| 释义 |
transmission|trɑːnsˈmɪʃən, træns-, -nz-|
[ad. L. transmissiōn-em, n. of action from transmittĕre to transmit. Cf. F. transmission (14th c. in Hatz.-Darm.).]
a. The action of transmitting or fact of being transmitted; conveyance from one person or place to another; transference.
1611Florio, Transmissione, a transmission. 1626Bacon Sylva §2 In the experiment of Transmission of the Sea-water into the Pits, the Water riseth; but in the experiment of transmission of the Water through the Vessels, it falleth. 1759Johnson Idler No. 68 ⁋2 Alphabetical writing made..the transmission of events more easy and certain. 1802–3tr. Pallas's Trav. (1812) I. 82 On the transmission of the Black Sea through the Propontis, a great part of its shallow banks consequently became a saline steppe. a1859De Quincey Posth. Wks. (1891) I. 308 One link in the transmission of the Homeric poems.
b. Conveyance or passage through a medium, as of light, heat, sound, etc.; spec. in Radio and Television (see transmit v. 3 b); also, a series of electric signals or electromagnetic waves transmitted, a broadcast.
1704Newton Opticks (1721) 238 Their Reflexion or Transmission depends on the constitution of the Air and Water behind the Glass. 1815J. Smith Panorama Sci. & Art I. 7 Which greatly retards the transmission of the heat. 1834M. Somerville Connex. Phys. Sc. xvii. 147 The transmission of sound as well as light is impeded in passing through an atmosphere of variable density. 1881Sir W. Armstrong in Nature 8 Sept. 449/1 To force a transmission of heat from the fire to the water in the boiler. 1907Rep. Brit. Assoc. Adv. Sci. 731 To determine how many oscillations..take place in a certain wireless transmission. 1921Wireless World IX. 52/2 In Surrey and Kent the transmissions were easily read. 1923Radio Times 5 Oct. 15/2 Transmission from London of Dance Music by Savoy Orpheans. 1929[see television transmission s.v. television 3 a]. 1959Viewpoint July 10 A few days before transmission the final camera script will be typed. 1962A. Nisbett Technique Sound Studio v. 99 We have..wide-range hi-fi, demanding not only high-quality transmissions but also a wide dynamic range. 1966Listener 11 Aug. 204/2 The Black and White Minstrel Show..has just completed eighty-five transmissions. 1977Rep. Comm. Future of Broadcasting (Cmnd. 6753) ii. 8 The Government..has to regulate the strength of the transmissions to prevent interference with other stations.
c. Biol. The transmitting of the peculiar nature, or of some character, of an organism to its descendants; hereditary conveyance.
1871Darwin Desc. Man ii. xviii. II. 297 Equal transmission of ornamental characters to both sexes. 1880E. R. Lankester Degener. 13 An organism..inherits, that is to say, is born with—the peculiarities of its parents; this is known as Transmission. 1890Sc. Gossip XXVI. 66 Questions of protective resemblance and hereditary transmission.
d. Mech. Transference of motive force from one place to another; concr. a device for effecting this; spec. short for transmission-gear (see e).
1906Daily Chron. 28 June 2/7 There are four large and eleven smaller electric motors driving the transmissions. Ibid., Improvements in devices for preventing accidents with transmissions. 1911Webster, Transmission,..Horol. the train of a watch, etc.
e. attrib.: transmission electron microscope, an electron microscope in which the electrons are detected after they pass through the specimen; spec. one in which all parts of the image are formed at the same time; so transmission electron microscopy; transmission-gear, mechanism for transmitting the power of an engine, etc.; transmission line, a conductor or set of conductors designed to carry electricity (esp. on a large scale) or electromagnetic waves with minimum loss and distortion; also transf.; transmission loss, dissipation of electrical or acoustic power during its passage from one point to another; transmission print (see quot. 1960).
