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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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Analysis of the redox environment and genesis of surface sediment in the northeast Indian Ocean at the Ninety-East Ridge

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Journal of Oceanology and Limnology 2025年第1期43卷 57-72页

作者： Zhourong CAI Qianru HUANG Zhengxin YIN Xin SUI Sibo LÜ Meng TANG Juan PENG School of Marine Sciences Sun Yat-sen UniversityZhuhai 519082China Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering Zhuhai 519082China South China Sea Marine Survey Center Ministry of Natural ResourcesGuangzhou 510275China Key Laboratory of Marine Environmental Survey Technology and Application Ministry of Natural ResourcesGuangzhou 510275China

The Ninety-East Ridge(NER)is located in the semioceanic to oceanic region of the southern Bengal Fan in the Northeast Indian *** sedimentary environment,ocean currents,and scientific issues related to climate change have always been the focus of *** well understand the sedimentary environment of the sea area,we studied the modern sedimentary environment of the NER by analyzing the redox-sensitive trace elements(RSEs)and biomarkers in the surface sediments of the northern region and both sides of the NER and the mechanism of their *** ratios of Mo/U(average 2.22),(Cu+Mo)/Zn(average 1.51),and the results ofδCe<1 of the sediment samples,all indicate the reduction of the sedimentary *** addition,the ratio of pristane(Pr)to phytane(Ph),C30diahopane to C30 hopane,and diasterane to sterane were low in all samples,on average of 1.03,0.9,and 0.33,*** analysis of RSE and biomarker data revealed that the sedimentary environment on seabed of the NER is generally a rare low-oxygen reduction *** the analysis of sediment characteristics,material sources,and ocean currents,we preliminarily constructed a genetic model for the low-oxygen reducing environment of surface sediments in the *** believe that the low-oxygen reduction environment of surface sediment in the NER could be influenced by multiple factors,such as terrestrial input of materials,productivity at sea surface,and sediment particle size.

关键词： Ninety-East Ridge(NER) surface sediment sedimentary environment redox-sensitive trace elements(RSEs) biomarker

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Targets capture by distributed active swarms via bio-inspired reinforcement learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 206-217页

作者： Kun Xu Yue Li Jun Sun Shuyuan Du Xinpeng Di Yuguang Yang Bo Li Institute of Biomechanics and Medical Engineering Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China Institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084China Shanghai Aerospace Control Technology Institute Shanghai 201109China Shanghai Key Laboratory of Aerospace Intelligent Control Technology Shanghai 201109China College of Automation Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China

Natural swarms arranged from cells to herds are usually decentralized but display intriguing collective intelligence in coordinating individuals across large scales to efficiently achieve their common *** from nature may provide new strategies for controlling collective dynamics of synthetic swarms to accomplish specific ***,we present a bioinspired computational framework that steers distributed active swarms to collectively capture and merge targets via reinforcement *** exploit collective milling structures of natural herds to cage the targets,and adopt a switching control policy inspired by sperms’chiral dynamics to optimize the trajectories of individuals,through which the active swarms can selforganize to enclose single or multiple distant targets in a dynamical,adaptive and scalable *** exists a critical swarm size,beyond which the excessive competition between agents would generate large mechanical forces,leading to capture instability but enabling the transition from short-distance to long-distance merging capture of multiple *** work provides physical insights into distributed active swarms and could offer a multilevel,decentralized strategy toward controlling swarm robotics in wide applications such as bio-medical devices,machine immunity,and target clearance.

关键词： swarm intelligence robotics multi-tasks artificial intelligence bionics

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Insight into catalytic performance and reaction mechanism for toluene total oxidation over Cu-Ce supported catalyst

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Journal of Environmental Sciences 2025年第3期149卷 476-487页

作者： Xuan Liang Jin Zhang Juntai Tian Zenghua Xie Yue Liu Peng Liu Daiqi Ye School of Environment and Energy South China University of TechnologyGuangzhou 510006China National Engineering Laboratory for VOCs Pollution Control Technology and Equipment Guangzhou 510006China Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control South China University of TechnologyGuangzhou 510006China Guangdong Provincial Engineering and Technology Research Centre for Environmental Risk Prevention and Emergency Disposal South China University of TechnologyGuangzhou 510006China

