| 释义 |
▪ I. nappe|næp|
[a. F. nappe table-cloth, nape n.2]
1. Hydraulics. A sheet of water falling over a weir or similar surface.
1892Marichal & Trantwine tr. Bazin in Proc. Engineers' Club Philadelphia IX. 231 We now proceed to study the form of the sheet of water passing over the weir. [translator's footnote] For want of a convenient English equivalent, we shall designate this sheet by its very appropriate French name, the nappe, a name applied primarily to a table-cloth, the form of which..is well imitated by the sheet of water passing over the weir. Ibid. [text], The upper surface of the nappe has already been studied by certain experimenters. 1945W. P. Creager et al. Engin. for Dams II. xi. 357 If the area below the lower nappe is filled with masonry, the shape of the sheet and the discharge will not be changed appreciably. 1966F. M. Henderson Open Channel Flow vi. 177 If the nappe is contained within parallel walls downstream of the weir, it may well enclose the air between itself, walls, and floor.
2. Geol. A sheet of rock which has moved sideways over neighbouring strata, usu. as a result of overthrusting.
Earlier used in F. as nappe de recouvrement sheet of overlaying (e.g. Bull. Soc. vaudoise des Sci. nat. (1893) XXIX. 252).
1922Q. Jrnl. Geol. Soc. LXXVIII. 87 In deciding upon the basal limit to be assigned to any particular nappe, one generally chooses some prominent thrustplane; failing this, one is entitled to select the axial plane of some recumbent anticline or syncline, according to local convenience. 1932[see allochthonous a.]. 1944A. Holmes Princ. Physical Geol. vi. 81 Tear faults are commonly developed in nappes, where they naturally arise if one part of a nappe has been driven forward further than the adjoining parts. 1970Linton & Moseley in Cambr. Anc. Hist. (ed. 3) I. i. i. 15 The Gulf of Oman, in which a series of ‘nappes’ or horizontally displaced rock sheets have been successively driven from north-east to south-west.
▪ II. nappe
obs. form of nap. |