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Improving aircraft nose wheel steering stability based on control continuation method

science China(Technological sciences) 2025年第3期68卷 258-277页

作者： Qiaozhi YIN Dexu KONG Jiawei WANG Hong NIE Xiaohui WEI National Key Laboratory of Helicopter Aeromechanics Nanjing210016China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing210016China Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle Nanjing210016China AVIC Nanjing Engineering Institute of Aircraft Systems Nanjing211106China

Aircraft steering instability during the taxiing process sometimes occurs resulting from the unstable bifurcation phenomena of the nonlinear steering dynamic system,which may lead to severe *** this study,the control parameter design of an aircraft nose wheel steering control system based on the control continuation method is proposed to reduce the number of unstable bifurcation points and enlarge the system stable region area in a certain parameter ***,the aircraft turning performance can be improved ***,a nonlinear aircraft rollout dynamic model is constructed,and the aircraft ground steering bifurcation characteristics are obtained under the open-loop steering control ***,the bifurcation performances under three closed-loop nose wheel steering controllers based on the feedback control method are compared,and the control parameter of the quadratic nonlinear controller with a better bifurcation control effect is selected as a second bifurcation parameter to analyze the directional system stability via two-parameter bifurcation ***,the influence of a crosswind on the aircraft ground steering bifurcation performance is studied for various control parameter ***,the control effects of a traditional proportional-integral-derivative(PID)nose wheel steering control law and the designed feedback controller are compared and ***,a semi-physical experiment of the aircraft nose wheel steering system is carried out,and different control parameter values are selected for test verification,which can further verify the control effect of the designed nonlinear feedback *** results indicate that the feedback control method is unable to vary the system bifurcation types,but appropriate control parameter design can effectively shrink the system instability region and even eliminate the unstable Hopf bifurcation points under some specific working conditions,improving the aircraft ground turning stability re

关键词： aircraft taxiing dynamics and stability nose wheel steering control system control continuation steering bifurcation characteristics quadratic feedback control

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From animal collective behaviors to swarm robotic cooperation

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National science Review 2023年第5期10卷 82-99页

作者： Haibin Duan Mengzhen Huo Yanming Fan State Key Laboratory of Virtual Reality Technology and Systems School of Automation Science and Electrical EngineeringBeihang University Virtual Reality Fundamental Research Laboratory Department of Mathematics and TheoriesPeng Cheng Laboratory AVIC Shenyang Aircraft Design and Research Institute

The collective behaviors of animals,from schooling fish to packing wolves and flocking birds,display plenty of fascinating phenomena that result from simple interaction rules among *** emergent intelligent properties of the animal collective behaviors,such as self-organization,robustness,adaptability and expansibility,have inspired the design of autonomous unmanned swarm *** article reviews several typical natural collective behaviors,introduces the origin and connotation of swarm intelligence,and gives the application case of animal collective *** this basis,the article focuses on the forefront of progress and bionic achievements of aerial,ground and marine robotics swarms,illustrating the mapping relationship from biological cooperative mechanisms to cooperative unmanned cluster ***,considering the significance of the coexisting-cooperative-cognitive human-machine system,the key technologies to be solved are given as the reference directions for the subsequent exploration.

关键词： collective behaviors swarm intelligence cooperative robotics swarm human-machine system

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Effect of High Content Limestone Powder on Microstructure and Mechanical Properties of Cement-based Materials

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Journal of Wuhan University of technology(Materials science) 2023年第3期38卷 557-566页

作者：陈梦梦何永佳吕林女 ZHANG Xulong State Key Laboratory of Silicate Materials for Architectures Wuhan University of TechnologyWuhan 430070China School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key Laboratory of Theory and Application of Advanced Materials Mechanics School of ScienceWuhan University of TechnologyWuhan 430070China Hubei Provincial Academy of Building Research and Design Co. LtdWuhan 430071China

Compared with the control sample without limestone powder(LP), the mechanical properties of the sample with 30% LP can be significantly improved by using a small amount of water reducer to reduce the water-cement ratio, without significantly affecting the fluidity of the fresh mixture and increasing the economic cost. In addition, compared with the sole addition of limestone powder, dual addition of metakaolin and limestone powder can effectively improve the strengths. The reason of this phenomenon was investigated by means of XRD, TG-DTG, SEM, LF-NMR and isothermal calorimetry, etc. The reactive aluminum-rich phases in metakaolin react with limestone powder in the hydration process, and the formed calcium carboaluminate reduces the porosity and makes the hardened paste denser. The addition of ground granulated blast furnace slag can also improve the strength of the specimen added with limestone powder, whereas, the effect is inferior to that of metakaolin, for the ground granulated blast furnace slag contains less reactive aluminate phases, and accordingly, the amount of calcium carboaluminate generated is lower than that of metakaolin.

