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Gust load alleviation wind tunnel tests of a large-aspect-ratio flexible wing with piezoelectric control

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Chinese Journal of Aeronautics 2017年第1期30卷 292-309页

作者： bi ying Xie Changchuan An Chao Yang Chao School of Aeronautic Science and Engineering Beihang University

An active control technique utilizing piezoelectric actuators to alleviate gust-response loads of a large-aspect-ratio flexible wing is investigated. Piezoelectric materials have been extensively used for active vibration control of engineering structures. In this paper, piezoelectric materials further attempt to suppress the vibration of the aeroelastic wing caused by gust. The motion equation of the flexible wing with piezoelectric patches is obtained by Hamilton＇s principle with the modal approach, and then numerical gust responses are analyzed, based on which a gust load alleviation（GLA） control system is proposed. The gust load alleviation system employs classic propor tional-integral-derivative（PID） controllers which treat piezoelectric patches as control actuators and acceleration as the feedback signal. By a numerical method, the control mechanism that piezoelectric actuators can be used to alleviate gust-response loads is also analyzed qualitatively. Furthermore, through low-speed wind tunnel tests, the effectiveness of the gust load alleviation active control technology is validated. The test results agree well with the numerical results. Test results show that at a certain frequency range, the control scheme can effectively alleviate the z and x wingtip accelerations and the root bending moment of the wing to a certain extent. The control system gives satisfying gust load alleviation efficacy with the reduction rate being generally over 20%.

关键词： Active control Aeroelastic wing Gust load alleviation Gust response Piezoelectric actuators Wind tunnel test

Energy-optimal trajectory planning for solar-powered aircraft using soft actor-critic

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Chinese Journal of Aeronautics 2022年第10期35卷 337-353页

作者： Wenjun NI ying bi Di WU Xiaoping MA Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

High-Altitude Long-Endurance(HALE)solar-powered Unmanned Aircraft Vehicles(UAVs)can utilize solar energy as power source and maintain extremely long cruise endurance,which has attracted extensive attentions from *** optimization is a promising way to achieve superior flight time because of the finite solar energy absorbed in a *** this work,a method of trajectory optimization and guidance for HALE solar-powered aircraft based on a Reinforcement Learning(RL)framework is *** to flight and environment information,a neural network controller outputs commands of thrust,attack angle,and bank angle to realize an autonomous flight based on energy *** validity of the proposed method was evaluated in a 5-km radius area in simulation,and results have shown that after one day-night cycle,the battery energy of the RL-controller was improved by 31%and 17%compared with those of a Steady-State(SS)strategy with a constant speed and a constant altitude and a kind of statemachine strategy,*** addition,results of an uninterrupted flight test have shown that the endurance of the RL controller was longer than those of the control cases.

关键词： Flight strategy Guidance and control Reinforcement learning Solar powered aeroplane Trajectory generation

Microstructure and Magnetic Anisotropy of FeCoNbB Films

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Chinese Journal of Aeronautics 2011年第6期24卷 823-828页

作者： YANG Youran WANG Yanyan LI ying bi Xiaofang Key Laboratory of Aerospace Materials and Performance （Ministry of Education） School of Materials Science and Engineering Beihang University Beijing 100191 China

Effect of Nb contents on microstructure and magnetic properties of FeCoNbB films has been studied. X-ray diffraction （XRD） analysis reveals that Nb plays a role in refining grain and in facilitating formation of amorphous structure. When Nb content is more than 8 at%, the films transform from crystalline to amorphous structure, accompanied by variations in magnetic properties. An unusual out-of-plane anisotropy component is consequently observed. It can be suggested that the anisotropy induced by increasing Nb contents be attributed to stress-related magnetoelastic anisotropy. The undesirable anisotropy is greatly reduced by thermal annealing, reducing film thicknesses or applying an external magnetic field together with Si addition.

关键词： FeCoNbB films magnetic anisotropy Nb contents annealing film thickness

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Paths out of poverty

Journal of Integrative Agriculture 2021年第4期20卷 851-856页

作者： NIE Feng-ying bi Jie-ying Apurv MARU Agricultural Information Institute Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081 P.R.China

Introduction Ending poverty in all its forms everywhere is the first Sustainable Development Goal(SDG) of the United Nations(2021a). Progress towards this goal has varied but also been fruitful. Between 1990 and 2015, over a billion people were lifted out of extreme poverty(World Bank 2018). From 36% of the population under extreme poverty in 1990 to 10% in 2015(United Nations 2021b).

关键词： Sustainable extreme poverty

Optimization of Vehicle Side Curtain Airbag Module Based on Computer Aided Engineering

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Chinese Journal of Mechanical Engineering 2009年第4期22卷 521-527页

作者： ZHANG Junyuan LI Dongjun bi ying YANG Donglin QIU Feng The State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130025 China Jinheng Automotive Safety System Co. Ltd. Jinzhou 121007 China

Compared with other kinds of airbags, curtain airbag（CAB） has more complex structures and larger coverage area. The product development process depends on many module tests, sled tests and full size vehicle tests. Computer aided engineering（CAE） technology can replace tests to a great extent, also save test costs and product development time. This paper introduces the way of setting up simulation models and application of static deployment tests and free motion headform（FMH） tests to verify simulation models. In the CAB simulation, uniform pressure airbag models and computational fluid dynamics（CFD） models are all used. The uniform pressure airbag models are not able to simulate the pressure difference among different parts inside the cushion during inflating process. CFD-based CAB models are used to help the curtain airbag optimization design. Based on effective CAE simulation, the optimization analyses related to diffuser tube parameters, inflator mass flow rate and cushion folding patterns are discussed and performed in different cases. The optimization result shows that the proposed techniques are helpful to the parametric optimization design of side curtain airbag module in curtain airbag development process.

