一类非线性系统解的有界性

该文研究了非线性微分系统(dx/dt)=h(y)-φ(x), (dy/dt)=-h(y)f(x)-g(x)k(y)解的有界性。获得该系统的所有解有界的充分条件。应用此结果于Liénard方程 d^2x/dt^2+f^*(x)(dx/dt)+g)^*(x)=0,改进和推广了文［1-6］中的相应结果。      

一类二阶非线性微分系统解的有界性

研究了如下一类二阶非线性微分系统解的有界性.得到了(E)的所有解有界的新的充分条件和充分必要条件.所获结果能够应用于Lienard类型方程它改进与扩展了[1-5]等文献中的相应结果.     

一类二阶非线性泛函微分方程解的有界性

§1.引言本文讨论二阶非线性泛函微分方程(r(t)y′)′ f(t,y) g(t,y_t)=p(t) (1)解的有界性.我们将证明,当方程(r(t)x′)′ f(t,x)=0 (2)的一切解有界,加上某些补充条件,可以保证方程(1)亦有同样的性质.我们约定,f:I=[t_0,∞)×D((?)R)→R=(-∞, ∞)及 r:I→R~ =[0,∞)为连续函数,f_x(t,x)在 I×D 存在、连续.用 x(t)=x(t;s,x_0,x′_0)表示方程(2)满足初始条件 x(s)=x_0,r(s)x′(s)=x′_0的唯一解.此方程的每一有界解可以延拓到全区间(?),因此在 I~2×D~2上关于它的四个独立变量连续可微.从一阶常微分方程组解关于初值     

具多个奇点的广义Liénard系统解的有界性

本文讨论具有有限多个奇点的广义Liénard系统解的有界性,得到一组保证系统的解正向有界的充分条件,进而得到存在极限环的条件。     

一类二阶非线性微分系统有界性与收敛性的充分必要条件

本文给出了如下一类二阶非线性微分系统 解的有界性的一些新的充分条件,获得了（Ｓ’）的所有解有界或收敛到零的充分必要 条件．所获的结果能够应用于Ｌｉｅｎａｒｄ类型方程 它改进与扩展了［１,２］等文献关于同样问题的一些重要结果．     

一类具时滞的Liénard型方程的周期解

利用Mawhin的重合度理论，研究了一类具时滞的Liénard型方程的周期解的存在性，并举例说明了其应用．     

周期扰动的非保守系统的周期解的存在性与唯一性

考虑具有周期扰动的Linard型非保守系统 +C+gradG(x)=p(t),其中C是n×n的实对称方阵,x=(x_1,x_2,…x_n)~T∈R~n,G∈C~2(R~n,R),p∈C(R,R~n)且p(t+ω)≡p(t),ω>0是常数,利用重合度理论讨论周期解的存在性与唯一性,得到了苦干简便的判别条件。     

一类二阶非线性微分系统解的有界性

§ 1 .　IntroductionThepurposeofthispaperistoobtainsharpconditionsfortheboundednessofallsolutionsofthefollowingnonlineardifferentialsystemsdxdt =y- φ(x) ,dydt=- yf(x) - g(x) . ( 1.1)Whereandthroughoutthispaper,f(x) ,g(x) ,φ(x)arecontinuousrealvaluefunctionsde finedonR .Moreover,weassumetheexistenceanduniquenessofthesolutionsoftheCauchyinitialvalueproblemof( 1.1) .Thebounedenssofsolutionsforsomespecialcaseof( 1.1)hasbeenextensivelystudiedintheliterature.Wereferto [1— 10 ]andthereferencesth…     

高维Linard型系统的周期解

本文讨论高维Ｌｉｅｎａｒｄ型系统的周期解问题，在文［１－８］的基础上得到了一些新的结果。     

关于Liénard方程周期解的存在性与唯一性

考虑微分方程x f(x) g(x)=p(t)其中g（x）∈C（R),p（t)∈πC2,f∈C(R),在g（x)满足（g（x）-g（y))／（x-y）＜ａ＜1时,给出周期解的存在性,并对f(x)=cx的特殊情形,ｇ（x）严格递减的条件下,给出周期解存在唯一的充要条件．     

ON THE BOUNDEDNESS CONDITIONS FOR SOLUTIONS OF A AUTONOMOUS DIFFERENTIAL SYSTEM

ＯＮＴＨＥＢＯＵＮＤＥＤＮＥＳＳＣＯＮＤＩＴＩＯＮＳＦＯＲＳＯＬＵＴＩＯＮＳＯＦＡＡＵＴＯＮＯＭＯＵＳＤＩＦＦＥＲＥＮＴＩＡＬＳＹＳＴＥＭ￥ＨｕａｎｇＬｉｈｏｎｇ（黄立宏）；ＷａｎｇＺｈｉｃｈｅｎｇ（王志成）（ＨｕｎａｎＵｎｉｖｅｒｓｉｔｙ，湖南大学...     

