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Nano Research 2024年第6期17卷 5179-5187页

作者： Jinlei qin Rui Wang Zilong Yuan pei Xiao Deli Wang Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of EducationHubei Key Laboratory of Material Chemistry and Service FailureSchool of Chemistry and Chemical EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Lithium-sulfur(Li-S)batteries have been considered as promising energy storage systems due to the merits of high energy density and low ***,the lithium polysulfides(LiPSs)diffusion and sluggish redox kinetics hamper t... 详细信息

关键词： Li-S batteries nitrogen-doped carbon confinement oxygen vacancies bidirectional Li_(2)S redox

Vertical-horizontal coupling nonlinear vibration characteristics of rolling mill under mixed lubrication

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Journal of Iron and Steel Research International 2021年第5期28卷 574-585页

作者： Dong-xiao Hou Liang xu pei-ming Shi School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004HebeiChina School of Electrical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

Considering the dynamic influence of the roll vibration on the lubricant film thickness in the rolling deformation area,nonlinear dynamic rolling forces related to film thickness in the vertical and horizontal directions were obtained based on the Karman balance *** on these dynamic rolling forces and the mechanical vibration of the rolling mill,a vertical-horizontal coupling nonlinear vibration dynamic model was *** amplitude-frequency equation of the main resonance was derived by using the multiple-scale *** last,the parameters of the 1780 rolling mill were used for numerical simulation,and the time-domain response curves of the system’s vibration displacement and lubricating film thickness under the steady and unsteady conditions were *** influences of parameters such as interface contact ratio,nonlinear parameters and external disturbances on the primary resonance frequency characteristics were obtained,which provided a theoretical reference for the suppression of rolling mill vibration.

关键词： Vertical-horizontal coupling Nonlinear vibration Mixed lubrication Dynamic rolling force Main resonance Amplitude-frequency characteristic

Estimation of velocity potential of water waves using a Luenberger-like observer

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Science China(Information Sciences) 2020年第12期63卷 139-152页

作者： Yang YU Hai-Long pei Cheng-Zhong xu Key Laboratory of Autonomous Systems and Networked Control Ministry of EducationSouth China University of Technology Unmanned Aerial Vehicle Systems Engineering Technology Research Center of Guangzhou South China University of Technology LAGEPP University Claude Bernard-Lyon 1

We propose a Luenberger-like observer for a water wave system. The water wave dynamics are assumed to be governed by the linearized water wave equation(LWWE). Our proposed observer estimates the velocity potential of water waves by measuring only the surface wave elevation. The information of the water-wave velocity field is then extracted from the gradient of the velocity potential. It is shown that the estimation error of the observer converges exponentially to zero as time tends to infinity. Furthermore,we numerically solve the LWWE and observer equation by the finite difference method. The efficiency of our proposed numerical scheme and the performance of the observer are validated by numerical simulation results.

关键词： linearized water wave equation LWWE Luenberger-like observer numerical simulations

Conceptual design and preliminary experiment of icing risk management and protection system

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Chinese Journal of Aeronautics 2022年第6期35卷 101-115页

作者： Qiang WU Haojun xu Binbin pei Yang WEI School of Aeronautics Engineering Air Force Engineering UniversityXi’an 710038China

Icing is one of the main external environmental factors that causes aircraft to lose *** flight safety assurance system under icing condition is particularly ***,most of the systems do not consider the coupling characteristics of aerodynamics and flight dynamics of icing *** will affect the accuracy of the calculation ***,the icing risk management system helps the pilot to realize the possible dangers in advance and perform correct maneuvers,based on quantitative assessment and visualization methods of flight *** envelope protection system realizes flight safety guarantee based on the real-time boundary protection method of key flight ***,based on distributed simulation technology,a flight simulator was used as a platform to integrate the icing risk management system and envelope protection system to realize man-in-the-loop *** fictional but historically motivated icing scenarios are designed to test the system,and the results demonstrate that the icing risk management and protection system would be useful for aviation safety and can also be used for pilot training and reproducing flight accidents to find the causes.

关键词： Flight risk Flight simulator Icing Quantitative assessment Visualization

Research on the intelligent internet nursing model based on the child respiratory and asthma control test scale for asthma management of preschool children

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World Journal of Clinical Cases 2023年第28期11卷 6707-6714页

作者： Chuan-Feng pei Li Zhang Xi-Yan xu Zhen qin Hong-Mei Liang Department of Nursing Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 201620China Department of Pediatrics Shanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 201620China

BACKGROUND Childhood asthma is a common respiratory ailment that significantly affects preschool *** asthma management in this population is particularly challenging due to limited communication skills in children and the necessity for consistent involvement of a *** the rise of digital healthcare and the need for innovative interventions,Internet-based models can potentially offer relatively more efficient and patient-tailored care,especially in *** To explore the impact of an intelligent Internet care model based on the child respiratory and asthma control test(TRACK)on asthma management in preschool *** The study group comprised preschoolers,aged 5 years or younger,that visited the hospital's pediatric outpatient and emergency departments between January 2021 and January *** of 200 children were evenly and randomly divided into the observation and control *** control group received standard treatment in accordance with the 2016 Guidelines for Pediatric Bronchial Asthma and the Global Initiative on *** addition to above treatment,the observation group was introduced to an intelligent internet nursing model,emphasizing the TRACK *** measures monitored over a six-month period included the frequency of asthma attack,emergency visits,pulmonary function parameters(FEV1,FEV1/FVC,and PEF),monthly TRACK scores,and the SF-12 quality of life ***-intervention asthma control rates were assessed at six-month *** The observation group had fewer asthma attacks and emergency room visits than the control group(P<0.05).After six months of treatment,the children in both groups had higher FEV1,FEV1/FVC,and PEF(P<0.05).Statistically significant differences were observed between the two groups(P<0.05).For six months,children in the observation group had a higher monthly TRACK score than those in the control group(P<0.05).The PCS and MCSSF-12 quality of life scores were relatively higher

