| 释义 |
time of flight
time of flightIn artillery, mortar, and naval gunfire support, the time in seconds from the instant a weapon is fired, launched, or released from the delivery vehicle or weapons system to the instant it strikes or detonates.time of flight
time of flight The time taken for light to travel a specified distance.time of flight[′tīm əv ′flīt] (mechanics) Elapsed time in seconds from the instant a projectile or other missile leaves a gun or launcher until the instant it strikes or bursts. (physics) The elapsed time from the instant a particle leaves a source to the instant it reaches a detector. time of flight
time of flightthe time for a photon created by annihilation of a positron-electron pair to reach a detector; because annihilation photons are created in pairs and travel in opposite directions at about 3 × 1010 cm/sec, measurement of the difference in arrival time at detectors with subnanosecond resolution allows calculation of the location of the event; the basic physics of positron emission tomography.time of flight An MRI term referring to a magnetic resonance angiography technique based solely on the flow of unsaturated blood into a magnetised presaturated slice. The difference between the unsaturated and presaturated spins creates a bright vascular image without needing contrast media.time of flight (tīm flīt) magnetic resonance imaging Rate of flow in a given time; causes some flowing nuclei to receive only one radiofrequency pulse and therefore produce a signal void. See TF
See TOF |