一类非线性系统解的有界性

本文研究了一类非线性系统解的正向有界性.运用常微分方程定性理论的方法,获得了这类方程所有解有界的充分条件和必要条件.推广和改进了已有文献中的结果.     

BOUNDEDNESS OF SOLUTIONS AND EXISTENCEOF LIMIT CYCLES FOR A NONLINEAR SYSTEMOF DIFFERENTIAL EQUATIONS

IntroductionTheautonomousplanarsystemoftheformwasfirststudiedbyLevinsonandSmithintheclassicalpaper[2]astheequivalelltsystellloftheequationofLienardtypeandlateronsomeauthorshavecontributedtotiletheoryofthissystemwithrespecttoqualitativebehaviorofsolutionsll--9].InthepresentpaperwestudyasystemOfaslightlymoregeneraltype,namely,wherethefllnctionsp(y),q(y),g(x)andh(x,y)arecontilluousforallvalueoftheirarguments,and3'resubjecttotheconditionswhichensurethattheexistenceofuniquesolutiontotheinitialvalu…     

ON POSITIVE SOLUTIONS OF ONE CLASS OF NONLINEAR DIFFERENTIAL EQUATIONS

ＯＮ　ＰＯＳＩＴＩＶＥＳＯＬＵＴＩＯＮＳＯＦＯＮＥＣＬＡＳＳＯＦＮＯＮＬＩＮＥＡＲＤＩＦＦＥＲＥＮＴＩＡＬＥＱＵＡＴＩＯＮＳ￥ＹａｎｇＣｈｕａｐｅｎｇ（杨春鹏）（Ｄｅｐｔ．ｏｆＳｙｓ．Ｓｃｉ．ａｎｄＭａｔｈ．，Ｚｈｅｎｇｚｈｏｕ，Ｕｎｉｖｅｒｓｉｔｙ...     

SELF-SIMILAR SOLUTIONS OF A CLASS OF NONLINEAR PAPTIAL DIFFERENTIAL EQUATION

1IntroductionInthispaper,westudythefollowingnonlinearpartialdeferentialequationwherea(20)andp(>1)areconstants.(z,Vu(t,x))isthescalarOfxandVu(f,x),i.e.nx=(xl,...tx.),y=(yi,'',ye)then(x,y)=Zfiji.Withoutlossofgenerality,wetarei=1a=1.Thepurposeofthispaperistwo-fold.Firstweprovetheealltenceofglobalsolutions(Theorem2.1),thenweshowthatthereedestsapositivesolutionwithzeroinitialvalueinW','(Theorem1.1),thusthenon-uniquenessisestablishedwhentheinitialvalueiszeroinWI,a(R").Theorem1.1canberegardedas…     

EXISTENCE OF SOLUTIONS IN THE FUTURE FOR A CLASS OF NONLINEAR DIFFERENTIAL SYSTEMS

1 IntroductionThe problem cited in the title above is an old problem, and has been studiedby many authors. Some good results can be found in [1-5] and referencesquoted therein.In this paper we are concerned with this problem for the nonlinear differential systemJ 1 -- ':)>.--,,<,> ~ F(x), (1 l)where E,P, F, q and g are continuous real functions defined on R. Clearly, ifputting E(z) = z, p(y) = y and q(y) H 1, then (1.1) gives the well-knownLi6nard system{ 1:,.:<">, (l 2)Therefore, (1.1) is…     

ON THE BOUNDEDNESS OF A CLASS OF NONLINEAR DYNAMIC EQUATIONS OF THE THIRD ORDER

In this paper, a modified nonlinear dynamic inequality on time scales is used to study the boundedness of a class of nonlinear third-order dynamic equations on time scales. These theorems contain as special cases results for dynamic differential equations, difference equations and $q$-difference equations.     

二阶非线性微分议程解的平方可积性与有界性(英文)

1 IntroductionIn this paPer, we consider the second order nonlinear differential equationwhere r(t) > 0 fOr t E [a, oo) and r(t) is absolutely continuous on [a, oc), p, q1and q2 are real functions defined on [a, oo) and f is a real function defined on[a, oo) x (--oc, oo) which satisfieswhere 0 S cr S 1, g(t) 2 0 and h(t) 2 0 for t E [a, oo).The behaviors of quadratic integrability and boundedness fOr some moreparticular forms of equation (l) such as have been studied (see [1--4]). And many …     

一类四阶非线性微分方程解的渐近性态

本文利用Liapunov函数方法，研究了一类四阶非线性微分方程解的渐近稳定性及有界性。