有符号的除法要耗费更多的时间，因为除法是使最终结果趋向于零的，而移位则是趋向于负无穷。

The signed division will take more time to execute because it rounds towards zero, while a shift rounds towards minus infinity.

youdao

速度的符号已经，由负变正了，可是加速度又还是正的。

It has changed from a minus sign to a plus sign because of this positive acceleration.

youdao

这个符号可正可负。

The sign could be positive or negative.

youdao

Delta v is positive in this direction here, the work is negative. So work on the system is positive. Work done by the system is negative.

功是负的，总而言之,外界对系统做功的符号为正。

麻省理工公开课 - 热力学与动力学课程节选

So, the system does work on the surroundings, hence the minus sign.

系统对环境做功，因此符号是负的。

麻省理工公开课 - 热力学与动力学课程节选

sa So we have 1 s a, and we're drawing this as having a positive amplitude, but since we have destructive interference we're going to draw 1 s b as having the opposite sign, so we have a plus and a minus in terms of signs.

我们有，我们把这画成一个正的振幅，但因为我们是相消干涉,我们把1sb画成相反的符号，所以我们有一正一负两个符号。

麻省理工公开课 - 化学原理课程节选