| 释义 |
Neumann|ˈnɔɪman|
The name of Johann G. Neumann, 19th-cent. Austrian geologist (?), used attrib. to designate narrow bands, lines, or lamellæ parallel to crystallographic planes which are seen in α-iron (ferrite) subjected to a sudden shock, and are usu. attributed to twinning (investigated by Neumann c 1848).
1886Proc. Amer. Acad. Arts & Sci. XXI. 498 On different sections of meteorites Widmanstättian figures and Neumann lines can be exhibited in every gradation, from the broadest bands to the finest markings. 1914Jrnl. Soc. Chem. Industry 15 Aug. 791/2 The Neumann lamellæ occurring in any given grain are parallel to not more than 6 planes corresponding to the crystalline orientation of the grain itself. 1922Chem. Abstr. XVI. 3845 (heading) Neumann bands as evidence of action of explosives upon metal. 1946Jrnl. Iron & Steel Inst. CLIV. 129p/1 The Neumann band is primarily a shearing or faulting movement operating along the pre-existent planar disjunctions of the mosaic structure, and..as a secondary operation twinning may be completed, as is known to be possible in ferrite. 1966C. R. Tottle Sci. Engin. Materials iii. 64 In alpha iron (b.c.c.) impact loading at room temperature can produce shear twins, called Neumann bands (which are found, incidentally, in metallic meteorites). |