A controllable water transfer rate across a tandem carbon nanotube

Water permeation across a carbon nanotube is important in carbon-based nanodevices. Water transfer rate is closely related to the radius of a carbon nanotube. It is hard to change water transfer rate by interior methods once the radius of the entrance of a carbon nanotube is chosen. In this paper, water transfer across a tandem carbon nanotube with a separation is investigated by molecular dynamics simulations. We find that water transfer rate experiences two different transfer behaviors: an increasing behavior and a decreasing behavior by changing the separation length. The result is important in designing a controllable carbon-based nanodevice.

A Globally Convergent Filter-Type Trust Region Method for Semidefinite Programming

When using interior methods for solving semidefinite programming (SDP), one needs to solve a system of linear equations at each iteration. For problems of large size, solving the system of linear equations can be very expensive. In this paper, based on a semismooth equation reformulation using Fischer's function, we propose a filter method with trust region for solving large-scale SDP problems. At each iteration we perform a number of conjugate gradient iterations, but do not need to solve a system of linear equations. Under mild assumptions, the convergence of this algorithm is established. Numerical examples are given to illustrate the convergence results obtained.