关键词： limestone powder aluminum-rich phase mineral admixture calcium carboaluminate

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Pan-genome analyses add ~1000 genes to the“complete”genome assemblyof chicken

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Journal of Genetics and Genomics 2025年第1期52卷 116-119页

作者： Jilong Ren Wenyan Kou Yuan Xu Meixuan Lu Mian Gong Xinmiao Zhang Zhenyu Liu Hengkuan Li Qimeng Yang Ali Mujtaba Shah Feng Zhu Zhuocheng Naiyi Xu Yu Jiang Fei Wang Key Laboratory of Animal Genetics Breeding and Reproduction of Shaanxi ProvinceCollege of Animal Science and TechnologyNorthwest A&F UniversityYanglingShaanxi 712100China Hou Frontiers Science Center for Molecular Design Breeding(MOE)&College of Animal Science and Technology China Agricultural UniversityBeijing 100193China College of Animal Science and Technology Southwest UniversityChongqing 400715China Chongqing Key Laboratory of Herbivore Science Chongqing 400715China Key Laboratory of Livestock Biology Northwest A&F UniversityYanglingShaanxi 712100China

Chicken(Gallus gallus)is a vital living organism and plays a crucial role in food *** and accurate chicken genomes are critical for insights into chicken breeding,avian evolution,and comparative genomics(Bravo et al.,2021).Pan-genomes possess more power to capture complete gene sets,thus presenting more comprehensive genomic information within species.

关键词： breeding comprehensive chicken

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Study on analysis method of loca dynamic response for steam generator heat transfer tube 29

Study on analysis method of loca dynamic response for steam ...

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2022 29th International Conference on Nuclear Engineering, ICONE 2022

作者： Lu, Xifeng Xiong, Furui Wang, Xinjun Ai, Honglei Li, Bingjin Shao, Xuejiao Yang, Kang Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China Nuclear Power Institute of China Chengdu China

ISBN: (纸本)9780791886359

The equivalent effect relationship formula of LOCA hydraulic load in the bend section of the heat transfer tube of the steam generator is deduced. The hydraulic load factors affecting the stress of the heat transfer tube are derived. The spectrum analysis of the corresponding LOCA hydraulic load is carried out, and the spectral curve of the hydraulic load and the spectral characteristics of the hydraulic load are obtained. Modal analysis of steam generator heat transfer tubes is done. The modal analysis of the steam generator heat transfer tubes is performed. The spectral characteristics of the hydraulic load and the natural frequency information of different heat transfer tubes are compared. According to the comparison results, eight heat transfer tubes with the first-order natural frequency and the frequency corresponding to the peak value of the hydraulic load in the frequency domain curve were selected as the analysis objects, and the LOCA dynamic response analysis is carried out. The time-domain analysis of the LOCA hydraulic load of the steam generator heat transfer tube was performed, and the relationship between the hydraulic load and the bending radius of the heat transfer tube was obtained. The transient load of the steam generator heat transfer tube with different bending radii is calculated. By establishing the finite element models of the first, 31, 43, 57, 72, 83, 87, and 112 rows of heat transfer tubes, the time history analysis of the heat transfer tubes under the LOCA load is performed, and The stress distribution of the heat transfer tube under the LOCA load is obtained. The stress of the heat transfer tube calculated by this method is the maximum LOCA response. This method can screen out sensitive heat transfer tubes, avoiding the process of analyzing each heat transfer tube. This method can effectively improve the efficiency of LOCA analysis of heat transfer tubes and is a practical method. © 2022 American Society of Mechanical Engineers (ASME).

