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Solution of ODE u″+p(u)(u′)2+q(u)=0 and Applications to Classifications of All Single Travelling Wave Solutions to Some Nonlinear Mathematical Physics Equations 被引量:8
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作者 LIU Cheng-Shi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第2期291-296,共6页
Under the travelling wave transformation, some nonlinear partial differential equations such as Camassa-Holm equation, High-order KdV equation, etc., are reduced to an integrable ODE expressed by u" +p(u)(u')^2... Under the travelling wave transformation, some nonlinear partial differential equations such as Camassa-Holm equation, High-order KdV equation, etc., are reduced to an integrable ODE expressed by u" +p(u)(u')^2 + q(u) = 0 whose generai solution can be given. Furthermore, combining complete discrimination system for polynomiai, the classifications of all single travelling wave solutions to these equations are obtained. The equation u"+p(u)(u')^2+q(u) = 0 includes the equation (u')^2 = f(u) as a special case, so the proposed method can be also applied to a large number of nonlinear equations. These complete results cannot be obtained by any indirect method. 展开更多
关键词 classification of travelling wave solution symmetry group nonlinear partial differential equation
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位移法浅水波方程的解及其特性 被引量:7
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作者 姚征 钟万勰 《计算机辅助工程》 2016年第2期1-4,13,共5页
不同于传统流体力学,在Lagrange坐标下推导浅水波方程.若将水平位移作为基本变量,则推导出的浅水波数学模型可描述为固体力学的非线性大位移问题.运用不可压缩条件,通过变分原理推导出位移法浅水波方程,给出椭圆函数形式的行波解,并分... 不同于传统流体力学,在Lagrange坐标下推导浅水波方程.若将水平位移作为基本变量,则推导出的浅水波数学模型可描述为固体力学的非线性大位移问题.运用不可压缩条件,通过变分原理推导出位移法浅水波方程,给出椭圆函数形式的行波解,并分析孤波解产生的条件.该基础研究建立了在分析结构力学中分析浅水波问题的理论基础,有利于进一步开展水动力学的研究. 展开更多
关键词 浅水波 Lagrange坐标 孤立波 椭圆函数 微分代数方程 保辛 分析结构力学
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双非线性隔振器的双层隔振系统模型的建立 被引量:6
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作者 曹利 冯奇 张乐乐 《噪声与振动控制》 CSCD 北大核心 2008年第2期1-3,共3页
冲击引起的振动与波是舰船破坏的主要原因之一。采用空间多刚体动力学基本理论,建立非线性双层抗冲隔振系统的数学力学模型,推导出适用于一般的双层抗冲隔振系统的牛顿-欧拉方程。然后以一个水泵设备的双层抗冲隔振的例子进行数值计算。
关键词 振动与波 多刚体动力学 双层隔振系统 非线性微分方程 牛顿-欧拉方程
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Approximate Generalized Conditional Symmetries for the Perturbed Nonlinear Diffusion-Convection Equations 被引量:4
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作者 张顺利 屈长征 《Chinese Physics Letters》 SCIE CAS CSCD 2006年第3期527-530,共4页
The concept of approximate generalized conditional symmetry (A GCS) as a generalization to both approximate Lie point symmetry and generalized conditional symmetry is introduced, and it is applied to study the pertu... The concept of approximate generalized conditional symmetry (A GCS) as a generalization to both approximate Lie point symmetry and generalized conditional symmetry is introduced, and it is applied to study the perturbed nonlinear diffusion-convection equations. Complete classification of those perturbed equations which admit cerrain types of AGCSs is derived. Some approximate solutions to the resulting equations can be obtained via the AGCS and the corresponding unperturbed equations. 展开更多
关键词 PARTIAL-differential-equationS FUNCTIONAL VARIABLE SEPARATION INITIAL-VALUE PROBLEMS POTENTIAL SYMMETRIES wave-equation REDUCTION CLASSIFICATION
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Selective Impact of Dispersion and Nonlinearity on Waves and Solitary Wave in a Strongly Nonlinear and Flattened Waveguide
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作者 Christian Regis Ngouo Tchinda Marcelle Nina Zambo Abou’ou Jean Roger Bogning 《Open Journal of Applied Sciences》 2024年第7期1730-1753,共24页
