We present a computer model of diffusion limited aggregation with linear seed. The clusters with varying linear seed lengths are simulated, and their pattern structure, fractal dimension and multifractal spectrum are ...We present a computer model of diffusion limited aggregation with linear seed. The clusters with varying linear seed lengths are simulated, and their pattern structure, fractal dimension and multifractal spectrum are obtained. The simulation results show that the linear seed length has little effect on the pattern structure of the aggregation clusters if its length is comparatively shorter. With its increasing, the linear seed length has stronger effects on the pattern structure, while the dimension D f decreases. When the linear seed length is larger, the corresponding pattern structure is cross alike. The larger the linear seed length is, the more obvious the cross-like structure with more particles clustering at the two ends of the linear seed and along the vertical direction to the centre of the linear seed. Furthermore, the multifractal spectra curve becomes lower and the range of singularity narrower. The longer the length of a linear seed is, the less irregular and nonuniform the pattern becomes.展开更多
In this paper,the Lauwerier map F a,b (x,y)=(bx(1-2y)+y,ay(1-y)) is considered for a=4 . This map possesses a nontrivial topologically transitive attractor Λ which is the closure of the unstable set of...In this paper,the Lauwerier map F a,b (x,y)=(bx(1-2y)+y,ay(1-y)) is considered for a=4 . This map possesses a nontrivial topologically transitive attractor Λ which is the closure of the unstable set of some hyperbolic fixed point. Periodic points are dense in Λ and all of them are hyperbolic with eigenvalues uniformly bounded away from 1 in norm. Moreover,any two periodic points are heteroclinically related (transversal intersection of their stable and unstable sets). The Sinai Bowen Ruelle measure supported on the attractor is constructed and its properties are studied.展开更多
People have been paying more attention to the influence of the transverse effect of light fields on instability in the lasert. Gao Jin-yue, Narducci and Lugiato have theoretically discussed the instability of the syst...People have been paying more attention to the influence of the transverse effect of light fields on instability in the lasert. Gao Jin-yue, Narducci and Lugiato have theoretically discussed the instability of the system of axially symmetrical and only radially varying distribution of laser fields. Ba En-xu et al. have made experimental researches展开更多
基金Supported by the Natural Science Foundation of Wuhan University of Science and Engineering under Grant No 20063133, and the Natural Science Foundation of Hubei Province under Grant No 2003ABA057.
文摘We present a computer model of diffusion limited aggregation with linear seed. The clusters with varying linear seed lengths are simulated, and their pattern structure, fractal dimension and multifractal spectrum are obtained. The simulation results show that the linear seed length has little effect on the pattern structure of the aggregation clusters if its length is comparatively shorter. With its increasing, the linear seed length has stronger effects on the pattern structure, while the dimension D f decreases. When the linear seed length is larger, the corresponding pattern structure is cross alike. The larger the linear seed length is, the more obvious the cross-like structure with more particles clustering at the two ends of the linear seed and along the vertical direction to the centre of the linear seed. Furthermore, the multifractal spectra curve becomes lower and the range of singularity narrower. The longer the length of a linear seed is, the less irregular and nonuniform the pattern becomes.
基金Supported by the Special Funds for Major State Basic Research Projects and NSF(1 0 0 71 0 55)
文摘In this paper,the Lauwerier map F a,b (x,y)=(bx(1-2y)+y,ay(1-y)) is considered for a=4 . This map possesses a nontrivial topologically transitive attractor Λ which is the closure of the unstable set of some hyperbolic fixed point. Periodic points are dense in Λ and all of them are hyperbolic with eigenvalues uniformly bounded away from 1 in norm. Moreover,any two periodic points are heteroclinically related (transversal intersection of their stable and unstable sets). The Sinai Bowen Ruelle measure supported on the attractor is constructed and its properties are studied.
文摘People have been paying more attention to the influence of the transverse effect of light fields on instability in the lasert. Gao Jin-yue, Narducci and Lugiato have theoretically discussed the instability of the system of axially symmetrical and only radially varying distribution of laser fields. Ba En-xu et al. have made experimental researches
