吳冬梅,陶元紅
(延邊大學 理學院數(shù)學系,吉林 延吉 133002)
帶有正負系數(shù)的非線性偏差分方程的不飽和解
吳冬梅,陶元紅?
(延邊大學 理學院數(shù)學系,吉林 延吉 133002)
利用數(shù)列的頻密測度的定義及其相關性質(zhì),對一類帶有正負系數(shù)的時滯偏差分方程的不飽和性問題做了深入的討論,得出此類方程的解具備不飽和性的充分條件.由于不飽和解一定是振動解,本文的結論不僅準確刻畫了解的振動頻率,而且完善了解的振動性描述.
偏差分方程;頻密測度;不飽和性
經(jīng)典的振動概念已經(jīng)不能準確描述數(shù)列的振動頻率,為了更細致地刻畫數(shù)列的振動性,田傳俊等[1]首次引進了數(shù)列的頻密測度的概念,并由此定義了數(shù)列的頻密振動性.朱志強等[2]又定義了數(shù)列的頻密正振動和負振動概念,并且利用這些概念刻畫了無窮雙序列的不飽和性概念,更加完善了對數(shù)列的頻密振動的描述.目前已有一些關于差分方程的解的頻密振動性結果,見文獻[3-9].
本文討論如下一類非線性偏差分方程的不飽和解:
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[2]Zhu Z Q,Cheng S S.Frequently oscillatory solutions of neutral difference equations[J].Southeast Asian Bulletin of Mathematics,2005,29(3):627-634.
[3]Cheng S S.Partial Difference Equations[J].Advances in Discrete Mathematics and Applications Taylor&Francis,London,UK,2003.
[4]Tian C J,Cheng S S,Xie S L.Frequently Oscillatory Crite?ria for a Delay Difference Equation[J].Funkcialaj Ekva?cioj,2003,46:421-439.
[5]Zhu Z Q,Cheng S S.Frequently oscillatory solutions for multi-level partial difference equations[J].Internat Math Forum,2006,31:1497-1509.
[6]Yang J,Zhang Y J.“Frequent oscillatory solutions of a nonlinear partial difference equation”[J].Journal of Math?ematical Analysis and Applications,2009,224:492-499.
[7]李冬梅,陶元紅.一類非線性時滯偏差分方程的不飽和解[J].延邊大學學報:自然科學版,2010,36(2):95-100.
[8]Tao Y H,Li X D.Frequently Oscillatory Solutions for Nonlinear Delay Partial Difference Equations[J].Journal of Natural Science of Hei Longjiang Univercity,2010,27(5):591-595.
[9]陶元紅,吳冬梅.一類中立型偏差分方程的差頻密振動性[J].延邊大學學報:自然科學版,2011,37(1):42-45.
Unsaturated Solutions of Nonlinear Partial Difference Equation with Positive and Negative Coefficients
WU Dongmei,TAO Yuanhong*
(Department of Mathematics,College of Sciences,Yanbian University,Yanji133002,China)
By employing the concept and the properties of frequency measures of sequences,the unsaturated solutions of the nonlinear partial difference equation with positive and negative coefficients are discussed.Some new criteria of un?saturated solutions are established and the sufficient conditions of solutions to be unsaturated are presented.Since the unsaturated solutions are oscillatory,the results not only well describe the oscillation frequency of the solution but also generalize the description of oscillation.
partial difference equation;frequency measure;unsaturated solution
O 177.3
A
1674-4942(2011)04-0355-04
2011-09-28
國家自然科學基金資助項目(11161049)*通訊作者
畢和平