全文获取类型
收费全文 | 264篇 |
免费 | 0篇 |
国内免费 | 2篇 |
专业分类
化学 | 32篇 |
力学 | 14篇 |
数学 | 70篇 |
物理学 | 150篇 |
出版年
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 2篇 |
2013年 | 8篇 |
2012年 | 7篇 |
2011年 | 13篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 14篇 |
2005年 | 19篇 |
2004年 | 16篇 |
2003年 | 14篇 |
2002年 | 16篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1992年 | 10篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1985年 | 3篇 |
1983年 | 2篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有266条查询结果,搜索用时 15 毫秒
131.
We experimentally demonstrate image transmission through a noninstantaneous self-focusing medium. A partially spatially incoherent soliton is used to form a multimode waveguide in a photorefractive crystal, and the modes of that waveguide are used to transmit an incoherent image through this nonlinear medium. 相似文献
132.
We present a theory of self-focusing and solitons in photorefractive InP, including the previously unexplained intensity resonance and the resonant enhancement of the space-charge field. 相似文献
133.
We report on new fundamental phenomena in soliton interactions: delayed-action interaction and "spin"-orbit coupling upon collision between two-dimensional composite solitons carrying topological charges. 相似文献
134.
Directional coupler with soliton-induced waveguides 总被引:6,自引:0,他引:6
We demonstrate a directional coupler that employs two waveguides induced by two mutually incoherent photorefractive solitons propagating in parallel at close proximity. Efficient coupling from one waveguide to the other is achieved for probe beams at wavelengths much longer than that of the solitons. We study the mutual coupling as a function of distance between solitons. 相似文献
135.
Hybrid-based molecular orbitals are constructed for puckered cyclobutane, and used subsequently in a configurational-interaction process. The bent-bond structure, diagonal interaction and excited states of the molecule are discussed. 相似文献
136.
We study the optimal distance in networks, l(opt), defined as the length of the path minimizing the total weight, in the presence of disorder. Disorder is introduced by assigning random weights to the links or nodes. For strong disorder, where the maximal weight along the path dominates the sum, we find that l(opt) approximately N(1/3) in both Erdos-Rényi (ER) and Watts-Strogatz (WS) networks. For scale-free (SF) networks, with degree distribution P(k) approximately k(-lambda), we find that l(opt) scales as N((lambda-3)/(lambda-1)) for 3 or =4. Thus, for these networks, the small-world nature is destroyed. For 2相似文献
137.
138.
Coskun TH Christodoulides DN Kim YR Chen Z Soljacic M Segev M 《Physical review letters》2000,84(11):2374-2377
We present the first observation of incoherent antidark spatial solitons in noninstantaneous nonlinear media. This new class of soliton states involves bright solitons on a partially incoherent background of infinite extent. In the case where the nonlinearity is of the Kerr type, their existence is demonstrated analytically by means of an exact solution. Computer simulations and experiments indicate that these incoherent antidark solitons can propagate in a stable fashion provided that the spatial coherence of their background is reduced below the incoherent modulation instability threshold. 相似文献
139.
This work presents a formulation of Cauchy's flux theory of continuum mechanics in the framework of geometric integration theory as formulated by H. Whitney and extended recently by J. Harrison. Starting with convex polygons, one constructs a formal vector space of polyhedral chains. A Banach space of chains is obtained by a completion process of this vector space with respect to a norm. Then, integration operators, cochains, are defined as elements of the dual space to the space of chains. Thus, the approach links the analytical properties of cochains with the corresponding properties of the domains in an optimal way. The basic representation theorem shows that cochains may be represented by forms. The form representing a cochain is a geometric analog of a flux field in continuum mechanics. 相似文献
140.
As a sequel to a recent work we consider the generalized stress concentration factor, a purely geometric property of a body
that for the various loadings indicates the ratio between the maximum of the optimal stress and maximum of the loading fields.
The optimal stress concentration factor pertains to a stress field that satisfies the principle of virtual work and for which
the stress concentration factor is minimal. Unlike the previous work, we require that the external loading be equilibrated
and that the stress field be a symmetric tensor field. 相似文献