What was neat about it is before that time, the predominant species to use for air conditioning or refrigeration was ammonia.
在这之前是很整洁的,之前最主要的用于空调或者冰箱的,物质是氨。
Or if they hit the ball in the air and they're caught, they're out.
或者他们在空中击球,并且被抓到了,他们就出局了。
I'm hot, compared to the air of the room, or cold if I'm somewhere that's warm.
我相对于室内的空气是热的,或是冷的如果我呆在一个温暖的地方。
It's got that kind of air of profundity about it that philosophy's thought to have or aspires to have.
带有某种哲学思想或追求,所具有的深刻性。
We, in fact, borrow oxygen or steal oxygen from the air free of charge.
我们事实上免费从空气中,借或者偷氧气。
Somehow, if you could manufacture a really smooth frictionless surface, that if you took a hockey puck or something and an air cushion and you give it a push, in some idealized world, it'll travel forever.
如果你制造一个绝对光滑无摩擦的表面,然后在上面放个冰球或者别的什么,或者气垫,然后推它一下,在理想条件下,它会永远运动下去
In this case, the basic column of air is twelve and a half feet long and there are something called "Partials" or the "Harmonic series" That happens in anything, on a string instrument or whatever, but on the horn it's very distinct and that's what makes the different notes.
像这样,基本空气柱有十二个,每个半英尺长,圆号能发出分音,或泛音列,弦乐器或是,其他别的乐器中都有,但在圆号上,效果相当不同,这就是它能奏出不同音符的原因
So, instead of having the periodic variation of water, or the periodic variation of air density here we're talking about an electric field.
不像水或者空气密度的,周期变化,我们这里,讨论的是电场。
It's going to take place in there. It's going to be a constant pressure, it might be open to the air, or even if it isn't, there might be plenty of room, and it's a liquid anyway, so the pressure isn't going to change significantly.
也许它是液体,它在这个位置,这是恒压的,它也许是连通大气的,就算不是,它也有,足够的空间,而它是液体,压强不会显著地改变。
应用推荐