| 释义 |
rotational, a.|rəʊˈteɪʃənəl|
[f. prec. + -al1.]
1. Acting in rotation; of or belonging to rotation.
1852De Morgan in Graves Life Hamilton (1889) III. 394 Members to go out by rotation each year... The rotational electors to be distributed through the year. 1870Proctor Other Worlds v. 111 The energies indicated by mere velocity of motion, whether orbital or rotational, must be equally disregarded. 1886Ball Story Heavens 534 In a similar manner we find the rotational moment of momentum for each of the other planets.
2. Physics. Of, pertaining to, or designating the (quantized) energy possessed by molecules, etc., by virtue of their rotation.
1914Chem. Abstr. VIII. 859 According to the quantum hypothesis the rotational energy of a mol[ecule] varies discontinuously, from which it follows that a band is made up of a series of lines whose vibration difference is a measure of the moment of inertia of a mol[ecule]. 1939J. W. T. Spinks tr. G. Herzberg's Molecular Spectra I. iii. 72 The rotational quantum number J..gives approximately the angular momentum in units h/2π. 1950W. J. Moore Physical Chem. xi. 327 A set of closely packed rotational levels is associated with each of these vibrational levels. 1973C. Sagan Cosmic Connection (1974) iv. 27 Molecules undergo rotational transitions, due to the free rotation of the molecule. 1978P. W. Atkins Physical Chem. xvii. 561 According to the gross selection rule, methane cannot give a rotational Raman spectrum, whereas the hydrogen molecule, and any other diatomic..can.
3. Agric. Applied to methods of land management in which animals are grazed on successive areas of land in turn, so that each area is empty for a time after having been grazed.
1931H. E. Woodman et al. in Jrnl. Agric. Sci. XXI. 267 It may be inferred that a similar result would follow from a system of rotational grazing, where the pasture enclosures, after being closely grazed, are permitted a 3-weeks' interval of unchecked growth before being grazed again. 1950N.Z. Jrnl. Agric. Apr. 307/1 Rotational cropping is now an excellent fertility builder. 1967C. D. Blake et al. Fundamentals Mod. Agric. ix. 208/1 In the broad sense, rotational grazing is any system of handling animals which involves holding them for short periods on small sections of the total area of an available pasture and then regularly moving them, as a group, to other sections of the whole area. There is an infinite number of rotational grazing systems available. |