| 释义 |
filtration|fɪlˈtreɪʃən|
Also 7 filteration.
[a. Fr. filtration, f. filtrer to filter.]
1. The action or process of filtering.
1605Timme Quersit. ii. iii. 115 Chymical workings, as distillations..filtrations. 1758Elaboratory laid open Introd. 60 Filtration is generally practised, by means either of flannel cloth, or paper. 1822J. Imison Sc. & Art II. 7 Filtration is a finer species of sifting. 1862Stanley Jew. Ch. (1877) I. v. 100 Vessels of stone, used..for the filtration of the delicious water from the sediment of the river-bed. 1943Gloss. Terms Electr. Engin. (B.S.I.) 142 Filtration, of X-rays, the absorption of the longer wavelengths to a greater extent than the shorter wavelengths by placing an absorbing medium in the path of the beam. 1970D. F. Shaw Introd. Electronics (ed. 2) x. 220 If a current of more than one milliamp is to be delivered by the rectifier, L—C filtration must be used.
fig.1843Prescott Mexico i. vi. (1864) 55 It is not easy to render his version into..English rhyme, without the perfume of the original escaping in this double filtration.
2. A gradual movement like that of water passing through a filter; percolation.
1664Power Exp. Philos. i. 70 For Motion the Spirits move impetuously down the Nervous filaments..but for Sensation they onely creep by a filtration down their Coats. 1707Curios. in Husb. & Gard. 69 If we pursue this Sap in its incomprehensible Filtration through the Pores of Plants. 1794G. Adams Nat. & Exp. Philos. II. xxi. 414 [The pervasiveness of light and heat] has been overlooked as an accidental filtration.
3. transf. (Cf. filter v. 3 b.)
1932Evening Standard 21 Jan. 4/4 ‘Filtration’ takes place whenever the lights give the ‘All Clear’ at a crossing; many vehicles in the stream which is let loose turn left or right despite the fact that in the road into which they are turning the traffic lights show red. |