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Wrinkle analysis of a space planar film reflect-array

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第1期12卷 24-32页

作者： Wei-wei XIAO Wu-jun CHEN Gong-yi fu Space Structures Research Centre Shanghai Jiao Tong University Shanghai 200030 China

The presence of wrinkles in a membrane is the main factor that induces surface errors on space planar film reflect-arrays. Based on the commercial finite element (FE) package ABAQUS, a numerical procedure for membrane wrinkle analysis was set up, and used to analyze a square planar film reflect-array under pure shear force to evaluate its induced wrinkle characteristics. First, the effect of shear force on the wrinkle pattern of the array was studied and validated by experiment. Second, the effect of prestress was studied. When the prestress increases, the quantity of the wrinkles increases, and the amplitude of the wrinkles decreases. Third, the influence of the boundary conditions was investigated. A frame side edge structure has a relatively smooth surface, but also relatively high stress. Finally, the behavior of a joint seam was analyzed. The results indicate that a joint band has a significant influence on the wrinkle pattern of the membrane.

关键词： Space planar film reflect-array Wrinkle analysis Joint seam

A new adaptive backstepping method for nonlinear control of turbine main steam valve

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控制理论与应用（英文版） 2007年第1期5卷 17-22页

作者： jun fu jun ZHAO School of Information Science find Engineering Northeastern University Shenyang Liaoning 110004 China Department of Mechanical and Industrial Engineering Concordia University Montreal Quebec H3G 2W 1 Canada

A new approach for nonlinear adaptive control of turbine main steam valve is developed. In comparison with the existing controller based on ＂classical＂ adaptive backstepping, this method does not follow the classical certaintyequivalence principle in the design of adaptive control law. We introduce this approach, for the first time, to power systems and present a novel parameter estimator and dynamic feedback controller for a single machine infinite bus （SMIB） system with steam valve control. This system contains unknown parameters such as reactance of transmission lines. Besides preserving useful nonlinearities and the real-time estimation of uncertain parameters, the proposed approach possesses better performances with respect to the response of the system and the speed of adaptation. The simulation results demonstrate that the proposed approach is better than the design based on ＂classical＂ adaptive backstepping in terms of properties of stability and parameter estimation, and recovers the performance of the ＂full-information＂ controller. Hence, the proposed method provides an alternative for engineers in applications.

关键词： Nonlinear control Adaptive backstepping Steam valve control Power systems

Cu(OH)2 supported on Fe(OH)3 as a synergistic and highly efficient system for the dehydrogenation of ammonia-borane

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Science Bulletin 2018年第23期63卷 1583-1590页

作者： Cheng-Yun Peng Chun-Chao Hou Qian-Qian Chen Chuan-jun Wang Xiao-jun Lv jun Zhong Wen-fu fu Chi-Ming Che Yong Chen Key Laboratory of Photochemical Conversion and Optoelectronic Materials & HKU-CAS Joint Laboratory on New Materials Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijmg 100190China University of Chinese Academy of Sciences Beijing 100049China College of Chemistry and Material Science Shandong Agricultural UniversityTaian 271018China Institute of functional Nano and Soft Materials Laboratory (fuNSOM) Jiangsu Key Laboratory for Carbon-Based Functional Materials and DevicesSoochow University Suzhou 215123China State Key Laboratory of Synthetic Chemistry and Department of Chemistry The University of Hong KongHongKongChina

Herein,we first describe the physical mixture of Cu(OH)_2/Fe(OH)_3 as a composite catalyst precursor for the dehydrogenation of ammonia borane(AB)in *** the initial period of catalytic reaction,Cu nanoparticles were formed *** catalytic activity of Cu nanoparticles can be significantly enhanced with the assistance of Fe species and OH~à.A maximum turnover frequency(TOF)of 50.3 mol_(H2)mol^(à1)_(total metal)min^(à1)(135.6 mol_(H2)mol_(Cu)^(à1)min^(à1))was achieved at ambient temperature,which is superior to those of previously reported Fe or Cu based systems.

