| 释义 |
rheid, n. and a.|ˈriːɪd|
[f. Gr. ῥέ-εῖν to flow + -id, after liquid.]
A. n. A substance which undergoes viscous flow when at a temperature below its melting point.
1954S. W. Carey in Jrnl. Geol. Soc. Australia I. 70 The substance deforms as a fluid. In order to distinguish it from a liquid (seeing that it is below its melting point)..such a substance is here named a rheid. 1963Turner & Weiss Struct. Anal. Metamorphic Tectonites viii. 321 We still have no knowledge of the threshold conditions beyond which rocks such as granite and schist..can be regarded as rheids.
B. adj. Characteristic of a rheid; that is a rheid.
1954Jrnl. Geol. Soc. Australia I. 83 There are..numbers of empirical observations of solid intrusion of serpentine by rheid flow. 1962L. C. King Morphol. Earth iv. 123 The long period over which the Jura folding has been accomplished, from Oligocene to late-Pliocene time, favours the idea of slow, rheid creep in the basement. 1965A. Holmes Princ. Physical Geol. (ed. 2) ix. 204 While ice or any other solid body in a rheid state is slowly flowing, the deformation stress may temporarily increase to a point where the material is compelled to fracture, if only momentarily. 1972J. G. Dennis Structural Geol. v. 102 A material is rheid by virtue of the time of observation. Rocks are not rheid in a quarry operation, but they are so during geological deformation.
Hence rheˈidity, the phenomenon of rheid behaviour; also, a measure of the rheid behaviour of a substance, equal to the time required for the viscous deformation to become one thousand times as great as the elastic deformation.
1954S. W. Carey in Jrnl. Geol. Soc. Australia I. 70 Duration..to allow the viscous term to become a thousand times as great as the elastic term... This may be adopted arbitrarily as the threshold of wholly fluid behaviour and will be referred to as the rheidity of the substance for the given conditions. 1965A. Holmes Princ. Physical Geol. (ed. 2) x. 238 The rheidity of salt is..about 108 to 109 seconds..i.e. between 3 and 30 years. Ibid. xi. 282 Fifty years ago little or nothing was known of the phenomena of rheidity and diapirism. |