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Kamenev-type criteria for nonlinear damped dynamic equations 被引量:13
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作者 BOHNER Martin LI TongXing 《Science China Mathematics》 SCIE CSCD 2015年第7期1445-1452,共8页
We establish a new Kamenev-type theorem for a class of second-order nonlinear damped delay dynamic equations on a time scale by using the generalized Riccati transformation technique. The criterion obtained improves r... We establish a new Kamenev-type theorem for a class of second-order nonlinear damped delay dynamic equations on a time scale by using the generalized Riccati transformation technique. The criterion obtained improves related contributions to the subject. An example is provided to illustrate assumptions in our theorem are less restrictive. 展开更多
关键词 OSCILLATION second-order dynamic equation nonlinear damped delay equation time scale
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利用欠阻尼振动测液体粘滞系数实验研究 被引量:10
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作者 张岩文 王鹏飞 乔红星 《大学物理实验》 2012年第5期35-37,共3页
实验通过分别测量无阻尼振动和受到阻尼振动时系统的实时受力,用Origin软件对实验数据进行非线性拟合,将两种情况下的角频率进行对比,得到了液体的阻尼系数,并给出了液体的粘滞系数。
关键词 阻尼振动 振动周期 动力学方程 粘滞系数
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微波法测量原油含水率计算公式的推导 被引量:8
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作者 吴国忠 穆磊 +1 位作者 张永攀 杨显志 《油气储运》 CAS 北大核心 2009年第7期35-37,共3页
基于微波双参数法测量原油含水率的基本原理,通过建立油气水三相混合流体的复介电常数模型,研究了储能因子和损耗因子与混合流体密度的关系,给出了消除混合流体密度影响的原油含水率微波测量方法,推导了原油含水率与微波测量参数的函数... 基于微波双参数法测量原油含水率的基本原理,通过建立油气水三相混合流体的复介电常数模型,研究了储能因子和损耗因子与混合流体密度的关系,给出了消除混合流体密度影响的原油含水率微波测量方法,推导了原油含水率与微波测量参数的函数表达式。 展开更多
关键词 原油 含水率 微波法 复介电常数 衰减量 公式 推导
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具阻尼项的二阶非线性中立型微分方程的振动准则
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作者 曾云辉 孙文杰 +1 位作者 罗李平 俞元洪 《浙江大学学报(理学版)》 CAS CSCD 北大核心 2024年第1期5-13,共9页
建立了二阶非线性中立型阻尼微分方程[a(t)|z′(t)|^(α-1 )z′(t)]′+b(t)|z′(t)|^(α-1) z′(t)+q(t)|x(σ(t))|^(β-1) x(σ(t))=0的若干振动准则,其中z(t)=x(t)+p(t)x(τ(t))。改进、推广和统一了已有文献的相关结果,并通过实例说... 建立了二阶非线性中立型阻尼微分方程[a(t)|z′(t)|^(α-1 )z′(t)]′+b(t)|z′(t)|^(α-1) z′(t)+q(t)|x(σ(t))|^(β-1) x(σ(t))=0的若干振动准则,其中z(t)=x(t)+p(t)x(τ(t))。改进、推广和统一了已有文献的相关结果,并通过实例说明了所得准则的广泛应用效果。 展开更多
关键词 振动准则 阻尼方程 中立型微分方程 EMDEN-FOWLER方程 半线性微分方程
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非自治强阻尼梁方程的渐近行为 被引量:6
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作者 任永华 张建文 《太原理工大学学报》 CAS 北大核心 2013年第1期116-118,共3页
研究了具有与时间相关的外力驱动的非自治强阻尼梁方程的渐近行为。当与时间有关的外力是平移紧的时候,首先利用算子半群理论证明了在一定的齐次边界条件和初值条件下系统存在连续解;再通过先验估计,构造了渐近紧的不变吸收集;最后证明... 研究了具有与时间相关的外力驱动的非自治强阻尼梁方程的渐近行为。当与时间有关的外力是平移紧的时候,首先利用算子半群理论证明了在一定的齐次边界条件和初值条件下系统存在连续解;再通过先验估计,构造了渐近紧的不变吸收集;最后证明了系统存在一致吸引子。 展开更多
关键词 非自治 强阻尼 梁方程 不变吸收集 一致吸引子
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具变指数非线性项的强阻尼波动方程的爆破
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作者 李海霞 曹春玲 《吉林大学学报(理学版)》 CAS 北大核心 2024年第1期78-86,共9页
考虑一类具变指数非线性项的强阻尼波动方程的有限时刻爆破.借助凹方法和适当选取的参数,给出该问题的一个新的爆破准则,并给出爆破时间的上下界估计.结果表明,该爆破准则特别蕴含对任意高的初始能量,该问题存在有限时刻爆破解.
