必要条件

However, insist on only a necessary condition for success, rather than a sufficient condition for success.

然而，坚持只是成功的必要条件，而不是成功的充分条件。

Low interest rates are a necessary but not sufficient condition.

低利率是一个必要条件，但不是充分条件。

As a result, we gave a sufficient and necessary condition for the existence of the essential component.

最后给出了一个本质连通区存在的充分必要条件。

There are two kinds of addition,namely,superposition and accumulation .

论述了叠加的必要条件并对叠加和累加作了区分。

The necessary condition of an important result of the probability that the supremum of a random walk with heavy-tailed increments crosses a curve on a random time interval is presented by using an important property of a general distribution class.

利用一类常见分布族的一个重要性质，给出了增量带重尾分布的随机游动在随机时段内的上确界超越曲线边界的概率的一个重要结果的必要条件。

This paper gives the concept and some properties of partition symmetric anti-circulate matrix, and the sufficient and necessary condition is discussed.

给出了分块对称反循环矩阵的概念，讨论了分块对称反循环矩阵的性质，给出了分块对称反循环矩阵的若干充分必要条件。

Our main work is as follows: the stable laser mode theory in uniform plasmas is extended to non-uniform plasma cases; the discussion of the sufficient and necessary conditions for laser self-focusing in uniform plasmas is developed to non-uniform plasma cases; a quantitative approach to judge the impact of different plasma density distribution on laser self-focusing is proposed; the evolution properties of asymmetric laser filed in non-uniform and uniform plasmas are discussed and mechanisms that symmetric channel-like plasmas can confine the laser centroid around the plasma channel axes and symmetrize initially asymmetric laser beams are proposed; the formation of solitary standing wave in moderate plasma density is studied by PIC simulations and can be explained by stimulated Raman scattering of laser beams in plasmas.

主要工作为：把均匀等离子体中激光的稳定模理论推广到横向非均匀等离子体情形；把均匀等离子体中激光自聚焦的充分和必要条件的讨论推广到横向非均匀等离子体情形；给出横向密度分布不同的等离子体影响激光自聚焦的定量判据。讨论了初始不对称的激光场在横向非均匀及均匀等离子体中的演化特性，并提出了具有对称腔道结构的等离子体箍缩激光质心和对称化初始不对称激光场的物理机制。用粒子模拟讨论了激光场在等离子体中形成孤立驻波的过程，认为前向受激拉曼散射是发生此现象的可能机制。

The formation that the network organizes is the requirement that realizes synergism, is not sufficient condition.

网络组织的形成是实现协同效应的必要条件，而不是充分条件。

A highly in uential source of this suspicion is Barry Stroud, who in his article 'Transcendental Arguments' suggested that for any claim concerning the necessary condition S,"the sceptic can always very plausibly insist that it is enough we believe that S is true, or it looks for all the world as if it is, but that S needn'tactually be true"(Stroud 2000: 24).3 So, in the case of the problem of the external world, for example, the concern is that no argument can be constructed to show that there must actually be an external world, but just that there must appear to us to be one, or that we must believe there to be one.

斯特劳德在《先验论证》一文中指出，任何涉及必要条件S的断言都会受到怀疑论者这样的反驳：我们确实要相信S是真的，或者说在所有的世界都是这样，但是，S不需要真正地为真。所以，在外在世界问题上，并没有一个论证可以给出证明，说外在世界必须真正实际地存在，而我们只能说，必须有一个外在世界向我们显现，或我们必须相信有一个外在世界。

After that, analytically using the Taylor formula, it reduces the expansion to one-variable function and makes a specific discussion.

在判别法失效的情况下，从几何方面引入了判别二元函数极值的一些必要条件，然后在分析方面利用Taylor公式，将展式化为一元函数，进行了比较细致的讨论。

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。