必要条件

In this paper,we consider necessary conditions for optional control of second order ordinary differential equation with coefficient control and two point boundary value,thenobtain the inequality of variation.

在这篇文章中，我们考虑控制出现在最高阶系数上二阶常微分方程系统最优控制满足的必要条件，得到了最优控制满足的变分不等式。

Here it is indicated that the retardance of diffusion process is the cause of"overshoot".

这里说明扩散的瞬态过程引起的滞后是引起"超调"的必要条件。

In this paper, we provide a necessary condition and several sufficient conditions for a digraph to have a pair of disjoint quasi-kernels.

在这篇文章中，我们给出了一个有向图有一对不相交的准核的一个必要条件和若干充分条件。

In chapter 5, we study necessary conditions for difference sets and we obtain the following: we proved that there are no nontrivial difference sets in dihedral group of order 4p〓, where p is a prime, d is a positive integer; we give a necessary condition for Hadamard difference sets in some group of order 4p〓, and completely solve a general case left in Dr.

在第五章中，我们研究了差集存在的必要条件。

His reasoning was disarmingly intuitive: in our hominid predecessors, communities of more sympathetic individuals were more successful in raising healthier offspring to the age of viability and reproduction -- the sine qua non of evolution.

他的理由完全是直觉性的：在我们原始祖先那里，那些其成员更具有同情心的群落在养育更加健壮的达到生育与繁殖能力的后代方面更成功——这是进化的必要条件。

We attain a sufficientcondition realizing ideal disentanglement by manipulating only one part of the states.Under the condition that one only knows partial information on the set of states weput forward the necessary and sufficient condition for ideal disentangling operations.

我们获得了，为了达到理想的消纠缠，量子态集合所应满足的充分条件；在仅知态集合中量子态的部分信息的限制下，我们得到了理想消纠缠的充分必要条件。

The entanglement of formation and the Peres condition have good correspondence, and if the mixed-state deviates the similar pure state slightly, its maximum entanglement drops suddenly. The conclusion of the entanglement of the infinite dimension mixed-state in J-C model never losing is demonstrated besides finding the necessary condition of disentanglement of the finite dimension mixed-state in J-C model.

通过研究有限维混合态光场与二能级原子相互作用系统中的纠缠，发现形成纠缠理论与Peres判据有着良好的对应，同时看到偏离纯态很小的混合态，其最大纠缠度急剧减小；找到了有限维混合态J-C模型在演化过程中出现消纠缠的必要条件，论证了在无限维情况总存在纠缠的结论。

The simulated results indicate that the properties of the chaotic dynamic system are sensitive to the driven frequency. A threshold value of amplitude exists for the appearance of chaos phase. The system is insensitive to the dissipative magnetic force.

数值模拟结果表明：混沌实验摆系统动力学性质灵敏地依赖于策动频率值；系统策动振幅必须大于一定阈值是混沌相出现的必要条件；磁阻尼参数对系统混沌相动力学状态影响不明显。

The distinguished method of the integer polynomial which is irreducibled on the region of rationality what is Eisenstein have been given in the article [1].This is not an essential condition but an sufficiency.

文[1]中给出了整系数多项式在有理数域上不可约的一个判别方法——艾森斯坦判别法，这是一个充分条件而不是必要条件。

The details are as following.The three necessary conditions for clustering are technical divisibility of production process, rich opportunity of product differentiation and low transportation cost.

本项目得到的一些重要学术成果包括：集群产生的三个必要条件是产品的技术可分性、存在丰富的产品差异化机会以及低运输成本。

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。