| 释义 |
Poincaré, n. Math. and Phys.|ˈpwæ̃kɑre|
The name of Jules-Henri Poincaré (1854–1912), French mathematician and physicist, used attrib. and in the possessive to designate various concepts introduced by him or arising out of his work, as Poincaré('s) conjecture, the hypothesis that any simply connected compact 3-dimensional manifold is topologically equivalent to a 3-dimensional sphere; Poincaré cycle, (a single circuit of) a simple closed curve in the phase space of a system, representing one possible solution of the governing differential equations; Poincaré sphere, a sphere on which the polarization of a beam of light can be represented by a particular point, and which is also used in other optical calculations.
[1928Communications Physical Lab. Univ. Leiden No. 191c. 29 The representation [of polarization] on a sphere given by Poincaré. ]1943Rev. Mod. Physics XV. 85 (heading) Boltzmann's estimate of the period of a Poincaré cycle. 1951Proc. Indian Acad. Sci. A. XXXIII. 201 To represent the Poincaré sphere in two dimensions the stereographic projection is used in this paper. 1976Encycl. Brit. Macropædia XVIII. 514/1 Poincaré conjecture. 1986New Scientist 4 Sept. 43/1 Poincaré's Conjecture concerns just how close these family resemblances are and, in particular, how closely the 3-sphere resembles the 2-sphere. 1988Physics Lett. A. CXXVI. 311 Tube-like standing waves subject to a ‘final’ condition may resemble unparametrised orbits of the universe, with ‘quantum Poincaré cycles’ coinciding with its durations. 1988Optik LXXIX. 185/2 Let us see fig. 4 presenting a Poincaré sphere with two points representing different birefringent media, located on the opposite ends of a diameter. |