1833Brewster Nat. Magic ix. 219 The sound will be partly reflected.., and the direction of the transmission wave changed. 1894Prospect. Tramway Motor Co. 2 A transmission gear giving a wide range of continuously varying speed and inversely varying tractive effort. 1894Daily News 3 Nov. 5/3 A large proportion of the sailors paid off there have gladly availed themselves of the transmission scheme. 1901Scaffolding (ed. J. Black) 60 The endeavour to dispense with transmission gear between motor and machine constitutes to-day a recognised principle of construction [in cranes]. 1906Westm. Gaz. 22 Jan. 8/1 The electricity will be conveyed at high pressure to a central spot on the transmission lines. 1908Ibid. 14 Nov. 14/2 Double universal joints to maintain true alignment between the power- and transmission-shafts. 1922Glazebrook Dict. Appl. Physics II. 862/1 The problem of finding the transmission loss due to a piece of apparatus inserted in..a telephone line is the problem of finding out how the current entering the receiving side is altered by the inserted or bridged apparatus. 1934Discovery Dec. 348/1 The transmission loss in steel framing is only one decibel per 1,000 feet, a loss which is acoustically negligible. 1946Jrnl. Inst. Electr. Engineers XCIII. IIIa. 33/1 It has become the common..practice to restrict the term ‘wave guide’ to devices employing a single hollow conductor, and to reserve the term ‘transmission line’ to devices employing two conductors. 1960O. Skilbeck ABC of Film & TV 137 Transmission print, positive copy of a film intended for T.V. showings. 1968Jrnl. Electron Microscopy XVII. 164/1 Experimental procedures to determine the direction and the sign of the Burgers vector..of a dislocation by means of transmission electron microscopy are described. 1969Jrnl. Ultrastructure Res. XXVII. 403 The resolution of the scanning instrument is an order of magnitude less than that of present transmission electron microscopes. 1970New Scientist 15 Oct. (Suppl.) 13/1 The basic elements in microwave circuits are always some form of transmission lines. 1971Sci. Amer. Apr. 26 The transmission electron microscope is analogous to a conventional light microscope. 1971Ibid. Sept. 235/1 (Advt.), This..guide is..suited for use as an optical transmission line, carrying laser beams in any direction it is bent. 1972[see scanning electron microscope s.v. scanning vbl. n. 4]. 1974Encycl. Brit. Macropædia XII. 137/2 Recently, scanning instruments have been used for transmission electron microscopy, with the advantage over the conventional transmission instrument that very low magnification..may be used. 1975D. G. Fink Electronics Engineers' Handbk. xviii. 67 The transmission loss [of a radio circuit] is usually expressed in decibels. 1976Broadcast 29 Nov. 18/2 Once ‘shot’ the film has to be ‘processed’... A transmission print is achieved several generations later.
Hence transˈmissional a.; transˈmissionist, one who holds the theory of the hereditary transmission of acquired characters; also attrib.
1899J. A. Thomson Sci. Life xvi. 226 The Lamarckians and Buffonians..believe in the transmission of acquired characters or modifications. They are sometimes, though not elegantly, called ‘transmissionists’. 1900C. L. Morgan Animal Behaviour iii. §5. 113 It forms a very pretty subject for transmissionists and their critics to quarrel over. Ibid. 114 Let us expand the transmissionist position a little further. 1930Observer 4 May 26 Sometimes the music sounded ghostly. There were a few transmissional hiccoughs too.
▸ Transmission Control Protocol n. Computing a protocol that governs the reliable delivery of data packets over a local or wide area network and sets up a connection between the sending and receiving computers; abbreviated TCP.
[1974V. Cerf et al. Request for Comments (Network Working Group) (Electronic text) No. 675. 1 This document describes the functions to be performed by the internetwork Transmission Control Program (TCP) and its interface to programs or users.] 1976L. Garlick Request for Comments (Network Working Group) (Electronic text) No. 721. 1 Such a satisfactory mechanism does not exist in the *Transmission Control Protocol (TCP) of Cerf et. al. 1985Canad. Jrnl. Operational Res. 23 294 The Transmission Control Protocol (TCP) of ARPANET is one of the most popular transport level communication protocols in use today. 2001Internat. Jrnl. Satellite Communications 19 29 High-bandwidth satellites offer the promise of a rapidly deployable communications infrastructure... However, many widely used versions of the transmission control protocol perform poorly over satellite links. |