| 释义 |
work function Physics.
[f. work n. + function n.]
1. The minimum quantity of energy, characteristic of the material concerned, which is required to remove an electron to infinity from the surface of a solid (usu. a metal). Symbol: ϕ.
1923Proc. R. Soc. A. CIV. 637 The estimations of the photo-electric work function..are in all cases a good deal greater than the corresponding values of the thermionic work function. 1950A. Kolin Physics xxxv. 715 The work function can be determined by finding the threshold frequency vo below which no photoelectrons are emitted. 1972Sci. Amer. Mar. 53/1 When two metals are placed in contact, electrons pass from one to the other because of the difference in the metals' quantum-mechanical work functions. This process continues until an equilibrium is reached.
2. A thermodynamic property of a system: its internal energy minus the product of its temperature and entropy. Symbol: A.
1929R. H. Fowler Statistical Mech. iv. 96, klog K(T) for the crystal is the thermodynamic function known as Planck's characteristic function, and —kT log K(T) is the more usual work function..A. 1937P. S. Epstein Textbk. Thermodynamics v. 92 When the temperature and the volume of a system are kept constant, its work function has a tendency to decrease. 1978P. W. Atkins Physical Chem. v. 139 If we know the value of ΔA for a change we can also state the maximum amount of work the system can do. This relation is the reason why A is sometimes called the maximum work function, or the work function. |