全文获取类型
收费全文 | 395篇 |
免费 | 32篇 |
国内免费 | 9篇 |
专业分类
化学 | 2篇 |
力学 | 17篇 |
综合类 | 5篇 |
数学 | 214篇 |
物理学 | 198篇 |
出版年
2023年 | 6篇 |
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 25篇 |
2019年 | 26篇 |
2018年 | 22篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 29篇 |
2013年 | 36篇 |
2012年 | 20篇 |
2011年 | 17篇 |
2010年 | 19篇 |
2009年 | 19篇 |
2008年 | 23篇 |
2007年 | 19篇 |
2006年 | 12篇 |
2005年 | 14篇 |
2004年 | 8篇 |
2003年 | 15篇 |
2002年 | 20篇 |
2001年 | 16篇 |
2000年 | 4篇 |
1999年 | 12篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有436条查询结果,搜索用时 15 毫秒
31.
《Communications in Nonlinear Science & Numerical Simulation》2014,19(11):3969-3987
By means of symbolic computation and Darboux transformation, analytically and numerically investigated in this paper is a two-coupled Sasa–Satsuma system, which can describe the pulse propagation in birefringent fibers, so as to increase the bit rate in optical fibers, or achieve wavelength-division multiplexing. Analytical bright N-soliton solution of the system is firstly derived. Based on the bright one- and two-soliton solutions, numerical simulation and figure illustration are carried out on through the multi-parametric management, i.e., different choices among eight parameters in the two-soliton solutions. The interaction mechanisms for the bright two-solitons are revealed in three aspects: Separating evolution behaviors, elastic collision behaviors and inelastic collision behaviors. There exist three different cases for the inelastic collision for the two-soliton, which reflect correspondingly different energy transfer mechanisms (by intensity redistribution) between the two components: Manakov-typed collision; a near-elastic collision and another completely inelastic collision between the two components; and four single-solitons in two components undergo shape changes (inelastic and elastic) due to intensity redistribution, where one single-soliton keeps invariant and the other three single-solitons change during the collision. The collision mechanisms may be viewed as the two-solitons interact in a waveguide supporting propagation of two nonlinear waves simultaneously. In general, partial suppression (enhancement) of intensity between the components is dependent on the values of the soliton parameters. 相似文献
32.
On the basis of some works on persistent centers and weakly persistent centers, in this paper we discuss a generalized version of persistent center and weakly persistent center for complex planar differential systems, in which conjugacy of variables may not be required. We give some complex systems which have a persistent center or weakly persistent center at the origin. Then, we find all conditions of persistent center for cubic systems and all conditions of weakly persistent center for complex cubic Lotka–Volterra system. Relations between complex systems and real ones are given concerning persistent centers and weakly persistent centers. 相似文献
33.
34.
Alexei Zhedanov 《Journal of Approximation Theory》1999,101(2):117
We present some general results concerning so-called biorthogonal polynomials of RII type introduced by M. Ismail and D. Masson. These polynomials give rise to a pair of rational functions which are biorthogonal with respect to a linear functional. It is shown that these rational functions naturally appear as eigenvectors of the generalized eigenvalue problem for two arbitrary tri-diagonal matrices. We study spectral transformations of these functions leading to a rational modification of the linear functional. An analogue of the Christoffel–Darboux formula is obtained. 相似文献
35.
主要考虑1+1维Boussinesq系统的一个Darboux变换,反复利用该Darboux变换,可以从该系统的一个已知解出发,通过代数运算和求导运算得到系统的新解. 相似文献
36.
Alexei Rybkin 《Studies in Applied Mathematics》2023,151(1):208-246
In the Korteweg–de Vries equation (KdV) context, we put forward a continuous version of the binary Darboux transformation (aka the double commutation method). Our approach is based on the Riemann–Hilbert problem and yields a new explicit formula for perturbation of the negative spectrum of a wide class of step-type potentials without changing the rest of the scattering data. This extends the previously known formulas for inserting/removing finitely many bound states to arbitrary sets of negative spectrum of arbitrary nature. In the KdV context, our method offers same benefits as the classical binary Darboux transformation does. 相似文献
37.
In this paper, a discrete KdV equation that is related to the famous continuous KdV equation is studied. First, an integrable discrete KdV hierarchy is constructed, from which several new discrete KdV equations are obtained. Second, we correspond the first several discrete equations of this hierarchy to the continuous KdV equation through the continuous limit. Third, the generalized (m, 2N − m)-fold Darboux transformation of the discrete KdV equation is established based on its known Lax pair. Finally, the diverse exact solutions including soliton solutions, rational solutions and mixed solutions on non-zero seed background are obtained by applying the resulting Darboux transformation, and their asymptotic states and physical properties such as amplitude, velocity, phase and energy are analyzed. At the same time, some soliton solutions are numerically simulated to show their dynamic behaviors. The properties and results obtained in this paper may be helpful to understand some physical phenomena described by KdV equations. 相似文献
38.
First, we give an algebraic proof to the Christoffel–Darboux identity of formal orthogonal rational functions on the real line by exposing some underlying algebraic properties. This proof does not involve the three-term recurrence relationship. Besides, it is shown that if a family of rational functions satisfies the Christoffel–Darboux relation, then it also admits a three-term recurrence relationship. Thus, the equivalence between both relations is revealed. 相似文献
39.
In this paper, we study a differential-difference equation associated with discrete 3 × 3 matrix spectral problem. Based on gauge transformation of the spectral problm, Darboux transformation of the differential-difference equation is given. In order to solve the differential-difference equation, a systematic algebraic algorithm is given. As an application, explicit soliton solutions of the differential-difference equation are given. 相似文献
40.
The notion of Darboux helix in Euclidean 3‐space was introduced and studied by Yayl? et al. 2012. They show that the class of Darboux helices coincide with the class of slant helices. In a special case, if the curvature functions satisfy the equality κ2 + τ2 = constant, then these curves are curve of the constant precession. In this paper, we study Darboux helices in Euclidean 4‐space, and we give a characterization for a curve to be a Darboux helix. We also prove that Darboux helices coincide with the general helices. In a special case, if the first and third curvatures of the curve are equal, then Darboux helix, general helix, and V4‐slant helix are the same concepts. 相似文献