Buckling of stiff polymers: Influence of thermal fluctuations
Buckling of stiff polymers: Influence of thermal fluctuations
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DOI：
10.1103/physreve.76.061907
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发表时间：
2007-12-01
影响因子：
2.4
通讯作者：
Kulic, Igor M.
中科院分区：
文献类型：
--
作者：
Emanuel, Marc;Mohrbach, Herve;Kulic, Igor M.
生物高分子的屈曲是一个经常被研究的现象，然而，热波动对屈曲转变的影响往往被忽略，也没有完全理解。基于配分函数的半经典近似，提出了蠕虫链屈曲的定量理论。热波动的贡献的力的延伸关系，允许一个超越经典的欧拉屈曲推导出的线性和非线性制度以及。结果表明，在非线性屈曲制度的热波动增加的半柔性杆的端到端的距离，如果它被限制到两个维度，而不是三维的情况下。在有限的温度下，向屈曲状态的转变软化。我们推导出了随着轮廓长度与持续长度之比的增加，过渡位移的标度行为。
The buckling of biopolymers is a frequently studied phenomenon The influence of thermal fluctuations on the buckling transition is, however, often ignored and not completely understood. A quantitative theory of the buckling of a wormlike chain based on a semiclassical approximation of the partition function is presented. The contribution of thermal fluctuations to the force-extension relation that allows one to go beyond the classical Euler buckling is derived in the linear and nonlinear regimes as well. It is shown that the thermal fluctuations in the nonlinear buckling regime increase the end-to-end distance of the semiflexible rod if it is confined to two dimensions as opposed to the three-dimensional case. The transition to a buckled state softens at finite temperature. We derive the scaling behavior of the transition shift with increasing ratio of contour length versus persistence length.