| 释义 |
Onsager Physics.|ʊnˈsagər, ˈɒnsɑːgə(r)|
The name of Lars Onsager (1903–76), Norwegian chemist, used attrib. and in the possessive with reference to a theorem orig. obtained for the thermodynamics of irreversible processes, but of wide applicability in physics and biophysics, as Onsager coefficient, a tensor coefficient expressing the degree of interference between two irreversible processes; Onsager('s) law or principle, a statement of the reciprocal nature of the interference between two irreversible processes occurring simultaneously, spec. that the Onsager coefficients for each direction of flow between the two processes are equal; cf. reciprocity theorem; Onsager (reciprocal or reciprocity) relation, a mathematical statement of the Onsager principle.
1945Rev. Mod. Physics XVII. 343 (heading) On Onsager's principle of microscopic reversibility. 1952Physica XVIII. 182 Verschaffelt has given an example of a linear transformation of flux and force variables which leaves the entropy production invariant and yet which destroys the Onsager relations. 1955I. Prigogine Introd. Thermodynamics Irreversible Processes iv. 46 These Onsager reciprocity relations express that when the flux, corresponding to the irreversible processes i, is influenced by the affinity Xk of the irreversible process k, then the flux k is also influenced by the affinity Xi through the same interference coefficient Lik. 1965W. C. Reynolds Thermodynamics xiv. 381 Some restrictions on the signs of the Onsager coefficients are provided by the requirement that the entropy-production rate be positive. 1965Katchalsky & Curran Nonequilibrium Thermodynamics in Biophysics x. 120 Onsager's law provides a quantitative relation between the phenomena of ultrafiltration and osmotic flow. 1968Times 31 Oct. 5/4 In the simplest terms possible, the Onsager principle or ‘reciprocity theorem’, as it is sometimes called, asserts that where two or more kinds of flow affect each other the equations describing them will be reciprocally related in a specific way. 1977S. H. Chue Thermodynamics ii. 248 In the Onsager coefficients the subscript i refers to the flux and the subscript j to the driving force. 1978B. H. Lavenda Thermodynamics Irreversible Processes ii. 29 The derivation of the Onsager reciprocal relations was based on an apparent analogy between the conditions of chemical equilibrium and the ‘principle of detailed balance at equilibrium’. |