| 释义 |
rotation|rəʊˈteɪʃən|
[ad. L. rotātiōn-em, n. of action f. rotāre: see rotate v. and -ation. So F. rotation, Sp. rotacion, It. rotazione.]
1. a. The action of moving round a centre, or of turning round (and round) on an axis; also, the action of producing a motion of this kind.
1555Eden Decades (Arb.) 185 The rotation or impulsion of the heauens. 1594Plat Jewell-ho. ii. 37 A trew & philosophicall rotation whereby the inwarde fire of nature may be stirred vppe in euery vegetable. 1605Timme Quersit. i. ii. 8 By the yearly and continual rotation and reuolution of the right heauen,..and thinges might be well gouerned. 1661Glanvill Van. Dogm. 158 [A] puzled Candidate,..being ask'd what a circle was, describ'd it by the rotation of his hand. a1680Butler Rem. (1759) I. 318 All Rotations and Wheelings cause a kind of Giddiness in the Brain. 1720Welton Suffer. Son of God I. viii. 200, I see..all Things..as if they were whirl'd about by the Quick Rotation of a Wheel. 1784Cowper Task iii. 160 Some..tell us whence the stars;..what gave them first Rotation. 1815J. Smith Panorama Sci. & Art I. 559 His diurnal rotation is believed to be performed in 10 hours, 16 minutes, 2 seconds. 1851Woodward Mollusca i. 64 Eyes fixed, incapable of rotation. 1876Tait Rec. Adv. Phys. Sci. xii. (ed. 2) 294 This property of rotation may be the basis of all that to our senses appeals as matter.
fig.1647May Hist. Parl. i. i. 4 The perpetuall Rotation of fortune. 1700Congreve Way of World ii. iv, She has that everlasting rotation of tongue. 1710Palmer Proverbs 245 A jest keeps an ill story alive and in countenance, and gives it a rotation.
b. Cryst., Math., Physics. The conceptual operation of turning a system about an axis.
1899W. J. Lewis Treat. Crystallogr. iii. 19 When the least angle which gives interchangeability is 90°, the rotation can be effected four times before the crystal returns to its original position. 1965, etc. [see reflection 10].
c. Math. = curl n. 3 e.
1909J. G. Coffin Vector Analysis v. 117 The operator ∇ × applied to F or curl F (read del cross F or curl of F), also sometimes written in German books, rot F (read rotation of F), is a new vector derived from F. 1911[see curl n. 3 e]. 1923H. Levy tr. Runge's Vector Analysis ii. 111 The vector field f, when its rotation is not zero, that is, when f is not the gradient of a scalar function, leads to a second vector field g = ∇ × f. 1972A. G. Howson Handbk. Terms Algebra & Anal. xxxv. 175 In physical applications, curl represents some measure of rotation (older texts often describe curl f as the rotation of f and denote it by rot f).
d. Statistics. The mathematical rearrangement of a body of data, regarded as representing a set of points in a space, so that the axes of the space come to lie in directions of particular relevance.
1935L. L. Thurstone Vectors of Mind ix. 222 Each independent rotation may be regarded as a disturbance of a pair of columns in the factorial matrix. 1952R. B. Cattell Factor Analysis xxi. 411 A great advance in speed in rotation processes is available now through the I.B.M. multiplier (a rotation of a 15 × 18 factor matrix can be done in a day). 1972Jrnl. Social Psychol. LXXXVII. 69 Rotation to simple structure was made for five factors in each case, though not all five could be interpreted.
2. a. The fact of coming round again in succession; return or recurrence; a recurring series or period.
1610Healey St. Aug. Citie of God xxi. 17. 858 That rotation, and circumvolution of misery and blisse, which he [Origen] held, that all mankind should run in. a1676Hale Prim. Orig. Man. (1677) 150 That by a kind of circulation or rotation Arts have their successive invention and perfection. 1756C. Lucas Ess. Waters I. 172 Medicines..suffer a rotation of fashions like our cloaths. 1765A. Dickson Treat. Agric. (ed. 2) 47 It observes a constant rotation, and is conveyed regularly from the earth to the air, and from the air to the earth. 1779J. Moore View Soc. Fr. (1789) I. xxix. 244 There is a constant rotation of society at Ferney. 1847W. C. L. Martin The Ox 33/1 It is not..until the close of the third [year] that the [teeth] next in rotation succeed.
b. Regular and recurring succession in office, duties, etc., of a number of persons. Freq. in phr. by rotation or in rotation.
The recent adoption of this sense in general use is noticed in the British Mag. for April 1763 (IV. 542), and ascribed to ‘advertisements from the Police relating to the justices sitting by rotation, the felony-rotation in Bow-street’, etc.
