Hexagonal Standing-Wave Patterns in Periodically Forced Reaction-Diffusion Systems

The periodically forced spatially extended Brusselator is investigated in the oscillating regime. The temporal response and pattern formation within the 2：1 frequency-locking band where the system oscillates at one half of the forcing frequency are examined. An hexagonal standing-wave pattern and other resonant patterns are observed. The detailed phase diagram of resonance structure in the forcing frequency and forcing amplitude parameter space is calculated. The transitions between the resonant standing-wave patterns are of hysteresis when control parameters are varied, and the presence of multiplicity is demonstrated. Analysis in the framework of amplitude equation reveals that the spatial patterns of the standing waves come out as a result of Turing bifurcation in the amplitude equation.     

Stochastic Simulation of Turing Patterns

We investigate the effects of intrinsic noise on Turing pattern formation near the onset of bifurcation from the homogeneous state to Turing pattern in the reaction-diffusion Brusselator. By performing stochastic simulations of the master equation and using Gillespie＇s algorithm, we check the spatiotemporal behaviour influenced by internal noises. We demonstrate that the patterns of occurrence frequency for the reaction and diffusion pro- cesses are also spatially ordered and temporally stable. Turing patterns are found to be robust against intrinsic fluctuations. Sfochastic simulations also reveal that under the influence of intrinsic noises, the onset of Turing instability is advanced in comparison to that predicted deterministically.     

Transition to Antispirals in the Complex Ginzburg-Landau Equation

We report a continuous transition from outwardly rotating spiral waves to antispirals in the complex GinzburgLandau equation. Numerical simulations demonstrate that the normal spiral to antispiral transition is fulfilled through a rest spiral wave with zero propagation speed. The propagation direction of spiral waves and the power law behaviour close to the transition boundary are examined.     

化学Lorenz模型中混沌的介观动力学

用系综模拟方法研究了化学Lorenz模型中混沌的介观动力学. 通过对主方程的随机模拟, 分析了盒频率(bin frequency)以及涨落和协方差在不同参数区的时间演化行为. 系综模拟分析在比通常宏观方程描述更为基本的层次上, 展示了确定性混沌的介观动力学图景. 对主方程也用累积展开法进行了分析.     

幼儿珠心算教学中的趣味教学法

<正>幼儿期的孩子好奇、好玩、好动,而且精力总是比较旺盛。他们不喜欢单调枯燥的训练,只有趣味的教学形式才能吸引和激发积极参与、主动学习的兴趣。我带的是小班,孩子年龄都在4岁左右,注意力特     

带电粒子辐照下石英玻璃和镀铝膜反射镜光学性能研究

提出低能带电粒子辐照下石英玻璃非弹性电离损伤的物理模型和速率方程,给出了电离效应产生带电离子、电子浓度的解析表达式.讨论了光密度与吸收剂量之间的变化关系,并与实验结果进行了比较.还给出光学反射镜反射率表达式及数学模拟结果.利用所建立的模型,可以定量描述低能带电粒子辐照特别是综合辐照时石英玻璃和镀金属膜反射镜光学性能随辐照剂量的变化情况. 关键词： 电离损伤 综合辐照 石英玻璃 光密度     

带电粒子辐照下石英玻璃和镀铝膜反射镜光学性能研究

提出低能带电粒子辐照下石英玻璃非弹性电离损伤的物理模型和速率方程，给出了电离效应产生带电离子、电子浓度的解析表达式.讨论了光密度与吸收剂量之间的变化关系，并与实验结果进行了比较.还给出光学反射镜反射率表达式及数学模拟结果.利用所建立的模型，可以定量描述低能带电粒子辐照特别是综合辐照时石英玻璃和镀金属膜反射镜光学性能随辐照剂量的变化情况.     

Stochasticity in the yeast mating pathway

We report stochastic simulations of the yeast mating signal transduction pathway. The effects of intrinsic and external noise, the influence of cell-to-cell difference in the pathway capacity, and noise propagation in the pathway have been examined. The stochastic temporal behaviour of the pathway is found to be robust to the influence of inherent fluctuations, and intrinsic noise propagates in the pathway in a uniform pattern when the yeasts are treated with pheromones of different stimulus strengths and of varied fluctuations. In agreement with recent experimental findings, extrinsic noise is found to play a more prominent role than intrinsic noise in the variability of proteins. The occurrence frequency for the reactions in the pathway are also examined and a more compact network is obtained by dropping most of the reactions of least occurrence.     

化学混沌主方程的随机模拟

在分子运动层次上,研究大量粒子的无序运动如何导致宏观上的集体行为已有很长的历史．在宏观层面上,耗散过程一般用一组唯象常微分或偏微分方程描述．虽然从微观上对无序的分子运动的描述在物理上更为基本,但是宏观上的唯象描述数学处理则更加方便．实际上,探讨诸如耗...     

化学混沌的控制及涨落的影响

用连续反馈控制模拟了Ｗｉｌｌａｍｏｗｓｋｉ－Ｒｏｓｌｌｅｒ模型中化学混沌的控制，研究了现实体系中涨落对混沌控制的影响，发现化学混沌的临界控制权重比一般体系大很多，并用连续反馈法与ＤＧＹ方法同样不具有噪音稳定性。