关键词： Ammonia borane Dehydrogenation Cu(OH)2 Fe(OH)3

Boosting viral-specific immunotherapy for chronic hepatitis B treatment

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Cellular & Molecular Immunology 2021年第12期18卷 2586-2587页

作者： Jin Fan jun-Liang fu fu-Sheng Wang Senior Department of Infectious Diseases the Fifth Medical Center of PLA General HospitalNational Clinical Research Center for Infectious DiseasesBeijing100039China

Hepatitis B virus(HBV)-specific antibody-producing B cells and functional HBV-specific helper and cytotoxic T cells are the primary influence of the clinical outcome of acute or chronic HBV ***,patients with chronic h... 详细信息

关键词： acute hepatitis clinical

基于改进龙贝格观测器的轨道交通IPMSM无感控制研究

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电工电气 2025年第1期 36-40,47页

作者：马志军王乃福黄凯中车大连电力牵引研发中心有限公司辽宁大连116052

针对轨道交通内置式永磁同步电机受IGBT开关频率限制难以实现高性能无感控制的问题,设计了一种基于龙贝格观测器的无位置传感器矢量控制。将电机电压方程改为基于扩展反电势的全阶模型,在此基础上进行龙贝格观测器的设计,从理论上分析... 详细信息

针对轨道交通内置式永磁同步电机受IGBT开关频率限制难以实现高性能无感控制的问题,设计了一种基于龙贝格观测器的无位置传感器矢量控制。将电机电压方程改为基于扩展反电势的全阶模型,在此基础上进行龙贝格观测器的设计,从理论上分析了系统的稳定性,并给出参数设计方法。为了适应低开关频率应用环境,将观测器模型进行四阶离散化设计,以提高观测器的精度。以一台永磁同步电机作为控制对象,采用设计的无位置传感器控制进行试验验证。试验结果表明,设计的基于龙贝格观测器的无位置传感器控制转矩控制精度在2%以内,并且系统具有良好的负载突变动态特性。

关键词：内置式永磁同步电机无感控制龙贝格观测器四阶离散化

A review on fault-tolerant cooperative control of multiple unmanned aerial vehicles

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Chinese Journal of Aeronautics 2022年第1期35卷 1-18,I0001页

作者： Ziquan YU Youmin ZHANG Bin JIANG jun fu Ying JIN College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 211106China Department of Mechanical Industrial and Aerospace EngineeringConcordia UniversityMontrealQC H3G 1M8Canada State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China

This paper presents the recent developments in Fault-Tolerant Cooperative Control(FTCC)of multiple unmanned aerial vehicles(multi-UAVs).To facilitate the analyses of FTCC methods for *** formation control strategies under fault-free flight conditions of multi-UAVs are first summarized and analyzed,including the leader-following,behavior-based,virtual structure,collision avoidance,algebraic graph-based,and close formation control methods,which are viewed as the cooperative control methods for multi-UAVs at the pre-fault ***,by considering the various faults encountered by the multi-UAVs,the state-of-the-art developments on individual,leader-following,and distributed FTCC schemes for multi-UAVs are reviewed in ***,conclusions and challenging issues towards future developments are presented.

关键词： Cooperative Fault Detection and Diagnosis(CFDD) Cooperative/formation/swarm control Fault Detection and Diagnosis(FDD) Fault-Tolerant Control(FTC) Fault-Tolerant Cooperative Control(FTCC) Unmanned Aerial Vehicles(UAVs)

Recent advances on environmental corrosion behavior and mechanism of high-entropy alloys

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Journal of Materials Science & Technology 2021年第21期80卷 217-233页

作者： Yu fu jun Li Hong Luo Cuiwei Du Xiaogang Li Institute for Advanced Materials and Technology University of Science and Technology BeijingBeijingJ 00083China Key Laboratory for Corrosion and Protection of The Ministry of Education(MOE) Beijing100083China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China National Materials Corrosion and Protection Scientific Data Center Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing100083China BRI Southeast Asia Network for Corrosion and Protection(MOE) Shunde Graduate School of University of Science and Technology BeijingFoshan528000China