The waveguide which is at the center of our concerns in this work is a strongly flattened waveguide, that is to say characterized by a strong dispersion and in addition is strongly nonlinear. As this type of waveguide... The waveguide which is at the center of our concerns in this work is a strongly flattened waveguide, that is to say characterized by a strong dispersion and in addition is strongly nonlinear. As this type of waveguide contains multiple dispersion coefficients according to the degrees of spatial variation within it, our work in this article is to see how these dispersions and nonlinearities each influence the wave or the signal that can propagate in the waveguide. Since the partial differential equation which governs the dynamics of propagation in such transmission medium presents several dispersion and nonlinear coefficients, we check how they contribute to the choices of the solutions that we want them to verify this nonlinear partial differential equation. This effectively requires an adequate choice of the form of solution to be constructed. Thus, this article is based on three main pillars, namely: first of all, making a good choice of the solution function to be constructed, secondly, determining the exact solutions and, if necessary, remodeling the main equation such that it is possible;then check the impact of the dispersion and nonlinear coefficients on the solutions. Finally, the reliability of the solutions obtained is tested by a study of the propagation. Another very important aspect is the use of notions of probability to select the predominant solutions. 展开更多
关键词 Flattened waveguide Solitary wave Characteristic Coefficient Probabilities Propagation Nonlinear DISPERSIVE Partial differential equation
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New applications of the two variable (G ′/ G,1/ G)-expansion method for closed form traveling wave solutions of integro-differential equations 被引量:2
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作者 M.Mamun Miah H.M.Shahadat Ali +1 位作者 M.Ali Akbar Aly R.Seadawy 《Journal of Ocean Engineering and Science》 SCIE 2019年第2期132-143,共12页
Most fundamental themes in mathematical physics and modern engineering are investigated by the closed form traveling wave solutions of nonlinear evolution equations.In our research,we ascertain abundant new closed for... Most fundamental themes in mathematical physics and modern engineering are investigated by the closed form traveling wave solutions of nonlinear evolution equations.In our research,we ascertain abundant new closed form traveling wave solution of the nonlinear integro-differential equations via Ito equation,integro-differential Sawada-Kotera equation,first integro-differential KP hierarchy equation and second integro-differential KP hierarchy equation by two variable(G/G,1/G)-expansion method with the help of computer package like Mathematica.Some shape of solutions like,bell profile solution,anti-king profile solution,soliton profile solution,periodic profile solution etc.are obtain in this investigation.Trigonometric function solution,hyperbolic function solution and rational function solution are established by using our eminent method and comparing with our results to all of the well-known results which are given in the literature.By means of free parameters,plentiful solitary solutions are derived from the exact traveling wave solutions.The method can be easier and more applicable to investigate such type of nonlinear evolution models. 展开更多
关键词 The two variable(G/G 1/G)-expansion method Travelling wave solutions Integro-differential ito equation Integro-differential Sawada-Kotera equation First integro-differential KP hierarchy equation Second integro-differential KP hierarchy equation.
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基于增量谐波平衡法的一维强非线性多自由度波动问题算法研究
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作者 王鸿宇 王雪峰 +2 位作者 赵剑 张健 黄毓 《机械工程学报》 EI CAS CSCD 北大核心 2024年第17期167-178,共12页
针对采用高阶基函数的增量谐波平衡法(Incremental harmonic balance,IHB)在分析多自由度非线性介质的带隙性质时存在计算量大且不易收敛的问题,提出一种改进的IHB方法以高效求解外部激励确定情况下频率已知而波矢未知的非线性波动问题... 针对采用高阶基函数的增量谐波平衡法(Incremental harmonic balance,IHB)在分析多自由度非线性介质的带隙性质时存在计算量大且不易收敛的问题,提出一种改进的IHB方法以高效求解外部激励确定情况下频率已知而波矢未知的非线性波动问题。该方法将原始波动方程转化为具有任意自由度和任意阶数基函数的时滞微分方程(Delay differential equation,DDE),并构造Jacobian矩阵的解析式,利用快速傅里叶变换(Fast Fourier transform,FFT)代替数值积分,并通过收敛性分析确定最小展开阶数及稳态解。以分数非线性(基于赫兹接触定律的晶格)和立方非线性(基于立方弹簧的晶格)模型为例,分析晶格结构的带隙性质。结果表明,当系统处于强非线性时,采用高阶基函数才可获得收敛的稳态解,且计算效率提高220余倍。已知频率计算波矢时的稳态解的收敛性高于已知波矢的情况。非线性强度可以调控带隙的频段和宽度,且非线性越强,带隙的调控范围越大。 展开更多
关键词 强非线性 增量谐波平衡法 波动问题 时滞微分方程 带隙性质
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Continuous-Time Channel Prediction Based on Tensor Neural Ordinary Differential Equation
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作者 Mingyao Cui Hao Jiang +2 位作者 Yuhao Chen Yang Du Linglong Dai 《China Communications》 SCIE CSCD 2024年第1期163-174,共12页
