充分利用了的

First we give some necessary and sufficient conditions for the oscillation of(1) by Lebesguge s dominated convergence theorem and Schauder — Tychonoff fixed point theorem.

这篇文章中，我们首先利用Lebesgue控制收敛定理，以及Schauder-Tychonoff不动点定理给出了方程(1)振动的若干充分必要条件。

It becomes a information exchange site,the exploration project,work area,research production,seismic datum,explainer datum,well datum can be organized into one system,which can share the research production in the exploration project;Through the datum expression of well decision,we can achieve the browsing of work area basemap,the seismic section"s remote display,the well position report"s display,the visual information of well"s wall.The system can lead to a right direction for those expert"s exploration decision .The system runs through all the process of well positon"s decision,deployment and management,which makes the exploration work becoming integrated.Now we can manage the well positon"s decision with computer,which improves work efficiency,condense whole exploration circle.

油田井位部署辅助决策系统以项目数据库的方式将分散在多个研究单位或个人手中的各类图档资料信息集中分类地保存起来，通过该系统使勘探项目、工区、研究成果、地震数据体、解释数据、井数据等有机地组织在一起，使勘探研究成果在勘探项目组内进行了充分共享；基于项目库，系统实现了井位部署决策所需的：工区底图浏览、地震剖面远程显示、井筒信息可视化，为论证专家提供了论证现场所需数据的展示；采用井位聚类分析和模糊数学综合评判决策方法，为井位论证决策提供了基本模型；利用井位部署流程子系统贯穿了井位论证、部署、管理业务的全过程中，使勘探业务有机的整合为一体，实现了井位论证工作的计算机管理。

Then using Positive definite quadratic theory to prove a sufficient condition of Multivariate function's extreme value problem and show some examples about it.

而后利用正定二次型理论，证明了多元函数条件极值的一个充分条件，并给出了其应用的例子。

Chapter two mainly considers the periodic boundary value problems for impul-sive differential equations. Some existence results, obtained by the help of Schaeffers fixed point theorem and the method of upper and lower solutions coupled with the monotone iterative technique.

第二章讨论了两类周期边值问题，通过利用Schaeffer不动点定理，上下解方法和单调迭代方法，建立了解存在的充分条件。

In chapter one, by using Krasnoselskii s fixed point theorem, necessary and sufficient c...

第一章讨论了一类带阻尼项的高阶非线性中立型差分方程正解的存在性，利用Krasnoselskii不动点定理，得到了非振动解存在的若干充分必要条件，这些结果改进和推广了一些已知的结果。

In the second chapter, we consider a kind of Kolmogorov system. The sufficient condition for nonexistence of the closed orbit and existence of the unique and stable limit cycle are obtained by using divergence integral, Poincare-Bendixson theorem and Zhang Zhifenunique theorem.

第二章讨论了一类Kolmogorov系统，利用发散量积分、环域定理和张芷芬唯一性定理，得到了该系统无闭轨的充分条件和存在唯一极限环的条件。

In the second chapter, we consider a kind of Kolmogorov system. The sufficient condition for nonexistence of the closed orbit and existence of the unique and stable limit cycle are obtained by using divergence integral, Poincare-Bendixson theorem and Zhang Zhifen\'unique theorem.

第二章讨论了一类Kolmogorov系统，利用发散量积分、环域定理和张芷芬唯一性定理，得到了该系统无闭轨的充分条件和存在唯一极限环的条件。

Some conditions for weakly Persistence and extinction are obtained;In the second part, we respectively use C_h space and C_g space theorem to study the existence of periodic solutions of Lotka-Volterra equation with infinite delay, in the end we get the condition of the existense of periodic solutions and estimate the interzone of it.

第二部分利用相空间理论，分别以C_h空间和C_g空间为相空间研究了具有无限时滞的Lotka-Volterra方程周期解的存在性问题，给出了周期解存在的充分条件，并估计出了周期解的存在区间。

This paper studies on weak invertibility of a linear finite automata based on its matrix model,gets a full and essential condition on which a linear finite automata weakly and invertibly delays finite steps,and also gives an algorithm whether or not a linear finite automata has weak invertibility .

主要讨论了基于矩阵模型表示的线性有限自动机的弱可逆性，利用矩阵模型得出了线性有限自动机延迟有限步弱可逆的充分必要条件，并且给出了线性有限自动机是否具有弱可逆的算法。

The sufficient-necessity condition for the system stability and the distribution of stationary queue length are obtained by means of matrix analysis in the third model.

在本文模型三假设下利用矩阵分析方法得到了系统达到稳态所应满足的充分必要条件。

We have no common name for a mime of Sophron or Xenarchus and a Socratic Conversation; and we should still be without one even if the imitation in the two instances were in trimeters or elegiacs or some other kind of verse--though it is the way with people to tack on 'poet' to the name of a metre, and talk of elegiac-poets and epic-poets, thinking that they call them poets not by reason of the imitative nature of their work, but indiscriminately by reason of the metre they write in.

索夫农 、森那库斯和苏格拉底式的对话采用的模仿没有一个公共的名称；三音步诗、挽歌体或其他类型的诗的模仿也没有——人们把&诗人&这一名词和格律名称结合到一起，称之为挽歌体诗人或者史诗诗人，他们被称为诗人，似乎只是因为遵守格律写作，而非他们作品的模仿本质。

The relationship between communicative competence and grammar teaching should be that of the ends and the means.

交际能力和语法的关系应该是目标与途径的关系。