释义 |
Coulomb Electr.|ˈkuːəʊm, -lɒm, kuːˈlɒm| In sense 1 also coulomb. [After the French physicist, C. A. de Coulomb (1736–1806), who first invented the method of measuring the quantity of electricity.] 1. The designation adopted by the Paris Electric Congress in 1881, for the unit of electrical quantity; the quantity of electricity conveyed in one second by a current of one ampère. (For this unit the name Weber had been previously introduced into partial use.) Also known as international coulomb when defined in terms of the international ampere; in 1948 this was replaced by the absolute coulomb, defined in terms of the absolute ampere and now incorporated in the International System of Units.
1881Nature XXIV. 512 The name Coulomb to be given to the quantity of electricity defined by the condition that an ampère gives one coulomb per second. 1891Gloss. Electr. Terms (Lightning Suppl. 3 Mar. 1892), The Coulomb is the quantity of electricity, which, when passed through a solution of nitrate of silver, deposits ·001118 of a gramme of silver on the plate by which it leaves the liquid. 1893Trans. Amer. Inst. Electr. Engin. X. 469 As the Unit of Quantity, the International Coulomb, which is the quantity of electricity transferred by a current of one international ampere in one second. 1911Encycl. Brit. XXVII. 742/2 The International Coulomb..is the quantity of electricity transferred by a current of one international ampere in one second. 1938Hackh's Chem. Dict. (ed. 2) 256/1 Coulomb..international ∼. 1 Int. coul. = 0·9999 absolute coul. 1959Chamber's Encycl. XIV. 188/1 The common practice is to introduce the absolute coulomb as the fourth fundamental unit [of absolute practical units]. 1963Jerrard & McNeill Dict. Sci. Units 35, 1 international coulomb = 0·99985 absolute coulomb. 2. attrib. and Comb., as Coulomb barrier, a repulsive electrostatic force constituted by the Coulomb field of a nucleus; Coulomb energy, the energy of a charged particle due to the electrostatic field of other charged particles, esp. when it constitutes part of its binding energy; Coulomb field, an electrostatic field that obeys the inverse-square law; Coulomb force, the electrostatic force of attraction or repulsion exerted by one charged particle upon another; Coulomb interaction, an interaction between two particles because of the electric charge that each has; Coulomb('s) law, either of two laws in electrostatics: (a) (see quot. 1908); (b) a law that like charges repel, and opposite charges attract each other, the force varying inversely as the squares of the distances between them, and proportionally to the product of the magnitudes of the charges; Coulomb repulsion, the repulsion between charges occasioned by Coulomb forces; Coulomb scattering (see quot.); coulomb-volt = joule.
1949Friedlander & Kennedy Introd. Radiochem. iii. 72 Charged particles which have to overcome Coulomb barriers. 1958Mansfield Elem. Nuclear Physics ii. 14 Protons, because they are charged, have an electrostatic (coulomb) barrier to overcome before they can escape from the nucleus.
1940Glasstone Physical Chem. i. 101, Q is called the Coulomb energy, due to the electrostatic attractions and repulsions between electrons and protons.
1937J. W. T. Spinks tr. Herzberg's Atomic Spectra i. 46 A point charge in a pure Coulomb field of force. 1970Physics Bull. Apr. 149/2 In the atom the motion of the electrons is dominated by the Coulomb field of the nucleus.
1930Engineering 9 May 595/3 The electrons and ions reacted on one another with the usual Coulomb forces. 1936W. Heitler Quantum Theory Radiation iii. 98 For the collision of an electron with a nucleus of charge Z, the Coulomb interaction is proportional to e2Z. 1970G. K. Woodgate Elem. Atomic Struct. ii. 9 This Coulomb interaction is of a special form with respect to its radial dependence (V(r) ∝ r-k where k = 1).
1854W. Thomson in Phil. Mag. VIII. 48 Coulomb's law. 1908J. H. Jeans Math. Theory Electr. & Magn. ii. 45 Coulomb's Law. If R is the outward intensity [of the electric field] at a point just outside a conductor, then R = 4πσ, where σ is the surface density of electrification on the conductor. 1938L. B. Loeb Atomic Structure i. 30 There thus seems to be a general limit at which the Coulomb law fails. 1947M. D. Kamen Radioactive Tracers i. 7 This attractive force far outweighs the Coulomb repulsion. 1955Gloss. Terms Radiology (B.S.I.) 16 Coulomb scattering, the scattering of a particle by the coulomb field of a nucleus.
1893Funk's Stand. Dict., Coulomb-volt. 1963B. Fozard Instrum. Nucl. Reactors i. 5 The electron volt (eV)..is related to the coulomb-volt or joule or watt-second by the factor 1·602 × 1019 given above. |