| 释义 |
ex·pan·sion
I. \ikˈspanchən, ek-, -paan-\ noun
(-s)
Etymology: Late Latin expansion-, expansio, from Latin expansus + -ion-, -io -ion
1. : the act or process of expanding: as
a.
(1) : the act or process of spreading out
< the easy expansion of the wing of a bird — Nehemiah Grew >
(2) : the mushrooming of a bullet upon striking the target
b.
(1) : the act or process of increasing in extent, size, number, volume, or scope : enlargement, growth
< localized pain along nerve trunks may be due to the expansion of the dissolved nitrogen without actual bubble formation — H.G.Armstrong >
< the bewildering expansion of science during the last century — C.H.Grandgent >
< this desire for territorial expansion is deeply rooted in human history — C.J.Friedrich >
(2) in an electronic sound amplifier : the widening of the range of an audio-frequency signal by making the gain vary directly with the amplitude of the input signal so that weak sounds become weaker and loud sounds louder
c.
(1) : the act of expressing fully or of developing in detail : amplification
< these lectures with some slight expansion … are here printed as delivered — A.N.Whitehead >
(2) mathematics : the developed result of an indicated or possible operation : the expression of a function in the form of a series
< the expansion of (a+b)2 is a2+2ab+b2 >
(3) logic : the operation or result of making the terms in a formula more explicit or of introducing new terms without changing the logical significance of the expression
2. : the quality or state of being expanded
< the gilded clouds in fair expansion lie — Alexander Pope >
3. : expanse
< the sky's serene expansion — Thomas Hood †1845 >
4. obsolete : pure space
< lost in expansion, void and infinite — Richard Blackmore >
5.
a. : the increase in volume of working fluid (as steam) in an engine cylinder after cutoff or in an internal-combustion engine after explosion by which it continues to propel the piston while expending part of its internal energy and losing in pressure and temperature
b. : the period during which such expansion occurs
c. : amount of increase of length, area, or volume
6.
a. : an expanded part
< the great expansion of the St. Lawrence called the Lake of St. Peter — Francis Parkman >
b. : something that results from an act of expanding
< this book was an expansion of a notable series of articles — A.C.Ames >
7. : expansiveness
< gradually tones of careless freedom, moments of reckless expansion come in, though never … any trace of sentimentality or of adoration — Havelock Ellis >
II. noun
Usage: often attributive
: the addition of one or more teams to a sports league
< an expansion team >
< an expansion year > |