摘要
The aim in this paper is to cite instances in illustration of the incorrectness of certain oscillation theorems in Yan [1] . We also point out that the proof of the main theorems in [ 1 ] is not true, and express our correct opinion upon these mistakes.
文[1]研究了一阶时滞微分方程 y＇(t)+α(t)y(t)+sum from i=1 to n(p_i(t))multiply from j=1 to m_1(|y(t-τ_(ij)(t))|~α_(ij)sgn y(t-τ_(ij)(t))=0)。 (1) 的解的振动性。其中p_i(t)≥0,τ_(ij)(t)>0在R_+=[0,∞)上连续且τ_(ij)(t)<t,i∈I={1,2,…,n},j∈J={1,2,…,m_i},α(t)是R_+上的连续函数且允许对任意大的t可取负值。非负数α_(ij)满足条件sum from j=1 to m_i(α_(ij)=1),i∈I。得到了一些振动和非振动定理。
