| 释义 |
quadruplex, a. and n.|ˈkwɒdrʊplɛks|
[a. L. quadruplex fourfold, f. quadru- + plic-, to fold.]
A. adj.
1. Electric Telegraphy. Applied to a system by which four messages can be sent over one wire at the same time.
1875Knight Dict. Mech. 1842/1 Quadruplex Telegraph. 1879G. B. Prescott Sp. Telephone p. iii, In 1874 Edison invented a quadruplex system for the simultaneous transmission of four communications over the same conductor. 1881Lubbock Pres. Addr. Brit. Assoc. in Nature No. 618. 411 Duplex and quadruplex telegraphy, one of the most striking achievements of modern telegraphy.
2. Engineering. Applied to an engine in which the expansion of the steam is used four times in cylinders of increasing diameter.
1896Westm. Gaz. 8 May 10/2 A steamer, fitted with five-crank quadruplex engines.
3. Genetics. Also quadri-. Of a tetraploid individual: having the dominant allele at some particular locus represented four times.
1923[see duplex a. 1 e]. 1932Sansome & Philp Rec. Adv. Plant Genetics v. 182 There are five possible types of zygote in the tetraploid, quadruplex SSSS, triple SSSs, duplex SSss, simplex Ssss and nulliplex ssss. 1963[see nulliplex a.].
B. n. A telegraphic instrument by means of which four simultaneous messages can be sent over the same wire.
Hence ˈquadruplex v., to make (a telegraph circuit, etc.) quadruplex. Cf. quad v.
1887Brit. Merc. Gaz. 15 June 43/2 The multiplication of wires soon attracted attention to methods of duplexing and quadruplexing the circuits. 1889Times (weekly ed.) 29 Mar. 5/2 If the line is already duplexed..the addition of the phonophore will quadruplex it. |