Nonlinear Dynamics in Chemical Systems

肯尼斯·肖瓦尔特教授得到了理论和计算化学计划的资助，继续他在化学系统中的非线性动力学方面的工作。这项研究涉及连续搅拌反应器、均相和非搅拌体系以及分布式化学体系中复杂化学动力学的研究。提出了三条研究主线：1)发展利用线性和非线性控制方法控制混沌的技术；2)研究非均匀和扰动可激发介质中的化学波；3)研究反应扩散前沿传播的不稳定性。将进行实验和理论研究。ShowAlter正在探索的一个新的实验项目是使用喷墨打印机来制备用于可激发化学体系的固定化催化剂的图案。这使他能够在系统设计的几何约束存在的情况下研究化学波的行为，这些几何约束是可兴奋的生物介质(如心肌)的模型。非线性动力学是理解自然界复杂性的有力工具，有着广泛的实际应用。生物学应用包括稳定心脏组织中的周期性节律和诱导海马脑组织中的周期性和混沌行为。在将可兴奋介质的原理应用于心脏病学方面也取得了重大成功，这导致了对螺旋波在心动过速和纤颤等心脏疾病中所起作用的理解。肖瓦尔特的研究为这些重要生物现象的机制基础提供了基本的化学理解。

Professor Kenneth Showalter is supported by a grant from the Theoretical and Computational Chemistry Program to continue his work on nonlinear dynamics in chemical systems. The research involves studies of complex chemical dynamics in continuously stirred reactors, in homogeneous and unstirred systems, and distributed chemical systems. Three main lines of research are proposed: 1) developing techniques to control chaos using linear and nonlinear control methods; 2) studies of chemical waves in inhomogeneous and perturbed excitable media; and 3) studies of instabilities in propagating reaction-diffusion fronts. Both experimental and theoretical studies will be performed. One novel experimental project being explored by Showalter is the use of an ink jet printer to prepare patterns of immobilized catalyst for excitable chemical systems. This enables him to study chemical wave behavior in the presence of systematically designed geometric constraints which are models for excitable biological media such as the heart muscle. Nonlinear dynamics is a powerful tool for understanding complexity in nature, and it has many practical applications. Biological applications include stabilizing periodic rhythms in heart tissue and inducing periodic and chaotic behavior in hippocampal brain tissue. Major successes can also be found in applications of the principles of excitable media to cardiology, which have led to an understanding of the role spiral waves play in heart maladies such as tachycardia and fibrillation. Showalter's research provides a fundamental chemical understanding of the mechanistic underpinnings for these important biological phenomena.