| 释义 |
centrifugal, a.|sɛnˈtrɪfjʊgəl, ˌsɛntrɪˈfjuːgəl|
[f. mod.L. centrifug-us (Newton, f. centrum centre + -fugus fleeing, avoiding) + -al1. (Cf. centripetal). In mod.F. centrifuge.]
1. Flying or tending to fly off from the centre as
a. centrifugal force, also centrifugal tendency: the force with which a body moving round a centre tends to fly off from that centre; the tendency which a revolving body has to do this.
(‘Centrifugal force’ is really Inertia.)
[1687Newton Principia Sect. ii. Prop. iv. Schol., Hæc est vis centrifuga, qua corpus urget circulum; et huic æqualis est vis contraria.] a1721J. Keill Maupertuis' Diss. (1734) 5 It is under the Equator that the Centrifugal Force is greatest. 1841–4Emerson Ess. Hist. Wks. (Bohn) I. 2 As the poise of my body depends on the equilibrium of centrifugal and centripetal forces. 1855Maury Phys. Geog. Sea i. (1860) 3 At the height of 26,000 miles from the earth, the centrifugal force would counteract gravity. 1866Airy Pop. Astron. 241 The centrifugal tendency is powerfully in operation at the equator, but not at all at the poles. 1876R. Routledge Discov. 7 If..the velocity of the engine increases, the balls diverge from increased centrifugal force.
b. fig. or transf.
1817Coleridge Biog. Lit. I. xii. 275. 1856 R. Vaughan Mystics (1860) I. 93 A process of evolution, a centrifugal movement in the Divine Nature. 1868G. Duff Pol. Surv. 21 So strong are the centrifugal forces in Spain.
c. centrifugal current: ‘applied to that arrangement of a battery in galvanizing an animal body, in which the positive pole is the nearer to the centre{ddd}of the nervous system’ (Syd. Soc. Lex.).
2. Applied to machines or parts of mechanism in which centrifugal force is employed: as † centrifugal bellows, a fan or blowing machine; centrifugal casting, the casting of objects (usu. cylindrical) in a rotating mould; centrifugal filter, a sugar-filter in which a porous cylinder rotates rapidly so as to drive off liquid from the sugar; centrifugal gun, a kind of machine-cannon with a rotating chambered disk whence balls are driven tangentially; centrifugal machine, gen. any machine in which centrifugal force is employed; spec. a machine, also called a hydro-extractor, for drying yarn, cloth, sugar, or other substance, this being placed in a rapidly revolving cage, whence the moisture is thrown off by centrifugal force; centrifugal mill, Barker's mill; centrifugal pump, a rotary pump in which the fluid is driven outward and upward from a centre; there are many forms of it; centrifugal dresser, etc.
1765Gentl. Mag. 555 This centrifugal machine. 1803Banks Power Machines 41 Centrifugal machine or Erskine's centrifugal pump. 1807T. Young Nat. Philos. I. 781 The centrifugal bellows. By the revolution of the fly the air is caused to enter at A and is discharged at B. 1874Knight Dict. Mech. 514 Le Demour's centrifugal pump is supposed to have been the first of its kind. Ibid. 515 Andrew's centrifugal pump resembles a helix or snail's shell. 1884Bath Herald 27 Dec. 6/5 After being carried through..detachers, the wheat passes through centrifugal dressers. 1925Jrnl. Iron & Steel Inst. CXII. 38 A method of centrifugal casting seemed to have come into commercial use. 1940J. D. Devons Metall. Deep Drawing xvi. 595 Centrifugal casting has always attracted the attention of imaginative foundrymen.
3. Bot.
a. Of inflorescence, in which the terminal flower opens first and the lateral ones successively after; inflorescence terminal or definite.
b. Of an embryo: Having the radicle turned toward the sides of the fruit.
c. Said of the order of cell division.
1830Lindley Nat. Syst. Bot. 134 Flowers often with a centrifugal inflorescence. 1870Hooker Stud. Flora 277 Labiatæ..Flowers solitary or in axillary opposite centrifugal cymes. 1884Bower & Scott De Bary's Phaner. & Ferns 545 In the course of the tangential divisions in an initial cell and the radial row derived from it, two extreme forms may in the first instance be distinguished..termed the centripetal and centrifugal forms.
4. Phys. Of nerve-fibres: Conveying impulses from a ‘centre’ (see centre n. 7 a); efferent.
1855H. Spencer Princ. Psychol. (1872) I. v. vi. 568 The centre..from which issue through centrifugal nerves motor impulses. 1876tr. Wagner's Gen. Pathol. 20 The properties of centrifugal fibres.
5. Obtained by the use of a centrifuge.
1880Army & Navy Co-op. Soc. Price List 34 Sugars..Centrifugal, or White Crystals. 1901U.S. Dept. Agric. Year-bk 1900 613 Fresh butter, made from sweet centrifugal cream. 1958Catal. County Stores, Taunton June 28 Sugars..centrifugal crystals.
Hence as n., a centrifuge.
1866‘Mark Twain’ Lett. fr. Hawaii (1967) 266 Close to the grinder are six centrifugals—small metallic tubs, whose sides are pierced with a few thousand pinholes to the square inch. 1904Brannt tr. Bersch's Cellulose ix. 221 The bleached skeins of silk are..dehydrated in a centrifugal. |