全文获取类型
收费全文 | 2211篇 |
免费 | 81篇 |
国内免费 | 30篇 |
专业分类
化学 | 1462篇 |
晶体学 | 11篇 |
力学 | 69篇 |
数学 | 490篇 |
物理学 | 290篇 |
出版年
2023年 | 11篇 |
2022年 | 19篇 |
2021年 | 40篇 |
2020年 | 38篇 |
2019年 | 44篇 |
2018年 | 31篇 |
2017年 | 33篇 |
2016年 | 63篇 |
2015年 | 54篇 |
2014年 | 51篇 |
2013年 | 129篇 |
2012年 | 113篇 |
2011年 | 128篇 |
2010年 | 122篇 |
2009年 | 84篇 |
2008年 | 133篇 |
2007年 | 149篇 |
2006年 | 149篇 |
2005年 | 141篇 |
2004年 | 127篇 |
2003年 | 98篇 |
2002年 | 91篇 |
2001年 | 46篇 |
2000年 | 29篇 |
1999年 | 29篇 |
1998年 | 23篇 |
1997年 | 22篇 |
1996年 | 28篇 |
1995年 | 9篇 |
1994年 | 17篇 |
1993年 | 21篇 |
1992年 | 10篇 |
1991年 | 22篇 |
1990年 | 13篇 |
1988年 | 17篇 |
1987年 | 6篇 |
1986年 | 13篇 |
1985年 | 7篇 |
1984年 | 7篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 14篇 |
1980年 | 9篇 |
1979年 | 17篇 |
1978年 | 12篇 |
1977年 | 13篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1974年 | 10篇 |
1973年 | 14篇 |
排序方式: 共有2322条查询结果,搜索用时 15 毫秒
1.
Mike R. Jeffrey 《Nonlinear dynamics》2015,81(4):1699-1716
2.
3.
Mathematical Notes - 相似文献
4.
Given a tree
with leaf set X, there are certain ways of arranging the elements of X in a circular order so that
can be embedded in the plane and ‘preserve’ this ordering. We investigate some new combinatorial properties of these ‘circular orderings.’ We then use these properties to establish two results concerning dissimilarity maps on X that are induced by edge-weighted trees with leaf set X. 相似文献
5.
We investigate the combinatorics of a topological space that is generated by the set of edge-weighted finite trees. This space arises by multiplying the weights of edges on paths in trees and is closely connected to tree reconstruction problems involving finite state Markov processes. We show that this space is a contractible finite CW-complex whose face poset can be described via a partial order on semilabelled forests. We then describe some combinatorial properties of this poset, showing that, for example, it is pure, thin and contractible. 相似文献
6.
Jean-Pierre Dedieu Gregorio Malajovich Mike Shub 《Foundations of Computational Mathematics》2005,5(2):145-171
We prove a linear bound on the average total curvature of the
central path of linear programming theory in terms of the number
of independent variables of the primal problem, and independent of
the number of constraints. 相似文献
7.
An efficient synthesis approach is developed which permits thecalculation of the steady-state frequency response of an assembly whichis comprised of linear components and nonlinear joints. Receptancematrices are used to characterize the linear components, which permitscondensation of the system to just the joint degrees-of-freedom.Furthermore, the calculated nonlinear joint forces are then used tostudy the power flow in the assembly, as well as detailed dynamicbehavior within the components. Integrated into the technique is acontinuation scheme which permits efficient parametric studies. 相似文献
8.
The many facets of linear programming 总被引:1,自引:0,他引:1
Michael J. Todd 《Mathematical Programming》2002,91(3):417-436
We examine the history of linear programming from computational, geometric, and complexity points of view, looking at simplex,
ellipsoid, interior-point, and other methods.
Received: June 22, 2000 / Accepted: April 4, 2001?Published online October 2, 2001 相似文献
9.
We study the tangent space at a monomial point M in the Hilbert scheme that parameterizes all ideals with the same Hilbert function as M over an exterior algebra. 相似文献
10.
Exterior tomographic data are taken over lines outside a central region, and such data occur in the industrial nondestructive evaluation of large objects such as rockets. We explain, using microlocal analysis, which singularities are well reconstructed from exterior data, and we explain how this phenomenon is reflected in the singular value decomposition for the exterior transform [E.T. Quinto, Singular value decompositions and inversion methods for the exterior Radon transform and a spherical transform, J. Math. Anal. Appl. 95 (1983) 437–448]. We extend Lambda Tomography to exterior data and to limited angle exterior data. The algorithm is tested on industrial data from Perceptics, Inc. 相似文献