关键词 强阻尼 波方程 变指数非线性项 爆破
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高维强阻尼非线性波动方程 被引量:4
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作者 刘亚成 谢瑰林 《哈尔滨工程大学学报》 EI CAS CSCD 1995年第2期82-87,共6页
研究当n≥4时强阻尼非线性波动方程utt-αΔut=f(u),(α>0)的初边值问题,在一定条件下得到整体强解的存在唯一性,推广了文献[1]与[2]的结果。
关键词 高维强阻尼非线性波动方程 初边值问题 唯一整体强解
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二阶非线性中立型阻尼微分方程的振动定理
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作者 曾云辉 罗李平 +1 位作者 俞元洪 罗慧慧 《振动与冲击》 EI CSCD 北大核心 2022年第13期112-118,共7页
建立了二阶非线性中立型阻尼微分方程(a(t)φα(z′(t)))′+b(t)φα(z′(t))+q(t)φβ(x(σ(t)))=0其中z(t)=x(t)+p(t)x(τ(t))的若干新的振动准则,我们的定理改进、推广和统一了一系列文献中的有关结果。所得准则的有效性也通过例子... 建立了二阶非线性中立型阻尼微分方程(a(t)φα(z′(t)))′+b(t)φα(z′(t))+q(t)φβ(x(σ(t)))=0其中z(t)=x(t)+p(t)x(τ(t))的若干新的振动准则,我们的定理改进、推广和统一了一系列文献中的有关结果。所得准则的有效性也通过例子给出说明。 展开更多
关键词 振动准则 阻尼方程 中立型微分方程 EMDEN-FOWLER方程 半线性微分方程
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四阶强阻尼非线性波动方程的整体W^(k,p)解 被引量:1
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作者 孙淑珍 《吉林大学自然科学学报》 CSCD 2000年第1期18-22,共5页
证明四阶强阻尼非线性波动方程的初边值问题utt-Δu -αΔut-εΔutt+ f ( u) =0  (α≥ 0 ,ε>0 ) ,u( x,0 ) =u0 ( x) ,  ut( x,0 ) =u1( x) ,u| Ω =0的整体广义解的存在惟一性 .利用“逐次磨光法”证明其整体 W2 ,p与 Wk,p的... 证明四阶强阻尼非线性波动方程的初边值问题utt-Δu -αΔut-εΔutt+ f ( u) =0  (α≥ 0 ,ε>0 ) ,u( x,0 ) =u0 ( x) ,  ut( x,0 ) =u1( x) ,u| Ω =0的整体广义解的存在惟一性 .利用“逐次磨光法”证明其整体 W2 ,p与 Wk,p的存在性 ,并讨论其整体古典解的存在性 . 展开更多
关键词 强阻尼 波动方程 整体古典解 非线性 存在性
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New Kamenev-type Oscillation Criteria for Half-linear Partial Differential Equations
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作者 Ge-feng YANG Zhi-ting XU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2012年第3期535-548,共14页
We establish new Kamenev-type oscillation criteria for the half-linear partial differential equation with damping div(A(x)|| u||^p-2 u)+〈b(x),|| u||^p-2 u〉+c(x)|u|^p-2u=0(E)under quite general ... We establish new Kamenev-type oscillation criteria for the half-linear partial differential equation with damping div(A(x)|| u||^p-2 u)+〈b(x),|| u||^p-2 u〉+c(x)|u|^p-2u=0(E)under quite general conditions. These results are extensions of the recent results developed by Sun [Y.C. Sun, New Kamenev-type oscillation criteria of second order nonlinear differential equations with damping, J. Math. Anal. Appl. 291 (2004) 341-351] for second order ordinary differential equations in a natural way, and improve some existing results in the literature. As applications, we illustrate our main results using two different types of half-linear partial differential equations. 展开更多
关键词 OSCILLATION HALF-LINEAR partial differential equations Kamenev-type damped equation
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Global Attractor of Two-Dimensional Strong Damping KDV Equation and Its Dimension Estimation
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作者 Cheng Zhang Guoguang Lin 《Applied Mathematics》 2014年第1期7-15,共9页
Firstly, a priori estimates are obtained for the existence and uniqueness of solutions of two dimensional KDV equations, and prove the existence of the global attractor, finally get the upper bound estimation of the H... Firstly, a priori estimates are obtained for the existence and uniqueness of solutions of two dimensional KDV equations, and prove the existence of the global attractor, finally get the upper bound estimation of the Hausdorff and fractal dimension of attractors. 展开更多
关键词 KDV equation STRONGLY damped Existence Global ATTRACTOR Dimension Estimation
