[en] Starting from iterated systems, it is shown that the homoclinic (heteroclinic) orbit is a kind of spiral structure. The emphasis is laid to show that there are homoclinic or heteroclinic orbits in complex discrete and continuous systems, and these homoclinic or heteroclinic orbits are some kind of spiral structure.
Journal
Communications in Theoretical Physics; ISSN 0253-6102; 
; v. 43(4); p. 601-603
; v. 43(4); p. 601-603
[en] The vortex is a common phenomenon in fluid field. In this paper, vortex can be represented by curvature c, which varies with arc length s. The variance of point (x,y) with arc length in stream line satisfies a 2-order variable-coefficient linear ordinary differential equation. The type vortex can be analyzed qualitatively by this ordinary differential equation.
Journal
Communications in Theoretical Physics; ISSN 0253-6102; ; v. 43(4); p. 604-606
; v. 43(4); p. 604-606