In the past decade, the sudden rise of high-entropy alloys(HEAs) has become a research hotspot in the domain of metal materials. HEAs break through the design concept of traditional single-principal element alloys, and the four core effects, especially the high entropy and cocktail effects, make HEAs exhibit much better corrosion resistance than traditional corrosion-resistant metal materials, e.g., stainless steels, copper-nickel alloys, and high-nickel alloys. Currently, the corrosion resistance of HEAs causes great concern in the field of corrosion research. This article reviews the corrosion behavior and mechanism of HEAs in various aqueous solutions, revealing the correlation among the composition, microstructure and corrosion resistance of HEAs, and elaborates the influence of heat treatment, anodizing treatment and preparation methods on the corrosion behavior of HEAs. This knowledge will benefit the on-demand design of corrosion-resistant HEAs, which is an important trend of future development. Finally, perspectives regarding the corrosion research of HEAs are outlined to guide future studies.

关键词： High-entropy alloys Corrosion behavior Corrosion mechanism Passive film Alloy design

Towards rational design in electrochemical denitrification by analyzing pH dependence

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National Science Review 2024年第6期11卷 223-232页

作者： Huan Li Dong Luan jun Long Xiaoyan fu Jianping Xiao State Key Laboratory of Catalysis Dalian Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

A small fraction of NOx（<1%） always exists in CO2feedstock（e.g. exhausted gas）, which can significantly reduce the efficiency of CO2electroreduction by ～30%. Hence, electrochemical denitrification is the precondi... 详细信息

A small fraction of NOx（further supported by more than 35 experiments over varying catalysts（Fe, Ni, Pd, Cu, Co, Pt and Ag）, partial pressures（20%, 50% and100%） and potentials（from -0.2 to 0.2 V vs. reversible hydrogen electrode）. All in all, the insights herein overturn long-lasting views in the field of NO electroreduction and suggest that rational design should steer away from catalyst engineering toward reactor optimization.

关键词： electrocatalysis denitrification pH-dependence nitric oxide reduction reaction mechanism

The influence of urbanization on karst rivers based on nutrient concentration and nitrate dual isotopes： an example from southwestern China

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Acta Geochimica 2017年第3期36卷 446-451页

作者： Zhong-jun Wang fu-jun Yue Jie Zeng Si-Liang Li State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of SciencesGuiyang 550081 China University of Chinese Academy of Sciences Beijing 100049China Puding Karst Ecosystem Research Station Institute of Geochemistry Chinese Academy of Sciences Anshun 562100 China School of Geographical and Earth Sciences University of Glasgow Glasgow G12 8QQ UK Key Laboratory of Karst Environment and Geohazard Ministry of Land and Resources Guizhou UniversityGuiyang 550025 China Institute of Surface-Earth System Science Tianjin University Tianjin 300072 China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin University Tianjin 300072 China

China is experiencing rapid urbanization that has changed the water quality of rivers, especially nutrient loads. In this study, a typical urban river located in a karst area, Chengguan River, was chosen to explore the influence of urbanization on river ecosystems based on nutrient concentration and nitrate isotopes. The results show monthly variability of water chemistry and nutrient concentration. Nutrient concentration in two tributaries and the mainstem showed significant spatial variability, with heavy N and P pollution in one tributary near a suburban area,indicating a response to different levels of *** of nitrate dual isotopes suggest thatvolatilization, assimilation, nitrification, and denitrification all occur in the polluted river. Water chemistry and nitrate isotopes show that major nitrogen sources included domestic waste and agricultural input, such as chemical fertilizer and manure. The results suggest that urbanization increases nutrient concentrations and accelerates the riverine nitrogen dynamic, and point to the need to manage point sources of sewage effluents to improve the water quality of urban rivers in southwestern China.

关键词： Urbanization Urban river Nitrate isotopes Southwestern China Chengguan River