对于线性非时变的无源二端口网络，在零初始条件下，若存在互易性及对称性，则其电路参数具有一定的特殊性。

If reciprocity and symmetry exist for passive two port networks of linear time invariant under zero intial condition, the circuit parameters will have some important characters.

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利用幂级数的方法，对三阶线性离散系统进行时域分析，其方法不仅可以研究线性非时变离散系统，而且还可以研究线性时变离散系统。

This paper presents the time domain analysis of three orders discrete system by power series, which can study not only the time invariant system, but also the time variant system.

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经济衰退时，消费者有可能会缩减玩具等非必需品的消费。

In a recession, consumers could be expected to cut down on nonessentials like toys.

《柯林斯英汉双解大词典》

So, he writes: To the psychologist alone can such questions occur as: Why do we smile when pleased and not scowl?

他这样写到：,对哲学家本身说,会出现这些问题：,为什么开心时我们微笑而非皱眉？

耶鲁公开课 - 心理学导论课程节选

Because, for the purposes of this class, I'm going to reserve the word "Soul" for the immaterialist conception of the mind.

为了讲课的需要,我会将"灵魂"这个词,留到讲心灵的非物质性概念时再用

耶鲁公开课 - 死亡课程节选

You might have thought before we started talking about molecular orbital theory that non-bonding was the opposite of bonding, it's not, anti-bonding is the opposite of bonding, and anti-bonding is not non-bonding.

你也许在我们讨论分子轨道之前,就想过非成键时成键的反面，它不是，反键才是成键的反面，反键不是非成键。

麻省理工公开课 - 化学原理课程节选