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In this paper, we consider the following second order retarded differential equations x″(t)+cx′(t)=qx(t-σ)-lx(t-δ) (1) x″(t)+p(t)x(t-τ)=0 (2) We give some sufficient conditions for the oscillation of all solutions of Eq. (1) in the case where q, ι, σ, δ are positive numbers and c is a real number. And also, we study the asymptotic behavior of the nonoscillatory solutions. If necessary, we give some examples to illustrate our results. At last, we study Eq. (2) with some conditions on p(t). 相似文献
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In this short note, we investigate the properties of positive solutions for some non-local parabolic equations. The conditions on the global existence and blowup in finite time of solution are given. 相似文献
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研究一类带有非线性梯度吸收项的快速扩散方程的自相似奇性解.通过自相似变换,该自相似奇性解满足一个非线性常微分方程的边值问题,再利用打靶法技巧研究该常微分方程初值问题解的存在唯一性并根据初值的取值范围对其解进行了分类.通过对这些解类的性质的分析研究,得出了自相似强奇性解存在唯一性的充分必要条件,此时自相似奇性解就是强奇性解. 相似文献
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The Hopfbifurcation for the Brusselator ordinary-differential-equation (ODE) model and the corresponding partial-differential-equation (PDE) model are investigated by using the Hopf bifurcation theorem. The stability of the Hopf bifurcation periodic solution is discussed by applying the normal form theory and the center manifold theorem. When parameters satisfy some conditions, the spatial homogenous equilibrium solution and the spatial homogenous periodic solution become unstable. Our results show that if parameters are properly chosen, Hopf bifurcation does not occur for the ODE system, but occurs for the PDE system. 相似文献
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LetD:~0'/0t'--bdenotetheD'AlembertianandR; ":=R xR",thenweconsiderthefollowingproblemDa~III',Da~III',(t,X)ERI ",(1)u(0,x)~6f(x),"t(0,x)=sg(x),xER",(2)v(0,x)~ej(x),yi(0,x)~E900,xER".(3)Herep,q,E>0andf,gii,gEC7(R").Thissystemarisesinphysicsandapplieds.i..ce[1].In1974,H.A.Levine[2]madeuseoftheconcavitymethodshowingthatthesolutionblowsupinfinitetimewithp,q>1andsufficientlylargedata.Veryrecently,K.Deng[31provedthatthereexistsaboundB(n)(5co)suchthatif1相似文献
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反应扩散方程组解的渐近性质 总被引:1,自引:0,他引:1
本文利用 L_p 估计、半群理论和 Liapunov 泛函方法,讨论一类反应扩散方程组齐次 Neumann 初边值问题解的渐近性质。证明了解 u(x,t)与其在Ω上的平均(?)(t)有相同的极限。 相似文献