| 释义 |
closed, ppl. a.|kləʊzd|
[f. close v.]
1. Made close, shut; spec. confined to a few people; limited by certain conditions; self-contained. (Cf. close a. 9, and sense 2 below.) Also with advs. as closed in, closed out.
closed syllable, one ending in a consonant, as the first and third of L. fes-tī-nat.
c1205Lay. 12823 Heo weoren in castle oðer y burhȝe iclused uaste. c1440Promp. Parv. 83 Closyd yn, inclusus. Ibid., Closyd owte, exclusus, seclusus. 1481Caxton Reynard v. (Arb.) 10 A cloysterer or a closyd recluse. 1526Pilgr. Perf. (W. de W. 1531) 254 b, Closed and festred woundes. 1881S. J. Whitmee in Trans. Victoria Instit. 20 Many of the syllables are closed. 1882Minchin Unipl. Kinemat. 140 The curve is closed, so that the extreme points A and B coincide. 1887Pall Mall G. 1 Nov. 2/2 In many cases a boy is sent for a closed (or partially closed) exhibition, who might get an open scholarship. 1927Carr-Saunders & Jones Soc. Struct. Eng. & Wales 82 There are a number of professions which are ‘closed’. Complete closure exists when, as among dentists, certain functions and certain titles are legally reserved to persons whose names appear upon a statutory register. 1963M. Ginsberg in Advancem. Sci. XIX. 418/2 We have to distinguish between ‘open’ and ‘closed’ ideologies. 1963P. Drackett Motor Rallying 77 Closed and restricted trials and rallies. 1964M. A. K. Halliday et al. Linguistic Sci. ii. 22 It is not the case..that all choices in language are clearly of one type or the other, closed or open.
2. Math.
a. Of a set of points: containing all its limit points. Of an interval: containing all its end points.
1902Proc. Lond. Math. Soc. XXXIV. 289 Every example of such a set [of points] is theoretically obtainable in this way. For..it cannot be closed, as it would then be perfect and nowhere dense. 1968P. A. P. Moran Introd. Probability Theory iv. 184 In one-dimensional Euclidean space R1 an interval (a ≤ x ≤ b), which contains its end points, is closed, and in Rn the sphere σxi2 ≤ d is closed.
b. Of a set of elements: having the property that any element produced by a (specified) allowed operation on elements of the set is also a member of the set; also used of the operation.
1909in Webster. 1939H. Weyl Classical Groups i. 1, k is any set of elements α, called numbers, closed with respect to the two binary operations: addition and multiplication. 1965Patterson & Rutherford Elem. Abstract Algebra i. 20 For a closed associative binary operation, the set of elements which possess inverses is closed with respect to the operation.
3. Special Combs.: closed book, something unknown or uncomprehended (cf. open book s.v. open a. 21); closed circuit, a complete, unbroken circuit; freq. attrib.; spec. (a) Electr. a complete electrical circuit formed entirely of conductive material; (b) a system of radio or television whereby the signal is transmitted by wire to the receiver and not broadcast for general reception; (c) a breathing apparatus that converts exhaled gases into oxygen for inhaling; closed cycle, a cycle of operations in which the same fuel, cooling fluid, etc., is used repeatedly; also attrib.; closed door fig., an obstacle, impasse, restriction; also attrib. or quasi-adj., restricted, obstructive, secret; closed-end a. (orig. U.S.), of an investment trust or the like: see quot. 1954; closed-loop a., characterized by a feed-back from a later to an earlier point in a cycle of operation; closed shop (orig. U.S.), a shop, factory, trade, etc., in which normally only trade-union members are employed; also transf. and attrib.; closed society, a society characterized by its rigid structure and beliefs; one having little or no contact with other peoples or intolerant of any disturbance of its existing order and traditions; closed system, a complete and essentially unalterable system (of ideas, doctrines, things, etc.); a material system in which the total mass or energy remains constant; a self-contained realm, unaffected by external forces.
1913‘Sax Rohmer’ Myst. Fu-Manchu xxviii. 282 The soul of Kâramanèh was a closed book to my shortsighted Western eyes. 1926J. S. Huxley Ess. Pop. Sci. xiii. 163 To whom much of art is a closed book. 1944F. Clune Red Heart 35 The desert is an open book to the man of the Vast Open Spaces, but to the schoolmaster it was a closed book.
