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Start-up current adaptive control for sensorless high-speed brushless DC motors based on inverse system method and internal mode controller

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Chinese Journal of Aeronautics 2017年第1期30卷 358-367页

作者： He Yanzhao zheng Shiqiang fang Jiancheng School of Instrumentation Science and Opto-electronics Engineering Beihang University Beijing 100083 China Beijing Engineering Research Center of High-Speed Magnetically Suspended Motor Technology and Application Beijing 100083 China

The start-up current control of the high-speed brushless DC（HS-BLDC） motor is a challenging research topic. To effectively control the start-up current of the sensorless HS-BLDC motor, an adaptive control method is proposed based on the adaptive neural network（ANN）inverse system and the two degrees of freedom（2-DOF） internal model controller（IMC）. The HS-BLDC motor is identified by the online least squares support vector machine（OLS-SVM） algorithm to regulate the ANN inverse controller parameters in real time. A pseudo linear system is developed by introducing the constructed real-time inverse system into the original HS-BLDC motor system. Based on the characteristics of the pseudo linear system, an extra closed-loop feedback control strategy based on the 2-DOF IMC is proposed to improve the transient response performance and enhance the stability of the control system. The simulation and experimental results show that the proposed control method is effective and perfect start-up current tracking performance is achieved.

关键词： Adaptive control Brushless DC motors Inverse systems Internal model controller Neural networks Start-up Support vector machines

The timing of continental collision between India and Asia

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Science Bulletin 2018年第24期63卷 1649-1654页

作者： Yongfei zheng Fuyuan wu Key Laboratory of Crust-Mantle Materials and Environments Chinese Academy of SciencesSchool of Earth and Space SciencesUniversity of Science and Technology of China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of Sciences

The timing of continental collision between India and Asia has been controversial for a long time because of the difficulty in screening isotopic ages for different types of tectonothermal event along the convergent continental boundary. After distinguishing the collisional orogeny from the precollisional accretionary orogeny and the postcollisional rifting orogeny, an age range of 55 ± 10 Ma is obtained to mark the collisional orogeny in the Early Cenozoic rather than throughout the Cenozoic. This age range provides the resolution to the timing of tectonic reactivation not only for reworking of the marginal arc systems in the Early Cenozoic but also for overprinting of granulite facies metamorphism on eclogites in the Late Cenozoic. In particular, superimposition of the rifting orogeny on both accretionary and collisional orogens in the Late Cenozoic is the key to the reactivation of both Gangdese and Himalayan orogens for contemporaneous metamorphism and magmatism at high thermal gradients. Therefore, rise of the plateau may be caused by underplating of the asthenospheric mantle for rifting orogeny in the composite Himalayan–Tibetan orogens after foundering of their roots in the Late Cenozoic.

关键词： Himalayan orogen Gangdese orogen Neo-Tethys Ocean Accretionary orogeny Collisional orogeny Rifting orogeny

Asynchronous Output Regulation Control for Continuous-Time Markovian Jump Systems with Colored-Noise

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Journal of Systems Science & Complexity 2023年第4期36卷 1463-1479页

作者： WANG Shitong wu zheng-Guang wu Zhaojing The Institute of Cyber-Systems and Control Zhejiang UniversityHangzhou 310027China The Institute of Intelligence Science and Engineering Shenzhen PolytechnicShenzhen 518055China The School of Mathematics and Informational Science Yantai UniversityYantai 264005China

The output regulation control problem for the Markovian jump systems with colored-noise is proposed in this *** the modes mismatch problem often exists in the Markovian switching system,the authors design a modes asynchronous controller with an internal model form,which can not only deal with external disturbance,but also reduce the influence of stochastic noise on the system,such that the mean square of the regulation error can be made arbitrarily small by turning the designed ***,a criterion of the m-th moment noise-to-state exponential stability is presented for continuous-time Markovian jump systems under the asynchronous control.

