Southwest University

About: Southwest University is a education organization based out in Chongqing, China. It is known for research contribution in the topics: Population & Bombyx mori. The organization has 29772 authors who have published 27755 publications receiving 409441 citations. The organization is also known as: Southwest University in Chongqing & SWU.

Facile Synthesis of Carbon-Supported Pd–Co Core–Shell Nanoparticles as Oxygen Reduction Electrocatalysts and Their Enhanced Activity and Stability with Monolayer Pt Decoration

Abstract: The rational synthesis of active, durable, and low-cost catalysts is of particular interest to fuel cell applications. Here, we describe a facile method for the preparation of Pd-rich PdxCo alloy nanoparticles supported on carbon, using an adsorbate-induced surface segregation effect. The electronic properties of Pd were modulated by alloying with different amounts of Co, which affects the oxygen reduction reaction (ORR) activity. The electrocatalytic activity of the Pd3Co@Pd/C nanoparticles for the ORR was enhanced by spontaneously depositing a nominal monolayer of Pt. The activities of the different catalysts for the ORR could be correlated with the oxygen adsorption energy and the d-band center of the catalyst surface, as calculated using density functional theory, which is in agreement with previous theoretical studies. The materials synthesized herein are promising cathode catalysts for fuel cell applications and the facile synthesis method could be readily adapted to other catalyst systems, facilita...

Completion Time and Energy Optimization in the UAV-Enabled Mobile-Edge Computing System

Abstract: Completion time and energy consumption of the unmanned aerial vehicle (UAV) are two important design aspects in UAV-enabled applications. In this article, we consider a UAV-enabled mobile-edge computing (MEC) system for Internet-of-Things (IoT) computation offloading with limited or no common cloud/edge infrastructure. We study the joint design of computation offloading and resource allocation, as well as UAV trajectory for minimization of energy consumption and completion time of the UAV, subject to the IoT devices’ task and energy budget constraints. We first consider the UAV energy minimization problem without predetermined completion time, a discretized nonconvex equivalent problem is obtained by using the path discretization technique. An efficient alternating optimization algorithm for the discretized problem is proposed by decoupling it into two subproblems and addressing the two subproblems with successive convex approximation (SCA)-based algorithms iteratively. Subsequently, we focus on the completion time minimization problem, which is nonconvex and challenging to solve. By using the same path discretization approximation model to reformulate problem, a similar alternating optimization algorithm is proposed. Furthermore, we study the Pareto-optimal solution that balances the tradeoff between the UAV energy and completion time. The simulation results are provided to corroborate this article and show that the proposed designs outperform the baseline schemes. Our results unveil the tradeoff between completion time and energy consumption of the UAV for the MEC system, and the proposed solution can provide the performance close to the lower bound.