Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in prac...Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in practical applications of LCT, there are challenges to image reconstruction due to limited-angle and insufficient data. In this paper, a new reconstruction algorithm based on total-variation （TV） minimization is developed to reconstruct images from limited-angle and insufficient data in LCT. The main idea of our approach is to reformulate a TV problem as a linear equality constrained problem where the objective function is separable, and then minimize its augmented Lagrangian function by using alternating direction method （ADM） to solve subproblems. The proposed method is robust and efficient in the task of reconstruction by showing the convergence of ADM. The numerical simulations and real data reconstructions show that the proposed reconstruction method brings reasonable performance and outperforms some previous ones when applied to an LCT imaging problem.展开更多
Porous electrodes with three-phase reaction in low temperature fuel cells have attracted much attention by their flooding phenomena. In order to have a better understanding of the flooding phenomena inside electrode, ...Porous electrodes with three-phase reaction in low temperature fuel cells have attracted much attention by their flooding phenomena. In order to have a better understanding of the flooding phenomena inside electrode, it is important to evaluate various discharge conditions of the flooded electrodes. A model of flooded porous electrode under the influence of potential sweep was developed to evaluate the flooding conditions in-situ. The hysteresis of current density vs. time was observed at high sweep rates （1 O0 mV.sl）. It was not observed at low sweep rate （0.1 mV-s~）. In this study, these characteristics of flooding and hysteresis conditions were found to be markedly dependent on the potential scan rate. These dynamic behaviors are interpreted in terms of water saturation response, velocity of water movement, and evaporation rate of water.展开更多
基金the National High Technology Research and Development Program of China(Grant No.2012AA011603)
文摘Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in practical applications of LCT, there are challenges to image reconstruction due to limited-angle and insufficient data. In this paper, a new reconstruction algorithm based on total-variation （TV） minimization is developed to reconstruct images from limited-angle and insufficient data in LCT. The main idea of our approach is to reformulate a TV problem as a linear equality constrained problem where the objective function is separable, and then minimize its augmented Lagrangian function by using alternating direction method （ADM） to solve subproblems. The proposed method is robust and efficient in the task of reconstruction by showing the convergence of ADM. The numerical simulations and real data reconstructions show that the proposed reconstruction method brings reasonable performance and outperforms some previous ones when applied to an LCT imaging problem.
文摘Porous electrodes with three-phase reaction in low temperature fuel cells have attracted much attention by their flooding phenomena. In order to have a better understanding of the flooding phenomena inside electrode, it is important to evaluate various discharge conditions of the flooded electrodes. A model of flooded porous electrode under the influence of potential sweep was developed to evaluate the flooding conditions in-situ. The hysteresis of current density vs. time was observed at high sweep rates （1 O0 mV.sl）. It was not observed at low sweep rate （0.1 mV-s~）. In this study, these characteristics of flooding and hysteresis conditions were found to be markedly dependent on the potential scan rate. These dynamic behaviors are interpreted in terms of water saturation response, velocity of water movement, and evaporation rate of water.
