[1] This paper presents a computational approach to the imaging of a partially immersed perfectly conducting cylinder by the steady state genetic algorithm. A conducting cylinder of unknown shape scatters the incident transverse magnetic (TM) wave in free space while the scattered field is recorded in free space. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an optimization problem. An improved steady state genetic algorithm is employed to search for the global extreme solution. Numerical results demonstrate that, even when the initial guess is far away from the exact one, good reconstruction can be obtained. Numerical results also show that the reconstructed image in the free space area is better than that in the medium area.
The time dependence of the decay of dark electrical conductivity σ(t) from C60 crystals under air exposure was investigated at different temperatures. The decay of σ(t) can be fitted via a stretched exponential function, indicating that the diffusion of O2 in C60 crystal follows a hierarchically constrained dynamic. The diffusivity of molecular oxygen in C60 crystal is estimated using the least-square fitted time constant, and an activation energy EA=1.5eV corresponding to the diffusion process is deduced from the Arrhenius plot. The mechanism of the diffusion process is then discussed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.