全文获取类型
收费全文 | 2134篇 |
免费 | 143篇 |
国内免费 | 295篇 |
专业分类
化学 | 26篇 |
力学 | 79篇 |
综合类 | 70篇 |
数学 | 2309篇 |
物理学 | 88篇 |
出版年
2024年 | 2篇 |
2023年 | 17篇 |
2022年 | 28篇 |
2021年 | 19篇 |
2020年 | 50篇 |
2019年 | 48篇 |
2018年 | 55篇 |
2017年 | 68篇 |
2016年 | 72篇 |
2015年 | 34篇 |
2014年 | 67篇 |
2013年 | 154篇 |
2012年 | 101篇 |
2011年 | 105篇 |
2010年 | 110篇 |
2009年 | 135篇 |
2008年 | 155篇 |
2007年 | 146篇 |
2006年 | 130篇 |
2005年 | 127篇 |
2004年 | 75篇 |
2003年 | 136篇 |
2002年 | 102篇 |
2001年 | 83篇 |
2000年 | 82篇 |
1999年 | 90篇 |
1998年 | 56篇 |
1997年 | 60篇 |
1996年 | 44篇 |
1995年 | 30篇 |
1994年 | 26篇 |
1993年 | 18篇 |
1992年 | 21篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 8篇 |
1988年 | 5篇 |
1987年 | 3篇 |
1986年 | 8篇 |
1985年 | 6篇 |
1984年 | 10篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1977年 | 8篇 |
1973年 | 3篇 |
排序方式: 共有2572条查询结果,搜索用时 8 毫秒
201.
For linear statistical ill-posed problems in Hilbert spaces we introduce an adaptive procedure to recover the unknown solution from indirect discrete and noisy data. This procedure is shown to be order optimal for a large class of problems. Smoothness of the solution is measured in terms of general source conditions. The concept of operator monotone functions turns out to be an important tool for the analysis.
202.
铝合金材料剪切断裂实验分析 总被引:4,自引:1,他引:4
金属材料受载作用发生断裂,断裂面形式有拉断,剪断和拉剪混合型,由于剪断过程中塑性变形较为复杂,问题的研究难度大,观点争论多,本文对LY12-M铝合金材料复合型平面应变载荷状态下的几种断裂试验结果作了分析,认为在II型,近II型时发生的剪切型断裂,启裂点在裂尖附近应力三维度取最大值处,剪断的开裂方向则与启裂点上最大剪应力方向有关,同时对LC9R超强铝合金作常规破坏试验,该材料在拉伸,扭转与压缩试验时均呈剪切断裂,断裂面沿最大剪应力方位,破坏剪应力随试件应力三维度的降低而增大,综合分析试验结果得到了一些有用的结论。 相似文献
203.
Jürgen Eichenauer-Herrmann 《Journal of Computational and Applied Mathematics》1992,40(3):345-349
The inversive congruential method for generating uniform pseudorandom numbers is a particularly attractive alternative to linear congruential generators with their well-known inherent deficiencies like the unfavourable coarse lattice structure in higher dimensions. In the present paper the modulus in the inversive congruential method is chosen as a power of an arbitrary odd prime. The existence of inversive congruential generators with maximal period length is proved by a new constructive characterization of these generators. 相似文献
204.
Noam Elkies Greg Kuperberg Michael Larsen James Propp 《Journal of Algebraic Combinatorics》1992,1(3):219-234
We continue the study of the family of planar regions dubbed Aztec diamonds in our earlier article and study the ways in which these regions can be tiled by dominoes. Two more proofs of the main formula are given. The first uses the representation theory of GL(n). The second is more combinatorial and produces a generating function that gives not only the number of domino tilings of the Aztec diamond of order n but also information about the orientation of the dominoes (vertical versus horizontal) and the accessibility of one tiling from another by means of local modifications. Lastly, we explore a connection between the combinatorial objects studied in this paper and the square-ice model studied by Lieb. 相似文献
205.
Monotone Chemical Reaction Networks 总被引:2,自引:1,他引:2
Patrick De Leenheer David Angeli Eduardo D. Sontag 《Journal of mathematical chemistry》2007,41(3):295-314
We analyze certain chemical reaction networks and show that every solution converges to some steady state. The reaction kinetics
are assumed to be monotone but otherwise arbitrary. When diffusion effects are taken into account, the conclusions remain
unchanged. The main tools used in our analysis come from the theory of monotone dynamical systems. We review some of the features
of this theory and provide a self-contained proof of a particular attractivity result which is used in proving our main result. 相似文献
206.
Jia Ming Shen Jianhua 《Annals of Differential Equations》2006,22(4):496-501
By using upper and lower solutions coupled with monotone iterative technique, we discuss the anti-periodic boundary value problem for first order functional diffenertial equation. A sufficient condition for the existence of the solution is obtained. 相似文献
207.
在实自反Banach空间,用补偿方法研究单调和Fuzzy单调广义非线性变分不等式,得到了几个解的存在性定理.改进和推广了Browder,Pascali-Sburlan,Zhang等人的各种结果. 相似文献
208.
In this paper, some new iterative schemes for approximating the common element of the set of fixed points of strongly relatively nonexpansive mappings and the set of zero points of maximal monotone operators in a real uniformly smooth and uniformly convex Banach space are proposed. Some weak convergence theorems are obtained, which extend and complement some previous work. 相似文献
209.
A determinantal expansion due to Okada is used to derive both a deformation of Weyl's denominator formula for the Lie algebra sp(2n) of the symplectic group and a further generalisation involving a product of the deformed denominator with a deformation of flagged characters of sp(2n). In each case the relevant expansion is expressed in terms of certain shifted sp(2n)-standard tableaux. It is then re-expressed, first in terms of monotone patterns and then in terms of alternating sign matrices. 相似文献
210.
对于1r∞与巴拿哈空间B=L~r(Ω,F,μ),我们研究了欧几里得空间R~n上B-值缓分布构成的哈代-洛伦茨空间H~(p,q)(R~n,B)及哈代-洛伦茨空间之间的内插,其中0p∞和0q≤∞,获得了H~(p,q)(R~n,B)的一系列等价的刻画及其原子分解.若Ω={1},则H~(p,q)(R~n,B)=H~(p,q)(R~n)是经典的情形;若Ω=Z是整数集且μ是Z上的计数测度并且r=2,0p∞及q=∞,则H~(p,q)(R~n,B)=H~(p,∞)(R~n,e~2)转化为Grafakos和He在文[Weak Hardy spaces,Preprint,2014]中讨论的情形. 相似文献