| 释义 |
motional, a.|ˈməʊʃənəl|
[f. motion n. + -al1.]
Of or pertaining to motion; characterized by (certain) motions. In Electr. applied spec. to an impedance that arises out of the motion of a conductor in a magnetic field.
1679tr. Willis's Pharmac. Rationalis i. i. ii. 7 This Coat contains manifold orders of motional Fibres. a1831Bentham Language Wks. 1843 VIII. 300/2 The existence of any expressible state of things, or of persons,..whether it be quiescent, or motional,..is what is called a fact. 1879Thomson & Tait Nat. Phil. I. i. §343 A system so constituted that the positional forces are proportional to displacements and the motional to velocities. 1892O. Heaviside Electr. Papers I. 446 In general h = VDv × 4π, where D is the displacement of the field, v the velocity, h the induced magnetic force, and V is as in equation (3). [Note] The force [so defined]..I now term the motional magnetic force, and its companion (21a) below, the motional electric force. 1912Kennelly & Pierce in Proc. Amer. Acad. Sci. XLVIII. 113 The difference obtained by subtracting the damped values from the corresponding free values may be called the motional values of resistance, inductance, etc.; since such differences are due to the motion of the diaphragm. Ibid. 144 This means that the impedance of the receiver has become increased, through the vibration of the diaphragm, by a motional impedance. 1957W. Fraser Telecommun. xvi. 510 The movement of the speech coil in the air gap induces a back e.m.f. in the coil so that the loudspeaker has a motional impedance under dynamic conditions. 1969F. A. Bovey Nuclear Magn. Resonance Spectrosc. i. 14 In liquids of ordinary viscosity..the local variations in magnetic field strength have become so short-lived that motional averaging is complete. |