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).

Discrete harmony search algorithm for flexible job shop scheduling problem with multiple objectives

Abstract: Flexible job-shop scheduling problem (FJSP) is a practically useful extension of the classical job shop scheduling problem. This paper proposes an effective discrete harmony search (DHS) algorithm to solve FJSP. The objectives are the weighted combination of two minimization criteria namely, the maximum of the completion time (Makespan) and the mean of earliness and tardiness. Firstly, we develop a new method for the initial machine assignment task. Some existing heuristics are also employed for initializing the harmony memory with discrete machine permutation for machine assignment and job permutation for operation sequencing. Secondly, we develop a new rule for the improvisation to produce a new harmony for FJSP incorporating machine assignment and operation sequencing. Thirdly, several local search methods are embedded to enhance the algorithm's local exploitation ability. Finally, extensive computational experiments are carried out using well-known benchmark instances. Computational results and comparisons show the efficiency and effectiveness of the proposed DHS algorithm for solving the FJSP with weighted combination of two objectives.

Ostwald Ripening Improves Rate Capability of High Mass Loading Manganese Oxide for Supercapacitors

Abstract: Realizing fast charging–discharging for high mass loading pseudocapacitive materials has been a great challenge in the field of supercapacitors because of the sluggish electron and ion migration kinetics through the thick electrode materials. Here we demonstrate for the first time a facile hydrothermal treatment that can substantially enhance the rate capability of a highly loaded manganese oxide electrode via the Ostwald ripening process. Hydrothermal treatment improves not only the electrical conductivity of manganese oxide but also the ion diffusion rate in the thick oxide film. At slow scan rates below 40 mV s–1, the capacitance of the hydrothermally treated manganese oxide electrode increases linearly with mass loading (up to 23.5 mg cm–2) as expected for a capacitor under the non-diffusion-limited conditions. At high scan rates beyond 100 mV s–1, capacitive saturation is observed only at a high mass loading of ∼9 mg cm–2, which is significantly greater than the values reported for other manganese ox...

A nanosized SnSb alloy confined in N-doped 3D porous carbon coupled with ether-based electrolytes toward high-performance potassium-ion batteries

Abstract: Potassium-ion batteries (PIBs) have been considered as a promising new-generation energy storage device because they can be used as a replacement or complement to lithium-ion batteries. However, the large radius and the sluggish diffusion kinetics of K+ make it a great challenge to develop high-performance electrode materials for PIBs. Herein, a novel nanocomposite of SnSb alloy confined in N-doped three-dimensional porous carbon (3D SnSb@NC) is fabricated by using the NaCl template-assisted in situ pyrolysis strategy and investigated as an anode for PIBs based on dimethoxyethane (DME)-based and conventional ester-based (EC/DEC) electrolytes. The uniformly anchored SnSb nanoparticles could effectively alleviate dramatic volume variation during potassiation/depotassiation owing to the synergistic effect of Sn and Sb. N-doped 3D porous carbon prevents the aggregation of SnSb nanoparticles, provides abundant active sites for K+, facilitates sufficient infiltration of the electrolyte, and serves as a conductive network to accelerate the electron transport. Moreover, the DME-based electrolyte shows superior wettability to the 3D SnSb@NC electrode and forms a thinner SEI film, resulting in negligible surface film impedance and reduced charge transfer impedance. Consequently, the rational 3D SnSb@NC structure coupled with an optimized DME-based electrolyte makes PIBs deliver a high reversible capacity of 357.2 mA h g−1 at 50 mA g−1, an remarkable initial coulombic efficiency (ICE) of 90.1%, good rate capability, and excellent cycling stability with a capacity retention of 80% after 200 cycles at 0.5 A g−1. This work presents an advanced concept for designing multifunctional anode materials with compatible electrolytes for high-performance PIBs.

Large Magnetostriction from Morphotropic Phase Boundary in Ferromagnets

Abstract: For more than half of a century, morphotropic phase boundary (MPB) in ferroelectric materials has drawn constant interest because it can significantly enhance the piezoelectric properties. However, MPB has been studied merely in ferroelectric systems, not in another large class of ferroic systems, the ferromagnets. In this Letter, we report the existence of an MPB in a ferromagnetic system TbCo2-DyCo2. Such a magnetic MPB involves a first-order magnetoelastic transition, at which both magnetization direction and crystal structure change simultaneously. The MPB composition demonstrates a 3-6 times larger "figure of merit" of magnetostrictive response compared with that of the off-MPB compositions. The finding of MPB in ferromagnets may help to discover novel high-performance magnetostrictive and even magnetoelectric materials.