0 If the amount, rate, or quality of something falls off, it becomes smaller or lower. -- （数量）减少；（比率）下降；（质量）降低
1 a reduction in the amount, rate, or quality of something -- 下降；减少
As discussed above, the inverse cubic fall-off of peak pressure with distance is only dominant at distances so large that the flow velocity has reached its vacuum-limiting value.
They increased these totals at the peak (at less than the national rate of increase), but above all both are marked by a rapid fall-off in the late period.
Even at the extreme of the 95 % confidence limit, a significant fall-off in species numbers is not seen until sample size is reduced to 15 000.
As discussed below, the principal reason for this fall-off was that on balance the early work failed to convincingly demonstrate a relationship between sleep and memory.
Suprathermal particles with an approximate power-law fall-off in velocity are a frequent feature of space plasmas.
The fall-off in the dust density is more rapid in the spherical case.
Finally, if the measurements were in the gas near field, non-ideal behaviour of the products and radiation could help to explain the more rapid fall-off.
The conditioned profile they obtained was flat for < 0.1, breaking sharply to a linear fall-off.