关键词： Child respiratory and asthma control test scale Intelligent internet nursing model Preschoolers Childhood asthma Administration Healthcare

A Coordinate-Free Approach to the Design of Generalized Griffis-Duffy Platforms

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 95-103页

作者： Chengwei Shen xu pei Lubin Hang Jingjun Yu College of Optical Mechanical and Electrical EngineeringZhejiang A&F UniversityHangzhou 311300China School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China School of Mechanical and Automotive Engineering Shanghai University of Engineering ScienceShanghai 201620China

Architectural singularity belongs to the Type II singularity,in which a parallel manipulator(PM)gains one or more degrees of freedom and becomes *** remaining permanently in a singularity are beneficial for linearto-rotary motion ***-Duffy(GD)platform is a mobile structure admitting a Bricard *** this paper,we present a coordinate-free approach to the design of generalized GD platforms,which consists in determining the shape and attachment of both the moving platform and the fixed *** generalized GD platform is treated as a combination of six coaxial single-loop mechanisms under the same *** to the inversion,hidden in the geometric structure of these single-loop mechanisms,the mapping from a line to a circle establishes the geometric transformation between the fixed base and the moving platform based on the center of inversion,and describes the shape and attachment of the generalized GD ***,the center of inversion not only identifies the location of rotation axis,but also affects the shape of the platform mechanism.A graphical construction of generalized GD platforms using inversion,proposed in the paper,provides geometrically feasible solutions of the manipulator design for the requirement of the location of rotation axis.

关键词： Generalized Griffis-Duffy platforms Self-motion Inversion Coordinate-free determination Manipulator design

Facile fabrication of a nanoporous Si/Cu composite and its application as a high-performance anode in lithiumion batteries

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Nano Research 2016年第4期9卷 908-916页

作者： Caixia xu qin Hao Dianyun Zhao School of Chemistry and Chemical Engineering University of Jinan Jinan 250022 China

Nanoporous （NP） Si/Cu composites are fabricated by means of alloy refining followed by facile electroless deaUoying in mild conditions. NP-SidCu composites with a three-dimensional porous network nanoarchitecture with different Cu contents are obtained by changing the feeding ratio of alloy precursors. Owing to the rich porosity and integration of conductive Cu into a nanoporous Si backbone, the NP-Si^Cu15 composite exhibits modified conductivity and reduced volumetric expansion/fracture during repeated charging-discharging processes in lithium-ion batteries （LIBs）, thus exhibiting much higher cycling reversibility than NP-Si92Cu8 and pure NP-Si. With the advantages of unique performance and easy preparation, NP-Si/Cu composite has potential for application as an advanced anode material for LIBs.

关键词： porous silicon composite lithium-ion batteries dealloying

Traveling Waves for Nonlocal and Non-monotone Delayed Reaction-difusion Equations

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Acta Mathematica Sinica,English Series 2013年第11期29卷 2159-2180页

作者： Zhi Ting xu pei xuan WENG School of Mathematical Sciences South China Normal University

We study the existence of traveling wave solutions for a nonlocal and non-monotone delayed reaction-diffusion equation. Based on the construction of two associated auxiliary reaction diffusion equations with monotonicity and by using the traveling wavefronts of the auxiliary equations, the existence of the positive traveling wave solutions for c 〉 c. is obtained. Also, the exponential asymptotic behavior in the negative infinity was established. Moreover, we apply our results to some reactiondiffusion equations with spatio-temporal delay to obtain the existence of traveling waves. These results cover, complement and/or improve some existing ones in the literature.

关键词： Nonlocal non-monotone delayed reaction-diffusion equation traveling wave solutions auxiliary equation

Traveling waves in nonlocal diffusion systems with delays and partial quasi-monotonicity

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Applied Mathematics(A Journal of Chinese Universities) 2011年第4期26卷 464-482页

作者： xu Zhao-quan WENG pei-xuan Department of Mathematics South China Normal University Gungzhou 510631 China.

This paper is devoted to the study of a three-dimensional delayed system with nonlocal diffusion and partial quasi-monotonicity. By developing a new definition of upper-lower solutions and a new cross iteration scheme, we establish some existence results of traveling wave solutions. The results are applied to a nonlocal diffusion model which takes the three-species Lotka-Volterra model as its special case.

关键词： Traveling wave nonlocal diffusion partial quasi-monotonicity upper and lower solution cross iteration scheme.

Energy Efficiency-Based Decision Making in Cognitive Radio Networks

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China Communications 2016年第11期13卷 205-213页

作者： Hongning Li qingqi pei Leilei xu State Key Laboratory of Integrated Services Networks Xidian University School of Telecommunications Engineering Xidian University

As a constraint for smart devices,energy consumption has attract people's attention for a long time period. How to get higher resource utilization with less energy consumption is a challenge for cognitive radio networks. Secondary users have to participate in spectrum sensing at the cost of energy and access idle spectrum without interfering primary users. However,not all participating secondary users can access idle spectrum. How to ensure the participation users access spectrum efficiently with a larger probability is an urgent problem to be solved. We propose an Energy Efficiency-based Decision Making(EEDM) for cognitive radio networks,which fully considers residual energy and probability of obtaining spectrum resources. Simulation and analysis show that the proposed scheme can maximize proportion of allocated users under the premise of ensuring the accuracy of spectrum sensing,then balance users' energy consumption and access efficiency,so as to effectively improve the utilization of spectrum resources.

关键词： cognitive radio networks spectrum sensing energy efficiency decision making