Other rockets of this class, such as Boeing’s Delta IV and the Atlas V, operated jointly by Boeing and Lockheed Martin, are children of the military-industrial complex.

然而同一级别的其他火箭，例如由波音公司与洛克斯勒马汀公司联合经营的波音德尔塔IV与阿特勒斯V火箭，是军工联合企业的子辈。

youdao

r So, let's remember that the amount by which we moved, t delta r, is approximately equal to v times delta t, OK, and just using the definition of a velocity vector.

所以记住移动的量△,约等于v*△,这是用速度矢量的定义。

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 delta v here is an exact differential, but this dw is not.

你是如何,到达这个状态的。

麻省理工公开课 - 热力学与动力学课程节选

So if delta v is negative, in this case delta v is negative, OK, delta v is negative, pressure is a positive number, negative times negative is positive, work is greater than zero.

也就是当活塞,压缩气体的时候，做的功是正的，按照这一规定,我们需要在这里，加上一个负号，这是习惯规定。

麻省理工公开课 - 热力学与动力学课程节选

It was a delta-v opposite to the direction of travel and that slowed Messenger enough so the relatively weak gravity of Mercury could capture the spacecraft and put it into an elliptical orbit around the planet rather than the Sun.

BBC: Juno Jupiter probe gets British boost

Their final design of the QSST jet is reminiscent of Concorde in its delta wing shape, but with a number of unique features, including an "inverted V-tail" and tailored nose cone.

CNN: Bang goes the sonic boom