标题： 理论和外部场下柔性及半柔性单聚合物链拉伸的蒙特卡罗模拟 显示英文标题

标题： Theory and Monte Carlo simulations for the stretching of flexible and semi-flexible single polymer chains under external fields

摘要： 最近微观机械实验的发展使得可以通过两种主要方式操控单个聚合物分子：\textit{均匀的}通过外部力拉伸和\textit{非均匀}通过外部场拉伸。 可以由此获得特定种类聚合物和特定几何结构的许多结果。 在本工作中，我们描述了通过外部场（例如均匀运动的流体或均匀电场）对单个非支化聚合物分子进行非均匀拉伸的通用物理框架，该框架得出了关于不同种类聚合物的一般结论。 我们基于经典统计力学推导了自由连接链和蠕虫状链模型的解析结果。 此外，我们提供了对一端固定的柔性及半柔性聚合物机械性能的蒙特卡洛数值分析。 模拟验证了解析结果，并且还可以研究理论无法提供明确和有用结果的情况。 在所有情况下，我们评估了聚合物的平均构象及其波动统计特性作为链长、弯曲刚度和场强的函数。 显示英文摘要

摘要： Recent developments of microscopic mechanical experiments allow the manipulation of individual polymer molecules in two main ways: \textit{uniform} stretching by external forces and \textit{non-uniform} stretching by external fields. Many results can be thereby obtained for specific kinds of polymers and specific geometries. In this work we describe the non-uniform stretching of a single, non-branched polymer molecule by an external field (e.g. fluid in uniform motion, or uniform electric field) by a universal physical framework which leads to general conclusions on different types of polymers. We derive analytical results both for the freely-jointed chain and the worm-like chain models based on classical statistical mechanics. Moreover, we provide a Monte Carlo numerical analysis of the mechanical properties of flexible and semi-flexible polymers anchored at one end. The simulations confirm the analytical achievements, and moreover allow to study the situations where the theory can not provide explicit and useful results. In all cases we evaluate the average conformation of the polymer and its fluctuation statistics as a function of the chain length, bending rigidity and field strength.