitely supported matrix mask, then all the components of φ must belong to a Lipschitz
space Lip(ν,Lp(ℝs)) for some ν>0. This paper generalizes the results in R.Q. Jia, K.S. Lau and D.X. Zhou (J. Fourier Anal. Appl. 7 (2001) 143–167)
in the univariate setting to the multivariate setting.
Dedicated to Professor Charles A. Micchelli on the occasion of his 60th birthday
Mathematics subject classifications (2000) 42C20, 41A25, 39B12.
Research was supported in part by the Natural Sciences and Engineering Research Council of Canada (NSERC Canada) under Grant
G121210654. 相似文献
60.
Banach空间二阶非线性脉冲微分-积分方程的极值解 总被引:1,自引:0,他引:1
通过建立一个新的比较定理研究了B anach空间二阶非线性混合型脉冲微分-积分方程初值问题的极值解,所得结果推广和改进了现有文献的主要结果. 相似文献