| 释义 |
Janus|ˈdʒeɪnəs|
1. a. The name of an ancient Italian deity, regarded as the doorkeeper of heaven, as guardian of doors and gates, and as presiding over the entrance upon or beginning of things; represented with a face on the front and another on the back of his head; the doors of his temple in the Roman Forum were always open in time of war, and shut in time of peace. Often used allusively, and in attributive and other relations.
1508Dunbar Gold. Targe 120 Ianus, god of entree delytable. 1598Hakluyt Voy. I. 488 Certaine idoll puppets..which they fasten to the doore of their walking houses, to be as Ianusses or keepers of their house. 1667Milton P.L. xi. 129 Four faces each Had, like a double Janus. 1713Lond. Gaz. No. 5118/6 Janus's Gate is now shut. 1814Cary Dante, Paradise vi. 83 Composed the world to such a peace That of his temple Janus barr'd the door.
b. attrib. and Comb., referring to the two-faced figure, as Janus face, Janus glance, Janus line, Janus word, etc.; Janus-faced, Janus-like, Janus-visaged adjs.
1654Whitlock Zootomia 549 An Experiment it is with a *Janus face. 1711Shaftesbury Charac. ii. i. §3 This Janus-face of writers, who with one countenance force a smile, and with another show nothing beside rage and fury.
1682Sir T. Browne Chr. Mor. iii. §3 Bivious Theorems and *Janus-faced Doctrines. 1841–4Emerson Ess., Friendship 172 A friend is Janus-faced: he looks to the past and the future.
1648Sanderson Serm. Heb. xii. 3 §35 Every affliction, *Janus-like, hath two faces, and looketh two ways. 1875Jowett Plato (ed. 2) III. 150 The Janus-like character of the Republic.
1822Shelley Triumph of Life 94 A *Janus-visaged Shadow.
2. a. Designating materials with a double facing, or things having a two-way action, as Janus-beaver, Janus-cloth, Janus-cord, Janus-lock.
1851Illustr. Catal. Gt. Exhib. iii. 486/2 Fur Janus beaver. Ibid. v. 1468/2 Janus locks. a1877Knight Dict. Mech. II. 1210/2 Janus-cloth, a fabric having each side dressed, and different colors on the respective sides. Such fabric is used for reversible garments. 1881in A. Adburgham Shops & Shopping (1964) vi. 64 Mourning materials such as Victoria Cords, Janus Cords, Cashmere, and so on. 1960Cunnington & Beard Dict. Eng. Costume 259/2 Janus cord, a black rep of wool and cotton, the fine cord showing equally on both sides. Much used for mourning.
b. Dye Chem. Appled to a group of basic azo dyes that contain a quaternary ammonium group, often with safranine as the diazo component, and are capable of dyeing cotton directly; Janus (also janus) green (B), either of the two basic dyes obtained by coupling diazotized safranine or dimethylsafranine with dimethylaniline, of little importance as dyes but extensively used as biological stains.
1898Jrnl. Soc. Dyers & Colourists XIV. 146 The first eight patterns..were dyed with Janus Colours on Union linings. Ibid. (Table), Janus Black I. Janus Blue R... Janus Green G. Janus Green B. 1926Stain Technol. I. 35 The use of janus green to stain mitochondria has long been known. While using it to study the mitochondria in Trichomonas buccalis it was found to stain flagella also. 1928C. E. Mullin Acetate Silk x. 142 Some of the Janus dyes are also applicable to acetate silk, however most of them give rather dull shades. 1949N. G. Heatley in H. W. Florey et al. Antibiotics I. iii. 118 The test organism was Welchii perfringens strain HA, the indicator was janus green. 1971D. R. Baer in K. Venkataraman Chem. Synthetic Dyes IV. iv. 165 Derivatives of (m-aminophenyl) trimethylammonium chloride..formed part of the Janus range of colors which were of limited use on rayon, silk-wool unions, and on cotton. 1971E. Gurr Synthetic Dyes 128 There are apparently two types of Janus green B, one from the USA and the other of European origin. Ibid. 129 Both types of Janus green are employed as oxidation-reduction indicators. |