dt If you divide both sides by dt, which mathematicians cannot do, but physicists can, then you get /dt=ds/dt d theta/dt equals ds/dt, and v/l that is the velocity divided by l.
如果两边同除以，数学家不会这么做，但是物理学家可以,得到dθ,等于。
2
Variants include V-shaped recovery, L-shaped recovery and: - shaped recovery.
其变体包括V型复苏、L型复苏和：-型复苏。
3
The light intensity (l) current (I) voltage (v) sweep is a series of measurements performed on VCSELs to determine their operating characteristics.