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: Microstructure & Control theory. 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).

Dual templating fabrication of hierarchical porous three-dimensional ZnO/carbon nanocomposites for enhanced photocatalytic and photoelectrochemical activity

Abstract: Herein, a novel fabrication strategy to synthesize the ZnO/C nanocomposite with hierarchical porous structure was proposed with dual templating method that combines both ice and micelle templating. The composite material annealed at 900 °C showed the best photocatalytic reactivity for organic dye degradation compared with samples annealed at other temperatures, which is 2.2/7.0 times of the control ZnO + C sample under UV and visible light irradiation. The sample also showed superior photoelectrochemical performance while ultrasonic assisted photodegradation of methylene blue was also observed. This work demonstrates a novel and feasible approach for processing ZnO based photocatalysts with enhanced reactivity, which can be extended to the design of a broad series of functional metal oxide composites with high electrochemical performance for energy applications.

Discrete-Time Nonzero-Sum Games for Multiplayer Using Policy-Iteration-Based Adaptive Dynamic Programming Algorithms

Abstract: In this paper, we investigate the nonzero-sum games for a class of discrete-time (DT) nonlinear systems by using a novel policy iteration (PI) adaptive dynamic programming (ADP) method. The main idea of our proposed PI scheme is to utilize the iterative ADP algorithm to obtain the iterative control policies, which not only ensure the system to achieve stability but also minimize the performance index function for each player. This paper integrates game theory, optimal control theory, and reinforcement learning technique to formulate and handle the DT nonzero-sum games for multiplayer. First, we design three actor-critic algorithms, an offline one and two online ones, for the PI scheme. Subsequently, neural networks are employed to implement these algorithms and the corresponding stability analysis is also provided via the Lyapunov theory. Finally, a numerical simulation example is presented to demonstrate the effectiveness of our proposed approach.

A memetic particle swarm optimization algorithm for multimodal optimization problems

Abstract: In this paper, a new memetic algorithm, which combines PSO and local search technique, is proposed for mul-timodal optimization problems. In the investigated algorithm, a local PSO model is used to disperse the individuals into different sub-regions, an adaptive local search method is employed to refine the quality of individuals and a triggered re-initialization scheme is introduced to enhance the algorithm's capacity of solving functions with numerous optima. Experimental results based on a set of benchmark functions show that the proposed memetic algorithm is a good optimizer in multimodal optimization domain.

Exponential Stability and Stabilization of Delayed Memristive Neural Networks Based on Quadratic Convex Combination Method

Abstract: This paper is concerned with the exponential stability and stabilization of memristive neural networks (MNNs) with delays. First, we present some generalized double-integral inequalities, which include some existing inequalities as their special cases. Second, combining with quadratic convex combination method, these double-integral inequalities are employed to formulate a delay-dependent stability condition for MNNs with delays. Third, a state-dependent switching control law is obtained for MNNs with delays based on the proposed stability conditions. The desired feedback gain matrices are accomplished by solving a set of linear matrix inequalities. Finally, the feasibility and effectiveness of the proposed results are tested by two numerical examples.

Novel microwave-assisted solvothermal synthesis of NaYF4:Yb,Er upconversion nanoparticles and their application in cancer cell imaging.

Abstract: This work reports the novel microwave-assisted solvothermal synthesis and structural, topographic, spectroscopic characterization of NaYF4:Yb,Er upconversion nanoparticles (UCNPs) as well as their application in the labeling of HeLa cells. The nanoparticles were prepared in ethylene glycol, with rare earth acetates as precursor and NH4F and NaCl as the fluorine and sodium sources. X-ray diffraction, transmission electron microscopy, and luminescence spectroscopy were applied to characterize the nanoparticles. Experimental results showed that the microwave-assisted solvothermal method is an effective approach to create highly crystalline, strongly luminescent UCNPs at a lower temperature (160 °C) and within a significantly shortened reaction time (only 1 h) compared to the traditional methods. The effect of fluorine source on the optical properties of UCNPs was investigated by using NH4F, NH4HF2, NaF, and 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4) as different fluorine sources; NH4F proved to ...