Dalian University of Technology

About: Dalian University of Technology is a education organization based out in Dalian, China. It is known for research contribution in the topics: Catalysis & Finite element method. The organization has 60890 authors who have published 71921 publications receiving 1188356 citations. The organization is also known as: Dàlián Lǐgōng Dàxué.

CO2 Electroreduction at Low Overpotential on Oxide-Derived Cu/Carbons Fabricated from Metal Organic Framework.

Abstract: Electrochemical reduction of CO2 to chemical feedstocks is an attractive solution that prevents CO2 accumulation in the atmosphere, but it remains a great challenge to develop the cost-effective catalysts. Herein, we synthesized oxide-derived Cu/carbon (OD Cu/C) catalysts by a facile carbonization of Cu-based MOF (HKUST-1). The resulting materials exhibited highly selective CO2 reduction to alcohol compounds with total faradic efficiencies of 45.2–71.2% at −0.1 to −0.7 V versus reversible hydrogen electrode (RHE). High-yield methanol and ethanol has been achieved on OD Cu/C-1000 with the production rates of 5.1–12.4 and 3.7–13.4 mg L–1 h–1, respectively. Notably, the onset potential for C2H5OH formation is near −0.1 V (versus RHE), corresponding to ∼190 mV of overpotential, which is among the lowest overpotentials reported to date for the reduction of CO2 to C2H5OH. The improvements in activity and selectivity of the oxide-derived Cu/carbon might be attributed to the synergistic effect between the highly ...

Adaptive Fuzzy Finite-Time Control of Nonlinear Systems With Actuator Faults

Abstract: This paper addresses the trajectory tracking control problem of a class of nonstrict-feedback nonlinear systems with the actuator faults. The functional relationship in the affine form between the nonlinear functions with whole state and error variables is established by using the structure consistency of intermediate control signals and the variable-partition technique. The fuzzy control and adaptive backstepping schemes are applied to construct an improved fault-tolerant controller without requiring the specific knowledge of control gains and actuator faults, including both stuck constant value and loss of effectiveness. The proposed fault-tolerant controller ensures that all signals in the closed-loop system are semiglobally practically finite-time stable and the tracking error remains in a small neighborhood of the origin after a finite period of time. The developed control method is verified through two numerical examples.

Joint Trajectory and Precoding Optimization for UAV-Assisted NOMA Networks

Abstract: The explosive data traffic and connections in 5G networks require the use of non-orthogonal multiple access (NOMA) to accommodate more users. Unmanned aerial vehicle (UAV) can be exploited with NOMA to improve the situation further. In this paper, we propose a UAV-assisted NOMA network, in which the UAV and base station (BS) cooperate with each other to serve ground users simultaneously. The sum rate is maximized by jointly optimizing the UAV trajectory and the NOMA precoding. To solve the optimization, we decompose it into two steps. First, the sum rate of the UAV-served users is maximized via alternate user scheduling and UAV trajectory with its interference to the BS-served users below a threshold. Then, the optimal NOMA precoding vectors are obtained using two schemes with different constraints. The first scheme intends to cancel the interference from the BS to the UAV-served user, while the second one restricts the interference to a given threshold. In both schemes, the non-convex optimization problems are converted into tractable ones. An iterative algorithm is designed. Numerical results are provided to evaluate the effectiveness of the proposed algorithms for the hybrid NOMA and UAV network.