"We are seeing progress. It's probably not as fast as we would like it to be but certainly the direction of travel is positive.

VOA: standard.2009.10.01

And we're going to have q2 prime, and we're going to draw the arrows in the positive direction in these cases.

还有q2一撇，在这个例子中,我们把箭头朝正方向。

麻省理工公开课 - 热力学与动力学课程节选

Then you guys know, you just told me, acceleration is -9.8, We call it "minus" because it's accelerating down and up was taken to be the positive direction.

然后你们都知道,你告诉我,加速度是-9.8,我们取负号是因为加速度方向朝下,而正方向为竖直向上

耶鲁公开课 - 基础物理课程节选

In Lebanon, which has known long periods of instability in recent years, Paul Haidostian, who is the president of Haigazian University, believes that Mr.Obama's Nobel is a step in the right direction and is a positive omen for the future.

VOA: standard.2009.10.09

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

"I think that the proposal that the President made in Geneva to have Iran withdraw its enriched uranium, or a good portion of it, outside Iran is a positive first step in that direction and I support and appreciate the President's ongoing efforts to unite the international community to address the challenge of Iran's attempts to become a nuclear military power,"

VOA: standard.2009.10.30

So, what this means is that when we're looking at an actual wave function, we're treating it as a wave, right, so waves can have both magnitude, but they can also have a direction, so they can be either positive or negative.

这意味着,当我们看一个波函数时,我们把它看做一个波，波不仅有幅值，还有方向，所以它们可正可负，如果。

麻省理工公开课 - 化学原理课程节选

The second particle was deflected almost not at all. But what he could tell from the fact that there was a second particle at all, and the fact that it was in this direction, is that in addition to his negative particle, he also, of course, had a positive particle that was within this stream of rays that were coming out.

粒子的强烈信号,有着强烈的对比,第二个粒子几乎，不发生偏转，他能判断这是，第二个粒子的原因是它在这个方向,所以在出射射线中,除了有带负电的粒子外。

麻省理工公开课 - 化学原理课程节选

But since it is a component it can have a direction, too, so can go up l between negative l and positive l.

但因为它是个分量,它是有方向的，所以它可以,从负的l一直到正的。

麻省理工公开课 - 化学原理课程节选

It says, if you pull it to the right, so that x is positive, the spring will exert a force which is in the negative direction; that's why you have a minus sign.

就是说,如果你向右拉,x 取正值,弹簧产生的力方向为负,这就是这里用负号的原因

耶鲁公开课 - 基础物理课程节选