| 释义 |
Gibbs, n. Chem. and Physics.
Brit. |gɪbz|, U.S. |gɪbz|
[‹ the name of Josiah Willard Gibbs (1839–1903), U.S. physicist, who described these concepts in 1875 (Trans. Connecticut Acad. Arts & Sci. 3152).]
1. Gibbs phase rule n. (also Gibbs' phase rule, Gibbs's phase rule) = phase rule n.
1896Jrnl. Physical Chem. 1 21 A system of r coexistent phases having as a whole n independently variable components is capable, according to the Gibbs phase rule, of n + 2 - r independent variations. 1939Sci. Monthly Aug. 149/2 Roozeboom..applied Gibbs's phase rule to a study of actual chemical systems. 1988J. D. Barrow & F. J. Tipler Anthropic Cosmological Princ. (rev. ed.) iii. 147 Henderson argued that an application of Gibbs' Phase Rule, a general theorem of thermodynamics which is so fundamental that it is unlikely ever to be overthrown, indicated that the elemental properties were indeed independent. 1999Science 25 June 2162/3 By Gibbs' phase rule, a system of two phases..and five chemical components..has 5 degrees of freedom.
2. Gibbs function n. (also Gibbs’ function) the equation expressing the Gibbs free energy.
[1919Jrnl. Amer. Chem. Soc. 41 986 The negative of the differential of the function of Gibbs, or of the Helmholtz free energy, is defined as [etc.] ]1928Proc. Royal Soc. (A.) 120469 In taking the difference ϕ - H/T to find the Gibbs’ function G/T, the second of these terms disappears, leaving only the first. 1943J. G. Geffner & A. G. Worthing Treatm. Exper. Data x. 237 From direct thermal measurements, with ΔG representing the change in Gibbs' function (the chemists' free energy) for the reaction specified, the following have been obtained. 2004Jrnl. Chem. Physics 12111208 The method is demonstrated using a two-dimensional, harmonic crystal with hexagonal symmetry for which the isobaric Gibbs function can be derived analytically.
3. Gibbs free energy n. (also Gibbs' free energy) the thermodynamic function G = H - TS (where H is the enthalpy, T the temperature, and S the entropy), representing the amount of energy that can be converted into work at constant temperature and pressure. Cf. free energy n. 2.
[1914Physical Rev. 3 277 Z = E + pv - τs, the Gibbs thermodynamic potential.] 1932Proc. Royal Soc. (A.) 135182 As it is more usual for chemists to use the Helmholtz free energy A and the Gibbs' free energy F, it is perhaps as well to define these various functions and give the exact relations between them. 1954T. Vickerstaff Physical Chem. Dyeing (ed. 2) iv. 100 The driving force in any reaction is represented by the Gibbs free energy change involved. 1968C. G. Kuper Introd.Theory Superconductivity v. 76 It is easy to satisfy oneself that this configuration minimizes the Gibbs free energy. 2004H. J. Morowitz Emergence of Everything xxxii. 177 The operative free energy in biochemistry is the Gibbs free energy, which is minimized as the entropy of the universe is maximized. |