Herein,three supported catalysts,CuO/Al_(2)O_(3),CeO_(2)/Al_(2)O_(3),and CuO-CeO_(2)/Al_(2)O_(3),were synthesized by the convenient impregnation method to reveal the effect of CeO_(2)addition on catalytic performance and reaction mechanism for toluene *** with CuO/Al_(2)O_(3),the T_(50)and T_(90)(the temperatures at 50%and 90%toluene conversion,respectively)of CuO-CeO_(2)/Al_(2)O_(3)were reduced by 33 and 39°C,respectively.N_(2)adsorptiondesorption experiment,XRD,SEM,EDS mapping,Raman,EPR,H_(2)-TPR,O_(2)-TPD,XPS,NH_(3)-TPD,Toluene-TPD,and in-situ DRIFTS were conducted to characterize these *** excellent catalytic performance of CuO-CeO_(2)/Al_(2)O_(3)could be attributed to its strong coppercerium interaction and high oxygen vacancies ***,in-situ DRIFTS proved that CuO-CeO_(2)/Al_(2)O_(3)promoted the conversion of toluene to benzoate and accelerated the deep degradation path of *** work provided valuable insights into the development of efficient and economical catalysts for volatile organic compounds.

关键词： Cu-Ce supported catalyst Copper-cerium interaction Oxygen vacancies Toluene oxidation Reaction mechanism

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Expression and characterization of a novel GH128 laminarinase OUC-Bs Lam26 harboring both hydrolyzing and transferring activities

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Food Science and Human Wellness 2025年第1期14卷 134-143页

作者： Yueyang Dong Yongyi Quan Hong Jiang Hamed I.Hamouda Zewei Lu Yimiao Chen Chengqiang Li Xiangzhao Mao State Key Laboratory of Marine Food Processing and Safety Control College of Food Science and EngineeringOcean University of ChinaQingdao 266404China Qingdao Key Laboratory of Food Biotechnology Qingdao 266404China Key Laboratory of Biological Processing of Aquatic Products China National Light IndustryQingdao 266404China Sanya Ocean Research Institute Ocean University of ChinaSanya 572025China Processes Design and Development Department Egyptian Petroleum Research InstituteCairo 11727Egypt Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology Qingdao 266237China

Laminarin oligosaccharides(LOSs)with a specific degree of polymerization prepared through the laminarin degradation via laminarinase present more significant nutritional functions and application *** intestinal bacteria are promising potential producers of novel carbohydrate-active enzymes with unique ***,a novel glycoside hydrolase family 128(GH128)laminarinase OUC-BsLam26 from the intestinal bacterium Bacteroides ***7301 was heterologously expressed and *** recombinant OUC-BsLam26 with a molecular mass of 49.86 kDa exhibits highest activity(6.60 U/mg)at 45℃ and pH 6.0,which shows noticeable temperature and pH *** purified OUC-BsLam26 could degrade laminarin via an endo-type mode with the generation of laminaripentaose,laminaritetraose,laminaritriose,and laminaribiose,among them,laminaritetraose is the principal product,which accounts for 45.25% of the total products,which is significantly different from the reported GH128 *** minimum recognition substrate of OUC-BsLam26 is ***,OUC-BsLam26 also could catalyze the transglycosylation process with the production of some novel ***,the intestinal bacterium Bacteroides ***7301 contains laminarinase with unique product composition and OUC-BsLam26 is a hopeful bio-catalyst with the potential to produce laminaritetraose and some novel glycosides.

关键词： Laminarinase Expression Laminarin oligosaccharides Hydrolytic pattern Novel glycosides

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Turbulent drag reduction by sector-shaped counter-flow dielectric barrier discharge plasma actuator

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Chinese Physics B 2025年第2期34卷 362-370页

作者： Borui Zheng Shaojie Qi Minghao Yu Jianbo Zhang Linwu Wang Dongliang Bian School of Automation and Information Engineering Xi’an University of TechnologyXi’an 710048China School of Mechanical and Precision Instrument Engineering Xi’an University of TechnologyXi’an 710048China Science and Technology on Plasma Dynamics Laboratory Air Force Engineering UniversityXi’an 710038China Shaanxi Key Laboratory of Complex System Control and Intelligent Information Processing Xi’an 710048China Shaanxi University Key Laboratory of Photonic Power Devices and Discharge Regulation Xi’an 710048China

