ON THE INTEGRATING FACTOR OF ABEL EQUATION

ＯＮＴＨＥＩＮＴＥＧＲＡＴＩＮＧＦＡＣＴＯＲＯＦＡＢＥＬＥＱＵＡＴＩＯＮＹｉｎｇＹｉｒｏｎｇ（应益荣）＆ＤａｎｇＸｉｎｙｉ（党新益）（ＮｏｒｔｈｗｅｓｔＵｎｉｖｅｒｓｉｔｙ，西安西北大学，邮编：７１００６９）Ａｂｓｔｒａｃｔ：Ｔｈｅｎｅｃｅｓｓａｒｙ...     

GLOBALLY ASYMPTOTIC STABILITY OF A RECURRENCE SEQUENCE

1 IntroductionConsider the difference equationwhere a, 5, c and the initial data x--1 and xo are positive numbers. In thispaper, we obtain a few sufficient conditions for the global attraction whichwere proposed by V.L.Kocic and G.Lada,[1].2 Main ResultsThe following lemma guarantee the following difference equation to have aunique positive equilibrium point x*. \Lemma 2.1 Ifthen equation {1) has a unique positive equilisrium point x*.Proof The equilibrium point x* of equation (1) satisfy …     

关于高维非自治系统周期解的判据

本文利用拓扑度的理论，研究了ｎ阶非线性系统ｘ＝ｐ（ｔ）ｘ＋μｈ（ｔ，ｘ）得到，若系统（＊）对应的齐次方程ｘ＝ｐ（ｔ）ｘｄ无非平凡ω周期解，系统（＊）的ω周期解存在及其个数的重要判据。