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A strategy resisting wrinkling of sandwich structures reinforced using functionally-graded carbon nanotubes

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Chinese Journal of Aeronautics 2023年第9期36卷 243-255页

作者： Xiaohui ren Senlin ZHANG zhen WU School of Mechanical Engineering Xi’an Aeronautical UniversityXi’an 710065China School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China

Sandwich structures have been widely applied in the wing and the horizontal tail of the aircraft,so face sheets of such structure might occur wrinkling deformation in the process of service,which will largely decrease capability of sustaining *** a result,this paper aims at proposing a reasonable strategy resisting wrinkling deformation of sandwich *** this end,an enhanced higher-order model has been proposed for wrinkling analysis of sandwich *** behaviors of a five-layer sandwich plate are firstly analyzed,which is utilized to assess performance of the proposed ***,wrinkling behaviors of four sandwich plates are further investigated by utilizing present model,which have been evaluated by using quasi threedimensional(3D)elasticity solutions,3D Finite Element Method(3D-FEM)results and experimental ***,the present model is utilized to study the buckling and the wrinkling behaviors of sandwich plates reinforced by Carbon Nano Tubes(CNTs).In addition,influence of distribution profile of CNTs on wrinkling behaviors has been analyzed,and a typical distribution profile of CNTs has been chosen to resist wrinkling *** increase of additional weight,the present strategy can effectively resist wrinkling deformation of sandwich plates,which is rarely reported in published literature.

关键词： Buckling Carbon nano tube Functionally graded plate Higher-order model Wrinkling

Overview of SSRF phase-Ⅱ beamlines

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Nuclear Science and Techniques 2024年第8期35卷 48-57页

作者： ren‑Zhong Tai zhen‑Tang Zhao Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201204China

The SSRF phase-Ⅱ beamline project was launched in 2016. Its major goal was to establish a systematic state-of-the-art experimental facility for third-generation synchrotron radiation to solve problems in cutting-edge science and ***, the construction is fully completed. All 16 newly built beamlines with nearly 60 experimental methods passed acceptance testing by the Chinese Academy of Sciences and are in operation.

关键词： SSRF phase-Ⅱbeamline project Accelerator upgrade User laboratory User data center Beamline technique support

In situ observation and modeling of austenite grain growth in a Nb-Ti-bearing high carbon steel

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Journal of Iron and Steel Research International 2019年第3期26卷 292-300页

作者： guang Ji Xiu-hua Gao zhen-guang Liu Ke Zhang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina Jiangsu Shagang Group Huaigang Special Steel Co. Ltd.Huaian 223002JiangsuChina School of Materials Science and Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina Institute of Research of Iron and Steel ShasteelZhangjiagang 215625JiangsuChina

In situ measurements of austenite grain growth were made at various temperatures in the range of 1273-1473 K with subsequent isothermal holding time of 3600 s for the Nb-Ti-bearing and Nb-Ti-free high carb on steel by using a confocal laser scanning *** solid solute behavior of Nb-Ti carbides during austenitizing process was *** experimental results indicate that the austenite grains of both steels grow up gradually with increasing the heating temperature and holding time;the size and growth rate of austenite grain of Nb-Ti-bearing high carbon steel are much lower than those of Nb-Ti-free high carbon steel.A large amount of(Nb,Ti)(C,N)nanoparticles are observed in Nb-Tibearing steel,which retain the strong pinning effect on austenite grain *** kinetics model of austenite grain growth of Nb-Ti-bearing steel during isothermal heat treatment is obtained and the predicted values calculated by using the model meet the experimental values very well.

关键词： Con focal laser scanning microscope Nb-Ti microalloying High carb on steel Grain growth Nanoparticle Grain growth model

Adaptive Preassigned Time Stabilisation of Uncertain Second-Order Sub-Fully Actuated Systems

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Journal of Systems Science & Complexity 2022年第2期35卷 703-713页

作者： SHI Wenrui HOU Mingzhe DUAN guang-ren Center for Control Theory and Guidance Technology Harbin Institute of TechnologyHarbin 150001China

For a class of second-order sub-fully actuated systems(SOSFASs),this paper presents a preset-trajectory-based(PT-based)adaptive stabilising control method by integrating the function augmented sliding mode control(FASMC)technique and the flat-zone introduced Lyapunov function *** SOSFASs under study are subject to internal uncertainties and external *** proposed PT-based stabilising control method exhibits several attractive features:1)The system states can converge to a predefined region close to zero in a preassigned time and can be confined in a preassigned‘safe’area,which can make the control coefficient matrix always full rank so as to preserve the realizability of the proposed controller;2)the utilization of flat-zone introduced Lyapunov function technique not only eliminates the chatting phenomenon,but also avoids the potential persistent increase problem of the adaptive law;and 3)the control gain increases as the adaptive law increases only when necessary,that is,when the current control gain is not sufficient to suppress uncertainties or disturbances,therefore,the conservativeness of the control design due to unnecessarily high control gain can be effectively *** effectiveness of the proposed control method is verified via a numerical example.

