| 释义 |
▪ I. Jordan2|ˈdʒɔːdən|
The name of a river in Palestine, the crossing of which is used (after Num. 33:51) in pietistic language to symbolize death.
1684Bunyan Pilgr. ii. 222 Mr. Stand-fast..went down to the River..he said..my Foot is fixed upon that, upon which the Feet of the Priests..stood while Israel went over this Jordan. 1707I. Watts Hymns & Spiritual Songs ii. No. lxv. 139 Could we but climb where Moses stood, And view the Landskip o're, Not Jordan's Stream, nor Death's cold Flood Should fright us from the Shore. 1772W. Williams Hymn, ‘Guide me, O Thou Great Jehovah’, When I tread the Verge of Jordan. 1786S. Stennett (title of hymn), On Jordan's stormy banks I stand. c1871in J. W. Johnson Bk. Amer. Negro Spirituals (1925) 63, I look'd over Jordan, an' what did I see... A band of angels comin' after me. a1890in Barrère & Leland Dict. Slang (1890) II. 368/1 (s.v. T'other), And I saw a mighty charret a comin'.., To take us to de odder side of Jordan... Jordan am a hard road to trabble. 1944D. Van de Voort in B. A. Botkin Treas. Amer. Folklore v. 682 Everybody thought that when Wiley's pappy died he'd never cross Jordan because the Hairy Man would be there waiting for him.
▪ II. Jordan3 Math.|ˈdʒɔːdən|
[Name of Marie Ennemond Camille Jordan (1838–1922), French mathematician.]
Jordan curve, any curve that is topologically equivalent to a circle, i.e. is closed and does not cross itself; so Jordan('s) (curve) theorem, the theorem that any Jordan curve in a plane divides the plane into just two distinct regions having the curve as their common boundary.
1900W. F. Osgood in Trans. Amer. Math. Soc. I. 310 By a Jordan curve is meant a curve of the general class of continuous curves without multiple points, considered by Jordan, Cours d'Analyse, vol. I, 2d edition, 1893, p. 90. 1919Ann. Math. XXI. 180 (heading) A proof of Jordan's theorem about a simple closed curve. 1939M. H. A. Newman Elem. Topology of Plane Sets of Points vi. 132 Theorem 2·3. (Jordan's Theorem for a polygon.) A simple polygon determines two domains, of each of which it is the frontier. 1947Courant & Robbins What is Math.? (ed. 4) v. 246 The Jordan curve theorem is quite simple to prove for the reasonably well-behaved curves, such as polygons or curves with continuously turning tangents, which occur in most important problems. 1965S. Barr Exper. Topology i. 13 A Jordan curve can be drawn on the side of the torus and still divide it into two, but not if it circles, or goes through the hole. |