全文获取类型
收费全文 | 436篇 |
免费 | 98篇 |
国内免费 | 101篇 |
专业分类
化学 | 38篇 |
力学 | 16篇 |
综合类 | 5篇 |
数学 | 357篇 |
物理学 | 219篇 |
出版年
2023年 | 1篇 |
2022年 | 9篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 10篇 |
2016年 | 15篇 |
2015年 | 9篇 |
2014年 | 16篇 |
2013年 | 14篇 |
2012年 | 32篇 |
2011年 | 22篇 |
2010年 | 23篇 |
2009年 | 47篇 |
2008年 | 80篇 |
2007年 | 65篇 |
2006年 | 72篇 |
2005年 | 22篇 |
2004年 | 23篇 |
2003年 | 17篇 |
2002年 | 41篇 |
2001年 | 11篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 13篇 |
1997年 | 17篇 |
1996年 | 7篇 |
1994年 | 7篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1978年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有635条查询结果,搜索用时 264 毫秒
71.
影响光孤子传输的因素分析和可能的解决方案 总被引:1,自引:0,他引:1
从光孤子传输所满足的非线性薛定谔方程出发,通过对方程中参数的分析和选择,对影响孤子传输的各种因素采用单独分析和综合分析对比方法得到了两个新的结论:(1)二阶色散参数在不太大的范围内变化只会影响脉冲的幅值,对脉冲形状影响不大,而输入脉冲的啁啾则是使脉冲发生畸变的主要原因;(2)在啁啾、三阶色散和五阶非线性同时存在的情况下,它们对脉冲都会产生很大的影响,且存在相互影响和制约关系,三者在某一参数值附近,对脉冲却存在着增益效应和"整容"作用。针对分析结果从理论上提出了改进光孤子传输特性的解决方案,这对光孤子通信的实践过程是有一定实际意义的。 相似文献
72.
We consider the critical nonlinear Schrödinger equation with initial condition in the energy space and study the dynamics of finite time blow-up solutions. In an earlier sequence of papers, the authors established for a certain class of initial data on the basis of dispersive properties in a sharp and stable upper bound on the blow-up rate: .
by exhibiting the dispersive structure in the scaling invariant space for this log-log regime. In addition, we will extend to the pure energy space a dynamical characterization of the solitons among the zero energy solutions.
In an earlier paper, the authors then addressed the question of a lower bound on the blow-up rate and proved for this class of initial data the nonexistence of self-similar solutions, that is,
In this paper, we prove the sharp lower bound
by exhibiting the dispersive structure in the scaling invariant space for this log-log regime. In addition, we will extend to the pure energy space a dynamical characterization of the solitons among the zero energy solutions.
73.
Shijun Zheng 《分析论及其应用》2006,22(4)
Let H be a Schr(o)dinger operator on Rn. Under a polynomial decay condition for the kernel of its spectral operator, we show that the Besov spaces and Triebel-Lizorkin spaces associated with H are well defined. We further give a Littlewood-Paley characterization of Lp spaces in terms of dyadic functions of H. This generalizes and strengthens the previous result when the heat kernel of H satisfies certain upper Gaussian bound. 相似文献
74.
Asim Patra 《Mathematical Methods in the Applied Sciences》2020,43(17):10287-10295
The present article deals with the similarity method to tackle the fractional Schrӧdinger equation where the derivative is defined in the Riesz sense. Moreover, the procedure of reducing a fractional partial differential equation (FPDE) into an ordinary differential equation (ODE) has been efficiently displayed by means of suitable scaled transform to the proposed fractional equation. Furthermore, the ODEs are treated effectively via the Fourier transform. The graphical solutions are also depicted for different fractional derivatives α . 相似文献
75.
The authors establish the boundedness of the variation operators associated with the heat semigroup, Riesz transforms and commutators generated by the Riesz transforms and BMO-type functions in the Schrödinger setting on the Morrey spaces. 相似文献
76.
Dynamical behaviour and exact solutions of thirteenth order derivative nonlinear Schr\"{o}dinger equation
下载免费PDF全文
![点击此处可从《Journal of Applied Analysis & Computation》网站下载免费的PDF全文](/ch/ext_images/free.gif)
In this paper, we considered the model of the thirteenth order derivatives of nonlinear Schr\"{o}dinger equations. It is shown that a wave packet ansatz inserted into these equations leads to an integrable Hamiltonian dynamical sub-system. By using bifurcation theory of planar dynamical systems, in different parametric regions, we determined the phase portraits. In each of these parametric regions we obtain possible exact explicit parametric representation of the traveling wave solutions corresponding to homoclinic, hetroclinic and periodic orbits. 相似文献
77.
Let L =△ + V be a SchrSdinger operator in Rd, d ≥ 3, where the nonnegative potential V belongs to the reverse HSlder class Sd. We establish the BMOL-boundedness of Riesz transforms З/ЗxiL-1/2, and give the Fefferman-Stein type decomposition of BMOL functions. 相似文献
78.
In this paper we consider the SchrSdinger operator -△G + W on the nilpotent Lie group G where the nonnegative potential W belongs to the reverse H51der class Bq1 for some q1 ≥ D and D is the dimension at infinity of G. The weighted L^p -L6q estimates for the operators W^a(-△G + W)^-β and W^a△G(-△G + W)^-β are obtained. 相似文献
79.
In this paper,we first prove the existence of the global attractor Aν ∈ C([-ν,0],2)(ν 0) for a weak damping discrete nonlinear Schrdinger equation with delay.Then we consider an upper semi-continuity of Aν as ν → 0+. 相似文献
80.
Addressed here is the occurrence of point singularities which owe to the fo-cusing of short or long waves,a phenomenon labeled dispersive blow-up.The context of this investigation is linear and nonlinear,strongly dispersive equations or systems of equa-tions.The present essay deals with linear and nonlinear Schr(o)dinger equations,a class of fractional order SchrSdinger equations and the linearized water wave equations,with and without surface tension.
Commentary about how the results may bear upon the formation of rogue waves in fluid and optical environments is also included. 相似文献