摘要
刚度是衡量材料弹性变形难易程度的一个定量表征参数,与DNA纳米管静动力学特性及其结构生物功能密切相关.本文致力于研究DNA纳米管的扭转刚度.首先,在六角形均匀封装条件下,考虑到单个DNA杆件弯扭组合问题的静不定特点,我们利用平衡方程、变形协调方程和弹性本构方程,合理预测了DNA纳米管扭转实验中单个DNA杆件的弯扭组合变形,由此给出了DNA纳米管扭转刚度预测的解析模型.最后的结果表明,随着DNA杆数的增加,DNA纳米管的弯曲刚度显著增加,而其扭转刚度却几乎不变,合理解释了扭转实验中发现的现象.相关结论为DNA折叠结构的设计和应用提供了参考.
Stiffness is a quantitive characterization of the elastic deformation of the material, which is closely related to the static and dynamic characteristics of a DNA nanotube and its structural bio-functions. This paper focuses on the torsional rigidity of a DNA nanotube. First, under the condition of the hexagonal homogenous packing, considering the statically indeterminate characteristic for bending-torsional coupling problem of a single DNA bar, the bending-torsional coupling deformation of a single DNA bar in the torsional experiment of DNA nanotubes was accurately predicted by using the equilibrium equations, the deformation compatibility equations and the elastic constitutive equations. An analytical model for predicting the torsional rigidity of a DNA nanotube was thereafter presented. The results show that the bending rigidity is greatly increased whereas the torsional rigidity is almost not changed with increase of the number of DNA bars, which well explains the phenomenon found in the torsional experiment. The related conclusion can provide useful information for design and application of DNA folding structures.
作者
卢伟
李孝斌
张乘胤
张能辉
LU Wei;LI Xiaobing;ZHANG Chengyin;ZHANG Nenghui(Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China;Department of Mechanics, College of Sciences, Shanghai University, Shanghai 200444, China)
出处
《力学季刊》
CSCD
北大核心
2018年第1期33-38,共6页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(11772182
11272193
10872121)
上海市浦江人才计划项目(15PJD016)
关键词
DNA折叠
弯扭耦合
静不定问题
扭转刚度
DNA folding
bending-torsional coupling
statically indeterminate problem
torsional rigidity
