CLASSIFICATION AND EXISTENCE OF POSITIVE SOLUTIONS OF SECOND ORDER NONLINEAR DIFFERENTIAL EQUATIONS WITH DELAY DEPENDING ON THE UNKNOWN FUNCTION

A class of second order nonlinear differential equations with delay depenging on the unknown function of the fromin the case where ∫0∞ ds/r(s) < ∞ is studied. Various classifications of their eventually positive solutions are given in terms of their asymptotic magnitudes, and necessary as well as sufficient conditions for the existence of these solutions are also obtained.

三阶有重根Poincar啨差分方程解的渐近性质

研究了三阶Poincar啨差分方程解的渐近性质这种差分方程对应的常系数线性差分方程的特征方程有重根

一类Pointaré差分方程解的渐近性质

以二阶的情形讨论了Ｐｏｉｎｃａｒ差分方程ｙ（ｎ＋ｍ）十（ａ１＋ｐ１（ｍ））ｙ（ｎ＋ｍ－１）＋…＋（ａｎ＋ｐｎ（ｍ））ｙ（ｍ）＝０当其常系数部分ｘ（ｎ＋ｍ）＋ａ１ｘ（ｎ＋ｍ－１）＋…＋ａｎｘ（ｍ）＝０的特征方程有相同的根时，解的渐近性质．通过不动点方法给出了Ｐｏｉｎｃａｒ差分方程的解渐近于其常系数方程解的条件，并给出了渐近式高阶项的估计．

一类非线性常微分方程正解的存在性与渐进性

本文讨论了一类非线性二阶常微分方程 0)()()1())((1=-++xuxpxxum 0],1,0(>mx 正解的存在问题,用非线性算子方法证明了正解的存在性、唯一性。并且,给出了这个正解的一个逼近。推广了文献[1]的某些结论。

具状态时滞的高阶非线性微分方程正解正在性及分类(英文)

本文研究一类形如 (r(t)x(n- 1) (t) )′+f(t,x(t) ,x(Φ(t,x(t) ) ) =0 的具状态时滞的高阶非线性微分方程 .按照最终正解的量级给出了它们的分类及存在的充分条件 .

时滞依赖于未知函数的高阶非线性微分方程正解的分类及存在性(英文)

研究了一类时滞依赖于未知函数的高阶非线性微分方程(an-1(t)(an-2(t)…(a1(t)(x(t))x′(t))′…)′)′+f(t,x(t),x(Δ(t,x(t))))=0.其中∫0∞aid(ss)<∞(i=1,2,…,n-1),n≥2为偶数.根据最终正解的渐近性给出了解的各种分类情况,并建立了存在这些解的充分和必要条件.

扰动的广义Emden-Fowler差分方程解的性质

利用不动点定理,得到了广义Emden-Fowler差分方程在扰动下的有界解和无界解,并分析了这些解的振动性和渐近性质。

一类二阶非线性微分方程的解的渐近性

利用Schauder不动点定理,研究二阶非线性微分方程u″=f(t,u,u)′,t≥1解(f∈C[[1,∞)×R×R,R])的渐近性,给出方程解渐近于直线at+b(a,b∈R)的一个充分条件.从而推广文献[2]定理1的结果,简化文献[3]中定理4成立的条件.

CONVERGENT AND DIVERGENT SOLUTIONS OF TWO-DIMENSIONAL NONLINEAR DIFFERENCE SYSTEM

In this paper, we are concerned with the existence of convergent or divergent solutions of two-dimensional nonlinear difference system of the form{xn＋1=αnxn＋bnf（yn）,yn=cnyn-1＋dng（xn）.We＇ classify their solutions according to asymptotic behavior and give some sufficient and necessary conditions for the existence of solutions of such classes by using the method of the fixed point theorem. We also give an example and show how the results can be applied to certain difference systems.