“group”的概念、定义、翻译、参考文献-科学参考

单词	group
释义	group [grüp] ^ASTRONOMY A number of stars moving in the same direction with the same speed. ^CHEMISTRY 1. A family of elements with similar chemical properties. 2. A combination of bonded atoms that behave as a unit under certain conditions, for example, the sulfate group, SO₄^2-. ^{COMMUNICATIONS} A subdivision containing a number of voice channels, either within a supergroup or separately, normally comprised of up to 12 voice channels occupying the frequency band 60-108 kilohertz; each voice channel may be multiplexed for teletypewriter operation, if required; the number of voice channels which may be simultaneously multiplexed for teletypewriter operation will vary according to equipment design. ^GEOLOGY A lithostratigraphic material unit comprising several formations. ^MATHEMATICS A set G with an associative binary operation where g₁.g₂ always exists and is an element of G; each g has an inverse element g^-1, and G contains an identity element.
随便看	nettle cell net ton net tonnage net-veined network network admittance network analysis network analyzer network architecture network constant network control program network data structure network filter network flow networking network input impedance network master relay network phasing relay network planning network relay network server network structure network synthesis network system network theory

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