Channel prediction is critical to address the channel aging issue in mobile scenarios.Existing channel prediction techniques are mainly designed for discrete channel prediction,which can only predict the future channe... Channel prediction is critical to address the channel aging issue in mobile scenarios.Existing channel prediction techniques are mainly designed for discrete channel prediction,which can only predict the future channel in a fixed time slot per frame,while the other intra-frame channels are usually recovered by interpolation.However,these approaches suffer from a serious interpolation loss,especially for mobile millimeter-wave communications.To solve this challenging problem,we propose a tensor neural ordinary differential equation(TN-ODE)based continuous-time channel prediction scheme to realize the direct prediction of intra-frame channels.Specifically,inspired by the recently developed continuous mapping model named neural ODE in the field of machine learning,we first utilize the neural ODE model to predict future continuous-time channels.To improve the channel prediction accuracy and reduce computational complexity,we then propose the TN-ODE scheme to learn the structural characteristics of the high-dimensional channel by low-dimensional learnable transform.Simulation results show that the proposed scheme is able to achieve higher intra-frame channel prediction accuracy than existing schemes. 展开更多
关键词 channel prediction massive multipleinput-multiple-output millimeter-wave communications ordinary differential equation
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Fluid State of Dirac Quantum Particles 被引量:2
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作者 Vu B. Ho 《Journal of Modern Physics》 2018年第14期2402-2419,共18页
In our previous works, we suggest that quantum particles are composite physical objects endowed with the geometric and topological structures of their corresponding differentiable manifolds that would allow them to im... In our previous works, we suggest that quantum particles are composite physical objects endowed with the geometric and topological structures of their corresponding differentiable manifolds that would allow them to imitate and adapt to physical environments. In this work, we show that Dirac equation in fact describes quantum particles as composite structures that are in a fluid state in which the components of the wavefunction can be identified with the stream function and the velocity potential of a potential flow formulated in the theory of classical fluids. We also show that Dirac quantum particles can manifest as standing waves which are the result of the superposition of two fluid flows moving in opposite directions. However, for a steady motion a Dirac quantum particle does not exhibit a wave motion even though it has the potential to establish a wave within its physical structure, therefore, without an external disturbance a Dirac quantum particle may be considered as a classical particle defined in classical physics. And furthermore, from the fact that there are two identical fluid flows in opposite directions within their physical structures, the fluid state model of Dirac quantum particles can be used to explain why fermions are spin-half particles. 展开更多
关键词 DIRAC equation wave MECHANICS Stan FLUID MECHANICS Stream Function Velocity POTENTIAL POTENTIAL Flow General RELATIVITY Maxwell Field equations CW Complexes differential Geometry Topology DIFFERENTIABLE Manifolds Topological Transformation
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Exact Traveling Wave Solutions for Generalized Camassa-Holm Equation by Polynomial Expansion Methods 被引量:1
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作者 Junliang Lu Xiaochun Hong 《Applied Mathematics》 2016年第14期1599-1611,共13页
We formulate efficient polynomial expansion methods and obtain the exact traveling wave solutions for the generalized Camassa-Holm Equation. By the methods, we obtain three types traveling wave solutions for the gener... We formulate efficient polynomial expansion methods and obtain the exact traveling wave solutions for the generalized Camassa-Holm Equation. By the methods, we obtain three types traveling wave solutions for the generalized Camassa-Holm Equation: hyperbolic function traveling wave solutions, trigonometric function traveling wave solutions, and rational function traveling wave solutions. At the same time, we have shown graphical behavior of the traveling wave solutions. 展开更多
