| 释义 |
underˈsaturated, ppl. a.
[under-1 10 a.]
a. Not saturated, falling short of being saturated; spec. (of a solution) not containing as much solute as is possible in equilibrium conditions.
1832Nat. Philos. (Libr. Useful Knowl.) II. v. ii. 13/1 In a deficiency of fluid, or in matter under-saturated [with electric fluid]. 1957G. E. Hutchinson Treat. Limnol. I. ix. 592 It appears that the surface of the lake is significantly undersaturated throughout the spring months. 1961L. Martin Clinical Endocrinol. (ed. 3) ii. 56 The arterial blood is chronically under-saturated with oxygen. 1973Sci. Amer. Jan. 105/2 When the bases of the clouds are fairly high and there is a thick layer of warm, undersaturated air below them.
b. Petrol. Of a rock or magma: containing insufficient free silica (or some other specified oxide) to saturate all the bases present; consisting wholly or partly of undersaturated minerals. Of a mineral: unable to form in the presence of free silica; unsaturated.
1913S. J. Shand in Geol. Mag. Decade V. x. 510 An undersaturated magma (i.e. one which on solidifying would give rise to a partsaturated or unsaturated rock) is capable of entering into chemical combination with the silica of invaded rock masses. 1947, etc. [see oversaturated ppl. a.]. 1965G. J. Williams Econ. Geol. N.Z. xi. 168/2 A very fine-grained phonolite or undersaturated trachyte of high soda content. 1983D. S. Barker Igneous Rocks xi. 259 All xenoliths for which a mantle origin seems likely have been found in silica-undersaturated rocks. |