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A new approach for modelling the damped Helmholtz oscillator:applications to plasma physics and electronic circuits 被引量:1
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作者 S A El-Tantawy Alvaro H Salas M R Alharthi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2021年第3期119-130,共12页
In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic function.The exact solution for ... In this paper,a new approach is devoted to find novel analytical and approximate solutions to the damped quadratic nonlinear Helmholtz equation(HE)in terms of the Weiersrtrass elliptic function.The exact solution for undamped HE(integrable case)and approximate/semi-analytical solution to the damped HE(non-integrable case)are given for any arbitrary initial conditions.As a special case,the necessary and sufficient condition for the integrability of the damped HE using an elementary approach is reported.In general,a new ansatz is suggested to find a semi-analytical solution to the non-integrable case in the form of Weierstrass elliptic function.In addition,the relation between the Weierstrass and Jacobian elliptic functions solutions to the integrable case will be derived in details.Also,we will make a comparison between the semi-analytical solution and the approximate numerical solutions via using Runge-Kutta fourth-order method,finite difference method,and homotopy perturbation method for the first-two approximations.Furthermore,the maximum distance errors between the approximate/semi-analytical solution and the approximate numerical solutions will be estimated.As real applications,the obtained solutions will be devoted to describe the characteristics behavior of the oscillations in RLC series circuits and in various plasma models such as electronegative complex plasma model. 展开更多
关键词 damped and undamped Helmholtz equation Korteweg-de Vries type equation plasma oscillations nonlinear RLC circuits Weierstrass ellliptic function periodical solution
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Symmetry Reduction of Two-Dimensional Damped Kuramoto-Sivashinsky Equation 被引量:1
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作者 Mehdi Nadjafikhah Fatemeh Ahangari 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第8期211-217,共7页
In this paper, the problem of determining the largest possible set of symmetries for an important nonlinear dynamical system: the two-dimensional damped Kuramoto-Sivashinsky ((21)) DKS ) equation is studied. By ... In this paper, the problem of determining the largest possible set of symmetries for an important nonlinear dynamical system: the two-dimensional damped Kuramoto-Sivashinsky ((21)) DKS ) equation is studied. By applying the basic Lie symmetry method for the (217)) DKS equation, the classical Lie point symmetry operators are obtained. Also, the optimal system of one-dimensional subalgebras of the equation is constructed. The Lie invariants as well as similarity reduced equations corresponding to infinitesimal symmetries are obtained. The nonclassicaJ symmetries of the (2D) DKS equation are also investigated. 展开更多
关键词 two-dimensional damped Kuramoto-Sivashinsky equation SYMMETRY optimal system similaritysolutions
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The phase shift analysis of the colliding dissipative KdV solitons
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作者 Wedad Albalawi S.A.El-Tantawy Sadah A.Alkhateeb 《Journal of Ocean Engineering and Science》 SCIE 2022年第6期521-527,共7页
