必要条件

Li reduces the surface tension of aluminum luquid obviously, increases the ratio and rate of heterogeneous nucleation, which is the necessary condition of the formation of fine grains. However, a large amount of unmelted Al3Sc, Al3Zr TiAl3 particles dispersively distribute in the luquid metal along the edge of the molten pool, which is the sufficient condition of the formation of fine grains.

Li显著地降低了铝液表面张力，大大提高了异质形核率和形核速率，是细晶层产生的必要条件；而熔池边缘液态金属中弥散均匀分布大量未熔化的Al_3Sc、Al_3Zr和TiAl_3质点，则是细晶层产生的充分条件。

Even the suggestion that that is at least a possibility could be dismissed as unthreatening. If our holding the belief to be true is a condition of our even finding that belief to be held by people, the possibility of its being held and being false is one we cannot take seriously as a threat to our current beliefs.

如果我们持有的信念的真，是我们发现信念被他人持有这个事实的必要条件，那么这个信念错的可能性就不能对我们现有的信念构成威胁。

Light is the necessary factor of plant upgrowth and developing. Low light become the main factor which restricts plant upgrowth, yield and quality in geeenhouse planting.

光照是植物生长和发育的必要条件，在植物的反季节栽培中，弱光成为制约植物生长、产量和品质的主要因素。

Moreover, the stability of unfoldings of such kind of bifurcation problems is discussed, and the sufficient condition of an unfolding of a bifurcation problem to be stable is that it is versal unfolding under certain conditions.

得到的这种分歧问题的无穷小稳定与稳定是等价的，而且讨论了这种分歧问题开折的稳定性，得到了一定条件下分歧问题开折稳定的充分必要条件为该开折是通用开折。

The results indicated that the effect of deep warm-wet air coming along the behind subtropical high , moving eastward deepening upper trough , shear line and cyclone trough was caused in Zhuanghe , but no strong thunderstorm . The main impact of system is surface cyclone trough ; Low vortex , shear line in 700hPa , 850hPa strengthen the lower convergence , forming a strong momentum of increase and pieces of water vapor ; strong and wide potential pseudo-equivalent temperature frontal zone lied in Zhuanghe area , the establishment of potential instability are indispensable conditions for producing heavy rain .

结果表明：受副热带高压后部深厚的暖湿气流及西风带高空槽、切变线及气旋倒槽等动力系统共同影响，庄河地区出现了大暴雨天气，但没有出现强雷暴，此过程主要影响系统是地面气旋倒槽；700hPa、850hPa低涡、切变线使中低层辐合加强，形成了较强的动力抬升和水汽辐合；庄河地区处于强而宽的假相当位温锋区中，位势不稳定的建立是造成此次强降水的必要条件。

You will find that it is the foundation, the imperative condition, the absolute law of well-doing, which means, well-being.

你会发现，它就是一切善行的基础、必要条件和绝对法则。

This mechanism may seem very simple when I give it to you, but read on; you will find that it is in reality the "Master Key," the "Aladdin's lamp," if you please; you will find that it is the foundation, the imperative condition, the absolute law of well-doing, which means, well-being.

这种机制，当我把它告诉你们的时候，看上去似乎非常简单，但你要继续往下读。你会发现，它实际上就是"万能钥匙"，如果你高兴的话，也可以叫它"阿拉丁神灯"。你会发现，它就是一切善行的基础、必要条件和绝对法则。

While well-done style is great to have, it is not absolutely necessary to produce a great gaming experience.

有一个优秀的表现形式固然很好，但这并不是游戏快感产生的必要条件。

However, what is woeful that it is indispensable condition.

可悲的是，这确是必要条件。

Riley, John G., Silver Signals: Twenty-Five Years of Screening and Signaling, Journal of Economics Literature, V. XXXIX, 432-478, June 2001

这个特点在信息经济学中称为单交叉(single-crossing)假设，这是解决甄别机制的一个必要条件。

We are in a real jam.

我们的麻烦大了。

Hey, it's Ahmet from India, that foreign exchange guy.

看，那是印度的阿曼特，国际交换生