铂电极BZ反应系双电层稀疏区中的Turing结构  

Turing Structure Appearing in Loose Region of Electric Double Layer of Pt-Electrode BZ Reaction System

作　　者：栗志[1] 韩玉民[1] 罗久里[1] 

机构地区：[1]四川大学化学学院化学物理研究所,成都610064

出　　处：《高等学校化学学报》2009年第2期360-364,共5页Chemical Journal of Chinese Universities

基　　金：教育部博士学科点基金(批准号:20050610012)资助

摘　　要：将扩散流作为场函数,考虑φ电势的空间分布,建立了铂电极BZ反应系在双电层稀疏区的动力学演化机制,确立了纳入稀疏区φ电势效应的反应-扩散型演化方程.采用Boltzmann分布近似,解决了演化方程中含φ电势的流项的线性化问题;导出了可在算法上实现的三变量体系线性化算子本征值的解析形式.分别以静态铂电极BZ反应系双电层稀疏区和对应的纯粹BZ反应系作为参考模型系,分析了经空间对称性破缺产生Turing结构的参数范围.数值模拟发现,φ电场的存在使铂电极BZ反应系的输运过程在静态双电层稀疏区趋于电化学平衡时,在对应的纯粹BZ反应体系中可呈现的Turing结构已趋于消失;而在电流强度不太大的恒流不可逆铂电极BZ反应体系双电层稀疏区中,鲜明稳定的Turing结构又重新出现在原参数区间内.同时,在静态双电层稀疏区不出现Turing结构的参数范围内也可找到类似的恒流稳定空间结构.In considering of the diffusion fluxes as field functions affected by the distribution of φ-potential a dynamical mechanism together with its evolutionary equation of reaction-diffusion type for the loose region of electrical double layer of Pt-electrode BZ reaction system is suggested in this paper. By taking a Boltzmann asymptotism of the φ-potential distribution to linearize the flux term in the evolutionary equation an analytic form of the eigenvalue of the linearized operator is also derived for this kind of three variables dynamical system. Furthermore, by adopting both the loose region of electrical double layer of static Pt-electrode BZ reaction system and the pure BZ reaction system as reference model the parameters regime for appearing Turing struc- ture through spatial symmetry breaking were analyzed quantitatively. By means of the numerical simulation for the solution of the corresponding evolutionary equation under conditions of expected parameters, it turns out that the Turing structure which appears in the pure BZ reaction system has tended to disappear in the loose region of statie electrical double layer following with the transport proeess reaching electro-chemical equilibrium by the effect of φ-potential. However, in the loose region of electrical double layer of irreversible Pt-eleetrode BZ reaction system under the condition of constant fluxes with small current a remarkable stable Turing structure appears again in former parameters regime. In addition, a kind of similar stable spatial pattern can be also observed in the parameters regime, in conditions of which the Turing pattern could not be found originally in the loose region of electrical double layer of statie Pt-electrode BZ reaction system.

关 键 词：铂电极BZ反应体系 双电层稀疏区 φ电势的空间分布 扩散流场函数 空间对称性破缺分支 Turing结构 

分 类 号：O646.54[理学—物理化学]