| 释义 |
free energy, n.
Brit. |ˌfriː ˈɛnədʒi|, U.S. |ˌfri ˈɛnərdʒi|
[‹ free adj. + energy n. In sense 2 after German freie Energie (H. von Helmholtz 1882: see Helmholtz free energy n. at Helmholtz n. Additions).]
1. Available or spare energy of a person; physical energy that is available to be utilized.
1872‘G. Eliot’ Middlemarch IV. vii. lxvi. 59 He had no longer free energy enough for spontaneous research and speculative thinking. 1910Wall St. Jrnl. 10 Sept. 6/1 The stability of the existing forms of business structure, the mines, factories..is only secured by a continuous stream of new productive energy. All this is done by adapting and directing the fresh flow of free energy stored in the minds and bodies of men. 1964D. M. Kaplan & A. Schwerner Domesday Dict. 208 Free energy is the fuel of creation: nuclei are only the ashes. 1972N.Y. Times 20 Dec. 63/2 The economic process normally consists of taking free energy—such as coal or oil—and ultimately converting it into forms of ‘bound’ energy—such as pollution or wastes that are no longer readily available to produce heat or power. 1996N.Y. Times 11 Oct. b12/3 Many of the fans not busy yelling at the Orioles spent much of their free energy heckling security personnel or fighting with the officers.
2. Physics and Chem. Energy that is available to do work; = Helmholtz free energy n. at Helmholtz n. Additions, Gibbs free energy n. at Gibbs n. 3.
1884Science 29 Aug. 181/1 Helmholtz has developed the conception of free energy, with very important applications to the theory of the galvanic cell. 1924A. J. Allmand & H. J. T. Ellingham Princ. Appl. Electrochem. (ed. 2) iv. 46 The decrease in free energy represents a decrease in the available chemical energy of the system, but an equivalent quantity of electrical energy is produced which is completely available for any desired purpose. 1967E. U. Condon & H. Odishaw Handbk. Physics (ed. 2) v. i. 8/1 This combination (U + pV - TS) is also called free energy, but is called the Gibbs free energy when it is necessary to distinguish it from the Helmholtz free energy. 1977J. March Adv. Org. Chem. (ed. 2) vi. 190 In order for a reaction to take place spontaneously, the free energy of the products must be lower than the free energy of the reactants. 2000Sci. Amer. Feb. 36/2 Warm water contains more free energy than cold water, and like all compounds it wants to reach a state of lowest free energy.
3. Energy which may be obtained or used at negligible cost.
1917Syracuse Herald (N.Y.) 4 Oct. 1/3 His system of utilizing free energy is as revolutionary as Franklin's discovery of electricity. 1974N.Y. Times 13 May 1/3 Sunlight provides a continuous source of free energy with no nighttime interruption. 1990New Scientist 15 Sept. 32/1 Carlton Caves..suggested that a microscopic device, known as a Maxwell demon, might be able to transfer heat from a cold body to a hot body and obtain ‘free’ energy. 2004Advertiser (South Australia) (Nexis) 24 Aug. 21 Free energy from the sun can meet 70 per cent or more of your hot water requirements. |