Harbin Engineering University

About: Harbin Engineering University is a education organization based out in Harbin, Heilongjiang, China. It is known for research contribution in the topics: Control theory & Microstructure. The organization has 31149 authors who have published 27940 publications receiving 276787 citations. The organization is also known as: HEU.

Self-supported NiMo-based nanowire arrays as bifunctional electrocatalysts for full water splitting

Abstract: Electrochemical water splitting has been considered as an efficient way for the production of clean hydrogen fuel. To achieve high efficiency and reduce the cost of electrolyzers, non-precious bifunctional electrocatalysts, which can operate in the same electrolyte, are highly required. Here, we report a facile method for synthesizing self-supported NiMo nitride nanowire arrays as high-performance, binder-free bifunctional electrocatalysts. The binder-free electrodes exhibit excellent catalytic activities with a current density of 10 mA cm−2 at overpotentials of 22 mV for the hydrogen evolution reaction and 230 mV for the oxygen evolution reaction, respectively. Remarkably, to drive a current density of 10 mA cm−2, the full water splitting system assembled with the self-supported nanowire arrays only needs a cell voltage of 1.507 V, significantly lower than that of the electrolyzer based on Pt/C and IrO2 catalysts (1.540 V). Furthermore, the full water splitting system assembled with the self-supported NiMo nitride nanowire arrays shows an outstanding durability with a negligible current change at a large current density of 370 mA cm−2 for 30 h continuous electrolysis. The results presented here demonstrate that the development of self-supported electrodes is an efficient way for fabricating a high-performance, low-cost, robust and stable full water splitting device.

Stability Analysis and Delay Control for Switched Positive Linear Systems

Abstract: In this paper, the problems of stability analysis and delay control for switched positive linear systems (SPLSs) are studied by using average dwell time (ADT) switching. By developing a new class of multiple piecewise-continuous linear copositive Lyapunov function (MPLCLF) approach, an improved stability condition for SPLSs is obtained, which can obtain a tighter bound on the ADT guaranteeing the stability. The obtained stability condition covers the existing results on stability analysis for SPLSs, since the multiple linear copositive Lyapunov function used in the literature can be viewed as a special case of our proposed MPLCLF, and our result can obtain a tighter bound of the ADT. Then, a more efficient controller design method over the existing ones is also established for SPLSs with switching delay to guarantee the underlying system to be exponentially stable. To illustrate the advantages of our proposed results, two numerical examples are finally given.