| 释义 |
differentiation|dɪfərɛnʃɪˈeɪʃən|
[n. of action f. differentiate: so in mod.F.]
1. a. The action of differentiating, or condition of being differentiated (see prec. 1, 2); any change by which like things become unlike, or something homogeneous becomes heterogeneous; spec. in Biol., etc., the process, or the result of the process, by which in the course of growth or development a part, organ, etc. is modified into a special form, or for a special function; specialization; also the gradual production of differences between the descendants of the same ancestral types. Esp. dependent differentiation and self-differentiation (see quot.).
1855H. Spencer Princ. Psychol. (1870) I. i. iii. 49 In the rudimentary nervous system, there is no such structural differentiation. 1863E. V. Neale Anal. Th. & Nat. 217 The differentiation of a diffused material substance into the opposite forms of suns and planets. 1865Gosse Land & Sea (1874) 213 The lower the rank of an organism..the less of differentiation we find, the less of specialty in the assignment of function to organ. 1871Darwin Desc. Man I. ii. 61 He [the naturalist] justly considers the differentiation and specialisation of organs as the test of perfection. 1874Sweet Eng. Sounds 23 The Roman alphabet has been further enriched by the differentiation of various forms of the same letter, of which the present distinction between u and v, i and j, are instances. 1875Lyell Princ. Geol. II. iii. xliii. 480 We cannot so easily account for the differentiation of the Papuan and the Malay races. 1880A. R. Wallace Isl. Life 278 Long continued isolation would often lead to the differentiation of species. 1926J. S. Huxley Ess. Pop. Sci. xviii. 269 The future differentiation of a particular region at a particular moment may be of two kinds. It may be entirely independent of other organs, in which case we speak of self-differentiation, or it may depend upon some other organ, when it is called dependent differentiation.
b. Philol. The action of differentiating or fact of being differentiated: used of two adjacent phonemes, the meanings of synonyms, etc.
1925P. Radin tr. Vendryès's Language i. iii. 60 The two contiguous phonemes..take advantage of their differences to exaggerate them until they no longer have anything in common. This is the process of differentiation as opposed to accommodation. 1926Fowler Mod. Eng. Usage 114/1 Differentiation. In dealing with words, the term is applied to the process by which two words that can be used indifferently in two meanings become appropriated one to one of the meanings & one to the other. 1928S.P.E. Tract xxxi. 323 Differentiation..consists in giving deliberate help to that natural process of language which is always tending to give different meanings to..synonyms. 1934M. K. Pope From Lat. to Mod. Fr. ii. i. 64 Differentiation is at times due to the same instinct, as for instance when plosive + plosive is differentiated to fricative + plosive. 1939L. H. Gray Found. Lang. iii. 69 Dissimilation..may be..either contiguous (differentiation) or incontiguous (dissimilation proper).
2. The action of noting or ascertaining a difference (see prec. 3); discrimination, distinction.
a1866Whewell in Macm. Mag. XLV. 142 Men rush..to differentiation on the slightest provocation. 1875G. H. Lewes Prob. of Life & Mind Ser. i. II. vi. iv. 504 The logical distinctions represent real differentiations, but not distinct existents. 1876Bartholow Mat. Med. (1879) 114 A careful differentiation of the causes.
3. Math. The operation of obtaining a differential or differential coefficient.
1802Woodhouse in Phil. Trans. XCII. 123 note, Processes of evolution, differentiation, integration, &c. are much more easily performed with the former expression. 1816tr. Lacroix's Diff. & Int. Calculus 21 The principles of differentiation having been deduced. 1885Watson & Burbury Math. Th. Electr. & Magn. I. 31 Performing the differentiations and substituting, we get [etc.]. |