| 释义 |
▪ I. spin-down, n.|ˈspɪndaʊn|
[f. spin v. + down adv.]
A decrease in the speed of rotation of something.
1963Jrnl. Fluid Mechanics XVII. 402 The initial angular velocity Ω0 = 3·668 sec—1, and the final angular velocity Ω1 = 3·033 sec—1. (This was a case of ‘spin-down’.) 1967Astrophysical Jrnl. Lett. CXLIX. l121 The ‘spin-down’ time of a cup of tea is approximately (R2/vΩ)½, where R is the radius of the cup and Ω is the angular velocity of the tea. 1971New Scientist 26 Aug. 452/2 The favourite explanation that decreases in period, or ‘spin-ups’, occur when starquakes take place in the deformed crust of the star seems to fall flat on its face when confronted with the discovery that the Crab pulsar, at least, also undergoes ‘spin-downs’. 1977Astron. & Astrophysics LX. 85/1 Braking by tidal torques and possibly magnetospheric friction can account for a spin-down of Venus within some 109 years.
▪ II. spin-down, a. Physics.|spɪnˈdaʊn|
[f. spin n.1 + down a.]
Being or pertaining to a particle whose spin points downwards.
1965, etc. [see spin-up a.]. |