关键词： Asynchronous control colored-noise Markovian jump systems output regulation control

Science Letters:Hydrothermal production of formic and acetic acids from syringol

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第8期11卷 613-618页

作者： Lu-ting PAN zheng SHEN Lei wu Ya-lei ZHANG Xue-fei ZHOU fang-ming JIN MOE Key Laboratory of Yangtze River Water Environment State Key Laboratory of Pollution Control and Resources Reuse College of Environmental Science and Engineering Tongji University Shanghai 200092 China

The production of formic and acetic acids （or salts） by hydrothermal oxidation of syringol, a model compound for lignin, was investigated using a batch reactor. Results show that the highest yields of formic and acetic acids were, respectively, 59.6% and 11.3% at the reaction condition of 0.5 mol/L NaOH, 120% H2O2 supply and 280 ℃. These results will inform studies aiming to develop more enviromnental friendly lignin conversion processes by obtaining products beyond a CO2 end product.

关键词： Lignin Syringol Formic acid. Acetic acid. Hvdrothermal process

Influence of Interfacial Enantiomeric Grafting on Melt Rheology and Crystallization of Polylactide/Cellulose Nanocrystals Composites

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Chinese Journal of Polymer Science 2022年第1期40卷 93-106页

作者： Hua-Gao fang Kang-Jie Yang Qi-zheng Xie Xu Chen Sheng-Li wu Yun-Sheng Ding Department of Polymer Science and Engineering School of Chemistry and Chemical EngineeringHefei University of TechnologyHefei 230009China Anhui Province Key Laboratory of Advanced Functional Materials and Devices Hefei 230009China Anhui Institute for Food and Drug Control Hefei230051China

Incorporating the surface-grafted cellulose nanocrystals(CNCs)with enantiomeric polylactide(PLLA or PDLA)is an effective and sustainable way to modify PLLA,but their difference in promoting matrix crystallization is still *** this study,the CNCs with identical content and length of PLLA and PDLA(CNC-g-L and CNC-g-D)were prepared and blended with *** rheological properties of PLLA/CNC-gD are greatly improved,indicating that the stereocomplexation can significantly improve the interfacial strength as compared with the conventional van der Waals force in PLLA/***,the matrix crystallizes at a higher rate in PLLA/CNC-g-L than PLLA/***/CNC-g-L15 reaches its half crystallinity in 8.26 min while a longer period of 13.41 min is required for PLLA/*** observation reveals that the superior crystallization behavior in PLLA/CNC-g-L is originated from its higher nucleation efficiency and faster growth *** formation of low content of sc-PLA at the interface can restrict the diffusion of PLLA but contribute less to generate crystalline nuclei,which synergistically leads to the retarded crystallization kinetics in PLLA/*** the mechanism of different interfacial enantiomeric grafting on the melt rheology and crystallization of PLLA is of great significance for the development of high-performance polylactide materials.

关键词： Cellulose nanocrystal Polylactide nanocomposite Interfacial stereocomplexation Crystallization Rheology

Disagreement and Antagonism in Signed Networks: A Survey

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IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1166-1187页

作者： Yuxin wu Deyuan Meng zheng-Guang wu Seventh Research Division Beihang University(BUAA)and also with the School of Automation Science and Electrical EngineeringBeihang University(BUAA)Beijing 100191China National Laboratory of Industrial Control Techno-logy Institute of Cyber-Systems and ControlZhejiang UniversityHangzhou 310027China IEEE

Signed networks refer to a class of network systems including not only cooperative but also antagonistic interactions among *** to the existence of antagonistic interactions in signed networks,the agreement of nodes may not be established,instead of which disagreement behaviors generally *** paper reviews several different disagreement behaviors in signed networks under the single-integrator linear dynamics,where two classes of topologies,namely,the static topology and the dynamic topology,are *** the static signed networks with the adjacency weights as(time-varying)scalars,we investigate the convergence behaviors and the fluctuation behaviors with respect to fixed topologies and switching topologies,respectively,and give some brief introductions on the disagreement behaviors of general time-varying signed ***,several classes of behavior analysis approaches are also *** the dynamic signed networks with the adjacency weights as transfer functions or linear time-invariant systems,we show the specific descriptions and characteristics of them such that the disagreement behaviors can be obtained by resorting to the derived static signed ***,we give their applications to the behavior analysis of static signed networks in the presence of high-order dynamics or communication delays.

