| 释义 |
superˈcritical, a.
[super- 9 a.]
1. Highly critical.
1610Holland Camden's Brit. i. 687 By our Critickes good leave (who..presuming so much of their great wits are supercriticall). 1661Gauden Consid. Liturgy 25 These supercritical censors. 1937Even. News 12 Feb. 11/1 Only the super-critical, rather cosmopolitanminded audience of the West End still look coolly on their simple robust brand of humour.
2. Of, pertaining to, or designating a fluid at a temperature and pressure greater than its critical temperature and pressure.
1934Econ. Geol. XXIX. 457 The first work on critical and supercritical phenomena of solutions was done by Hannay and Hogarth in 1879. 1968New Scientist 27 June 697/1 Supercritical boilers probably present more problems. 1972Physics Bull. Apr. 236 The use of supercritical helium for cooling superconducting and other low temperature equipment. 1981E. Corlett Revolution Merchant Shipping 40/1 Natural gas..at normal temperatures..is supercritical... It cannot be liquefied by pressure unless below -82° C.
3. Of a flow of fluid: faster than the speed at which waves travel in the fluid. Of an aerofoil: giving rise to such a flow over much of its surface when its speed relative to the bulk fluid is subcritical, but in such a way that flow separation is largely avoided.
1941, etc. [see subcritical a. 2]. 1967Aviation Week 24 July 25/1 Whitcomb describes the shape as a ‘supercritical airfoil’ because it enables aircraft in subsonic flight to achieve these higher critical Mach numbers before the normal drag rise is experienced in transonic flight. The shape of the upper surface of the transonic wing permits predominantly supersonic air flow to be maintained across the wing. 1969Ibid. 17 Feb. 22/1 Improved version of the National Aeronautics and Space Administration's ‘supercritical wing’..will begin test flights in mid-1970. 1977McGraw-Hill Yearbk. Sci. & Technol. 422/1 Supercritical compressor blades. 1979Time 2 Apr. 21/2 With only two engines and a ‘supercritical’ wing that cuts aerodynamic drag, it is the most fuel-efficient commercial jet flying today.
4. Nucl. Physics. Containing or being more than the critical mass (see critical a. 7 b).
1950Glasstone Sourcebk. Atomic Energy xiv. 394/2 The presence of stray neutrons in the atmosphere makes it impossible to prevent a chain reaction in a supercritical mass. 1958J. Cleugh tr. Jungk's Brighter than Thousand Suns xii. 191 If he passed the point or was not quite quick enough in breaking contact, the mass might become ‘super-critical’ and produce a nuclear explosion. 1973Nature 23 Mar. 251/1 Assuming a relative 235U abundance throughout the [hypothetical] planet equal to the terrestrial crustal abundance, there is just enough energy to disperse the planet if the 235U could be assembled into a super-critical mass.
Hence ˌsupercritiˈcality, supercritical state.
1959Times 5 Mar. 2/4 (Advt.), Join a section concerned with the assessment of criticality hazards in the handling and processing of fissile materials and to carry out theoretical research into the factors governing criticality and supercriticality. 1976L. Sanders Hamlet Warning (1977) i. xi. 95 The blast..would be well into the kiloton range. The trick was..to bring the mass to supercriticality uniformly and at the same instant. |