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Mechanical-electro-magnetic coupling in strained bilayer CrI3

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Science China(Technological Sciences) 2020年第7期63卷 1265-1271页

作者： ZHANG ShuQing zou x.aoLong CHENG HuiMing Shenzhen Geim Graphene Center(SGC) Tsinghua-Berkeley Shenzhen Institute(TBSI)&Tsinghua Shenzhen International Graduate School(TSIGS)Tsinghua UniversityShenzhen 518055China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

The discovery of intrinsic 2D ferromagnets provides ex.iting possibilities for spintronics applications. A particularly attractive ex.mple is CrI3, whose monolayer is ferromagnetic while bilayer shows antiferromagnetic coupling. Because of weak interlayer coupling, the magnetism of bilayer CrI3 can be easily modulated by ex.ernal perturbations, such as gating or pressure. Here, we constructed a magnetic phase diagram of bilayer CrI3 under arbitrary biax.al strain(within ±4%) from compression to stretch,and found that compressive strain can effectively convert the antiferromagnetic coupling of bilayer CrI3 to *** analyses on electronic structure were then performed to unravel the underlying mechanism of the magnetic phase transition. It was shown that both band gap and orbital composition at conduction band minimum play important roles in determining magnetic ground states of strained bilayer CrI3. These results strengthen our understanding of the interlayer magnetism of 2D magnets and provide a feasible way to modulate the magnetism in 2D layered materials.

关键词： bilayer Crl3 magnetic coupling strain band gap orbital composition

Model-driven full system dynamics estimation of PMSM-driven chain shell magazine

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Defence Technology（防务技术） 2024年第9期39卷 147-156页

作者： Kai Wei Longmiao Chen Quan zou School of Mechanical Engineering NanJing University of Science and TechnologyNanjing210094China

Based on the system dynamic model, a full system dynamics estimation method is proposed for a chain shell magazine driven by a permanent magnet synchronous motor(PMSM). An adaptive ex.ended state observer(AESO) is proposed to estimate the unmeasured states and disturbance, in which the model parameters are adjusted in real time. Theoretical analysis shows that the estimation errors of the disturbances and unmeasured states converge ex.onentially to zero, and the parameter estimation error can be obtained from the ex.ended state. Then, based on the ex.ended state of the AESO, a novel parameter estimation law is designed. Due to the convergence of AESO, the novel parameter estimation law is insensitive to controllers and ex.itation signal. Under persistent ex.itation(PE) condition, the estimated parameters will converge to a compact set around the actual parameter value. Without PE signal, the estimated parameters will converge to zero for the ex.ended state. Simulation and ex.erimental results show that the proposed method can accurately estimate the unmeasured states and disturbance of the chain shell magazine, and the estimated parameters will converge to the actual value without strictly continuous PE signals.

关键词： Chain shell magazine Full system dynamics estimation Disturbance estimation Parameter estimation Adaptive ex.ended state observer

Nitrogen and ox.gen co-doped mesoporous carbon spheres as capacitive anode for high performance sodium-ion capacitors

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Journal of Materials Science & Technology 2021年第24期83卷 188-195页

作者： Chunhai Jiang Wenyang Zhou Zhimin zou Fujian Provincial Key Laboratory of Functional Materials and Applications Institute of Advanced Energy MaterialsSchool of Materials Science and EngineeringXiamen University of TechnologyXiamen361024China

The poor rate capability of battery-type anode is usually the bottleneck of the power-energy outputs of a hybrid alkaline metal ion *** this work,nitrogen and ox.gen co-doped mesoporous carbon spheres with ex.ellent rate performance and cycle stability are used as anode materials of sodium ion capacitors(SICs).The high N and O element doping levels as well as the amorphous and mesoporous structure have enabled prominent capacitive Na ion storage behavior,which in turn match well with the capacitive cathode in the hybrid *** optimum conditions,the SIC delivers a high energy density of 103.1 Wh kg^(-1)at a power density of 205.6 W kg^(-1).Even at a high power density of 7520 W kg^(-1),an energy density of 23.5 Wh kg^(-1)is still ***,a robust cycle stability with capacity retention of 84.6%after 2500 cycles at 1 A g^(-1)is *** ex.ellent electrochemical performances convincingly demonstrate that the all-carbon based SICs with the highly capacitive N and O co-doped mesoporous carbon anode can be promising Na ion-based energy storage devices alternative to their Li ion-based counterparts.

