| 释义 |
orthodromic, a.|ɔːθəʊˈdrɒmɪk|
[f. Gr. type *ὀρθόδροµ-ος (cf. ὀρθοδροµεῖν to run straight, ἀνάδροµ-ος running up, etc.) + -ic.]
1. (See quot. 1775.) Also, representing great circles as straight lines. So ˈorthodrome, a great circle or a route forming part of one. orthoˈdromics n., orˈthodromy (see quots.).
1704J. Harris Lex. Techn. I, Orthodromiques,..the Art of sailing in the Ark of some great Circle. 1706Phillips, Orthodromy, such a Course, which is the most direct and shortest distance between any two Points on the Surface of the Globe. 1775Ash, Orthodromic, sailing on the arch of a great circle, sailing the most direct course. 1855J. Pryde Treat. Pract. Math. 455 The arc of a great circle, which is the shortest distance between two places, is called the orthodrome. 1922R. Keen Direction & Position Finding by Wireless iv. 103 A chart on which all Great Circles are represented as straight lines is known as orthodromic. 1928L. S. Palmer Wireless Princ. & Pract. xii. 487 This type of projection is the orthodromic projection and the map of the district surrounding the tangent point is termed a Gnomonic chart. 1935Geogr. Jrnl. LXXXV. 466 The equation of the orthodrome (geodesic line). 1956McGraw-Hill Yearbk. Sci. & Technol. VI. 267/2 The longer the distance, the greater the deviation between loxodromes and orthodromes.
2. Physiol. Being or involving a nerve impulse that is propagated in the normal direction.
1943Jrnl. Neurophysiol. VI. 143 (heading) The interaction of antidromic and orthodromic volleys in a segmental spinal motor nucleus. 1954Jrnl. Physiol. CXXVI. 501 (heading) Interaction between direct current and orthodromic stimulation. 1972Science 2 June 1043/1 The prolonged inhibition of the monographic excitation of motoneurons by orthodromic volleys in muscle and cutaneous afferent fibers.
Hence orthoˈdromically adv.
1954Penfield & Jasper Epilepsy & Functional Anat. Human Brain v. 203 Distant projection of the impulses from a local after-discharge has been shown to be conducted only orthodromically (not antidromically) over transcortical bundles of fibers. 1976Nature 4 Mar. 56/2 When the interval between the two spikes was reduced progressively, the antidromic response eventually disappeared because it collided with the direct spike travelling orthodromically along the same nerve fibre. |