In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equat... In this work,the head-on collisions of the non-stationary dissipative soliton in ultracold neutral plasmas(UNPs)are investigated.The extended Poincare-Lighthill-Kuo(PLK)approach is adopted for reducing the fluid equations of the UNPs to two-counterpropagating damped Korteweg-de Vries(dKdV)equations.The dKdV equation is not an integrable Hamiltonian system,i.e.,does not have an exact solution.Thus,one of the main goal of this paper is to find a new general approximate analytical solution to the dKdV equation for investigating the mechanism of the propagation and interaction of the non-stationary dissipative solitons.The residual error is estimated for checking the accuracy of the new obtained solution.The approximate analytical soliton solutions are adopted for deriving the temporal phase shifts after the collision.The impact of physical parameters on the nonstationary dissipative soliton profile and the temporal phase shifts is discussed.The obtained results will contribute to understand the mechanism of propagation and interaction of many nonlinear phenomena in different nonlinear mediums such as ocean,sea,optical fiber,plasma physics,etc. 展开更多
关键词 Dissipative soliton collisions damped Korteweg-de Vries equation The extended Poincare-Lighthill-Kuo method The temporal phase shifts
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一类带阻尼项的奇性Duffing方程周期解的存在性 被引量:1
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作者 姚绍文 程志波 《数学物理学报(A辑)》 CSCD 北大核心 2018年第3期543-548,共6页
通过用Manasevich-Mawhin连续定理,证明了一类奇性Duffing方程周期解的存在性和唯一性,给出了新的结论并改进了已有的一些结论.
关键词 周期解 Manasevich-Mawhin定理 奇性 阻尼项 DUFFING方程
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DECAY RATES TOWARD STATIONARY WAVES OF SOLUTIONS FOR DAMPED WAVE EQUATIONS 被引量:1
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作者 Fan Lili Yin Hui Zhao Huijiang 《Journal of Partial Differential Equations》 2008年第2期141-172,共32页
Abstract This paper is concerned with the initial-boundary value problem for damped wave equations with a nonlinear convection term in the half space R+{utt-txx+ut+f(u)x=0,t〉0,x∈R+,u(0,x)=u0(x)→u+,asx→... Abstract This paper is concerned with the initial-boundary value problem for damped wave equations with a nonlinear convection term in the half space R+{utt-txx+ut+f(u)x=0,t〉0,x∈R+,u(0,x)=u0(x)→u+,asx→+∞,ut(0,x)=u1(x),u(t,0)=ub.For the non-degenerate case f](u+) 〈 0, it is shown in [1] that the above initialboundary value problem admits a unique global solution u(t,x) which converges to the stationary wave φ(x) uniformly in x ∈ R+ as time tends to infinity provided that the initial perturbation and/or the strength of the stationary wave are sufficiently small. Moreover, by using the space-time weighted energy method initiated by Kawashima and Matsumura [2], the convergence rates (including the algebraic convergence rate and the exponential convergence rate) of u(t, x) toward φ(x) are also obtained in [1]. We note, however, that the analysis in [1] relies heavily on the assumption that f'(ub) 〈 0. The main purpose of this paper is devoted to discussing the case of f'(ub)= 0 and we show that similar results still hold for such a case. Our analysis is based on some delicate energy estimates. 展开更多
关键词 damped wave equation stationary wave asymptotic stability decayrates space-time weighted energy method.
