| 释义 |
envelope, n.|ˈɛnvələʊp, ˈɒnv(ə)ləʊp|
Also 8–9 envelop.
[ad. Fr. enveloppe, f. envelopper: see envelop v.
Walker 1791 records the custom then prevailing of pronouncing this word like the Fr. enveloppe |ɑ̃vlɔp|. In sense 2 this pronunciation, or rather some awkward attempt at it |ɑ̃vələʊp, ˈɒnvələʊp| is still very frequently heard, though there is no good reason for giving a foreign sound to a word which no one regards as alien, and which has been anglicized in spelling for nearly 200 years.]
1. a. That in which anything is enveloped; ‘a wrapper, integument, covering’ (J.).
1715Kersey, Envelope, a cover for anything. 1796C. Burney Mem. of Metastasio iii. 142 He has consigned to my messenger..six volumes..not only without a box, but without any kind of envelope, or direction. 1811Edin. Rev. XVIII. 226 The earth which serves as the envelope of the bones [in certain caverns]. 1830Herschel Stud. Nat. Phil. 79 The statue might be conceived encrusted in its marble envelope. 1845Stocqueler Handbk. Brit. India (1854) 346 The better class of females..are covered with an immense piece of cloth..these envelopes are of white cloth. 1854Brewster More Worlds ii. 21 The Earth is surrounded with an aerial envelope or atmosphere. 1865Sat. Rev. 28 Oct. 555 The spirits have behind them the crass and heavy envelope of their earthly tenement. 1873H. Rogers Orig. Bible ii. (ed. 3) 90 The envelope which protects the chrysalis.
b. fig.
1741Warburton Div. Legat. II. 629 Their obvious sense that serves only for the envelope. 1797Godwin Enquirer ii. xii. 370 Style should be the transparent envelop of our thoughts. 1829I. Taylor Enthus. iv. (1867) 78 The leading intention of both [Antinomianism and Stoicism] is to enclose the human mind in a perfect envelop of abstractions. 1865Lecky Ration. (1878) I. 300 Every dogmatic system..should be regarded as the vehicle or envelope of pure religion. 1952Brit. Jrnl. Psychol. July 239 The ‘envelope’ is the late Dr. Plant's name for the processes by which the individual selects from the environment those features with which he can deal and shuts out the rest. 1957N. Frye Sound & Poetry 136 Traditional literary scholarship, chiefly..concerned with the sender and receiver in reaction with the cultural envelope. 1963Listener 28 Feb. 370/2 The Liverpool building..is a palpable volume, held in place by a semi-translucent envelope of concrete and glass, to which the ribs are clearly accessory.
2. spec. The cover of a letter; now a small sheet of paper folded and gummed to serve as a cover for a letter.
a1714Burnet Own Time I. (1724) 302 A letter from the King of Spain was given to his daughter by the Spanish Ambassador, and she tore the envelope, and let it fall. 1726Swift To Grub St. Poets, Wks. 1735 II. 368 Lend these to Paper-sparing Pope..No letter with an Envelope Could give him more Delight. 1826J. Neal Bro. Jonathan III. 351 Our hero was tearing off the envelope. 1839Sir R. Hill in G. B. Hill Life (1880) I. 346 The little bags called envelopes. 1874Burnand My Time xxvii. 250 He quickly opened the envelope to see if the enclosed fee was in notes or a cheque.
3. In physical science often used in general sense; also spec. in Bot. the calyx or the corolla, or both taken together; in Astron. the nebulous covering of the head of a comet, the coma.
1830R. Knox Béclard's Anat. 234 The envelopes of the muscles, or the enveloping aponeuroses..furnish..insertions to muscular fibres. 1830Lindley Nat. Syst. Bot. 99 Stamens single, without any floral envelope. 1834M. Somerville Connex. Phys. Sc. xxxvi. (1849) 404 The luminous envelope was of a decided yellow. 1851Carpenter Man. Phys. 519 A general contraction of the mantle or muscular envelope. 1870Hooker Stud. Flora 14 Papaveraceæ..envelopes and stamens very caducous.
4. Fortification. (See quot.)
1707in Glossogr. Angl. Nova. 1715Kersey, Envelope, In Fortification, a Work of Earth rais'd either in the Ditch of a Place, or beyond it. 1853Stocqueler Mil. Encycl., Envelope, in fortification, a work of earth, sometimes in form of a single parapet, and at others like a small rampart.
5. a. Math. The locus of the ultimate intersections of consecutive curves (or surfaces) in a ‘family’ or system of curves (or surfaces).
1871Todhunter Diff. Calc. xxv. (1875) 359 The locus of the ultimate intersections of a series of curves is called the envelop of the series of curves. 1873Williamson Diff. Calc. xv. 250 The envelope of the system..is touched by every curve of the system.
b. Electr. Engineering. A curve formed by joining the successive peaks of a graph of an oscillation, esp. a modulated wave.