关键词 Camassa-Holm equation Partial differential equation Polynomial Expansion Methods Traveling wave Solutions
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Closed Form Exact Solutions to the Higher Dimensional Fractional Schrodinger Equation via the Modified Simple Equation Method
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作者 M. Nurul Islam M. Ali Akbar 《Journal of Applied Mathematics and Physics》 2018年第1期90-102,共13页
In this article, we investigate some exact wave solutions to the higher dimensional time-fractional Schrodinger equation, an important equation in quantum mechanics. The fractional Schrodinger equation further precise... In this article, we investigate some exact wave solutions to the higher dimensional time-fractional Schrodinger equation, an important equation in quantum mechanics. The fractional Schrodinger equation further precisely describes the quantum state of a physical system changes in time. In order to determine the solutions a suitable transformation is considered to transmute the equations into a simpler ordinary differential equation (ODE) namely fractional complex transformation. We then use the modified simple equation (MSE) method to obtain new and further general exact wave solutions. The MSE method is more powerful and can be used in other works to establish completely new solutions for other kind of nonlinear fractional differential equations arising in mathematical physics. The affect of obtaining parameters for its definite values which are examined from the solutions of two dimensional and three dimensional time-fractional Schrodinger equations are discussed and therefore might be useful in different physical applications where the equations arise in this article. 展开更多
关键词 MODIFIED SIMPLE equation (MSE) METHOD FRACTIONAL differential equation Nonlinear Evolution equations Higher Dimensional Schrodinger equation Traveling wave Transformation
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A robust fuzzy-fractional approach for the atmospheric internal wave model 被引量:1
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作者 Parthkumar P.Sartanpara Ramakanta Meher 《Journal of Ocean Engineering and Science》 SCIE 2023年第3期308-322,共15页
The study of internal atmospheric waves,also known as gravity waves,which are detectable inside the fluid rather than at the fluid surface,is presented in this work.We have used the time-fractional and fuzzy-fractiona... The study of internal atmospheric waves,also known as gravity waves,which are detectable inside the fluid rather than at the fluid surface,is presented in this work.We have used the time-fractional and fuzzy-fractional techniques to solve the differential equation system representing the atmospheric inter-nal waves model.The q-Homotopy analysis Shehu transform technique(q-HAShTM)is used to solve the model.The method helps find convergent solutions since it helps solve nonlinearity,and the fractional derivative can be easily computed using the Shehu transform.Finally,the obtained solution is compared for the particular case ofα=1 with the HAM solution to explain the method’s accuracy. 展开更多
关键词 Atmospheric internal wave Fractional differential equation Fuzzy-fractional differential equation q-Homotopy analysis Shehu transform method
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一种抑制激波计算中数值振荡现象的双重小波收缩方法 被引量:2
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作者 赵勇 宗智 王天霖 《应用数学和力学》 CSCD 北大核心 2014年第6期620-629,共10页
在激波数值计算中,容易出现数值振荡的问题,振荡激烈时会掩盖真实解,为此提出了许多高精度复杂计算格式或采用人工粘性抑制数值振荡.从信号处理的角度,提出双重小波收缩方法,它能自适应提取激波数值振荡解中的真实物理解.先用局部微分... 在激波数值计算中,容易出现数值振荡的问题,振荡激烈时会掩盖真实解,为此提出了许多高精度复杂计算格式或采用人工粘性抑制数值振荡.从信号处理的角度,提出双重小波收缩方法,它能自适应提取激波数值振荡解中的真实物理解.先用局部微分求积法求解浅水波方程和理想流体Euler运动方程中的激波问题,发现其数值振荡现象严重,然后采用双重小波收缩方法对其处理,获得了无数值振荡解,它能准确捕捉激波的位置并且保持激波结构.相比于复杂的Riemann(黎曼)求解格式,借助小波收缩方法,可以采用相对简单的计算格式如微分求积法求解激波问题. 展开更多
关键词 激波 数值振荡 小波收缩 微分求积法 浅水波方程 EULER方程
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Solitary Wave and Periodic Wave Solutions for the Relativistic Toda Lattices 被引量:2
