全文获取类型
收费全文 | 720篇 |
免费 | 20篇 |
国内免费 | 49篇 |
专业分类
化学 | 19篇 |
力学 | 63篇 |
数学 | 601篇 |
物理学 | 106篇 |
出版年
2023年 | 7篇 |
2022年 | 3篇 |
2021年 | 8篇 |
2020年 | 10篇 |
2019年 | 19篇 |
2018年 | 16篇 |
2017年 | 13篇 |
2016年 | 8篇 |
2015年 | 16篇 |
2014年 | 39篇 |
2013年 | 80篇 |
2012年 | 29篇 |
2011年 | 39篇 |
2010年 | 37篇 |
2009年 | 71篇 |
2008年 | 70篇 |
2007年 | 53篇 |
2006年 | 48篇 |
2005年 | 30篇 |
2004年 | 31篇 |
2003年 | 14篇 |
2002年 | 19篇 |
2001年 | 21篇 |
2000年 | 15篇 |
1999年 | 13篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 12篇 |
1995年 | 15篇 |
1994年 | 9篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1984年 | 1篇 |
1982年 | 2篇 |
排序方式: 共有789条查询结果,搜索用时 15 毫秒
31.
We show that a hyperbolic chaos can be observed in resonantly coupled oscillators near a Hopf bifurcation, described by normal-form-type equations for complex amplitudes. The simplest example consists of four oscillators, comprising two alternatively activated, due to an external periodic modulation, pairs. In terms of the stroboscopic Poincaré map, the phase differences change according to an expanding Bernoulli map that depends on the coupling type. Several examples of hyperbolic chaos for different types of coupling are illustrated numerically. 相似文献
32.
Popp and Yan [F.A. Popp, Y. Yan, Phys. Lett. A 293 (2002) 93] proposed a model for delayed luminescence based on a single time-dependent coherent state. We show that the general solution of their model corresponds to a luminescence that is a linear function of time. Therefore, their model is not compatible with experimental delayed luminescence. Moreover, the functions that they use to describe the oscillatory behaviour of delayed luminescence are not solutions of the coupling equations to be solved. 相似文献
33.
In this note we show how to include low order terms in the C∞ well-posedness results for weakly hyperbolic equations with analytic time-dependent coefficients. This is achieved by doing a different reduction to a system from the previously used one. We find the Levi conditions such that the C∞ well-posedness continues to hold. 相似文献
34.
35.
José A. Gálvez Antonio Martínez José L. Teruel 《Journal of Mathematical Analysis and Applications》2014
The paper deals with the study of complete embedded flat surfaces in H3 with a finite number of isolated singularities. We give a detailed information about its topology, conformal type and metric properties. We show how to solve the generalized Weyl?s problem of realizing isometrically any complete flat metric with Euclidean singularities in H3 which gives the existence of complete embedded flat surfaces with a finite arbitrary number of isolated singularities. 相似文献
36.
David Ariza-Ruiz Chong Li Genaro López-Acedo 《Journal of Mathematical Analysis and Applications》2014
We give a direct proof of Schauder's fixed point theorem in the setting of geodesic metric spaces, generalizing the classical Schauder's theorem and improving a recent version of this theorem in CAT(κ) spaces. As an application we prove an existence result for a variational inequality in the setting of CAT(κ) spaces. 相似文献
37.
We show that every finite volume hyperbolic manifold of dimension greater than or equal to 3 is stable under rescaled Ricci flow, i.e. that every small perturbation of the hyperbolic metric flows back to the hyperbolic metric again. Note that we do not need to make any decay assumptions on this perturbation. 相似文献
38.
39.
Inna Bumagina 《Geometriae Dedicata》2004,106(1):211-230
A group is said to be Hopfian if every surjective endomorphism of the group is injective. We show that finitely generated subgroups of torsion-free hyperbolic groups are Hopfian. Our proof generalizes a theorem of Sela (Topology
35 (2) 1999, 301–321). 相似文献
40.