必要条件

The two kinds of symmetries in holonomic and non-holonom-ic mechanical systems,i.e.symmetries of differential equations of motion(ab-breviated as SDEM)and symmetries of Noether-type,and interrela-tions among all kinds of symmetries are investigated.The necessary and suffi-cient conditions of SNT to be SDEM are found out.It is pointed out thatSDEM have distinct geometric properties which are equivalent to the geodesiccharacteristic of differential equations of motion and geodesic deviation.

文中研究了完整与非完整力学系统的两类对称性，即运动微分方程的对称性和Noether型对称性，以及各种对称性之间的相互关系，确定了Noether型对称性为运动微分方程对称性的充分必要条件，并指出运动微分方程的对称性具有明确的几何性质，即它等价于运动微分方程的测地性质以及测地偏离性质。

Opinions vary on the genesis of this type of gold deposits. On the basis of observation and study in this area, with information up to date from other researchers, the authors bring forward that the formation of Muruntau-type of gold deposits in South Tianshan area is closely related to giant nappe structures, especially to the ductile shear zone.

关於该类金矿床的成因也是众说纷纭，根据作者近几年在南天山地区的调研得到的一些认识，以及其他学者对该地区穆龙套型金矿床的最新研究成果，认为南天山地区穆龙套型金矿床的形成与南天山褶皱造山带形成过程中板块边缘的大型逆冲推覆构造，特别是与其伴随的韧性剪切变质变形带具有密切的关系，而与这些构造作用伴随的花岗质岩浆的侵入作用是形成该类金矿床的必要条件。

About the existence of duadic codes, Ward and Zhu(1994) obtained necessary and sufficient conditions for existence of duadic abelian codes, Zhang(1997) gave the existent conditions for such codes by some parameters and obtained necessary and sufficient conditions for existence of central duadic group algebra codes.

对duadic群代数码的存在性问题，Ward和朱烈(1994)解决了域上duadic阿贝尔码存在性；张胜元(1997)年用参数形式给出更具体的判定条件和中心duadic群代数码存在的充分必要条件。

That must be the guiding principle of international cooperation.

这是成功的必要条件，也必须是国际合作的指导原则。

Creation of Classical Haiku and ...

上一篇范文：创新教育的必要条件∶建设良好的校。。。

The stability problems are analyzed and discussed. The optimal control problem is formulated to determine the necessary conditions for optimality in networks. Three theorems about the properties of the steady state-costate solution in Hamilton function are confirmed leading to the natrual meaning and the optimal policy which can be implemented in practice. In chapter Ⅴ, the methods for nonstationary simulation of computer networks are discussed.

第四章表述了计算机通信网动态特性研究的主要数字方法；提出了排队与随机存取机制、网络链路传输和节点分流的状态空间模型，并作了稳定性研究；应用最优控制理论得到网络最优控制的必要条件，证明了哈密尔顿函数协状态变量的稳定解性质，据此研究分析了网络最优控制的本质意义及实现途径，并给出计算及建模实例。

In this paper,we psesented that the principle of least action or Hamilton principle is ample and necessary condition of Lagrangian equation,pointed out the properties of Lagrangian function briefly,and gave the generalization and application of Lagrangian function in physics.

本文论述了力学最小作用量原理或哈密顿原理是拉格朗日方程的充分必要条件，简述了拉格朗日函数的性质，指出最小作用量原理及拉格朗日函数在物理学中的推广及应用。

It can accommodate 12 guests and crew and has all the requisites to appease Mr. Moneybags; helipad and swimming pool included!

它可容纳12位客人和机组人员，并拥有所有必要条件，以安抚先生馅饼，直升机停机坪和游泳池，包括！

The close relationship between the Hybrid polynomial approximation and the classical Hermite polynomial approximation to rational curves and surfaces are studied, Hermite approximation is in fact a special case of Hybrid approximation. The sufficient and necessary condition for the convergence of Hybrid approximation to rational Bézier surface is deduced and proved.

围绕着有理曲线曲面的Hybrid逼近，作者研究了有理曲线曲面的Hybrid多项式逼近与传统的Hermite多项式逼近之间的密切关系，并指出Hermite逼近事实上是Hybrid逼近的一种特例，此后演绎并证明了有理Bézier曲面的Hybrid多项式逼近收敛的充分必要条件。

Second, the principles of differential land rent and function control are adopted in land use planning to optimize land resource exploitation. Third, traffic corridors are simple and convenient, and the resort hotels can keep integrating with the plage and sand beach. Fourth, the business centers with various tourism services are planned reasonably to meet holidaymaker＇s needs, and to benefit the local people＇s employment. The successful planning of the two resorts can play an exemplary role to the domestic coastal resorts development.

科学合理的规划控制措施是综合型海滨度假区成功开发的必要条件，如何合理安排度假区的空间分区、项目开发、基础设施建设、商业配套设施等形态要素，实现度假区综合性功能定位和开发目标，是度假区规划和管理人员必须深人研究的问题。1 文献评述及研究目的海滨度假区的形态规划Coastal resort morphologgy是国内外旅游地理学者共同关注的话题，而针对这一问题的研究。。。。。。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。