AI 中文总结
研究粘弹性流体中胶体模型的随机动力学，发现来回跳动可利用流体记忆使跳动频率增加，单向旋转运动则相反，揭示了主动振荡器利用流体记忆的机制，为聚合物流体中鞭毛跳动增强提供解释。
AI 中文摘要
纤毛和鞭毛跳动常发生在粘弹性流体中，周围流体强烈影响跳动动力学，但粘弹性对跳动动力学的影响仍知之甚少。本文研究了杰弗里斯流体中实验实现的胶体模型的随机动力学。发现来回跳动会使驱动力和聚合物力暂时对齐，一旦流体记忆与冲程持续时间可比，跳动频率会迅速增加，且跳动周期波动有最大值。而单向旋转运动时，跳动会随流体记忆增加而减慢。结果表明来回跳动是主动振荡器利用流体记忆的通用机制，为聚合物流体中鞭毛跳动增强提供了解释。
英文摘要
Ciliary and flagellar beating often occurs in viscoelastic fluids. The surrounding fluid strongly influences the beating dynamics. Viscoelastic effects on beating dynamics, however, remain poorly understood. Here, we investigate the stochastic dynamics of experimentally realized colloidal models in a Jeffreys fluid. We find that back-and-forth beating transiently aligns the driving and polymeric forces, leading to a rapid increase in the beating frequency once the fluid memory becomes comparable to the stroke duration. The crossover is marked by a maximum in beating-period fluctuations. For unidirectional rotational motion, however, beating slows down with increasing fluid memory. Our results identify back-and-forth beating as a generic mechanism for exploiting fluid memory in active oscillators, providing a possible explanation for enhanced flagellar beating in polymeric fluids.
Comments6 pages, 4 figures
