| 释义 |
tangential, a. (n.)|tænˈdʒɛnʃəl|
[f. L. type *tangentia (see tangency) + -al1.]
A. adj. Of or pertaining to tangency or a tangent.
1. a. Of, pertaining to, or of the nature of a tangent; identical with, or drawn at, a tangent to a curve or curved surface.
1630R. Delamain Grammalogia App. 62 If the Declination be above 38. gr. 3. m. you may move the Tangent of 45. softly alonge by the Tangentiall degrees of Declination in the fixed, untill 45. gr. in the moveable be opposite to 45. gr. in the fixed. 1763Phil. Trans. LIII. 68 The proposed demonstration of this tangential property. 1828J. M. Spearman Brit. Gunner 265 The apparent level is a straight line tangential to the surface of the earth, or true level. 1881Tait in Nature XXV. 128 The glass is extended in a radial and compressed in a tangential direction.
b. Of motion or force: Acting along a tangent to a curved line or surface.
1709Steele Tatler No. 43 ⁋7 The Tangential and Centripetal Forces, by their Counter-struggle, make the Celestial Bodies describe an exact Ellipsis. 1768Tucker Lt. Nat. (1834) I. 413 He might give the heavy planets their tangential motion by one strong and exactly poised stroke. 1880Bessey Botany 129 The tangential growth of the surrounding cells. 1883Science I. 523/1 The tangential tension of the bark increases with the growth of the stem.
c. Of a thing: That lies in a tangent to a curved surface.
1854J. Scoffern in Orr's Circ. Sc., Chem. 388 One part [of a globular box] is furnished with a tangential jet. 1899Allbutt's Syst. Med. VIII. 331 The tangential fibres of the cortex. 1901A. J. Evans in Oxf. Univ. Gaz. 12 Feb. 339/2 A small vase with incised returning spirals and tangential leaves. 1905Bond Goth. Archit. 164 The ambulatory with tangential chapels.
d. spec. (a) Of the spokes of a wheel (as in a bicycle): Arranged as tangents to the hub. (b) Of a fabric (as a tyre-cover): Having layers of thread lying diagonally from edge to edge, so as to distribute the strain.
1898Cycling 63 The best results are obtained from a fabric which..consists of layers of independent threads running diagonally from edge to edge of the cover and not interwoven. This is called a ‘tangential’ fabric because the pull travels lengthwise along the threads (as in a tangent spoke) and not across them.
(c) Of the pick-up of a record-player: so mounted that it is kept at a tangent to the groove by a rectilinear motion of the arm.
1937Electronics X. 9/2 The whys and wherefores of the ‘tangential’ type pick-up mount and its effects on distortion and record wear. 1977Time 10 Oct. 43/1 (Advt.), The Beogram 4002 has an electronically controlled tangential arm which plays records in the same way that they were cut: tracing a straight line from the edge of the record to its centre instead of tracing an arc.
2. a. fig. Going off suddenly ‘at a tangent’; erratic; divergent; digressive.
1867F. H. Ludlow Genre Pict., Little Briggs & I, 199 A remedy to this day sovereign..for all tangential aberrations from the back of a colt or the laws of society. 1876T. Hardy Ethelberta (1890) 297 Those devious impulses and tangential flights which spoil the works of every would⁓be schemer who instead of being wholly machine is half heart. 1903Spectator 31 Jan. 184/2 A collection of mixed and tangential information.
b. That merely touches a subject or matter.
1825Hazlitt Spirit of Age, Coleridge (1886) 46 Our author's mind is (as he himself might express it) tangential. There is no subject on which he has not touched, none on which he has rested. 1885O. W. Holmes Emerson 165 Emerson had only tangential relations with the experiment.
c. tangential energy: in the writings of P. Teilhard de Chardin, the form of energy that is manifest in the workings of the physical world and is described by the laws of thermodynamics. Cf. radial energy s.v. radial a. 6. [tr. F. énergie tangientielle, introduced c 1938 by P. Teilhard de Chardin (Le Phénomène Humain (1956) i. ii. 62).]
1959,1965[see radial a. 6]. 1969A. Richardson Dict. Christian Theol. 332/2 Tangential energy links units at the same level of organization.
B. n. Geom. tangential of a point (in a curve of the third or higher order), the point at which a tangent at the given point meets the curve again.
1858Cayley Coll. Math. Papers II. 558 A derivative which may be termed the ‘tangential’ of a cubic, viz. the tangent at the point (x,y,z) of the cubic curve (*)(x,y,z)3 = 0 meets the curve in a point (ξ, η, ζ), which is the tangential of the first-mentioned point. 1859Ibid. IV. 188. 1879 G. Salmon Higher Plane Curves v. (ed. 3) 130.
Hence tangentiality |-ʃɪˈælɪtɪ|, the quality or condition of being tangential.
1889Philos. Mag. Apr. 335 The perpendicularity of E and the tangentiality of H to the surface. |