关键词： curtain airbag Computer aided engineering simulation optimization

Chlorine-Induced Hydrogen-Bonding Network of A Novel Dimer Based on Nickel and Tridentate Ligand： 3-Hydrazine-4-amino-1,2,4-Triazole

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Chinese Journal of Chemistry 2015年第7期33卷 792-796页

作者： Yangang bi Wenyuan Zhao ying Li Tonglai Zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

The reaction of NiCl2 and 3-hydrazine-4-amino-1,2,4-triazole （Hatr） in the mixed solvent of EtOH and H2O yielded a dimer compound （[Ni2（Hatr）2（H2O）2（EtOH）2Cl2]ClzoEtOH） with water and EtOH molecules coordinated to nickle ions. It crystallized in trigonal space group R-3, a=b=29.67（1） A, c=8.95（7） A, β= 120（1）°, as determined by single-crystal X-ray diffraction. Then, they were fully characterized by the IR spectroscopy, differential scanning calorimetry （DSC）, thermogravimetry （TG）, and elemental analysis.

关键词： dimer compound tridentate ligand nickel X-ray diffraction differential scanning calorimetry

Seasonal Gametogenesis of Host Sea Anemone(Entacmaea quadricolor) Inhabiting Hong Kong Waters

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Journal of Ocean University of China 2015年第1期14卷 143-148页

作者： bi ying ZHANG bin ZHANG Zhifeng QIU Jianwen Key Laboratory of Marine Genetics and Breeding of Ministry of Education Ocean University of China Department of biology Hong Kong Baptist University

Studying gonadal development of annual cycle can reveal the process of gametogenesis and reproductive period, and evaluate fertility and source utilization of a species. Host sea anemones are conspicuous members of tropical and subtropical reef ecosystems, but little is known about its biology including reproductive seasonality. Here we reported a one-year study on the gametogenesis and reproduction of host sea anemone(Entacmaea quadricolor) inhabiting Hong Kong waters. E. quadricolor tissues were sampled in 12 occasions from 5 m and 15 m depths of water, respectively. Histological sectioning of the tissues showed that E. quadricolor was dioecious, and populational ratio of female to male was 1:1.6. The gonadal development was asynchronous within an annual cycle, which included proliferating, growing, maturing, spawning, and resting stages. The spawning occurred between August and October when surface seawater temperature reached the annual maximum(28℃), suggesting that temperature is an important factor modulating the gonadal development and mature of E. quadricolor.

关键词： Entacmae aquadricolor gonad annual cycle histology seawater temperature

A Spatiotemporal Causality Based Governance Framework for Noisy Urban Sensory Data

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Journal of Computer Science & Technology 2020年第5期35卷 1084-1098页

作者： bi-ying Yan Chao Yang Pan Deng Qiao Sun Feng Chen Yang Yu Institute of Software Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China School of Mathematical Sciences.Peking University Beijing 100871China Peng Cheng Laboratory Shenzhen 518052China Research Institute for Frontier Science Beihang UniversityBeijing 100191China Guiyang Academy of Information Technology Guiyang 550081China Guiyang Municipal Commission of Transport Guiyang 550003China

Urban sensing is one of the fundamental building blocks of urban *** uses various types of sensors deployed in different geospatial locations to continuously and cooperatively monitor the natural and cultural environment in urban ***,issues such as uneven distribution,low sampling rate and high failure ratio of sensors often make their readings less *** paper provides an innovative framework to detect the noise data as well as to repair them from a spatial-temporal causality perspective rather than to deal with them *** can be achieved by connecting data through monitored objects,using the Skip-gram model to estimate spatial correlation and long shortterm memory to estimate temporal *** framework consists of three major modules:1)a space embedded bidirectional Long Short-Term Memory(biLSTM)-based sequence labeling module to detect the noise data and the latent missing data;2)a space embedded biLSTM-based sequence predicting module calculating the value of the missing data;3)an object characteristics fusion repairing module to correct the spatial and temporal dislocation sensory *** approach is evaluated with real-world data collected by over 3000 electronic traffic bayonet devices in a citywide scale of a medium-sized city in China,and the result is superior to those of several referenced *** a 12.9%improvement,in data accuracy over the raw data,the proposed framework plays a significant,role in various real-world use cases in urban governance,such as criminal investigation,traffic violation monitoring,and equipment maintenance.

关键词： trajectory data recurrent neural network spatiotemporal(ST)big data urban computing

Catalytic Oxidation of Hexanol to Hexanal with H_2O_2 Over P-W Heteropoly Compounds

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Chemical Research in Chinese Universities 2001年第3期17卷 293-298页

作者： ZHOU Guang-dong GUO Xiao-hong LIU Yan bi ying-li ZHEN Kai-ji Department of Chemistry Jilin UniversityChangchun 130023P.R.China

The syntheses of Keggin and Dawson-structural phospho-tungsto heteropoly compounds and their Peroxo-derivatives(PCWP), and the catalytic performance over this series of catalysts for the selective oxidation of hexanol to hexylaldehyde are reported. By means of IR, NMR and UV-DRS techniques the catalysts were characterized and a comparison of the structural properties of these catalysts before and after the reaction was made. The correlation between the catalytic performance and the structure of this series of catalysts was discussed as well.

关键词： P-W Heteropoly compound Hexanol Hexanal