Northeastern University (China)

About: Northeastern University (China) is a education organization based out in Shenyang, China. It is known for research contribution in the topics: Control theory & Microstructure. The organization has 36087 authors who have published 36125 publications receiving 426807 citations. The organization is also known as: Dōngběi Dàxué & Northeastern University (东北大学).

Short communication: An effective global harmony search algorithm for reliability problems

Abstract: This paper proposes an effective global harmony search algorithm (EGHS) to solve two kinds of reliability problems: the complex (bridge) system optimization problem and the reliability-redundancy optimization problem of the overspeed protection system for a gas turbine. In general, the two problems are formulated as mixed-integer nonlinear programming problems with several constraints. The EGHS combines harmony search algorithm (HS) with concepts from the swarm intelligence of particle swarm optimization algorithm (PSO) to solve optimization problems. The proposed algorithm has been applied to two typical problems with results better than previously reported. The results have demonstrated that the EGHS has strong convergence and capacity of space exploration on solving reliability optimization problems.

From polybenzimidazoles to polybenzimidazoliums and polybenzimidazolides

Abstract: Polybenzimidazoles represent a large family of high-performance polymers containing benzimidazole groups as part of the structural repeat unit New application areas in electrochemical cells and separation processes have emerged during the last two decades, which has been a major driver for the tremendous development of new polybenzimidazole chemistries and materials in recent years This comprehensive treatise is devoted to an investigation of the structural scope of polybenzimidazole derivatives, polybenzimidazole modifications and the acid–base behavior of the resulting materials Advantages and limitations of different synthetic procedures and pathways are analyzed, with focus on homogeneous solution polymerization The discussion extends to solution properties and the challenges that are faced in connection to molecular weight determination and processing Methods for polybenzimidazole grafting or crosslinking, in particular by N-coupling, are reviewed and successful polymer blend strategies are identified The amphoteric nature of benzimidazole groups further enriches the chemistry of polybenzimidazoles, as cationic or anionic ionenes are obtained depending on the pH In the presence of protic acids, such as phosphoric acid, cationic ionenes in the form of protic polybenzimidazoliums are obtained, which dramatically changes the physicochemical properties of the material Cationic ionenes are also derived by complete N-alkylation of a polybenzimidazole to the corresponding poly(dialkyl benzimidazolium), which has been intensively explored recently as a new direction in the field of anion exchange membranes In the higher end of the pH scale in aqueous hydroxide solutions, anionic ionenes in the form of polybenzimidazolides are obtained as a result of deprotonation of the benzimidazole groups The ionization of the polymer results in dramatically changed physicochemical properties as compared to the pristine material, which is described and discussed From a technological point of view, performance and stability targets continue to motivate further research and development of new polybenzimidazole chemistries and energy materials The overall aim of this review is therefore to identify challenges and opportunities in this area from synthetic chemistry and materials science perspectives to serve as a solid basis for further development prospects

A Self-Powered Wearable Noninvasive Electronic-Skin for Perspiration Analysis Based on Piezo-Biosensing Unit Matrix of Enzyme/ZnO Nanoarrays

Abstract: The emerging multifunctional flexible electronic-skin for establishing body–electric interaction can enable real-time monitoring of personal health status as a new personalized medicine technique. A key difficulty in the device design is the flexible power supply. Here a self-powered wearable noninvasive electronic-skin for perspiration analysis has been realized on the basis of a piezo-biosensing unit matrix of enzyme/ZnO nanoarrays. The electronic-skin can detect lactate, glucose, uric acid, and urea in the perspiration, and no outside electrical power supply or battery is used in the biosensing process. The piezoelectric impulse of the piezo-biosensing units serves as the power supply and the data biosensor. The working mechanism can be ascribed to the piezoelectric-enzymatic-reaction coupling effect of enzyme/ZnO nanowires. The electronic-skin can real-time/continuously monitor the physiological state of a runner through analyzing the perspiration on his skin. This approach can promote the development...