函数的周期

In this paper,by using the comparison theorems and constructing suitable Lyapunov function, the sufficient conditions are obtained for the permanence and existence of globally asymptotically stable positive periodic solution of the system.

研究了具有反馈控制的n种群非自治周期竞争系统的持续性，利用微分不等式并构造适当的Lyapunov函数得到系统存在惟一、全局吸引的正周期解的充分条

With the help of comparison theorem, sufficient conditions which guarantee permanence of the system are obtained. For the almost periodic case, by constructing a suitable Liapunov function, we obtained that the system has a unique globally asymptotically stable positive almost periodic solution. Finally, we study a multispecies predator-prey system with stage structure and Holling II type functional response.

第二部分考虑具有阶段结构的非自治扩散捕食系统，利用比较定理得到该系统持久生存的充分条件，其后在概周期情形下通过构造合适的Liapunov函数得到了保证该系统存在唯一一个全局渐近稳定的概周期解的条件。

Firstly, we consider SIQR epidemical models with continuous and pulse vaccinations; the reproduction numbers have been obtained for those models; by using Dulac function, we prove the global stabilities of equilibrium of SIQR model with continuous vaccination. In the SIQR epidemical models with pulse vaccinations, we have also discussed the existence of the infection-free periodic solution, the global stabilities of the infection-free periodic solutions, and the effectiveness of pulse vaccination and continuous vaccination policies has been compared for the two models.

文中首先考虑具有连续免疫接种和脉冲免疫接种的SIQR传染病模型，分别获得了它们各自的基本再生数；利用Dulac函数方法证明了具有连续免疫接种的SIQR模型无病平衡点的全局渐近稳定性；在脉冲免疫接种下SIQR传染病模型里，讨论了无病周期解的存在性，证明了该周期解的全局渐近稳定性，并且对连续和脉冲接种下的SIQR传染病模型的接种效率进行了比较。

This system is permanent by comparative principle and globally asymptotically stable through constructing a Liapunov function; for the periodic case, the research has obtained conditions for existence, uniqueness and stability of a positive periodic solution.

利用比较原理研究了系统的持久性，通过构造Liapunov函数证明了系统的全局渐近稳定性，在假设系统为周期系统的条件下得到了正周期解的存在唯一性和全局渐近稳定的充分条件。

SP. transient electromagnetic method: An electromagnetic method in which the waveform of the transmitted signal is a pulse, step function, ramp, or other form which can be considered to be nonperiodic and in which measurements are made after the primary field has stopped changing.

瞬变电磁法：一种电磁勘探方法，其中发射信号的波形是一个脉冲，阶跃函数，斜升函数或其它可认为是非周期的信号形式，且测量是在一次场停止变化后进行的。

On the basic of NNLSE and the Poisson equation, using the Green function approach, we obtain the response function of the lead glass of finite-size, which is a strong nonlocal medium. Starting with the paraxial ray equation, we obtain the analytical solutions of the oscillation trajectory and period of the beam.

基于非局域非线性薛定谔方程以及热传导的泊松方程，采用格林函数法求出了强非局域介质铅玻璃的响应函数和临界功率；从光线方程出发得到了偏离材料中心入射的光束中心振荡轨迹以及周期的解析解。

The existence of solution is studied for a class of second - order periodic boundary value problems with first applying Leray - Schauder fixed point theorem, two exislence theorems are established.

考察了一类非线性项含有一阶导数的二阶周期边值问题的解的存在性，其中非线性项是Carathèodory函数。通过构造非线性项的高度函数并且利用Leray-Schauder不动点定理建立了两个存在定理。

Using the method of singular Lyapunov's function, we give the theories which singular systems exist stationary oscillation.

第四章对广义系统给出其有界性的相关定义，利用广义Lyapunov函数，讨论了广义非线性系统的有界性问题，并得到了周期广义系统若存在一个最终有界解，则必存在周期解的结论，推广了古典系统相应的结论。

The feedback controls, including linear, speed, doubly-periodic function, hyperbolic function and trigonometric function are used to suppress chaos to one of the three unstable equilibrium. The Routh-Hurwtiz theorem is applied to derive the conditions of stability of the controlled system.

利用反馈控制方法，包括线性、速度、双周期函数、双曲函数和三角函数反馈控制方法将系统的混沌运动控制到稳定态，根据Routh-Huriwtz准则获得了系统达到控制目标时反馈系数所满足的条件。

By Independent-subsystem method, the results of existence and global attractivity of a positive periodic solution are obtained.

本文运用重合度理论中的Mawhin延拓定理或系统的持久性结果得到了几类种群生态学模型正周期解的存在性条件；并通过构造Lyapunov泛函(或Razumikhin函数)研究了某些模型正周期解的全局吸引性。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了