Delay‐dependent criteria on the global attractivity of Nicholson's blowflies model with patch structure

In this paper, we investigate the effect of delay on the asymptotic behavior of Nicholson's blowflies model with patch structure and multiple time‐varying delays. By using the fluctuation lemma and some differential inequality technique, delay‐dependent criteria are obtained for the global attractivity of the addressed system. Meanwhile, some numerical examples are given to illustrate the feasibility of the theoretical results. Copyright © 2017 John Wiley & Sons, Ltd.     

Oscillation theorems for fourth‐order delay differential equations with a negative middle term

This paper deals with the oscillation of the fourth‐order linear delay differential equation with a negative middle term under the assumption that all solutions of the auxiliary third‐order differential equation are nonoscillatory. Examples are included to illustrate the importance of results obtained.     

Global exponential convergence for a class of neutral functional differential equations with proportional delays

This paper is concerned with a class of non‐autonomous neutral functional differential equations with multi‐proportional delays. It is shown that all solutions of the addressed system are globally exponentially convergent by employing the differential inequality technique and a novel argument. The obtained results improve and supplement existing ones. We also use numerical simulations to demonstrate our theoretical results. Copyright © 2016 John Wiley & Sons, Ltd.     

Oscillation of Second-order Delay Differential Equation

By using some differential inequality, a second-order delay differential equation(r(t)x′(t))′ p(t)x(q(t)) = 0has been investigated and some necessary condition for this equation has a nonoscillatorysolution and some sufficient condition which ensures that all of the solutions of the aboveequation are oscillatory are obtained.     

Structured populations with distributed recruitment: from PDE to delay formulation

In this work, first, we consider a physiologically structured population model with a distributed recruitment process. That is, our model allows newly recruited individuals to enter the population at all possible individual states, in principle. The model can be naturally formulated as a first‐order partial integro‐differential equation, and it has been studied extensively. In particular, it is well posed on the biologically relevant state space of Lebesgue integrable functions. We also formulate a delayed integral equation (renewal equation) for the distributed birth rate of the population. We aim to illustrate the connection between the partial integro‐differential and the delayed integral equation formulation of the model utilising a recent spectral theoretic result. In particular, we consider the equivalence of the steady state problems in the two different formulations, which then lead us to characterise irreducibility of the semigroup governing the linear partial integro‐differential equation. Furthermore, using the method of characteristics, we investigate the connection between the time‐dependent problems. In particular, we prove that any (non‐negative) solution of the delayed integral equation determines a (non‐negative) solution of the partial differential equation and vice versa. The results obtained for the particular distributed states at birth model then lead us to present some very general results, which establish the equivalence between a general class of partial differential and delay equation, modelling physiologically structured populations. Copyright © 2016 John Wiley & Sons, Ltd.     

时滞微分方程的稳定性

该文利用时滞Gronwall Bellman不等式得到了一些判定时滞微分方程稳定性的充分条件, 特别地,为方便应用,对线性时滞微分方程给出了一些仅与方程右端项有关的简明判据.     

非线性中立型抛物微分方程解的振动性

This paper deals with the oscillatory properties of a class of nonlinear neutral parabolic partial differential equations with several delays. Sufficient criteria for the equation to be oscillatory are obtained by making use of some results of first-order functional differential inequalities. These results fully reveal the essential difference between this type and that without delays.     

广义泛函微分方程解的稳定性

本文首先给出广义泛函微分方程解的稳定性的概念,同时建立了有关稳定与不稳定的二个判据,然后作为例子,讨论二阶线性常系数广义微分差分程,得到了这类系统有关稳定与不稳定的若干结果,并发现了一些关于稳定性的分支或类似于分支的现象。     

Properties of stationary states of delay equations with large delay and applications to laser dynamics

We consider properties of periodic solutions of the differential‐delay system, which models a laser with optical feedback. In particular, we describe a set of multipliers for these solutions in the limit of large delay. As a preliminary result, we obtain conditions for stability of an equilibrium of a generic differential‐delay system with fixed large delay τ. We also show a connection between characteristic roots of the equilibrium and multipliers of the mapping obtained via the formal limit τ→∞. Copyright © 2004 John Wiley & Sons, Ltd.     

非线性时滞双曲型偏泛函微分方程的振动准则

研究一类多滞量非线性双曲型偏泛函微分方程解的振动性,借助广义Riccati变换和微分不等式技巧,获得了该类方程振动的若干新的充分条件,同时也给出了实际应用的例子.     

