全文获取类型
收费全文 | 1203篇 |
免费 | 427篇 |
国内免费 | 38篇 |
专业分类
化学 | 13篇 |
晶体学 | 3篇 |
力学 | 51篇 |
综合类 | 13篇 |
数学 | 295篇 |
物理学 | 1293篇 |
出版年
2024年 | 1篇 |
2023年 | 11篇 |
2022年 | 21篇 |
2021年 | 35篇 |
2020年 | 52篇 |
2019年 | 34篇 |
2018年 | 31篇 |
2017年 | 29篇 |
2016年 | 41篇 |
2015年 | 17篇 |
2014年 | 73篇 |
2013年 | 80篇 |
2012年 | 72篇 |
2011年 | 105篇 |
2010年 | 113篇 |
2009年 | 86篇 |
2008年 | 105篇 |
2007年 | 99篇 |
2006年 | 93篇 |
2005年 | 82篇 |
2004年 | 72篇 |
2003年 | 66篇 |
2002年 | 71篇 |
2001年 | 63篇 |
2000年 | 33篇 |
1999年 | 26篇 |
1998年 | 38篇 |
1997年 | 32篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有1668条查询结果,搜索用时 62 毫秒
991.
The governing equation of the dust fluid with non-thermal ions and
variable dust charge on dust particles in hot dust plasmas is
obtained. Both the compressive and rarefactive waves in this
system are investigated. They can be determined by plasma
parameters including the temperatures of dust fluid, ions and
electrons, as well as the non-thermal parameter of ions, and the
number densities of the dust particles, the ions and the
electrons, etc. 相似文献
992.
With the aid of an improved projective approach and a linear variable separation method,new types of variable separation solutions (including solitary wave solutions,periodic wave solutions,and rational function solutions)with arbitrary functions for (2 1)-dimensional Korteweg-de Vries system are derived.Usually,in terms of solitary wave solutions and rational function solutions,one can find some important localized excitations.However,based on the derived periodic wave solution in this paper,we find that some novel and significant localized coherent excitations such as dromions,peakons,stochastic fractal patterns,regular fractal patterns,chaotic line soliton patterns as well as chaotic patterns exist in the KdV system as considering appropriate boundary conditions and/or initial qualifications. 相似文献
993.
DUAN Wen-Shan CHEN Jian-Hong HONG Xue-Ren WAN Gui-Xin 《理论物理通讯》2007,47(1):149-154
A modified Zakharov-Kuznetsov equation for small but finite dustic waces in a magnetized votex-like ion distribution dusty plasma is obtained in this paper.It seems that there are instability for a soliton under higher-order transverse perturbations in this system. There is a certain critical value 4λ0. If the ratio of the wave length of the higher-order perturbations to the width of the soliton is larger than this critical value, the solitary wave is unstable, otherwise it is stable. 相似文献
994.
995.
996.
In this paper, nonlocal residual symmetry of a generalized (2+1)-dimensional Korteweg–de Vries equation is derived with the aid of truncated Painlevé expansion. Three kinds of non-auto and auto Bäcklund transformations are established. The nonlocal symmetry is localized to a Lie point symmetry of a prolonged system by introducing auxiliary dependent variables. The linear superposed multiple residual symmetries are presented, which give rise to the th Bäcklund transformation. The consistent Riccati expansion method is employed to derive a Bäcklund transformation. Furthermore, the soliton solutions, fusion-type -solitary wave solutions and soliton–cnoidal wave solutions are gained through Bäcklund transformations. 相似文献
997.
Regarded as the integrable generalization of Camassa-Holm (CH) equation, the CH equation with self-consistent sources (CHESCS) is derived. The Lax representation of the CHESCS is presented. The conservation laws for CHESCS are constructed. The peakon solution, N-soliton, N-cuspon, N-positon, and N-negaton solutions of CHESCS are obtained by using Darboux transformation and the method of variation of constants. 相似文献
998.
Under investigation in this paper are two coupled integrable dispersionless (CID) equations modeling the dynamics of the current-fed string within an external magnetic field. Through a set of the dependent variable transformations, the bilinear forms for the CID equations are derived. Based on the Hirota method and symbolic computation, the analytic N-soliton solutions are presented. Infinitely many conservation laws for the CID equations are given through the known spectral problem. Propagation characteristics and interaction behaviors of the solitons are analyzed graphically. 相似文献
999.
Investigated in this paper is the generalized nonlinear Schrodinger equation with radial symmetry. With the help of symbolic computation, the one-, two-, and N-soliton solutions are obtained through the bilinear method. B~cklund transformation in the bilinear form is presented, through which a new solution is constructed. Graphically, we have found that the solitons are symmetric about x = O, while the soliton pulse width and amplitude will change along with the distance and time during the propagation. 相似文献
1000.