| 释义 |
truncated, ppl. a.|ˈtrʌŋkeɪtɪd, -ˈkeɪt-|
[f. L. truncāt-us, pa. pple. of truncāre (see prec.) + -ed1 2, or f. prec. + -ed1.]
Cut short (actually or apparently); having a part cut off, or of such a form as if a part were cut off.
1. Her. Of a cross or tree: Having the arms or boughs cut off, so as not to extend to the boundaries of the shield; couped. ? Obs.
1486Bk. St. Albans, Her. C vj b, A cros truncatid, And hit is calde trunkatid for hit is made of ij treys the boys [= boughs] cut a Way. 1572J. Bossewell Armorie ii. 95 b, These trees are truncated, that is to saie, ye boughes cut of from the body, and laide in the forme of a Saltier. The endes whereof may not touch the Angles of the shield.
2. In modern scientific and technical use. (Const. as adj. preceding the noun, or as pa. pple. following the noun.)
a. Geom., etc. Of a figure: Having one end cut off by a transverse line or plane; esp. of a cone or pyramid: Having the vertex cut off by a plane section, esp. one parallel to the base: thus truncated cone or truncated pyramid = frustum of a cone or pyramid.
1704J. Harris Lex. Techn. I, Truncated Pyramid or Cone, is one whose top is cut off by a Plane parallel to its Base; and therefore the Figure of the truncated top must always be similar to the Base. 1827Faraday Chem. Manip. ii. (1842) 26 Weights..constructed in sets, each weight..having the form of a truncated cone. 1831R. Knox Cloquet's Anat. 581 The Cartilages of the apertures of the Nose..represent an ellipse truncated posteriorly. 1840Lardner Geom. 68 A trapezium is a truncated triangle. Ibid. 166 A figure formed by the section of a prism by a plane not parallel to its base is called a truncated prism. 1868Lockyer Guillemin's Heavens (ed. 3) 73 The southern horn of the crescent was truncated.
b. Cryst. and Solid Geom. Of an edge or solid angle: Cut off or replaced by a plane face, esp. one equally inclined to the adjacent faces; also said of a solid figure having its edges or angles thus cut off.
1796Kirwan Elem. Min. (ed. 2) I. 128 [Fluor] the angles or edges rarely truncated or bevilled. 1823H. J. Brooke Introd. Crystallogr. 24 When an edge, or solid angle, is replaced by one plane, it is said to be truncated. When an edge is replaced by two planes, which respectively incline on the adjacent primary planes at equal angles, it is bevilled. 1863Geo. Eliot Romola xxvi, The wide doorway, standing at the truncated angle of a great block..of houses. 1875Bennett & Dyer Sachs' Bot. 51 The separate crystalloids are thin plates, single regular rhombs, often with truncated angles. 1891Cent. Dict. s.v. Truncate v., Truncated cube, cuboctahedron, dodecahedron [etc.].
c. Nat. Hist. Appearing as if the tip or end were cut off transversely; terminating in a flat or broad edge or surface instead of a point.
1752J. Hill Hist. Anim. 3 The Enchelis, with the head small, and the tail truncated. 1753Chambers Cycl. Supp. s.v. Leaf, Truncated Leaf, that whose summit or point seems to have been cut off, or is terminated by a strait line in a transverse direction. 1816Stephens in Shaw Gen. Zool. IX. ii. 236 Quills dusky black; the points..truncated. 1835J. Duncan Beetles (Nat. Libr.) 184 The elytra are short and truncated at the extremity. 1899Allbutt's Syst. Med. VIII. 774 These truncated hairs are of..importance for diagnosis.
d. So in Archit., Geol., etc.
1723Chambers tr. Le Clerc's Treat. Archit. I. 114 Pediments..supported by an Entablature truncated in the middle. 1727–41Chambers Cycl. s.v. Roof, Sometimes it is truncated; that is, instead of terminating in a ridge or angle, it is cut square off at a certain heighth. 1829Scott Anne of G. xi, A truncated column of marble, having its base sculptured with hieroglyphical imagery. 1830Lyell Princ. Geol. (1872) I. ii. xxiii. 588 The summit of the loftiest peak is truncated. 1869Boutell Arms & Arm. ii. (1874) 11 In some [Assyrian] examples, the raised upper crest-like part of the helm is seen to have been bent backwards and truncated.
e. Statistics. Of a frequency distribution or sample: obtained by disregarding values of the variate greater than or less than some chosen value. Of a variate: treated in this way.
1931R. A. Fisher Truncated Normal Distribution in Math. Tables (Brit. Assoc. Adv. Sci.) I. p. xxxiii, The frequency of the truncated distribution in the range dx. 1952A. Hald Statistical Theory with Engin. Applications vi. 146 The cumulative distribution functions of three truncated distributions..with degrees of truncation of 10, 30 and 50% respectively. 1971C. R. Heathcote Probability v. 240 Truncated variables are often easier to handle than the original ones, and..under wide conditions, the two sequences have the same asymptotic behaviour.
f. Of soil: having lost the upper horizon(s) as a result of rapid erosion.
1938A. B. Yolland tr. A. de Sigmond's Princ. Soil Sci. xiv. 206 These truncated forest soils possess a peculiar dynamics of their own. 1941H. Jenny Factors of Soil Formation v. 100 Owing to differences in color of the A and B horizons, truncated profiles are often readily discernible on freshly plowed slopes. 1976L. F. Curtis et al. Soils Brit. Isles 315 Truncated podzols. Here the surface soil has the characters of a B horizon.
3. Maimed, mutilated; also fig.
1731Bailey, Truncated, cut shorter, maimed, mangled. 1791–1823D'Israeli Cur. Lit. (1858) III. 181 All the Italian editions continued to be reprinted in the same truncated condition. 1845R. W. Hamilton Pop. Educ. v. (ed. 2) 97 The truncated frame of man is without power of locomotion or external action. 1890J. Stalker Imago Christi v. (1891) 104 It is a truncated and most imperfect friendship when this region is closed. |