The primary objective in aircraft transportation is to minimize turbulent drag, thereby conserving energy and reducing emissions. We propose a sector-shaped counter-flow dielectric barrier discharge plasma actuator, which leverages jet synthesis for drag reduction. A drag control experiment was conducted in a low-speed wind tunnel with a controlled flow velocity of 9.6 m/s(Re = 1.445 × 10^(4)). This study investigated the effects of varying pulse frequencies and actuation voltages on the turbulent boundary layer. Using a hot-wire measurement system, we analyzed the pulsating and time-averaged velocity distributions within the boundary layer to evaluate the streamwise turbulent drag reduction. The results show that the local TDR decreases as the pulse frequency increases, reaching a maximum reduction of approximately 20.97% at a pulse frequency of 50 Hz. In addition, as the actuation voltage increases, the friction coefficient decreases, increasing the drag reduction rate. The maximum drag reduction of approximately 33.34% is achieved at an actuation voltage of 10 kV.

关键词： plasma flow control turbulent boundary layer turbulent drag reduction

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Adsorption of typical gasoline vapor emitted from service stations by commercial activated carbon:static/dynamic adsorption and kinetics simulation

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Frontiers of Environmental Science & engineering 2025年第3期19卷 87-98页

作者： Wei Hu Quanming Liang Dan Lu Beibei Li Biqi Ren Qingye Luan Jia Liu Wenjun Liang Yuhu Huang National Engineering Research Center of Urban Environmental Pollution Control Beijing Key Laboratory of Urban Atmospheric Volatile Organic Compounds Control Technology and ApplicationsBeijing Municipal Research Institute of Eco-Environmental ProtectionBeijing 100037China Key Laboratory of Beijing on Regional Air Pollution Control Faculty of Environment and LifeBeijing University of TechnologyBeijing 100124China Institute of Urban Safety and Environmental Science Beijing Academy of Science and TechnologyBeijing 100054China

Gasoline vapor emissions from service stations significantly affect urban *** the research on the mechanisms and effectiveness of gasoline vapor removal is limited,this study innovatively investigates the static and dynamic adsorption of xylene—a typical gasoline vapor and one of the most active secondary organic aerosol(SOA)species—by commercial activated carbon(AC).The results showed that the saturation static adsorption capacity(Q_(e))of 12 ACs varied from 0.9 to 870.7 mg/g,which correlated with the specific surface area(SSA)and pore *** them,11#and 12#ACs were identified as the most effective adsorbents for typical gasoline vapor *** maximum dynamic Q_(e) increased from 301.5 to 414.3 mg/g when the initial xylene concentration rose from 918 to 2008 mg/m^(3) for 11#AC,and from 201.4 to 406.2 mg/g when the initial xylene concentration increased from 589 to 2120 mg/m^(3) for 12#*** findings implied a direct correlation between higher initial xylene concentrations and greater dynamic Q_(e) values,with static Q_(e) values surpassing dynamic *** adsorption kinetics simulation were analyzed by the pseudo-first-order(PFO)and pseudo-second-order(PSO)*** kinetics results demonstrated that the PFO was more effective in characterizing the adsorption of xylene onto ACs(R2>0.989),indicating that the adsorption of typical gasoline vapor by ACs primarily involves physical *** findings of static/dynamic adsorption and kinetics provide valuable guidance for practical applications of gasoline vapor removal in service stations.

关键词： Activated carbon Gasoline vapor Xylene Dynamic adsorption Breakthrough curve

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Safety-Certified Distributed Formation control of Networked Autonomous Surface Vehicles by Unifying control Lyapunov and control Barrier Functions

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Journal of Systems Science & Complexity 2025年第2期38卷 837-856页

作者： CONG Siming GU Nan WANG Haoliang WANG Dan PENG Zhouhua School of Marine Electrical Engineering Dalian Maritime University State Key Laboratory of Maritime Technology and Safety Dalian Maritime University Dalian Key Laboratory of Swarm Control and Electrical Technology for Intelligent Ships School of Marine Engineering Dalian Maritime University Department of Automation Shanghai Jiaotong University Dalian KeyLaboratory of Swarm Control and Electrical Technology for Intelligent Ships