关键词： Frequency domain analysis

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3D-printed MoS_(2)/Ni electrodes with excellent electro-catalytic performance and long-term stability for dechlorination of florfenicol

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Journal of Environmental sciences 2024年第3期137卷 420-431页

作者： Jianhui Xu Pengxu Wang Shenggui Chen Lei Li Dan Li Yunfei Zhang Qi Wu Jinhong Fan LumingMa School of Environment and Civil Engineering Dongguan University of TechnologyDongguan 523808China School of Art and Design Guangzhou Panyu PolytechnicGuangzhou 511483China National Engineering Research Center for Urban Pollution Control State Key Laboratory of Pollution Control and Resources ReuseCollege of Environmental Science and EngineeringTongji UniversityShanghai 200092China Dongguan Institute of Science and Technology Innovation Dongguan University of TechnologyDongguan 523808China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Here,we report the production of 3D-printed MoS_(2)/Ni electrodes(3D-MoS_(2)/Ni)with longterm stability and excellent performance by the selective laser melting(SLM)*** a cathode,the obtained 3D-MoS_(2)/Ni could maintain a degradation rate above 94.0%for forfenicol(FLO)when repeatedly used 50 times in *** also found that the removal rate of FLO by 3D-MoS_(2)/Ni was about 12 times higher than that of 3D-printed pure Ni(3D-Ni),attributed to the improved accessibility of H^(*).In addition,the electrochemical characterization results showed that the electrochemically active surface area of the 3D-MoS_(2)/Ni electrode is about 3-fold higher than that of the 3D-Ni electrode while the electrical resistance is 4 times *** on tert-butanol suppression,electron paramagnetic resonance and triple quadrupole mass spectrometer experiments,a“dual path”mechanism and possible degradation pathway for the dechlorination of FLO by 3D-MoS_(2)/Ni were ***,we also investigated the impacts of the cathode potential and the initial pH of the solution on the degradation of ***,this study reveals that the SLM 3D printing technique is a promising approach for the rapid fabrication of high-stability metal electrodes,which could have broad application in the control of water contaminants in the environmental field.

关键词： 3D-print Electroreduction MoS_(2)/Ni Antibiotic Florfenicol

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Photolabile ortho-Nitro-Benzyl Carbonate as a Permanent Hydroxyl Protecting Group for the Synthesis of Digalactosyl Diacylglycerol

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Chinese Journal of Chemistry 2025年第2期43卷 169-174页

作者： Jibin Zheng Hongyu Chen Jintao Shang Lvfeng Zhang Youling Liang Dongsheng Chang You Yang Shanghai Frontiers Science Center of Optogenetic Techniques for Cell Metabolism Shanghai Key Laboratory of New Drug DesignSchool of PharmacyEast China University of Science and Technology130 Meilong RoadShanghai200237 China Engineering Research Center of Pharmaceutical Process Chemistry Ministry of EducationEast China University of Science and Technology130 Meilong RoadShanghai200237 China

Traditional protecting groups are often removed under harsh conditions with potentially hazardous reagents,thereby impeding the convenient synthesis of oligosaccharides and ***,we present to utilize the photolabile ortho-nitro-benzyl carbonate(oNBC)as a permanent hydroxyl protecting group for stereocontrolled synthesis of *** Ph3PO-modulated glycosylation with strongly disarmed per-O-oNBC-protected glycosyl ynenoates preferred to afford glycosides with excellentα-selectivities via theβ-phosphonium transition *** on the oNBC-mediated galactosylation,synthesis of the glycolipid digalactosyl diacylglycerol(DGDG)containing six double bonds and two esters was achieved in a straightforward manner.

关键词： Carbohydrates Protecting groups Glycosylation Glycolipids Glycosides Photocatalysis Gold catalysis Synthetic methods

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Influence of the Radial Inertia Effect on the Propagation Law of Stress Waves in Thin-Walled Tubes

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Advances in Applied Mathematics and Mechanics 2023年第5期15卷 1216-1232页

作者： Shitang Cui Yongliang Zhang CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsUniversity of Science and Technology of ChinaHefeiAnhui 230027China

This investigation focused on the influence of the radial inertia effect on the propagation behavior of stress waves in thin-walled tubes subjected to combined longitudinal and torsional impact *** characteristics theory was used to analyze the main features of the characteristic wave speeds and simple wave solutions in thin-walled *** incremental elastic-plastic constitutive relations described by the rate-independent plasticity were adopted,and the finite difference method was used to investigate the evolution and propagation behaviors of combined elasticplastic stress waves in thin-walled tubes when the radial inertial effect was *** numerical results were compared with those obtained when the radial inertia effect was not *** results showed that the speed of the coupled stress wave increased when the radial inertia effect was *** hardening modulus of the material in the plastic stage had a greater impact on the coupled slow waves than on the coupled fast waves.