1928Exper. Wireless & Wireless Engin. V. 302/1 When the voltages..are applied to the grid of an anode bend detector whose A.C. characteristic is a straight line, the envelopes indicated by curves 1 and 2 (Fig. 8) are rectified. 1929Ibid. VI. 620/1 R, when plotted against time, will give the outline of the envelope representing the succession of carrier wave peaks. 1970D. F. Shaw Introd. Electronics (ed. 2) xi. 256 The audio-frequency signal is represented by the envelope of the radio-frequency wave and..a device is employed which will give an output voltage proportional to the positive (or negative) envelope of the waveform.
6. Aeronaut. The gas or air container of a balloon or airship.
1901Sci. Amer. 10 Aug. 89/3 The balloon is inflated with hydrogen, and in order to maintain at all times a tension on the envelope—that is to say, perfect inflation—a compensating balloon filled with air is placed in the interior. 1909Rep. Advisory Committee Aeronautics 15 July 121 There will be some risk of [electrical] discharges between the airship and a charged cloud..while with a non-conducting envelope, if wet, there would be the same risk. 1950Gloss. Aeronaut. Terms (B.S.I.) I. 49 Envelope. a. The gas-containing unit of a balloon or non-rigid or semi-rigid airship. b. The outer cover of an airship in which the gas-containing units are surrounded by a layer of air or inert gas. 1961R. Higham Brit. Rigid Airship vii. 118 This was despite the fact that the engineer had to climb on to the top of the envelope each time it was necessary to switch to a new tank of petrol.
7. The outer containing-vessel of a vacuum tube.
1932F. E. Terman Radio Engineering xi. 395 The 280 tube has two cathodes and two anodes and so is essentially two half-wave rectifiers enclosed in one envelope. 1959Listener 12 Mar. 454/1 Extra high pressure mercury vapour lamps in quartz envelopes.
8. attrib. and Comb., as envelope cementer, envelope cutter, envelope flap, envelope folder; envelope conditions Aeronaut. (see quot.); envelope delay Electr. Engineering (see quot. 1940).
1904Daily Chron. 12 Jan. 10/6 Envelope Cementer wanted... Envelope Folder wanted. 1944Jrnl. R. Aeronaut. Soc. XLVIII. 117 Tests at other heights can then be confined to what are termed ‘envelope’ conditions; that is, the engine conditions which will give the maximum economy at any given speed.
1901Daily Chron. 16 Apr. 8/6 Envelope Cutter. 1940Chambers's Techn. Dict. 301/1 Envelope delay, the time taken for the envelope of a signal to travel through a transmission system, without reference to the time taken by the individual components. 1943F. E. Terman Radio Engineers' Handbk. v. 443 Envelope delay is of particular importance in tuned amplifiers handling television signals, because any variation in the envelope delay with modulating frequency adds to the total delay error of the system. 1956Amos & Birkinshaw Television Engin. II. i. 20 A more sensitive indication of the seriousness of any phase distortion is given by the slope of the curve itself, usually measured by the slope of the tangent to the curve... The slope of the tangent is the envelope delay or group delay.
1891Kipling Light that Failed xi. 191 A letter with a black M. on the envelope flap. 1904Envelope folder [see envelope cementer].
Hence ˈenvelope, v. colloq. to put (a letter) in an envelope.
1857De Morgan in Graves Life Sir W. R. Hamilton III. (1889) 519 You write letters..Lady Hamilton finds them, envelopes them, puts them before you, etc.
▸ Aeronaut. = flight envelope n. at flight n.1 Compounds 2. Hence: gen. an operating or performance boundary; an established parameter or limit. See to push the envelope at push v. Phrases 13
1944Jrnl. Royal Aeronaut. Soc. 48 488 The best known of the envelope cases is the ‘flight envelope’, which is in general use in this country and in the United States... The ‘flight envelope’ covers all probable conditions of symmetrical manoeuvring flight. 1978Aviation Week & Space Technol. (Nexis) 3 July 110 The aircraft's altitude envelope must be expanded to permit a ferry flight across the nation. NASA pilots were to push the envelope to 10,000 ft. 1980G. Kaufman How to be Minister xvi. 161 Such standard items of Eurojargon as ‘envelope’ and ‘margins’. An envelope is a limit within which budgetary dispositions can be juggled. 1989Cycle Oct. 7/1 There were so many holes in the Harley performance envelope. 2001Today's Pilot Feb. 33/3 In addition to being great fun, aerobatics demonstrate the whole handling envelope of the aircraft and are a great confidence boost.
▸ Virol. The lipoprotein membrane that surrounds the nucleocapsid of many viruses.
1960Science 15 July 119/1 Such a virus..can then acquire an outer envelope in its passage through the cell membrane. 1963Science 15 Nov. 933/1 In these RNA-containing viruses the RNA is surrounded by protein units arranged in the form of a helix, which is folded and included in a membranous, lipid-containing envelope. 1984M. J. Taussig Processes in Pathol. & Microbiol. (ed. 2) iii. 224 In their envelopes, these viruses usually appear roughly spherical as the nucleocapsid is flexible enough to coil up within the loose-fitting lipid membrane. 1990EMBO Jrnl. 9 4155/2 The progeny can contain a mixture of the two envelope glycoproteins, resulting in pseudotyped viruses with altered tropism. 2002Washington Post (Home ed.) 26 Feb. a2/5 The compound blocks gp120, a part of the HIV ‘envelope’ that attaches to the CD4 receptor. |