Aharonov-Bohm spectral features and coherence lengths in carbon nanotubes

The electronic properties of carbon nanotubes are investigated in the presence of disorder and a magnetic field parallel or perpendicular to the nanotube axis. In the parallel field geometry, the $\phi_{0}(=hc/e)$-periodic metal-insulator transition (MIT) induced in metallic or semiconducting nanotubes is shown to be related to a chirality-dependent shifting of the energy of the van Hove singularities (VHSs). The effect of disorder on this magnetic field-related mechanism is considered with a discussion of mean free paths, localization lengths and magnetic dephasing rate in the context of recent experiments.Comment: 22 pages, 6 Postscript figures. submitted to Phys. Rev.

Removing border protection on wheat and rice: effects on rural income and food self-sufficiency in China *

In this paper, I use the Monash Multi-Country model - a dynamic Computable General Equilibrium model of China, Australia and the Rest of the World - to analyse the effects of removing border protection on wheat and rice in China. The analysis points to the possibility that removing border protection on wheat and rice may lead to an increase in rural income in China. This is mainly due to the following two factors. First, removing border protection on wheat and rice not only leads to a contraction in agricultural activities, but also leads to an expansion in manufacturing and services activities. Second, on average, rural households in China obtain over half of their income from manufacturing and services activities. Copyright 2008 The Author. Journal compilation 2008 Australian Agricultural and Resource Economics Society Inc. and Blackwell Publishing Ltd.