title: Dynamics of Scroll Wave in a Three-Dimensional System with Changing Gradient.
abstract: The dynamics of a scroll wave in an excitable medium with gradient excitability is studied in detail. Three parameter regimes can be distinguished by the degree of gradient. For a small gradient, the system reaches a simple rotating synchronization. In this regime, the rigid rotating velocity of spiral waves is maximal in the layers with the highest filament twist. As the excitability gradient increases, the scroll wave evolutes into a meandering synchronous state. This transition is accompanied by a variation in twisting rate. Filament twisting may prevent the breakup of spiral waves in the bottom layers with a low excitability with which a spiral breaks in a 2D medium. When the gradient is large enough, the twisted filament breaks up, which results in a semi-turbulent state where the lower part is turbulent while the upper part contains a scroll wave with a low twisting filament.
authors.affiliation: Information Engineering School, Hangzhou Dianzi University, Hangzhou 310018, P.R. China.
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Yuan
authors.affiliation: Department of Physics, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
authors.forename: Jiang-Xing
authors.initials: JX
authors.lastname: Chen
authors.affiliation: Department of Physics, Hangzhou Dianzi University, Hangzhou 310018, P. R. China.
authors.forename: Ye-Hua
authors.initials: YH
authors.lastname: Zhao
authors.affiliation: Department of Physics, China Jiliang University, Hangzhou 310018, P. R. China.
authors.forename: Gui-Quan
authors.initials: GQ
authors.lastname: Liu
authors.affiliation: Department of Physics, Zhejiang University, Hangzhou 310027, P. R. China.
authors.forename: He-Ping
authors.initials: HP
authors.lastname: Ying
mesh_terms: D000465:Algorithms; D002320:Cardiovascular Physiological Phenomena; D003198:Computer Simulation; D006801:Humans; D057446:Hydrodynamics; D008955:Models, Cardiovascular; D010363:Pattern Recognition, Automated; D012399:Rotation