偶数阶时滞偏微分方程组解的振动性定理

本文获得了一类偶数阶时滞偏泛函微分方程组解振动的若干充分条件     

Global attractivity in a perturbed linear delay differential equation

In the main result of this paper, some sharp conditions are obtained for global attractivity in a scalar perturbed linear delay differential equation. The proof of the main theorem is based on a new estimate for the infinite integral of the absolute value of the fundamental solution of a linear delay differential equation. We also derive sufficient conditions for asymptotic stability of a system of linear delay differential equations.     

The RKHSM for solving neutral functional–differential equations with proportional delays

In this paper, the reproducing kernel Hilbert space method (RKHSM) is applied to neutral functional–differential equations with proportional delays. Its approximate solution is obtained by truncating the n‐term of exact solution. Some examples are displayed to demonstrate the computation efficiency of the method. We also compare the performance of the method with a particular Runge–Kutta method, a one‐leg θ‐method and variational iteration method. Experiment dates indicate that the RKHSM is an accurate and efficient method to solve neutral functional–differential equations with proportional delays. Copyright © 2012 John Wiley & Sons, Ltd.     

GENERIC OSCILLATIONS OF FIRST ORDER IMPULSIVE DELAY DIFFERENTIAL EQUATIONS

In this paper, we will study generic oscillation and generic nonoscillation of first order impulsive delay differential equations. A necessary and sufficient condition and some sufficient conditions are obtained for both phenomena based on the root of characteristic equation.     

A Hilbert space approach to homogenization of linear ordinary differential equations including delay and memory terms

We present an abstract approach to homogenization in a Hilbert space setting. Related compactness results are obtained. Moreover, the homogenized equations may be computed explicitly, if periodicity is imposed. Examples for the applicability of our homogenization result for linear ordinary (integro‐)differential equations are given. Copyright © 2012 John Wiley & Sons, Ltd.     

Delay driven Hopf bifurcation and chaos in a diffusive toxin producing phytoplankton‐zooplankton model

This paper deals with a diffusive toxin producing phytoplankton‐zooplankton model with maturation delay. By analyzing eigenvalues of the characteristic equation associated with delay parameter, the stability of the positive equilibrium and the existence of Hopf bifurcation are studied. Explicit results are derived for the properties of bifurcating periodic solutions by means of the normal form theory and the center manifold reduction for partial functional differential equations. Numerical simulations not only agree with the theoretical analysis but also exhibit the complex behaviors such as the period‐3, 5, 6, 7, 8, 11, and 12 solutions, cascade of period‐doubling bifurcation in period‐2, 4, quasi‐periodic solutions, and chaos. The key observation is that time delay may control harmful algae blooms (HABs). Moreover, numerical simulations show that the chaotic states induced by the period‐doubling bifurcation are purely temporal, which is stationary in space and oscillatory in time. The investigations may provide some new insights on harmful phytoplankton blooms.     

一类具连续分布滞量的高阶偏微分方程的振动性

研究一类具有连续分布滞量中立项的非线性偏微分方程解的振动性,得到该方程在给定边值条件下振动和非振动的一些充分条件.     

超线性时滞微分方程解的振动性

研究一阶超线性时滞微分方程x′(t) p(t)[x(t—γ)]^α＝0(α＞1)解的振动性及非振动性,获得了保证其所有解振动的“almost sharp”准则,并应用所得结果于混合型时滞微分方程x′（t） ∑^ni=1pi（t）[x（t-γi]^αi=0,得到一族振动准则。     

Finite‐time stability of CNNs with neutral proportional delays and time‐varying leakage delays

In this paper, a class of cellular neural networks with neutral proportional delays and time‐varying leakage delays is considered. Some results on the finite‐time stability for the equations are obtained by using the differential inequality technique. In addition, an example with numerical simulations is given to illustrate our results, and the generalized exponential synchronization is also established. Copyright © 2016 John Wiley & Sons, Ltd.     

Periodic solutions to second order nonautonomous differential systems with unbounded nonlinearities

We investigate the existence of periodic solutions of differential systems with a skew‐symmetric matrix term and unbounded nonlinearities. Under new generalized Ahmad‐Lazer‐Paul conditions, some existence results are obtained and some results in the literature are improved.