关键词： Adaptive control fully-actuated systems sliding mode control sub-fully actuated systems

Almansi Decomposition for Poly-Ultrahyperbolic Functions

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Acta Mathematica Sinica,English Series 2009年第9期25卷 1561-1566页

作者： guang Bin ren Uwe KAHLER Department of Mathematics University of Science and Technology of China Hefei 230026 P. R. China Departamento de Matemdtica Universidade de Aveiro P-3810-159 Aveiro Portugal

In this paper we construct Almansi decompositions for powers of the ultrahyperbolic operator. The construction will be done in a constructive way.

关键词： Almansi decompositions ultrahyperbolic operator

Output Feedback Stabilization of Spacecraft Autonomous rendezvous Subject to Actuator Saturation

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International Journal of Automation and computing 2016年第5期13卷 428-437页

作者： Qian Wang guang-ren Duan Center for Control Theory and Guidance Technology Harbin Institute of Technology

This paper studies the output feedback dynamic gain scheduled control for stabilizing a spacecraft rendezvous system subject to actuator saturation. By using the parametric Lyapunov equation and the gain scheduling technique, a new observer-based output feedback controller is proposed to solve the semi-global stabilization problem for spacecraft rendezvous system with actuator saturation. By scheduling the design parameter online, the convergence rates of the closed-loop system are improved. Numerical simulations show the effectiveness of the proposed approaches.

关键词： Dynamic gain scheduling output feedback parametric Lyapunov equation input saturation spacecraft rendezvous.

Robust Global Stabilization of Spacecraft rendezvous System via Gain Scheduling

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International Journal of Automation and computing 2014年第4期11卷 426-433页

作者： Qian Wang guang-ren Duan Center for Control Theory and Guidance Technology Harbin Institute of Technology

The problem of robust global stabilization of a spacecraft circular orbit rendezvous system with input saturation and inputadditive uncertainties is studied in this paper. The relative models with saturation nonlinearity are established based on ClohesseyWiltshire equation. Considering the advantages of the recently developed parametric Lyapunov equation-based low gain feedback design method and an existing high gain scheduling technique, a new robust gain scheduling controller is proposed to solve the robust global stabilization problem. To apply the proposed gain scheduling approaches, only a scalar nonlinear equation is required to be *** from the controller design, simulations have been carried out directly on the nonlinear model of the spacecraft rendezvous operation instead of a linearized one. The effectiveness of the proposed approach is shown.

关键词： Robust global stabilization spacecraft rendezvous system parametric Lyapunov equation input saturation input-additive uncertainties gain scheduling

Effect of copper precursors on the catalytic performance of Cu-ZSM-5 catalysts in N2O decomposition

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Chinese Journal of Chemical Engineering 2018年第5期26卷 1051-1058页

作者： Tao Meng Nan ren zhen Ma School of Chemical and Environmental Engineering Shanghai Institute of Technology Shanghai 201418 China Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP^3) Department of Environmental Science and Engineering Fudan University Shanghai 200433 China Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Department of Chemistry Fudan University Shanghai 200433 China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092 China

Five Cu-ZSM-5 catalysts were obtained by treating Na-ZSM-5 （Si/Al ratio = 15） with aqueous solutions of differ- ent Cu precursors （CuCl2, Cu（NO3）2, CuSO4, Cu（CH3COO）2, and ammoniacal copper （II） complex ion）. After being pretreated in flowing He at 500 ℃ to form active Cu＋, these catalysts exhibited quite different activities in cata- lytic decomposition of N2O. CZM-AC（II）（prepared by ammoniacal copper （II） complex ion） with 9.4 wt% Cu con- tent was the most active among these Cu-ZSM-5 catalysts, achieving almost complete N2I conversion at 400 ℃. CZM-CA （prepared using Cu（ CH3COO）2 as the Cu precursor） with 2.8 wt% Cu content was the second most active catalyst among these Cu-ZSM-5 catalysts, achieving almost complete N2I conversion at 425 ℃. CZM-CC, CZM- CN, and CZM-CS prepared by using CuCl2, Cu（NO3）2, or CuSO4 as the Cu precursor with similar Cu contents （≈1.7 wt%） were the least active among these Cu-ZSM-5 catalysts, achieving ca. 90% N2O conversion at 500 ℃. XRD, ICP, SEM, TEM, EDX-mapping, and CO-IR experiments were conducted to characterize relevant samples. The superior activity of CZM-AC（II） can be attributed to the high contents of total Cu＋ and dimeric Cu＋ among these samples. The influence of co-fed O2 or H2O on the catalytic performance of typical samples was also studied.

关键词： Copper precursor Cu-ZSM-5 N2O decomposition Catalysis Catalyst Zeolite

New robust fault-tolerant controller for self-repairing flight control systems

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Journal of Systems Engineering and Electronics 2011年第1期22卷 77-82页

作者： Zhang ren Wei Wang zhen Shen National Key Laboratory of Science and Technology on Holistic Control Beihang University Beijing 100191 E R. China Civil Aviation Management Institute of China Beijing 100102 P. R. China

A new robust fault-tolerant controller scheme integrating a main controller and a compensator for the self-repairing flight control system is *** main controller is designed for high performance of the original faultless *** compensating controller can be seen as a standalone loop added to the system to compensate the effects of fault guaranteeing the stability of the system.A design method is proposed using nonlinear dynamic inverse control as the main controller and nonlinear extended state observer-based *** stability of the whole closed-loop system is *** and validity of the new controller is demonstrated with an aircraft simulation example.

关键词： robust control self-repairing flight control nonlinear dynamic control extended state observer compensator.