1827J. Cumming Man. Electro Dynamics 230 If a series of galvanic elements be placed in order round the circumference of a circle, and forming a closed circuit, a current will circulate in it continually. 1832Nat. Philos. II. Electro-Magnet. xi. §232 (Usef. Knowl. Soc.) When an electric current, after traversing a certain line..returns upon itself..it has been denominated a closed circuit. 1925P. J. Risdon Crystal Receivers & Circuits 22 It should perhaps be explained here that an aerial circuit is known as an ‘open’ circuit, and a receiver circuit as a ‘closed’ circuit. 1930Engineering 28 Feb. 279/2 The fire-alarm system is of the pre-signal, electrically supervised, closed-circuit, code-ringing type. 1941B.B.C. Gloss. Broadcasting Terms 6 Closed circuit, channel between microphone and loudspeaker, or between microphone and recording unit, for testing, rehearsal, or other purposes not involving broadcast transmission. Hence closed-circuit recording. 1946T. H. Hutchinson Here is Television 363 Closed circuit. The picture is not broadcast, but fed to viewing screens at certain locations by wire. 1951Time 25 June 49/1 Though not telecast over the air, the Louis–Savold fight was experimentally piped by coaxial cable over closed circuits to six cities. 1953J. Hunt Ascent of Everest 257 Three principal types of (oxygen) apparatus were used: Open-Circuit, Closed-Circuit and Sleeping Sets. 1954B. & R. North tr. Duverger's Pol. Parties i. iii. 152 Here the parliamentary representatives are chosen by the inner circle; the party in this case is a closed circuit. 1957Times 22 Oct. 10/1 Later their occupants watched and heard the after-dinner speakers on closed-circuit television.
1950Jane's Fighting Ships 1950–51 A 5/2 Closed-cycle powered submarine, 2,000 tons—no external sources of oxygen. 1957Gloss. Terms Nuclear Sci. 30/2 Closed cycle, cycle of operation of a heat engine in which the same power fluid is used repeatedly, as a steam engine that condenses the steam for reuse... Also applicable to a cooling system in which the coolant is cycled repeatedly through the source of heat, itself being cooled in another part of the cycle. 1960Gloss. Atomic Terms (H.M.S.O.) 13 Closed cycle, usually refers to reactor coolant circuit where the gas or liquid travels in a completely enclosed path.
1934Webster, Closed door, restriction, esp. in the colonies and spheres of influence, of the land laws, concessions, tariffs, etc., in favor of the nationals of the controlling power...closed-door, adj. 1950in M. McLuhan Mech. Bride (1951) 2/1 Today's closed-door session, which began the decisive phase in the committee's long deliberations. 1955H. Roth Sleeper ii. 19 This [court martial]..had been so closed-door, so hush-hush, so big-brass. 1956A. H. Compton Atomic Quest 323 There are no closed doors in the field of nuclear engineering. 1960Times 9 Feb. 17/5 The old protectionist closed-door policy.
1952Time 12 May 41 The Fund began as a ‘closed-end’ trust (i.e., issuing a limited number of shares). 1954Webster Add., Closed-end adj., of an investment trust, operating with its initial capital changed only by new issues or retirements, not by redemption of shares; opp. to open-end. 1958Spectator 20 June 815/3 The three leading ‘closed-end’ investment trusts. 1958New Biol. XXVI. 107 A closed-loop machine is one that feeds a part of its own output back into itself. 1960Times 9 Nov. 16/4 The introduction of closed-loop models from control engineering. 1962Simpson & Richards Junction Transistors xiii. 296 The voltage gain is therefore changed from A to A/(—AB) by the feedback. The latter value is often called the closed-loop voltage gain.
1904N.Y. Even. Post 15 Aug. 1 An increase in wages, recognition of the union, and ‘closed shops’ are demanded. 1923J. D. Hackett Labor Terms in Management Engin. IV. 343/1 Closed shop, a plant in which only union men, or prospective union men are hired. 1947Ann. Reg. 1946 85 The expression ‘closed shop’ was an inaccurate term to use in describing the aims of the trade unions in dealing with non-unionists. 1949Koestler Promise & Fulf. ii. v. 275 Owing to the closed-shop system of political coteries, most of the diplomatic jobs go to little yes-men.
