A new method of controlling chemical chaos——Nonlinear artificial neural network (ANN)-occasional perturbation feedback control in the whole chaotic region

A new method of controlling chemical chaos to attain the stabilized unstable periodic orbit (UPO) is proposed. It is an extension of the occasional proportional feedback (OPF) control strategy which spans the limitations of OPF, i.e. the linear region of the control rule, and extends to the whole chaotic region. It also expresses the nonlinear control rule with the back propogation-artificial neural network (BP-ANN) in order to increase the robustness of the control. Its effectiveness is examined through controlling an autocatalytic chaotic reaction model numerically.     

电促灰岩离解动态除氟实验研究

高氟地下水的除氟是保证居民远离氟地方病的有效手段之一。本研究利用新型封闭除氟装置探究电促灰岩动态除氟的化学驱动力、主控因素及稳定除氟能力。结果表明,在电场强化条件下,与灰岩接触的高氟水会形成局部萤石过饱和,可有效去除水中过量的氟。整个反应过程可分为启动阶段与稳定阶段。电压梯度是除氟反应主控因素,当电压梯度大于4. 8V·cm~(-1)时,除氟效果较好。反应过程中阳极附近F-富集高于初始浓度,而阴极附近更易生成CaF_2沉淀,表明阴极除氟效果更优。灰岩固体颗粒表面形态变化巨大,存在明显的腐蚀现象。当两极电压差为24V、极板间距3cm时,阴极附近氟浓度能迅速地由10mg·L~(-1)降低至国家饮用水标准以下。