| 释义 |
catalyst Chem.|ˈkætəlɪst|
[f. catalysis, on the analogy of analyst.]
A substance which when present in small amounts increases the rate of a chemical reaction or process but which is chemically unchanged by the reaction; a catalytic agent. (A substance which similarly slows down a reaction is occas. called a negative catalyst.) Also fig.
1902Nature 3 Apr. 523/1 No reactions are possible under the influence of catalysts that could not take place in their absence without a breach of one of the laws of energy. 1920Chambers's Jrnl. 284/1 Nickel is used as a ‘catalyst’, or a carrier of hydrogen in the hydrogenation.. of oils for use in the manufacture of margarine. 1927Haldane & Huxley Anim. Biol. viii. 169 We have begun to isolate many of the intermediate products of metabolism and the catalysts that govern the course of the reactions by which they are formed. 1943H. Read Politics of Unpolitical xiv. 160 Shelley called poets the unacknowledged legislators of the world, and the epithet was well chosen. The catalyst is unchanged, unabsorbed; its activity therefore not acknowledged. 1948Glasstone Physical Chem. (ed. 2) xiii. 1126 If the reaction is hindered by the added substance it is said to be a negative catalyst, and the word catalyst, when used alone, is almost invariably taken to imply acceleration of the chemical process. 1953Sci. News XXVIII. 117 There is no reason why a catalyst..should be rendered totally inactive by a change in the geometry of the substance acted upon. 1954J. I. M. Stewart Mark Lambert's Supper 139 In the intricate chemistry that gives motive-power to the machine he has himself acted as an obscure catalyst. 1968A. White et al. Princ. Biochem. (ed. 4) x. 209 Enzymes are catalysts peculiar to living matter. |