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作者 MAZheng-Yi ZHUJia-Min ZHENGChun-Long 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第1期27-30,共4页
In this work, an adaptation of the tanh/tan-method that is discussed usually in the nonlinear partial differential equations is presented to solve nonlinear polynomial differential-difference equations. As a concrete ... In this work, an adaptation of the tanh/tan-method that is discussed usually in the nonlinear partial differential equations is presented to solve nonlinear polynomial differential-difference equations. As a concrete example,several solitary wave and periodic wave solutions for the chain which is related to the relativistic Toda lattice are derived.Some systems of the differential-difference equations that can be solved using our approach are listed and a discussion is given in conclusion. 展开更多
关键词 tanh-method solitary wave and periodic wave solutions differential-difference equation Toda lattice
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波浪能装置设计模型及其解析求解 被引量:1
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作者 黄河 柳世纯 周正 《数学建模及其应用》 2023年第1期44-51,共8页
本文通过对波浪能装置设计模型进行简化,得出一种快速且准确地提升波浪能转化效率的解决方案.首先,从分析波浪能装置在海水中的垂荡运动出发,将该装置简化为多自由度线性系统,通过分别对浮子和振子进行受力分析、建立微分方程,利用数值... 本文通过对波浪能装置设计模型进行简化,得出一种快速且准确地提升波浪能转化效率的解决方案.首先,从分析波浪能装置在海水中的垂荡运动出发,将该装置简化为多自由度线性系统,通过分别对浮子和振子进行受力分析、建立微分方程,利用数值模拟的方式求解,给出浮子和振子从静止到进行垂荡运动各时刻的运动状态;然后,通过调节阻尼器阻尼系数的形式及其数值,计算出使得PTO系统平均输出功率最大的阻尼系数;最后,通过对弹簧刚度的稳定性检验说明该模型可拓展至其他不同的情况,具有普适性.本文模型对于提高波浪能装置的能量转换效率具有指导意义. 展开更多
关键词 波浪能装置 垂荡运动 多自由度线性系统 多元微分方程
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光波场在垂直光轴方向的参考面上的复振幅研究 被引量:1
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作者 薛冬 李国华 +1 位作者 王吉明 郑春红 《曲阜师范大学学报(自然科学版)》 CAS 2003年第1期56-59,共4页
从波动微分波动方程出发推导光波场在垂直光轴方向的参考面上的复振幅表示 .
关键词 光轴 参考面 波动微分方程 光波场 复振幅 空间频率 波动光学
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一类带时滞和全局反应项生物模型的行波解 被引量:1
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作者 王宗毅 《数学的实践与认识》 北大核心 2016年第3期238-245,共8页
研究了带时滞的微分方程异宿轨解的存在条件,并通过时滞微分系统和反应扩散系统解之间的关联性,得到了一类带全局反应项的生物反应扩散模型的行波解.
关键词 异宿轨解 行波解 时滞微分方程 反应扩散方程
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A Differential Continuation-Regularization Method for Solving Inverse Problems of Acoustic Wave Equations
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作者 张大力 韩波 +1 位作者 刘家琦 姜立功 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 1995年第1期10-14,共5页
ADifferentialContinuation-RegularizationMethodforSolvingInverseProblemsofAcousticWaveEquations¥(张大力)(韩波)(刘家琦... ADifferentialContinuation-RegularizationMethodforSolvingInverseProblemsofAcousticWaveEquations¥(张大力)(韩波)(刘家琦)(姜立功)ZHANGDali;H... 展开更多
关键词 ss:Inverse problems geophysical prospecting differential CONTINUATION method ACOUSTIC wave equation REGULARIZATION
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2—D与3—D横向各向同性介质中地震波动方程的解耦
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作者 张中杰 何樵登 《西安石油学院学报》 CAS 1992年第4期10-18,共9页
在2-D横向各向同性介质中,似P波与似SV波耦合;3-D介质中,似P波与似SV波及似SH波均耦合于偏微分波动方程组中,为便于2-D与3-D横向各向同性介质中震波激发以及地震记录合成研究,本文首先对波动方程组本身进行了讨论,进而分别研究了二维与... 在2-D横向各向同性介质中,似P波与似SV波耦合;3-D介质中,似P波与似SV波及似SH波均耦合于偏微分波动方程组中,为便于2-D与3-D横向各向同性介质中震波激发以及地震记录合成研究,本文首先对波动方程组本身进行了讨论,进而分别研究了二维与三维横向各向同性介质中波动方程组的解耦问题,得到了解耦后的关于位移分量偏微分方程。 展开更多
关键词 各向同性介质 地震波 方程 解耦
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Existence of Travelling Wave Fronts to a Delayed Lattice Model for Population 被引量:1
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作者 孙风兰 汤燕斌 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第1期96-102,共7页
This paper considers the travelling wave fronts to a delayed lattice differential equation. The existence of the travelling wave solutions is proved by making use of the technique of the upper and lower solutions deve... This paper considers the travelling wave fronts to a delayed lattice differential equation. The existence of the travelling wave solutions is proved by making use of the technique of the upper and lower solutions developed by J Wu and X Zou in [6]. This work extends that of [4] in a general class of nonlinear terms. 展开更多
关键词 travelling wave front lattice differential equation delay upper and lower solutions
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