This paper investigates the path-guided distributed formation control of networked autonomous surface vehicles(ASVs) subject to model uncertainties and environmental disturbances. A safety-certified path-guided coordinated control method is proposed for multiple ASVs to achieve a distributed formation in obstacle environments. Specifically, a neural predictor with a high-order tuner is presented to approximate unknown nonlinearities with accelerated learning performance. Subsequently, control Lyapunov functions(CLFs) and control barrier functions(CBFs) are constructed for mapping stability constraints and safety constraints on states to control inputs. A quadratic optimization problem is constructed with the norm of control inputs as the objective function, CLFs and CBFs as constraints. Neurodynamic optimization is used to deal with the quadratic programming problem and generate the optimal kinetic control signals, thereby attaining the desired safe formation. Unlike the high-order CBF, a CBF backstepping method is proposed to establish safety constraints such that repeated time derivatives of system nonlinearities can be avoided. The multi-ASVs system is ensured to be input-to-state safe irrespective of high-order relative degree. Through the Lyapunov theory, the multi-ASVs system is proven to be input-to-state stable. Finally, simulation results are presented to validate the efficacy of the presented safety-certified distributed formation control for networked ASVs.

关键词： Autonomous surface vehicles control barrier functions neurodynamic optimization path-guided formation control safety-certified control

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A self-supported P-TiO2（B）/Ni2P hybrid achieves efficient sunlight-driven seawater splitting

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Science China Chemistry 2025年第5期68卷 1888-1896页

作者： Zhijie Cheng Xianghui Yu Shuang Cao Chunhu Li Qi Wang Lingyu Piao CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nanoscience and Technology Key Laboratory of Marine Chemistry Theory and Technology (Ministry of Education) College of Chemistry & Chemical EngineeringOcean University of China College of Chemistry and Chemical Engineering Institute for Sustainable Energy and ResourcesQingdao University Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

The low hydrogen（H2） production efficiency and catalyst deactivation for seawater splitting are the significant challenges that should be addressed to achieve practical *** study develops a highly efficient seawater splitting system and extends the utilization of the solar spectrum to the infrared region using a phosphorus-doped Ti O2（B）-based photocatalyst decorated Ni2P on nickel foam(P-TiO2（B）/Ni2P/NF) ***2P serves not only as a co-catalyst for H2production but also as a photothermal conversion layer,harnessing the concentrated heat from solar radiation to vaporize *** far significance is it shifts the H2production from the traditional three-phase system involving solid,liquid,and gas to a more efficient two-phase system involving solids and gases,which effectively reduces the barrier to the thermodynamic reactions and accelerates the processes of transferring mass,resulting in improved efficiency and stability of the *** efficient light absorption,super hydrophilic surfaces,and excellent mechanical stability,this system achieves a H2production rate of 4.22μmol cm-2h-1under AM 1.5G light irradiation without using any noble metals or sacrificial *** rate is line with its performance in pure water and exceeds that of similar reported *** importantly,after more than 300 h of irradiation,the system still demonstrated high H2production activity,indicating the potential for practical *** work provides a valuable strategy to improve both the efficiency and stability of the photothermal catalytic seawater splitting under natural sunlight conditions.

关键词： seawater splitting photothermal catalysis titanium dioxide nickel phosphide

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Interbasin groundwater flows in the Yarlung Zangbo River Basin and its surrounding areas:A perspective

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Science China(Technological Sciences) 2025年第4期68卷 299-301页

作者： Jianxin CHEN Xingxing KUANG Linfeng FAN Chunmiao ZHENG Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen518000China State Key Laboratory of Mountain Hazards and Engineering Resilience Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610000China

Interbasin groundwater flows(IGFs)are movements of groundwater across topographic basin boundaries,which can either contribute to or deplete the water resources of a basin[1].Basins that net-export groundwater beyond their topographic boundaries are termed groundwater exporters,whereas those that receive groundwater from beyond their topographic confines are known as groundwater *** studies have highlighted that the Yarlung Zangbo River Basin(YZRB)is under the impact of IGFs[2,3].

关键词： interbasin groundwater flows interbasin groundwater flows igfs groundwater importers water resources movements groundwater groundwater exporters Yarlung Zangbo River Basin

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