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Modulation space estimates for damped fractional wave equation 被引量:1
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作者 ZHANG ChunJie ZHANG YuHuai REN FangFang 《Science China Mathematics》 SCIE CSCD 2016年第4期687-696,共10页
Instead of the L^p estimates,we study the modulation space estimates for the solution to the damped wave equation.Decay properties for both the linear and semilinear equations are obtained.The estimates in modulation ... Instead of the L^p estimates,we study the modulation space estimates for the solution to the damped wave equation.Decay properties for both the linear and semilinear equations are obtained.The estimates in modulation space differ in many aspects from those in L^p space. 展开更多
关键词 damped wave equation modulation space decay property
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Novel anlytical solution to the damped Kawahara equation and its application for modeling the dissipative nonlinear structures in a fluid medium
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作者 Noufe H.Aljahdaly S.A.El-Tantawy 《Journal of Ocean Engineering and Science》 SCIE 2022年第5期492-497,共6页
A novel approximate analytical solution to the linear damped Kawahara equation using a suitable hypothesis is reported for the first time.Based on the exact solutions(such as solitary waves,cnoidal waves,etc.)of the u... A novel approximate analytical solution to the linear damped Kawahara equation using a suitable hypothesis is reported for the first time.Based on the exact solutions(such as solitary waves,cnoidal waves,etc.)of the undamped Kawahara equation,the dissipative nonlinear structures like dissipative solitons and cnoidal waves are investigated.The obtained solution is considered a general solution,i.e.,it can be applied for studying the properties of all dissipative traveling waves described by the linear damped Kawahara equation.Our technique is not limited to solve the linear damped Kawahara equation only,but it can be used for solving a large number of non-integrable evolution equations related to the realistic natural phenomena.Moreover,the maximum global residual error in the whole space-time domain is estimated for checking the accuracy of the obtained solutions.The obtained solutions can help many researchers in explaining the ambiguities about the mechanisms of propagation of nonlinear waves in complex systems such as seas,oceans,plasma physics,and much more. 展开更多
关键词 Semi-analytical solutions damped Kawahara equation A collisional plasma Dissipative Kawahara solitons and cnoidal WAVES
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一类具非线性记忆的非线性阻尼波方程全局吸引子的存在性 被引量:1
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作者 李婧 蒲志林 《四川师范大学学报(自然科学版)》 CAS 北大核心 2016年第1期20-25,共6页
研究一类具非线性记忆的非线性阻尼波方程全局吸引子的存在性,采用新的先验估计证明解半群S(t)是渐近紧的,从而证明该方程带有Dirichlet边界条件在H=H01(Ω)×L2(Ω)中吸引子是存在的.
关键词 全局吸引子 非线性阻尼 非线性记忆 先验估计 波方程
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Damped Mathieu Equation with a Modulation Property of the Homotopy Perturbation Method
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作者 Yusry O.El-Dib Nasser S.Elgazery 《Sound & Vibration》 EI 2022年第1期21-36,共16页
In this article,the main objective is to employ the homotopy perturbation method(HPM)as an alternative to classical perturbation methods for solving nonlinear equations having periodic coefficients.As a simple example... In this article,the main objective is to employ the homotopy perturbation method(HPM)as an alternative to classical perturbation methods for solving nonlinear equations having periodic coefficients.As a simple example,the nonlinear damping Mathieu equation has been investigated.In this investigation,two nonlinear solvability conditions are imposed.One of them was imposed in the first-order homotopy perturbation and used to study the stability behavior at resonance and non-resonance cases.The next level of the perturbation approaches another solvability condition and is applied to obtain the unknowns become clear in the solution for the firstorder solvability condition.The approach assumed here is so significant for solving many parametric nonlinear equations that arise within the engineering and nonlinear science. 展开更多
关键词 damped Mathieu equation parametric nonlinear oscillator resonance instability homotopy perturbation method(HPM)
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