| 释义 |
▪ I. ‖ meta, n.1 Rom. Antiq.|ˈmiːtə|
Pl. metæ |ˈmiːtiː|.
[L. mēta.]
One of the conical columns set in the ground at each end of the Circus, to mark the turning-place in a race. Hence transf. A boundary.
1577Harrison Descr. Brit. i. 2 in Holinshed, So that the aforesaid line shall henceforth be their Meta and partition from such as be ascribed to America. 1662Ray Three Itin. iii. 183 In Somersetshire they have a way of setting their mows of corn on a frame..standing upon four stones cut with a shank, and upon that an head like a meta. 1845Athenæum 1 Feb. 126 We have the cross erected between two ‘metæ’.
▪ II. ˈmeta, Meta, n.2
Abbrevs. of metaldehyde. Spec. a block of metaldehyde used (a) as fuel for cooking and heating, (b) for killing slugs. Also attrib.
Registered as a proprietary term by Lonza Elektrizitätswerke, Switzerland, in 1924 Trade Marks Jrnl. 26 Mar. 717 (as a fuel) and in 1938 Ibid. 18 May 603 (slug-killer).
1925E. F. Norton Fight for Everest 1924 v. 102 Our loads..comprise one 10-lb. tent, two sleeping bags, food and ‘meta’ (solid spirit). Ibid. 706 The meta cooker doing its indifferent best to produce half a pot of warm water. 1938Times 26 Nov. 15/6 Tablets of Meta crushed and used by itself or mixed with bran, may be put about among plants before dark and the victims collected in the morning. 1947F. Smythe Again Switzerland vi. 120 He carries with him a packet of ‘meta’ fuel. 1952E. R. Janes Flower Garden 119 Metaldehyde (Meta) is a very fine slug killer... Under some conditions in the dead of winter it is hardly possible to apply Meta. 1955P. Bauer Kanchenjunga Challenge iv. iv. 196 We went on travelling light with perhaps the Zdarsky sack and a small meta-tablet cooker.
▪ III. meta, a. Chem.|ˈmɛtə|
Now usu. italicized.
[f. meta- prefix.]
Characterized by or relating to (substitution at) two carbon atoms separated by one other in a benzene ring; at a position next but one to some (specified) substituent in a benzene ring. Also as adv.
1876Jrnl. Chem. Soc. XXIX. 237 The author places the sulpho-acids obtained by the action of sulphuric acid on..iodobenzene in the meta (1:3) series. 1924E. J. Holmyard Outlines Org. Chem. xix. 367 The para isomer C6H4X2 can yield only one trisubstitution product C6H3X3, while the ortho can give two and the meta can give three. 1938L. F. Fieser in H. Gilman Org. Chem. I. ii. 146 There is..no such enormous difference in reaction rate..as there is between the ortho-para directing amines and the meta orienting ammonium salts. 1949[see orient v. 4 a]. 1968R. O. C. Norman Princ. Org. Synth. xi. 357 Position a, which is ortho to acetamido and meta to methyl, is more reactive than position b, which is meta to acetamido and ortho to methyl. |