Collective Behavior and Spatiotemporal Dynamics in Chemical Systems

在这个由化学系化学结构、动力学和机制项目资助的项目中，西弗吉尼亚大学的Kenneth Showalter教授和他的学生将研究三个主要研究方向：(i)自推进粒子的动力学和集体行为，（ii）沉淀反应中传播的靶波和螺旋波，以及（iii）耦合化学振荡子群体中的同步行为。在第一个项目中，研究自推进粒子群体中的集体行为，例如过氧化氢溶液中的pt -二氧化硅粒子，以确定粒子间相互作用的机制。基于酶催化和表面催化反应的新型自推进粒子体系正在被开发，n-mer粒子聚集体的运动正在被表征。在第二个项目中，对最近发现的NaOH-AlCl3反应沉淀锋中的传播波进行了研究。引起传播波行为的正反馈正在得到表征，并且正在开发具有传播波的新降水系统。第三个项目涉及耦合化学振荡子的种群和网络的研究。通过在无催化剂的Belousov-Zhabotinsky反应混合物中使用负载催化剂的光敏粒子，实验和计算研究了理论预测的嵌合体状态，即同步和非同步振荡子共存亚群。用峰值时序相关可塑性算法控制的仿生振子网络中链路权的自优化问题也得到了研究。所有这三个研究方向都有望产生关于化学系统中的集体行为和时空动力学的新的重要信息，并为生物系统中的动态行为提供有价值的见解。对自推进粒子的研究将为生物单细胞生物（如细菌和藻类）的推进和相互作用提供机制见解。在降水系统中传播靶波和螺旋波的研究将提供依赖于介质结构特征的化学波传播的新机制，就像许多生物系统中的波传播一样。研究同步和非同步耦合化学振子共存的新状态以及化学振子网络中的自优化，有助于深入了解生命系统中普遍存在的基本动力学行为。该研究项目将研究和教学整合到大学课程中，预计将对当地产生广泛的影响。通过包括国际理论物理中心在内的外联活动，这项工作的影响进一步扩大，这些活动为亚洲、非洲、南美洲和中美洲发展中国家的科学家带来了实际的研究经验。

In this project, funded by the Chemical Structure, Dynamics and Mechanisms Program of the Division of Chemistry, the Professor Kenneth Showalter of West Virginia University and his students will investigate three main lines of research: (i) the dynamics and collective behavior of self-propelled particles, (ii) the propagating target and spiral waves in precipitation reactions, and (iii) the synchronization behavior in populations of coupled chemical oscillators. In the first project, studies of collective behavior in populations of self-propelled particles, such as Pt-silica particles in hydrogen peroxide solutions, are carried out to determine the mechanism of inter-particle interactions. New self-propelled particle systems based on enzyme catalysis and surface catalyzed reactions are being developed and the motion of n-mer particle aggregates is being characterized. In the second project, studies of recently discovered propagating waves in the precipitation front of the NaOH-AlCl3 reaction are conducted. The positive feedback giving rise to the propagating wave behavior is being characterized and new precipitation systems exhibiting propagating waves are being developed. The third project involves studies of populations and networks of coupled chemical oscillators. The theoretically predicted chimera state, with coexisting subpopulations of synchronized and unsynchronized oscillators, is studied experimentally and computationally by using light-sensitive, catalyst-loaded particles in catalyst-free Belousov-Zhabotinsky reaction mixtures. Self-optimization of link weights in biomimetic networks of oscillators controlled with an algorithm for spike-timing dependent plasticity is also being studied. All three lines of research are expected to yield new and important information about collective behavior and spatiotemporal dynamics in chemical systems and offer valuable insights into dynamic behavior in biological systems. The studies of self-propelled particles will provide mechanistic insights into the propulsion and interaction of biological unicellular organisms, such as bacteria and algae. The studies of propagating target and spiral waves in precipitation systems will offer new mechanisms for chemical wave propagation that rely on structural features of the medium, much like wave propagation in many biological systems. The studies of new states of coexisting synchronized and unsynchronized coupled chemical oscillators and self-optimization in networks of chemical oscillators provide insights into basic dynamical behaviors pervasive in living systems. The research program is expected to have a broad local impact from the integration of research and teaching into the university curriculum. The impact of the work is further broadened through outreach activities involving the International Center for Theoretical Physics that bring hands-on research experiences to scientists in developing countries in Asia, Africa, and South and Central America.