| 释义 |
hexagonal, a. (n.)|hɛkˈsægənəl|
Also 7 erron. exagonal.
[f. hexagon + -al1.]
A. adj.
1. a. Of or pertaining to a hexagon; of the shape of a hexagon; having six sides and six angles.
1571Digges Pantom. iv. v. V iij b, The Diameter of the circle described within a Pentagonum is equall to the sides hexagonall and decagonall of the comprehending circle. 1664Power Exp. Philos. i. 49 Poppy Seeds..are like an Hony-Comb on the Surface, with regular Sides and Angles, making all of them pentagonal and hexagonal areola's. 1862Tyndall Mountaineer. viii. 67 Nature, prodigal of beauty, rains down her hexagonal ice-stars year by year.
b. hexagonal numbers, the series of polygonal numbers 1, 6, 15, 28, 45, 66, 91, etc., formed by continuous summation of the arithmetical series 1, 5, 9, 13, 17, 21, 25, etc.
(If any one of these be multiplied by 32 and 4 added to the product the result will be a square number.)
1727–41Chambers Cycl. s.v. Polygonal number. 1796Hutton Math. Dict. I. 468/2 If that common difference..be 4, the series will be hexagonal numbers or hexagons.
2. Of solids: Whose section is a hexagon; constructed on a hexagon as base.
1646Sir T. Browne Pseud. Ep. ii. i. 53 As for the figure of crystall..it is for the most part hexagonall or six cornerd. 1774Goldsm. Nat. Hist. (1776) VIII. 101 Each cell is like that of the bee, hexagonal. 1794Sullivan View Nat. I. 447 Quartz..When crystallized in hexagonal pyramids..is called mountain crystal. 1871Tyndall Fragm. Sc. (1879) I. xii. 357 When silica crystallises, we have formed these hexagonal prisms capped at the ends by pyramids.
3. Cryst. Denominating one of the principal systems of crystallization, which is referred to three lateral axes, normally inclined to each other at 60°, and a vertical axis at right angles to these and differing from them in length. Also, Of or belonging to this system. hexagonal close-packed adj., applied to a type of crystal structure or lattice with hexagonal symmetry in which each ion or atom has twelve equidistant neighbours; so hexagonal close-packing (see quot. 1917); hexagonal symmetry, the symmetry of a figure or body that coincides with its original position after rotation about an axis through an angle of 60° or any multiple of this.
1837Dana Min. ii. (1844) 35 Hexagonal System. The vertical solid angles of the rhombohedron are formed by the meeting of three equal planes. 1878Gurney Crystallogr. 38 The line of intersection of six symmetral planes is an axis of hexagonal symmetry. 1895Story-Maskelyne Crystallogr. Index, Hexagonal axes. 1917Physical Rev. X. 678 The so-called hexagonal close-packing..is one of the two alternative arrangements which the atoms would assume if they were hard spheres and were forced by pressure into the closest possible packing. 1920Science 3 Sept. 228/1 The arrangement of atoms in zinc is like that in magnesium, namely: hexagonal close packed. 1966L. G. Bassett et al. Princ. Chem. iii. 171 The difference between hexagonal close packing and face-centered close packing arises from the two arrangements for atoms in the third layer.
B. n. A hexagonal number.
1796Hutton Math. Dict. II. 258/2 The angles..of the hexagonals [are] six.
Hence heˈxagonally adv., in a hexagonal manner; in the form of a hexagon; according to the hexagonal system of crystallization. heˈxagonalize v. trans., to form into hexagons.
1727Bailey vol. II, Hexagonally. 1794G. Adams Nat. & Exp. Philos. II. xvi. 233 Its sides are flat, and from its base, hexagonally divided. 1837Dana Min. (1844) 67 A hexagonally prismatic crystal of white lead. 1870Athenæum 2 Apr. 454 With a small hexagonalized map in his pocket, the traveller..could always tell his distance to a nicety. |