1656Harrington Oceana (1700) 54 Equal Rotation is equal vicissitude in Government, or succession to Magistracy confer'd for such convenient terms..as take in the whole body by parts. 1660Milton Free Commw. Wks. 1851 V. 439 A numerous Assembly of them all form'd and conven'd on purpose with the wariest Rotation. a1721Sheffield (Dk. Buckhm.) Wks. (1753) II. 180 This is no small advantage in Republicks, where a sort of rotation is necessary, by which men are seen under several capacities. 1762Falconer Shipwr. ii. 483 So the brave mariners their pumps attend, And help incessant by rotation lend. 1800Colquhoun Comm. Thames xiii. 366 Five of the twenty-one Directors shall go out of office by rotation every year. 1833H. Martineau Manch. Strike 73 Three members..sit daily,..viz., the treasurer, secretary, and one of the other members in rotation. 1888Bryce Amer. Commw. (1890) II. 88 In America..the tendency is towards ‘rotation’ in office.
c. Agric. A change or succession of crops in a certain order on a given piece of ground, in order to avoid the exhaustion of the soil.
1778W. H. Marshall Minutes Agric. Digest 76 A regular rotation of Crops and Fallow is, perhaps, more convenient than profitable. 1792Young Trav. France 346 The effects derived from the rotation of crops. Ibid., The miserable rotations commonly practised in France. 1845McCulloch Taxation ii. vi. (1852) 247 By narrowing the demand for barley, and obliging the farmers to adopt imperfect rotations. 1874Stubbs Const. Hist. I. iii. 50 The proper rotation of crops and fallow might be observed.
d. Forestry. The cycle of planting, felling, and replanting; the period of this, the (actual or planned) time between the formation or regeneration of a crop and its felling.
1888E. E. Fernandez Man. Indian Sylviculture i. 6 The existence of a rotation implies the more or less simultaneous appearance of the old generation, and a similarly more or less simultaneous removal of that generation and the appearance of the new one. There can hence be no rotation in the case of selection-worked forests. 1889W. Schlich Man. Forestry I. ii. ii. 170 The selection of the rotation..should be so fixed under the method of natural regeneration as to admit of a proper regeneration of the wood, whether by seed or coppice shoots. 1890W. J. Gordon Foundry 127 The Earl of Seafield's forest.., which is regularly planted and felled so as to cut a thousand acres annually on a rotation of sixty years. 1927Forestry I. 101 A more detailed investigation of the returns from quality class V forests showed that at 100 years (the financial rotation) the yield was 1.06 per cent., and at 120 years (the more usual rotation) it was 1.03 per cent. 1938G. S. Cansdale et al. Black Poplars 9 The poplar is essentially a tree to be grown on short rotation. 1977M. Clawson Decision Making in Timber Production 26 For many sites, the earnings from the next rotation of timber growing are highly speculative or dubious, partly because it is so far in the future.
3. attrib. and Comb., as rotation axis, rotation group, rotation-movement, rotation-tide; rotation-like adj.; † rotation-office (see sense 2 b, note); rotation grasses, grasses sown in a rotation of crops.
1768Ann. Reg., Chron. 57/2 The sitting Magistrates..at the Rotation-office in Whitechapel. 1812Sporting Mag. XL. 283 At the Leeds Rotation-office this month, John Waddington, of Farnley.., was convicted..for shooting a hare. 1865Proc. Amer. Phil. Soc. X. 165 Evidences of rotation-tides. 1886Daily News 11 Dec. 6/3 As temporary pastures, that is to say, rotation grasses (including clover), are included in the arable area, one would naturally look for a proportional diminution in rotation grasses. 1899Allbutt's Syst. Med. VII. 883 The balancing, nodding, and rotation movements are more especially likely to preserve a definite rhythm. 1903Rotation axis [see holoaxial s.v. holo-]. 1952Dylan Thomas Let. 11 Dec. (1966) 388 It was, I think, originally a little ‘organ’..full of rotation-like gossip. 1971I. G. Gass et al. Understanding Earth i. 19/1 The stereogram of zircon..shows a four-fold rotation axis in the centre and also shows a number of reflection planes. 1974G. Reece tr. Hund's Hist. Quantum Theory xiii. 177 These two-valued representations of the rotation group had been discovered by Hermann Weyl.
Add:[2.] e. Baseball. The (usual) order in which pitchers start successive games during a season; also, a team's regular starting pitchers. Freq. in starting rotation.
1963E. Richter Making of Big-League Pitcher x. 107 He is expected to instruct, to advise the manager on rotation plans. 1970R. Hoopes What Baseball Manager Does 45 For a starting rotation, he wants at least three..solid starters. 1978Detroit Free Press 2 Apr. 6e/3 The Pirates have Bert Blyleven in the same starting rotation with John Candelaria. 1988First Base Autumn 31/3 Mets pitcher David Cone, who replaced injured Rick Aguilera in the starting rotation. 1989P. Dickson Baseball Dict. 329/2 A modern manager likes to leave spring training with his rotation set for, at least, the early weeks of the season. |