Existence and Uniqueness Results for Quaternion-Valued Nonlinear Impulsive Differential Systems

This paper studies the existence and uniqueness conditions for the quaternion-valued nonlinear impulsive system. Firstly, a space of quaternion-valued piecewise functions is constructed and completeness of the space is also proved. Then by taking advantage of the Bielecki norm and fixed point theorem, existence and uniqueness criteria of quaternion-valued nonlinear impulsive system are obtained. At last, an example is given to illustrate our theoretical results.     

EXISTENCE AND UNIQUENESS AND STABILITY OF SOLUTIONS FOR STOCHASTIC IMPULSIVE SYSTEMS

This paper studies the existence, uniqueness, and stability of solutions for stochastic impulsive systems. By employing Lyapunov-like functions, some sufficient conditions of the global existence, uniqueness, and stability of solutions for stochastic impulsive systems are established. Furthermore, the results are specialized to the case of linear stochastic impulsive systems. Finally, some examples are given to illustrate the applications of our theory.     

On the Meromorphic Solutions of Linear Differential Equations

In this paper, we investigate the growth of meromorphic solutions of higher order linear differential equation f^（k） ＋Ak-1 （z）e^Pk-1^（z） f^（k-1） ＋…＋A1 （z）e^P1（z） f′ ＋Ao（z）e^Po（z） f = 0 （k ≤ 2）, where Pj（z） （j = 0, 1,..., k - 1） are nonconstant polynomials such that deg Pj = n （j = 0, 1,..., k - 1） and Aj（z）（≠ 0） （j = 0, 1,..., k - 1） are meromorphic functions with order p（Aj） 〈 n （j = 0, 1,..., k - 1）.     

THE EXISTENCE OF ORBITS CONNECTING CRITICAL POINTS OF DIFFERENTIAL EQUATIONS DEPENDING ON A PARAMETER

Using the concept of an isolated invariant set,some existence criteria of orbits connectingtwo critical points bifurcating from a single critical point for ordinary differential equations dependingon a parameter are given.     

Finite-Time Stochastic Stability of Random Impulsive Positive System

The paper focuses on the finite-time stochastic stability(FTSS) problems for positive system with random impulses. Combining Lyapunov functions with the probability property of the impulsive interval, first, the sufficient conditions of FTSS for the positive systems affected by one type of random impulses are given; second, the criteria of FTSS for positive systems suffered from multiple types of random impulses are established. Finally, two examples are presented to show the validity of results.     

常微分方程与代数方程求根

讨论了常微分方程与代数方程求根之间的联系。建立了常微分方程的解与代数方程根的一种联系关系，通过这种联系借助于常微分方程的求解，给出以大范围的初值求出代数方程全部实根的一种方法。还讨论了这种方法的几种具体数值求根算法，并对其中的一些有意义的现象进行了分析。     

EXISTENCE AND UNIQUENESS OF ENDEMIC STATES FOR THE AGE-STRUCTURED SEIR EPIDEMIC MODEL

An age-structured SEIR epidemic model of a vertically as well as horizontally transmitteddisease is investigated.Threshold results for the existence of endemic states are established for mostcases.Under certain conditions,uniqueness is also shown.Threshold used are explicitly computablein term of demographic and epidemiological parameters of the model.     

求解常微分方程的一类线性多步方法

本文给出常微分方程y′=f(t,y)及″=f(t,y)的一类线性多步方法,它们的系数容易在计算机上生成。     

IMPULSIVE BOUNDARY VALUE PROBLEMS FOR STURM-LIOUVILLE TYPE DIFFERENTIAL INCLUSIONS

In this paper, the authors investigate the existence of solutions of impulsive boundary value problems for Sturm-Liouville type differential inclusions which admit non-convex-valued multifunctions on right hand side. Two results under weaker conditions are presented. The methods rely on a fixed point theorem for contraction multi-valued maps due to Covitz and Nadler and Schaefer＇s fixed point theorem combined with lower semi-continuous multi-valued operators with decomposable values.     

ON THE COMPLEX OSCILLATION OF HIGHER ORDER LINEAR DIFFERENTIAL EQUATIONS WITH MEROMORPHIC COEFFICIENTS

In this paper, we investigate the complex oscillation of higher order homogenous and non- homogeneous linear differential equations with meromorphic coefficients of iterated order, and obtain some results which improve and extend those given by Z. X. Chen, L. Kinnunen, etc.     

