Nanjing University of Science and Technology

About: Nanjing University of Science and Technology is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Computer science. The organization has 31581 authors who have published 36390 publications receiving 525474 citations. The organization is also known as: Nánjīng Lǐgōng Dàxué & Nánlǐgōng.

H/sub /spl infin// state feedback control for discrete singular systems

Abstract: Deals with the problem of state feedback H/sub /spl infin// control for discrete singular systems It is not assumed that the singular system under consideration is necessarily regular The problem we address is the design of a state feedback controller, such that the resulting closed-loop system is not only regular, causal, and stable, but also satisfies a prescribed H/sub /spl infin//-norm-bound condition In terms of certain matrix inequalities, a necessary and sufficient condition for the solution to this problem is obtained, and a suitable state feedback-control law is also given

A piecewise analysis method to stability analysis of linear continuous/discrete systems with time‐varying delay

Abstract: The delay-dependent stability problem of linear continuous/discrete systems with time-varying delay is investigated based on a piecewise analysis method (PAM). In the method, the variation interval of the time delay is firstly divided into several subintervals. By checking the variation of the Lyapunov functional in every subinterval, some new delay-dependent stability criteria are derived. Several numerical examples show that our method can lead to much less conservative results than those in the existing references. Moreover, when the number of the divided subintervals increases, the corresponding criteria can provide an improvement on the results. Copyright © 2008 John Wiley & Sons, Ltd.

Experimental and Theoretical Study on the Inhibition Performances of Quinoxaline and Its Derivatives for the Corrosion of Mild Steel in Hydrochloric Acid

Abstract: The inhibition of mild steel corrosion in 1.0 M HCl solution by quinoxaline and its derivatives were evaluated at 25 °C using weight loss measurement and Tafel polarization technique. These measurements reveal that the inhibition efficiency increased with increase in the concentrations of inhibitors, and the inhibition efficiencies decrease in the order 4-(quinoxalin-2-yl)phenol (PHQX) > 2-quinoxalinethiol (THQX) > 2-chloroquinoxaline (CHQX) > quinoxaline (QX). Tafel polarization curves show that all the investigated inhibitors act as mixed-type inhibitors. Quantum chemical calculation was applied to correlate electronic structure parameters of quinoxaline and its derivatives with their inhibition performances. Molecular dynamics simulations were also used to optimize the equilibrium configurations of the inhibitor molecules on the iron surface. The efficiency order of the studied inhibitors obtained by experimental results was verified by theoretical calculations.

First-principles band gap criterion for impact sensitivity of energetic crystals: a review

Abstract: In this article, we review some recent studies in predicting impact sensitivity for different classes of energetic crystals based on first-principles band gap. Based on these investigations on metal azides, a first-principles band gap criterion is founded to measure impact sensitivity for a series of energetic crystals. For energetic crystals with similar structure or with similar thermal decomposition mechanism, the smaller the band gap is, the easier the electron transfers from the valence band to the conduction band, and the more they becomes decomposed and exploded. Applications of this criterion on other series of energetic crystals show that the first-principles band gap criterion is applicable to different series of energetic crystals with similar structure or with similar thermal decomposition mechanism. This criterion may be useful for molecular design of high-energy density materials.

GeSe monolayer semiconductor with tunable direct band gap and small carrier effective mass

Abstract: Two dimensional materials, befitting nanoscale electronics, can benefit strain-tunable applications due to their ultrathin and flexible nature. Based on the first-principles calculations within the generalized gradient approximation, GeSe monolayer with a distorted NaCl-type structure is predicted. The GeSe monolayer is found to be a direct semiconductor with a band gap of (1.16 ± 0.13) eV against the bulk counterpart. The electronic responses of the GeSe monolayer to strain are found to be sensitive and anisotropic, and the transitions between direct and indirect band gap are repeatedly met in the course of energy engineering by uniaxial and biaxial strains. The direct band gap of the GeSe monolayer is tunable by small strain within a large energy range (0.95–1.48 eV). The carrier effective masses in the GeSe monolayer are also tunable by strain in a low mass range (0.03–0.61 m0). These intriguing properties make GeSe monolayer a promising two-dimensional material for nanomechanics, thermoelectrics, and ...