| 释义 |
rhombic, a.|ˈrɒmbɪk|
[f. rhomb + -ic.]
1. a. Of the form of an oblique equilateral parallelogram; rhomb-shaped; spec. applied to a radio aerial with a horizontal rhombic shape. Also ellipt. as n.
1701[see rhomboid A. 1]. 1798Greville in Phil. Trans. LXXXVIII. 426 The Abbé Hauy, by measuring the rhombic plane of Corundum, found its two diagonals to be as two to three. 1816P. Cleaveland Min. 444 Dodecaedrons with rhombic faces. 1849D. Campbell Inorg. Chem. 50 Sulphur occurs in nature crystallized in acute octohedrons with rhombic bases. 1888Rolleston & Jackson Anim. Life 577 Grooves pierced by pores which form a rhombic figure. 1935Proc. IRE XXIII. 24 The structure was descriptively termed the ‘diamond-shaped’ antenna.., but it has since become known as the ‘rhombic’ antenna and will be so designated here... Checking measurements were made on small-scale rhombic antennas operating at correspondingly short wavelengths. 1950K. Henney Radio Engin. Handbk. (ed. 4) xiv. 653 When two rhombics are used in broadside as a single system, one common support can be used without balance problems, when fed symmetrically. 1968Radio Communication Handbk. (ed. 4) xiii. 62/1 The average gain of a rhombic is 3db greater than that of a V aerial with the same legs and this is to be expected because the rhombic is twice as large. Ibid. 62/2 The design of V and rhombic aerials is quite flexible and both types will work over a 2 : 1 frequency range. 1975D. G. Fink Electronics Engineers' Handbk. xxii. 64 The rhombic antenna is in wide use.
b. Zool. Lozenge- or diamond-shaped, often with the corners somewhat rounded.
1815E. J. Burrow Conch. 76 The form differs much, being subglobose, reniform, cordate, or rhombic. 1851Woodward Mollusca 69 Loligo Vulgaris:..body tapering behind..; fins terminal, united, rhombic. 1870Gillmore tr. Figuier's Reptiles & Birds iii. 109 Strobilosaura have the scales of the back and sides imbricate, generally rhombic.
c. Bot. Oval but angular at the sides.
1857A. Gray First Less. Bot., Gloss. 1870Hooker Stud. Flora 318 Atriplex patula,..sepals rhombic or deltoid.
2. Of solid figures:
a. Having a rhomb for its base or section plane; also, bounded by equal and similar rhombs; Cryst. = orthorhombic.
1670Phil. Trans. V. 2041 The Figure of this Chrystal stone is like a Rhombick or Rhomboid Prisme. 1802Playfair Illustr. Hutton. The. 246 The spar taking the form of rhombic crystals. 1841Brande Man. Chem. 123 The rhombic dodecaëdron contained between twelve equal rhombic planes. 1842Francis Dict. Arts, Rhombic spar, Iceland spar, or the doubly-refractive carbonate of lime. 1869Roscoe Elem. Chem. (1874) 158 Rhombic or common neutral sodium phosphate. 1879Rutley Stud. Rocks ix. 84 In the rhombic system the three axes of elasticity coincide with the three crystallographic axes.
b. In the specific names of minerals.
1788J. H. de Magellan tr. Cronstedt's Syst. Min. (ed. 2) I. 198 Rhombic Quartz, Spatum Scintillans. Feltspatum. 1844Dana Min. 322 Rhombic Mica. 1867Hunt & Rudler Descr. Guide Mus. Pract. Geol. 101 Marcasite occurs in a series of prismatic forms, which have suggested the name of rhombic pyrites.
3. Comb., as rhombic-based, rhombic-scaled adjs.; also with adjs. = ‘partly rhombic (and partly{ddd})’.
1828Stark Elem. Nat. Hist. I. 395 Body rhombic-ovate, slightly lengthened. 1870Hooker Stud. Flora 317 Leaves rhombic-triangular. Ibid. 319 Lower leaves opposite rhombic or rhombic-hastate. 1895Maskelyne Crystallogr. 334 A rhombic based prism. 1896Guide Fossil Reptiles Brit. Mus. 105 The Eugnathidæ are the rhombic-scaled forerunners of the modern Amia. |