摘要

The numerical and the analytical studies of the opening-up vesicles have become hot topics since the experimental observation by A. Saitoh et al. This paper deals with how to obtain the analytical solution of an opening-up shape from the Ouyang biconcave analytical solution. We find only two of the three boundary conditions for the vesicle rims to be independent. The second boundary condition can be satisfied by the Gaussian bending modulus k(g) = -2, then we obtain the geometric equation for the rims of an opening-up vesicle from the first boundary condition. By analyzing the Ouyang analytic solutions for a closed circular biconcave vesicle and periodic noduloidlike vesicle, we obtain three kinds of shapes with tube topology, which are the convex tube, the toruslike tube, and the catenoidlike tube.