| 释义 |
cycloidal, a.|saɪˈklɔɪdəl, sɪk-|
[f. as prec. + -al1.]
1. Geom., etc. Of, pertaining to, or of the form of a cycloid.
cycloidal engine: an instrument used in engraving an ‘engine-turned design’ upon the plates for bank-notes, etc., as a precaution against counterfeiting; the graver-point having a motion compounded of translation and rotation. cycloidal paddle: a name erroneously given to a paddle-wheel in which each float is divided longitudinally into several strips in a slightly retreating order, en echelon, so as to lessen the concussion and make the resistance more uniform (Knight). cycloidal pendulum: a pendulum constructed to swing in a cycloid, so as to be perfectly isochronous.
1704J. Harris Lex. Techn. s.v. Cycloid, The space within this Curve and the Subtense..is called the Cycloidal Space. 1830Kater & Lardner Mech. xi. 159 Availing himself of this property of the curve, Huygens constructed his cycloidal pendulum. 1884F. J. Britten Watch & Clockm. 122 The upper part of the pendulum is a double cord hanging between two cycloidal cheeks to give a cycloidal path to the bob.
2. Zool. = cycloid a. a.
1872Nicholson Palæont. 326 The scales..are cycloidal in shape, and are arranged in an imbricate manner.
Hence cyˈcloidally adv., in the form of a cycloid.
1727Chambers Cycl. s.v. Phonicks, A smooth wall..arched..cycloidally or elliptically. |