改进的向后微分公式

采用增加方法步数的办法构造了两类求解刚性微分方程的改进的向后微分公式IBDF1及IBDF2。理论分析和数值试验表明,这两类新方法在较大地改善了BDF的稳定性的同时保持了BDF原有的主要优点。     

Existence of Positive Periodic Solutions for the SIV Epidemic Model with Impulsive Vaccination and Infection-Age

In this paper, we discuss the SIV epidemic model with impulsive vaccination and infection-age. Bifurcation theory and Lyapunov-Schmidt series expansion are used to show the existence of the positive periodic solutions under some conditions.     

IMPLICITIZATION OF PARTIAL DIFFERENTIAL RATIONAL PARAMETRIC EQUATIONS

In this paper, we propose algorithms for the following problems in the implicitization of a set of partial differential rational parametric equations P. （1）To find a characteristic set for the implicit prime ideal of P; （2） To find a canonical representation for the image of P; （3）To decide whether the parameters of P are independent, and if not, to re-parameterize P so that the new parametric equations have independent parameters; （4） To compute the inversion maps of P, and as a consequence, to decide whether P is proper.     

基于局部微分方程组的生态系统模拟

将变系数微分方程组描述的一个生态系统模型,分解为几个常系数微分方程组描述的子模型。调用Matlab中的odes函数,通过研究这些局部常系数微分方程组而实现对整个生态系统的模拟与仿真。运行结果表明,模型的拟合性教好;抗性分析表明,计算结果可信。因此这种仿真算法在生态系统模拟中可行。     

非线性中立型延迟微分方程的散逸性

主要研究非线性中立型延迟微分方程本身及其数值方法的散逸性问题。首先,对此类中立型延迟微分方程理论解的散逸性给出了充分条件;随后,应用一类线性多步法求解至该类问题,证明了在适当条件下,其数值解也具有散逸性;最后,数值试验进一步验证了理论结果的正确性。     

Parallel Rosenbrock Methods for DifferentialAlgebraic Equations

1. INTRODUCTIONWe consider the system of dtherelltial-algebraic equations(DAE)where y is in some space E and z in EI. For convenience of notations we assume that y and z are scalarqualities. All subsequeDt formulas remain valid for vectors if the derivatives are interpreted as multilinearmappings. We suppose that the initial values are consistent, i.e. g(yo, to) = 0. Moreover j and g are assumedto be sufficiently differentiable. We also assume the DAE system to be of index one; it me…     

Rational Solutions of High-Order Algebraic Ordinary Differential Equations

This paper considers algebraic ordinary differential equations(AODEs) and study their polynomial and rational solutions. The authors first prove a sufficient condition for the existence of a bound on the degree of the possible polynomial solutions to an AODE. An AODE satisfying this condition is called noncritical. Then the authors prove that some common classes of low-order AODEs are noncritical. For rational solutions, the authors determine a class of AODEs, which are called maximally comparable, such that the possible poles of any rational solutions are recognizable from their coefficients. This generalizes the well-known fact that any pole of rational solutions to a linear ODE is contained in the set of zeros of its leading coefficient. Finally, the authors develop an algorithm to compute all rational solutions of certain maximally comparable AODEs, which is applicable to 78.54% of the AODEs in Kamke's collection of standard differential equations.     

微分差分方程的稳定性与时变不确定系统的鲁棒性研究

本文用矩阵测度和比较定理研究了具有滞后的时变不确定系统和微分差分方程，得到了不确定系统能稳和微分差分方程零解一致渐近稳定的充分条件。     

Boundary Value Problems for Singular and Time-delay Measure Differential Systems with Impulsive Effects

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Mean Square Stability of Impulsive Stochastic Delayed Reaction-Diffusion Equations via Comparison Principle with Razumikhin Method

This paper investigates the mean square stability problem for impulsive stochastic delayed reaction-diffusion equations. By employing stochastic analysis theory, impulsive differential inequality technique and Razumikhin method, comparison principle for impulsive stochastic delayed reactiondiffusion equations is firstly established. Then, by using the comparison principle, some sufficient conditions are derived to ensure the mean square stability, mean square uniform stability, mean square asymptotic stability and mean square exponential stability of such systems. Finally, an example is provided to show the effectiveness of the proposed results.