| 释义 |
gyromagnetic, a.|ˌdʒaɪərəʊmægˈnɛtɪk|
[See gyro-.]
1. Physics. Of or pertaining to the interdependence of the angular momentum of a spinning charged particle and its resulting magnetic moment; gyromagnetic effect: any effect arising from this interdependence, esp. the fact that a change in the angular momentum of a freely suspended magnetizable body will produce a change in its magnetic moment, and vice versa; gyromagnetic ratio: the ratio of the angular momentum of a spinning charged particle to its magnetic moment; also, the reciprocal of this, expressed either as a true ratio (symbol γ) or as a dimensionless quantity (symbol g′).
1922O. W. Richardson in Proc. R. Soc. (1923) A. CII. 538 (heading) The magnitude of the gyromagnetic ratio. Ibid. 539 We are now practically driven..to the conclusion that the motions of the positively charged parts of the atoms cannot be disregarded in considering these gyromagnetic phenomena. 1922Phil. Trans. R. Soc. A. CCXXIII. 257 (heading) On the Richardson gyro⁓magnetic effect. 1930S. J. Barnett Evidence on Elem. Magnet from Res. on Gyromagnetic Phenomena 12 Rotating a rod about its axis at a speed of N revolutions per second magnetizes it exactly as it would be magnetized by applying to it an axial magnetic field with intensity H = 2πsN, where s is the ratio of the rotary momentum of the elementary magnet to its magnetic moment. This ratio is known as the gyromagnetic ratio, or magneto⁓mechanical ratio. 1953C. Kittel Introd. Solid State Physics x. 165 Gyromagnetic experiments identify the magnetization in ferromagnetics as arising largely from the electron spin, rather than from the orbital moment. Ibid., The magnetomechanical ratio is defined as the ratio of the magnetic moment to the angular momentum. [Note] This quantity..is sometimes called the gyromagnetic ratio, but strictly speaking the gyromagnetic ratio is the reciprocal of the magnetomechanical ratio. 1961Encycl. Dict. Physics III. 551/1 Gyromagnetic phenomena are to be expected in paramagnetic as well as ferromagnetic materials. 1967Electronics 6 Mar. 54/2 The NBS now uses the gyromagnetic ratio of a proton to determine the constancy of its standard voltage.
2. Applied to a type of compass in which a magnetic compass automatically corrects the gradual deviations of a directional gyroscope, which in turn provides the compass reading.
1946Wells & Glenny in M. Davidson Gyroscope iii. ii. 170 A gyro-magnetic compass..should not be confused with a gyro-stabilised magnetic compass. 1952Hitchins & May Lodestone to Gyro-Compass viii. 159 In the gyro-magnetic system a gyroscope is maintained in a nearly fixed direction by intermittent or continuous signals from some sort of magnetic compass. The gyroscope then operates the repeaters. 1957Encycl. Brit. VI. 176/1 In the gyro-magnetic compass..the gyro-direction indicator and magnetic compass are combined in one instrument and the necessity for hand adjustment disappears. |