关键词： Radial inertia effect thin-walled tube stress waves finite difference method characteristic theory

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A novel high-order scheme for numerical simulation of wake flow over helicopter rotors in hover

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Chinese Journal of Aeronautics 2022年第5期35卷 260-274页

作者： Shaoqiang HAN Wenping SONG Zhonghua HAN Institute of Aerodynamic and Multidisciplinary Design Optimization National Key Laboratory of Science and Technology on Aerodynamic Design and ResearchSchool of AeronauticsNorthwestern Polytechnical UniversityXi’an 710072China

Accurate prediction of tip vortices is crucial for predicting the hovering performance of a helicopter rotor.A new high-order scheme(we call it WENO-K)proposed by our research group is employed to minimize numerical dissipation and extended to numerical simulation of unsteady compressible viscous flows dominated by tip vortices over hovering ***-K is referred to as an adaptively optimized WENO scheme with Gauss-Kriging reconstruction,and its advantage is to reduce dissipation in smooth regions of flow while preserving high-resolution around *** WENO-K scheme is adopted to reconstruct left and right state values within the Roe Riemann solver updating the inviscid fluxes on a structured dynamic overset *** minimize the accuracy loss for high-order reconstruction on artificial boundaries of overset grid,a method of multilayer fringes is proposed to carry out interpolation between background grid and blade *** parallel computing considering automatic load balance on averagely partitioned overset grid is developed to reduce the wall-clock time of an unsteady *** results for Caradonna-Tung(C-T)rotor in hover at the conditions of subsonic and transonic tip Mach numbers show that the thrust coefficient error for the result of WENO-K scheme is no more than 3%.Compared with WENO-JS scheme,WENO-K scheme achieves about 40%improvement on accuracy of predicting rotor thrust with only 4.1%extra computational *** importantly,WENO-K scheme can capture more sophisticated unsteady flow structures and resolve tip vortices to a larger wake age with an increment of about 270°compared to WENO-JS scheme.

关键词： Dynamic overset grid Helicopter rotors High-order scheme Unsteady flow Vortex flow WENO scheme

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Effects of the windshield inclination angle on head/brain injuries in car-to-pedestrian collisions using computational biomechanics models

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Transportation Safety and Environment 2024年第2期6卷 1-12页

作者： Fang Wang Mingliang Wang Lin Hu Ke Peng Jiajie Yin Danqi Wang Liangliang Shi Zhou Zhou School of Automotive and Mechanical Engineering Changsha University of Science and TechnologyChangsha 410114HunanChina Hunan Province Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle Changsha University of Science and TechnologyChangsha 410114HunanChina State Key Laboratory of Vehicle NVH and Safety Technology China Automotive Engineering Research Institute Co.Ltd.Chongqing 401122China Division of Neuronic Engineering KTH Ro y al Institute of TechnologyStockholm 14152Sweden

Car-to-pedestrian collision(CPC)accidents occur frequently,and pedestrians often suffer serious head/brain *** major cause is the primary impact with the ***,we use an umerical sim ulation method to study the influence of the windshield in-clination angle of a passenger car on pedestrian head/brain injury due to CPC *** range of the windshield inclination angle was set at 24°-50°,with an interval of 2°.The results show that the windshield angle significantly affects the pedestrian kine-matics and exerts different effects on the head injury when evaluating with various head injury *** the head peak linear/rotational acceleration and acceleration-based head injury criterion(HIC)/rotational injury criterion(RIC),the predictions at the secondary impact stage have no clear relationship with the windshield angle(R^(2)=0.04,0.07,0.03 and 0.26,respectively)and their distributions are *** the primary impact,the peak linear acceleration and HIC show a weak trend of first decreasing and then increasing with the increasing of the windshield angle,and the rotational acceleration and RIC tend to remain relatively *** the cum ulative strain dama ge measure(CSDM)criterion,the predictions at the primary impact are slightly lower than those at the secondary impact,and the trend of first decreasing and then increasing with the increase in the windshield angle is observed at both impact *** the windshield inclination angle is approximately 32°-40°,the head injury severity in both impact phases is generally lower than that predicted at other windshield angles.

关键词： car-to-pedestrian collision(CPC) head/brain injury head injury criterion(HIC) windshield inclination angle computa-tional biomechanics model(CPCBM)

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