关键词： N and O co-doping Carbon anode Na-ion capacitors Energy density Cycle stability

Continuous deacylation of amides in a high-temperature and high-pressure microreactor

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Frontiers of Chemical Science and Engineering 2022年第12期16卷 1818-1825页

作者： Pengcheng zou Kai Wang Guangsheng Luo State Key Lab of Chemical Engineering Department of Chemical EngineeringTsinghua UniversityBeijing 100084China

The deacylation of amides,which is widely employed in the pharmaceutical industry,is not a fast reaction under normal *** intensify this reaction,a high-temperature and high-pressure continuous microreaction technology was developed,whose space-time yield was 49.4 times that of traditional batch *** the deacylation of acetanilide as a model reaction,the effects of the temperature,pressure,reaction time,molar ratio of reactants,and water composition on acetanilide conversion were carefully *** on the rapid heating and cooling capabilities,the kinetics of acetanilide deacylation at high temperatures were investigated to determine the orders of reactants and activation *** microreaction technology was further applied to a variety of other amides to understand the influence of substituents and steric hindrance on the deacylation reaction.

关键词： amide deacylation microreactor flow chemistry reaction intensification

Bending results of graphene origami reinforced doubly curved shell

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Defence Technology（防务技术） 2024年第5期35卷 198-210页

作者： Nan Yang Yunhe zou Mohammad Arefi School of Architecture and Civil Engineering Qiqihar UniversityQiqihar 161006HeilongjiangChina School of Mechanical Engineering Inner Mongolia University of TechnologyHohhot 010051Inner MongoliaChina Inner Mongolia Key Laboratory of Special Service Intelligent Robotics Hohhot 010051Inner MongoliaChina Faculty of Mechanical Engineering Department of Solid MechanicsUniversity of KashanKashan87317-51167Iran

The present work investigates higher order stress,strain and deformation analyses of a shear deformable doubly curved shell manufactures by a Copper(Cu)core reinforced with graphene origami aux.tic metamaterial subjected to mechanical and thermal *** effective material properties of the graphene origami aux.tic reinforced Cu matrix.are developed using micromechanical models cooperate both material properties of graphene and Cu in terms of temperature,volume fraction and folding *** principle of virtual work is used to derive governing equations with accounting thermal *** numerical results are analytically obtained using Navier's technique to investigate impact of significant parameters such as thermal loading,graphene amount,folding degree and directional coordinate on the stress,strain and deformation responses of the *** graphene origami materials may be used in aerospace vehicles and structures and defence technology because of their low weight and high stiffness.A verification study is presented for approving the formulation,solution methodology and numerical results.

关键词： Graphene origami Copper matrix Doubly curved Shear deformable Aux.tic metamaterial

Test of a model coupling of electromagnetic and gravitational fields by using high-frequency gravitational waves

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Science China(Physics,Mechanics & Astronomy) 2021年第5期64卷 22-27页

作者： Yinhua zou Mengjie Wang Jiliang Jing Department of Physics Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Educationand Synergetic Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

Models of the coupling of electromagnetic and gravitational fields have been studied ex.ensively for many years. In this paper,we consider the coupling between the Max.ell field and the Weyl tensor of the gravitational field to study how the wavevector of the electromagnetic wave is affected by a plane gravitational wave. We find that the wavevector depends upon the frequency and direction of polarization of the electromagnetic waves, the parameter that couples the Max.ell field and the Weyl tensor, and the angle between the direction of propagation of the electromagnetic wave and the coordinate ax.s. The results show that this coupling model can be tested by the detection of high-frequency gravitational waves.

