中立型微分差分方程解的振动性

On the Oscillation of Solutions for Differential Difference Equations of the Neutral Type

对中立型微分差分方程ｄ［ｙ（ｔ）＋Ｐｙ（ｔ－τ）］／ｄｔ＋Ｑ（ｔ）ｙ（ｔ—τ）＝０，其中Ｐ∈Ｒ，τ∈（０，∞），σ∈［０，∞），Ｑ∈Ｃ（［ｔ０，∞），Ｒ＋），得到了其一切解振动的充分条件及非振动解的渐近性质，其结果推广并改进了文献中的一些熟知定理．

The sufficient conditions for the oscillation of all solutions and the asymptotic charactehatics of non-oscillatory solutions of the neutral differential difference equation d [y (t) +Py (t - τ) ] /dt + Q (t) y (t-τ) =0 are obtained, where P∈R, τ∈e(0, ∞), τ∈[0,∞ ), Q∈C([t0,∞ ), R+). These results can extend and improve on some of the known theorems in the literature.