正二十面体壳体屈曲转变附近的软模式
摘要：Icosahedral shells undergo a buckling transition as the ratio of Young's modulus to bending stiffness increases. Strong bending stiffness favors smooth, nearly spherical shapes, while weak bending stiffness leads to a sharply faceted icosahedral shape. The transition from smooth to faceted is interpreted as a soft-mode transition based on the phonon spectrum of a simplified mass-and-spring model of the shell. The mean curvature of the sphere smooths the transition, in contrast to a disclinated planar network. Elastic susceptibilities are defined as the response to forces applied at vertices, edges, and faces of an icosahedron. At the soft-mode transition, the vertex susceptibility is the largest, but as the shell becomes more faceted, the edge and face susceptibilities greatly exceed the vertex susceptibility. The limiting behaviors of the susceptibilities are analyzed and related to the ridge-scaling behavior of elastic sheets. These results are applicable to virus capsids, liposomes with crystalline order, and other shell-like structures with icosahedral symmetry.
作者：M. Widom, J. Lidmar and D. R. Nelson
论文ID：0706.4291
分类：Biological Physics
分类简称：physics.bio-ph
提交时间：2009-11-13