| 释义 |
leading edge
[leading ppl. a.]
1. The forward edge of a moving body; also transf.; spec. (a) that of a blade of a screw-propeller; (b) that of a wing, tailplane, or other part of an aircraft; (c) that of one of the plates of the earth's crust.
1877W. H. White Man. Naval Archit. xiv. 579 When the plane is moved obliquely, its leading edge, corresponding to the forward edge of a rudder, may be regarded as continually entering water which was comparatively little disturbed by the previous motion. 1888Lockwood's Dict. Mech. Engin. 205 Leading edge, that edge of the blade of a screw propeller which cuts the water, as distinguished from the following edge. 1912Aeroplane 12 Dec. 592/1 Looking over the leading edge of the wings from a constant position the ground disappeared regularly. 1922Glazebrook Dict. Appl. Physics I. 364/1 That part [of the suface]..over which the particles of fluid are being gradually retarded—i.e. the part in the neighbourhood of the leading edge of the surface such as, for example, the immersed surface of a ship. 1939Archit. Rev. LXXXVI. 63/2 At the ‘leading edge’ of each wing⁓like roof, the wooden slats with which it is faced are slightly separated to allow for..ventilation. 1946Taylor & Allward Spitfire 99/2 Special wings were fitted, the leading edge portion of each being constructed as a fuel tank. 1959H. Barnes Oceanogr. & Marine Biol. i. 49 On sand, where there is considerable resistance to the leading⁓edge of either the mud bucket or naturalist's oval dredge, only a small sample is usually brought up and deeper burrowing animals frequently avoid capture. 1967M. Chandler Ceramics in Mod. World vi. 177 For very high⁓speed aircraft the sharp leading edges of engines and wings will also probably have to be made of ceramic materials. 1971I. G. Gass et al. Understanding Earth xx. 289/2 A plate whose leading edge is of continental material will gradually increase in size; for new crust will be added where oceanic crust is generated at its trailing edge but little or no continental crust is being consumed at the leading edge. 1972Sci. Amer. Mar. 33/3 The drifting of the continents is another theme; every continent must have a leading edge and a trailing edge.
2. Electronics. The part of a pulse in which the amplitude increases.
1945Nature 15 Sept. 319/2 The beginning or ‘leading edge’ of the pulse marks a packet of energy which can be re-identified after the vicissitudes of travel, thus permitting accurate measurement of time of travel. 1962Simpson & Richards Physical Princ. Junction Transistors vii. 139 In the amplification of small pulses with sharp leading and trailing edges the frequency range may be very broad. 1972Radio Times 6 Jan. 5/3 Listeners may have noticed a change in the Greenwich Time Signals broadcast since January 1... The exact time is signalled by the beginning or ‘leading edge’ of the long pip.
3. fig. The forefront or vanguard, esp. of technological development. Freq. (with hyphen) attrib.
1977Sci. Amer. Sept. 49/2 (Advt.), We are a young, publicly held, leading-edge technology company. 1983Fortune 13 June 24/3 Professors, commonly assumed to be on the leading edge of thought. 1983Austral. Microcomputer Mag. Aug. 44/2 Pioneering, leading edge developments in micro applications. 1984Financial Rev. (Austral.) 17 Jan. 8/4 Video games which are based on leading-edge technology. 1985Church Times 29 Nov. 4/4 If family services were ‘the leading edge’ for such people, the Church needed to see that those services were available. 1986Daily Tel. 26 Feb. 13/8 Three choices from the Burton Group's spring ranges. Sophisticated style from Principles... Leading-edge young fashion from Top Shop... Mainstream young fashion from Dorothy Perkins. |