关键词： Antagonistic interaction disagreement behavior dynamic topology signed network static topology

Small modifications of endo-functionalized cavities lead to large changes in molecular interaction in water

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Science China Chemistry 2025年第1期 369-376页

作者： Song-Meng Wang Hao Nian Yan-fang Wang Li-Shuo zheng Yu-Tao zheng Yi-Wei Dong Liping Huang Xiaoping Wang Wei Jiang Liu-Pan Yang Department of Chemistry Southern University of Science and Technology School of Chemistry and Pharmaceutical Sciences State Key Laboratory for Chemistry and Molecular Engineering of Medicinal ResourcesGuangxi Normal University School of Pharmaceutical Science Hengyang Medical School University of South China

Studying molecular recognition in aqueous environments is crucial for understanding biological processes. Herein, we present a series of N-doped endo-functionalized anthracene-based cavities by introducing inward-directed pyridine units. The subtle modifications can significantly affect the binding properties of these receptors, which is similar to the mutations in biological systems. Combining theoretical calculations and molecular recognition experiments demonstrated that these “mutations” have an impact on the hydrophobicity and charge distribution of the hosts, consequently significantly influencing molecular *** is crucial for understanding the intricate mechanisms of molecular-level interactions in biological receptors.

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Development of surface reconstruction algorithms for optical interferometric measurement

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Frontiers of Mechanical Engineering 2021年第1期16卷 1-31页

作者： Dongxu wu Fengzhou fang Centre of Micro/Nano Manufacturing Technology(MNMT-Dublin) University College DublinDublin 4Ireland School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004China State Key Laboratory of Precision Measuring Technology and Instruments Centre of Micro/Nano Manufacturing Technology(MNMT)Tianjin UniversityTianjin 300072China

Optical interferometry is a powerful tool for measuring and characterizing areal surface topography in precision manufacturing.A variety of instruments based on optical interferometry have been developed to meet the measurement needs in various applications,but the existing techniques are simply not enough to meet the ever-increasing requirements in terms of accuracy,speed,robustness,and dynamic range,especially in on-line or on-machine *** paper provides an in-depth perspective of surface topography reconstruction for optical interferometric ***,configurations,and applications of typical optical interferometers with different capabilities and limitations are *** background and recent advances of fringe analysis algorithms,including coherence peak sensing and phase-shifting algorithm,are *** new developments in measurement accuracy and repeatability,noise resistance,self-calibration ability,and computational efficiency are *** paper also presents the new challenges that optical interferometry techniques are facing in surface topography *** address these challenges,advanced techniques in image stitching,on-machine measurement,intelligent sampling,parallel computing,and deep learning are explored to improve the functional performance of optical interferometry in future manufacturing metrology.

关键词： surface topography measurement optical interferometry coherence envelope phase-shifting algorithm

The Initial Mesoscale Vortexes Leading to the Formation of Tropical Cyclones in the Western North Pacific

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Advances in Atmospheric Sciences 2023年第5期40卷 804-823页

作者： Shenglan wu Juan fang Shanghai Central Meteorological Observatory CMAShanghai 200030China Key Laboratory of Mesoscale Severe Weather(MOE) School of the Atmospheric SciencesNanjing University163 Xianlin RoadNanjing 210046China

A statistical analysis of the initial vortexes leading to tropical cyclone(TC)formation in the western North Pacific(WNP)is conducted with the ECMWF ERA5 reanalysis data from 1999 to *** is found that TCs in the WNP basically originate from three kinds of vortexes,i.e.,a mid-level vortex(MV),a low-level vortex(LV),and a relatively deep vortex with notable vorticity in both the lower and middle troposphere(DV).Among them,LV and DV account for 47.9%and 24.2%of tropical cyclogenesis events,respectively,while only 27.9%of TCs develop from the MV,which is much lower than that which occurs in the North Atlantic and eastern *** a difference might be ascribed to the active monsoon systems in the WNP all year *** to the nearly upright structure of mid-level convergence in the early pre-genesis stage,TC genesis efficiency is the highest in *** with MV,LV generally takes a shorter time to intensify to a TC because of the higher humidity and the stronger low-level cyclonic circulation,which is related to air-sea interaction and boundary-layer *** examination of the relationship between tropical cyclogenesis and large-scale flow patterns indicate that the TC genesis events associated with LV are primarily related to the monsoon shear line,monsoon confluence region,and monsoon gyre,while those associated with MV are frequently connected with easterly waves and wave energy dispersion of preexisting *** with other flow patterns,tropical cyclones usually form and intensify faster in the monsoon confluence region.

关键词： TC formation initial mesoscale vortexes TC genesis efficiency large-scale flow patterns