关键词： modified theory gravitational wave wave vector

Reinforcement Learning Based Data Fusion Method for Multi-Sensors

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IEEE/CAA Journal of Automatica Sinica 2020年第6期7卷 1489-1497页

作者： Tongle Zhou Mou Chen Jie zou College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China IEEE Science and Technology on Electron-Optic Control Laboratory Luoyang Institute of Electro-Optical Equipment of AvicLuoyang 471023China

In order to improve detection system robustness and reliability, multi-sensors fusion is used in modern air combat. In this paper, a data fusion method based on reinforcement learning is developed for multi-sensors. Initially, the cubic B-spline interpolation is used to solve time alignment problems of multisource data. Then, the reinforcement learning based data fusion(RLBDF) method is proposed to obtain the fusion results. With the case that the priori knowledge of target is obtained, the fusion accuracy reinforcement is realized by the error between fused value and actual value. Furthermore, the Fisher information is instead used as the reward if the priori knowledge is unable to be obtained. Simulations results verify that the developed method is feasible and effective for the multi-sensors data fusion in air combat.

关键词： Air combat cubic B-spline interpolation data fusion reinforcement learning

Set-Membership Filtering Approach to Dynamic Event-Triggered Fault Estimation for a Class of Nonlinear Time-Varying Complex.Networks

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IEEE/CAA Journal of Automatica Sinica 2024年第3期11卷 638-648页

作者： x.aoting Du Lei zou Maiying Zhong the College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266590China IEEE the College of Information Science and Technology Donghua UniversityShanghai 201620 the Engineering Research Center of Digitalized Tex.ile and Fashion Technology Ministry of EducationShanghai 201620China

The present study addresses the problem of fault estimation for a specific class of nonlinear time-varying complex.networks,utilizing an unknown-input-observer approach within the framework of dynamic event-triggered mechanism(DETM).In order to optimize communication resource utilization,the DETM is employed to determine whether the current measurement data should be transmitted to the estimator or *** guarantee a satisfactory estimation performance for the fault signal,an unknown-input-observer-based estimator is constructed to decouple the estimation error dynamics from the influence of fault *** aim of this paper is to find the suitable estimator parameters under the effects of DETM such that both the state estimates and fault estimates are confined within two sets of closed ellipsoid *** techniques of recursive matrix.inequality are applied to derive sufficient conditions for the ex.stence of the desired estimator,ensuring that the specified performance requirements are met under certain ***,the estimator gains are derived by minimizing the ellipsoid domain in the sense of trace and a recursive estimator parameter design algorithm is then ***,a numerical ex.mple is conducted to demonstrate the effectiveness of the designed estimator.

关键词： Dynamic event-triggered mechanism(DETM) fault estimation nonlinear time-varying complex.networks set-member-ship filtering unknown input observer

Optimization for sound insulation of a sandwich plate with a corrugation and aux.tic honeycomb hybrid core

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Applied Mathematics and Mechanics(English Edition) 2024年第9期45卷 1595-1612页

作者： Fenglian LI Yiping WANG Yux.ng zou School of Mechanical and Electrical Engineering Beijing Information Science and Technology UniversityBeijing 100192China

A sandwich plate with a corrugation and aux.tic honeycomb hybrid core is constructed,and its sound insulation and optimization are ***,the motion governing equation of the sandwich plate is established by the third-order shear deformation theory(TSDT),and then combined with the fluid-structure coupling conditions,and the sound insulation is *** theoretical results are validated by COMSOL simulation results,and the effects of the structural parameter on the sound insulation are ***,the standard genetic algorithm is adopted to optimize the sound insulation of the sandwich plate.

关键词： optimization sound insulation hybrid core layer genetic algorithm