1935Audra & Brereton tr. Bergson's Two Sources Mor. & Relig. iv. 229 The closed society is that whose members hold together, caring nothing for the rest of humanity, on the alert for attack or defence. 1945K. R. Popper Open Soc. & Enemies I. x. 154 The problem of the tension between the classes..is raised for the first time by the breakdown of the closed society. 1955Koestler Trail of Dinosaur 84 ‘Closed’ societies such as prison camps.. also tend to develop a monolithic system of values.
1896W. James Will to Believe (1897) 13 A system, to be a system at all, must come as a closed system, reversible in this or that detail, perchance, but in its essential features never! 1912J. S. Huxley Individ. in Animal Kingdom v. 143 The tendency towards the formation of closed systems has manifested itself. 1922A. N. Whitehead Princ. Relativ. ii. 21 We are treating nature as a closed system. 1925O. W. Holmes in Holmes–Laski Lett. (1953) I. 706, I take it that he thinks no one a philosopher who hasn't a closed system—a cosmos that accounts for and sustains itself and is seen as necessary. 1947Mind LVI. 64 It is asserted in the science of physics that in a closed system where there are exchanges of energy, energy is conserved. 1948E. F. Obert Thermo-dynamics ii. 27 A closed system contains a constant mass, and only energy is allowed to cross the boundary. 1951T. J. Benac tr. Waismann's Introd. Math. Thinking 60 Each of the three systems—the natural numbers, the integers, the rational numbers—forms a closed system by itself, and it is quite impossible to go from one of these domains to another by adjoining new elements. 1958Oxf. Dict. Chr. Ch. 100/2 For practical purposes it is necessary to treat the material world as a closed system.
▸ Math. and Physics. Of a curve or surface: completely enclosing an area or volume; having no end points.
1851Philos. Trans. (Royal Soc.) 141275 The resultant force at any point external to a lamellarly-magnetized magnet will..depend solely upon the edges of the shells into which it may be divided by surfaces perpendicular to the lines of magnetization..,and not at all on the forms of these shells, within the bounding surface, nor upon any closed shells of which part of the magnet may consist. 1882G. M. Minchin Uniplanar Kinematics 140 The curve is closed, so that the extreme points A and B coincide. 1935C. J. Smith Intermediate Physics (ed. 2) v. xxxvii. 626 Gauss's theorem for electrostatics states that the total flux of electric induction across any closed surface is 4π times the sum of the charges enclosed in that surface. 1972M. Kline Math. Thought xxvii. 660 A Riemann surface may have boundary curves or be closed like a sphere or a torus. 1994Sci. Amer. Mar. 52/2 Suppose space-time becomes so distorted that some worldlines form closed loops.
▸ Astron. Of the universe: spatially finite, esp. through having a positive radius of curvature.
If the universe is spatially finite and also contains sufficient matter for gravity to halt the expansion begun at the big bang, it could eventually recontract.
1922H. L. Brose tr. H. Weyl Space—Time—Matter iv. 278 We conclude that space is closed and hence finite... If the world is closed, spatially, it becomes possible for an observer to see several pictures of one and the same star. 1937E. Hubble Observational Approach Cosmol. iii. 55 A positive curvature implies closed space, a universe with a definite, finite volume but with no boundary. 1966Proc. Royal Soc. (A.) 294511 However, the Cauchy surface of the universe may be compact (a ‘closed’ model). 2003Nature 9 Oct. 566/3 Positively curved space sections are necessarily closed, but the converse does not necessarily follow: both flat and negatively curved space sections can be finite if their connectivity is more complicated than in Euclidean space.
▸ closed season n. = close season n. 1.
1878Burlington (Ohio) Hawkeye 4 Apr. 4/6 No person can buy or sell game during the *closed season. 1924Amer. Mercury Sept. 99/1 Offenses that are merely malum prohibitum, such as motor-speeding, hunting in the closed season, or buying or selling bootleg whisky. 1999Angling Times 16 June 12/1 All the moronic arguments about the closed season are coming out of the woodwork. |