| 释义 |
isomerism Chem.|aɪˈsɒmərɪz(ə)m|
[f. isomer + -ism: in mod.F. isomérisme.]
a. The fact or condition of being isomeric; identity of percentage composition in compounds differing in properties. physical isomerism: see quot. 1896.
1838T. Thomson Chem. Org. Bodies 58 This is one of the most extraordinary examples of isomerism at present known. 1851Richardson Geol. v. 78 Isomerism, discovered by Berzelius, is a principle which is somewhat vague and doubtful in its application. 1880E. Cleminshaw Wurtz' Atom. The. 291 Isomerism is due to the difference in molecular grouping. 1884Frankland & Japp Inorg. Chem. 111 Allotropy stands in the same relation to elements that isomerism does to compounds. 1892Morley & Muir Watts' Dict. Chem. III. 81/1 Berzelius never intended that polymerism should be regarded as a form of isomerism. 1896I. Remsen Comp. Carbon 163 Bodies may conduct themselves chemically in exactly the same way, and yet differ in some of their physical properties, as in their action towards polarized light. To distinguish this kind of isomerism..it is called physical isomerism... The branch of chemistry which has to deal with the kind of isomerism just referred to, is called stereo-chemistry.
b. Physics. The fact or condition of being nuclear isomers.
1938R. W. Lawson tr. Hevesy & Paneth's Man. Radioactivity (ed. 2) x. 124 This isotope of silver..has two half-value periods, 24·5 m. and 8·2 d., the former being associated with positron emission, and the latter with the emission of β- and γ-rays... Here we are confronted with the phenomenon of nuclear isomerism. 1950[see isomeric a. 1 b]. |