具有正负系数中立型时滞微分方程的振动性

Oscillation for Neutral Differential Equations with Positive and Negative Coefficients

研究具有正负系数的中立型微分方程(x(t)-R(t)x(t-τ))′+p(t)x(t-r)-Q(t)x(t-σ)=0.(*)在允许条件R(t)+∫tt-r+σQ(s)ds=1不成立的条件下,获得了方程(*)所有解振动的充分条件.

Consider the neutral differential equations with positive and negative coefficients （x（t）-R（t）x（t-τ））＇＋p（t）x（t-r）-Q（t）x（t-σ）=0. Two sufficient conditions for solutions of Eq. （ ＊ ） to oscillate are obtained under the assumption that the equation R（t）＋∫l t-r＋σ Q（s）ds=1 does not hold.