共查询到20条相似文献,搜索用时 0 毫秒
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Yu. A. Chirkunov 《Mathematical Notes》2010,87(1-2):115-121
We obtain a sufficient condition for the absence of tangent transformations admitted by quasilinear differential equations of second order and a sufficient condition for the linear autonomy of the operators of the Lie group of transformations admitted by weakly nonlinear differential equations of second order. We prove a theorem concerning the structure of conservation laws of first order for weakly nonlinear differential equations of second order. We carry out the classification by first-order conservation laws for linear differential equations of second order with two independent variables. 相似文献
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We study existence and uniqueness of solutions for a general class of second order abstract differential equations with state-dependent delay. Some examples related to partial differential equations with state dependent delay are presented. 相似文献
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Hypoelliptic second order differential equations 总被引:34,自引:0,他引:34
Lars Hörmander 《Acta Mathematica》1967,119(1):147-171
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Ravi P. Agarwal Alexander Domoshnitsky Abraham Maghakyan 《Czechoslovak Mathematical Journal》2015,65(4):1047-1068
We propose a new method for studying stability of second order delay differential equations. Results we obtained are of the form: the exponential stability of ordinary differential equation implies the exponential stability of the corresponding delay differential equation if the delays are small enough. We estimate this smallness through the coefficients of this delay equation. Examples demonstrate that our tests of the exponential stability are essentially better than the known ones. This method works not only for autonomous equations but also for equations with variable coefficients and delays. 相似文献
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通过建立几个微分不等式将经典的微分方程零点比较定理推广到二阶非线性微分方程,得到若干新的结论. 相似文献
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《Quaestiones Mathematicae》2013,36(1):95-117
Abstract The equations for the Lie point symmetries of autonomous systems of second order linear ordinary differential equations are derived. The results for a two dimensional system are treated in detail and some consideration is extended to higher dimensional systems. The effect of the introduction of time-dependent elements into the coefficient matrix is briefly discussed. 相似文献
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陈永劭 《应用数学学报(英文版)》1989,5(3):234-241
In this paper, we consider the oscillation of the second order neutral delay differential equations[x(t) cx(t-τ)]" p(t)x(t-σ)=0 (1)and obtain some sufficient conditions of the oscillation of (1) for the case c≥0, -1≤c<0 and c<-1. 相似文献
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Václav Tryhuk 《Czechoslovak Mathematical Journal》2000,50(3):499-508
The paper describes the general form of an ordinary differential equation of the second order which allows a nontrivial global transformation consisting of the change of the independent variable and of a nonvanishing factor. A result given by J. Aczél is generalized. A functional equation of the form
f( t,uy,wy + uuz ) = f( x,y,z )u2 u+ g( t,x,u,u,w )uz + h( t,x,u,u,w )y + 2uwzf\left( {t,\upsilon y,wy + u\upsilon z} \right) = f\left( {x,y,z} \right)u^2 \upsilon + g\left( {t,x,u,\upsilon ,w} \right)\upsilon z + h\left( {t,x,u,\upsilon ,w} \right)y + 2uwz 相似文献
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Using the fixed point method we prove an existence result for positive solutions of nonlinear second order ordinary differential equations. An application to semilinear Schrödinger equations in exterior domains is also presented. Mathematics Subject Classification (2000) 34C10 相似文献
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I. T. Kiguradse 《Annali di Matematica Pura ed Applicata》1969,81(1):169-191
Summary The sufficient conditions for the existence and uniqueness of solution u(t) of the differential equation u″=f(t, u, u′), are
established, satisfying the condition
u(t)= =u0, u(t)≥0 and u′(t)≥0 for t ε (0,+∞).
Entrata in Redazione il 26 aprile 1968. 相似文献
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Kwang Ho SHON 《中国科学A辑(英文版)》2007,50(6):786-800
In this paper, we investigate the existence and the form of subnormal solution for a class of second order periodic linear differential equations, estimate the growth properties of all solutions, and answer the question raised by Gundersen and Steinbart. 相似文献
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Y.
ahiner 《Applied mathematics and computation》2004,150(3):2671-706
Oscillation criteria are obtained by using the so called H-method for the second order neutral type delay differential equations of the form
(r(t)ψ(x(t))z′(t))′+q(t)f(x(σ(t)))=0, tt0, The results of the paper contains several results obtained previously as special cases. Furthermore, we are also able to fix an error in a recent paper related to the oscillation of second order nonneutral delay differential equations. 相似文献 19.
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