| 释义 |
plasticity|plæˈstɪsɪtɪ|
[f. plastic a. + -ity; so F. plasticité (1785 in Hatz.-Darm.).]
a. The quality of being plastic, in various senses of the adj.; spec. capacity for being moulded or undergoing a permanent change in shape.
1782–3W. F. Martyn Geog. Mag. I. 325 Inclining to plasticity, (or easiness of impression). 1793Smeaton Edystone L. §218 note, The lime will receive the most sand in that way, without losing its plasticity. 1801W. Taylor in Monthly Mag. XII. 588 Moulded into metaphors, or carved into comparisons, with marvellous plasticity. 1859Bain Emotions ii. ix. §20. 519 Some natures are distinguished by plasticity or the power of acquisition, and therefore realize more closely the saying that man is a bundle of habits. 1867V. Ottolini et al. Terracotta Archit. N. Italy 5 Plasticity and homogeneity of ingredients are the two conditions essential to the composition of any ceramic paste. 1878Stewart & Tait Unseen Univ. iii. §108 Effects of the extraordinary plasticity of glacier-ice. 1933L. F. Rahm Plastic Molding ii. 24 In molding, shellac compounds are generally preheated to sufficient plasticity to require no further heat from the mold. 1935G. E. Doan Princ. Physical Metallurgy v. 109 If deformation is continued until the temperature of the object is below the recrystallization temperature.., the plasticity of the metal may be insufficient and the object may crack in the operation. 1968W. J. Patton Materials in Industry iii. 61 Most forming operations during manufacture require plasticity for their execution. 1971B. Scharf Engin. & its Lang. i. 2 Ductility, malleability and plasticity are closely related properties.
b. Biol. Adaptability of an organism to changes in its environment.
1868Clifford Lect. (1879) I. 102 The race must at a certain time have a definite amount of plasticity, that is, a definite power of adapting itself to altered circumstances by changing in accordance with them. 1908J. A. Thomson Heredity iii. 72 It is certain that many unicellular organisms are very plastic, and it seems reasonable to suppose that as differentiation increased, restrictions were placed on the primary plasticity, while a more specialised secondary plasticity was gained in many cases, where the organisms lived in environments liable to frequent vicissitudes. 1951Jrnl. Ecol. XXXIX. 217 Ecological plasticity..may be defined as the potentialities of expression of physiological characters that determine what factors of the environment shall limit the distribution of a species or other taxon. 1976Bell & Coombe tr. Strasburger's Textbk. Bot. 401 The wild strawberry..reproduces vegetatively by vigorous runners..and each clone can only develop the desirable genetic plasticity by means of stepwise somatic mutations (bud sparts). 1978Nature 14 Sept. 140/2 The potential for plasticity of the developing mammalian visual system has been the subject of several investigations. |