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An improved high-fidelity adaptive model for integrated inlet-engine-nozzle based on mechanismdata fusion

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Chinese Journal of Aeronautics 2024年第8期37卷 190-207页

作者： Chen WANG Ziyang yu xian DU Ximing SUN School of Control Science and Engineering Dalian University of TechnologyDalian 116024China Key Laboratory of Intelligent Control and Optimization for Industrial Equipment Ministry of EducationDalian University of TechnologyDalian 116024China

Nowadays,there has been an increasing focus on integrated flight propulsion control and the inlet-exhaust design for the aero-propulsion *** component-level models are inadequate due to installed performance deviations and mismatches between the real engine and the model,failing to meet the accuracy requirements of supersonic *** paper establishes a quasi-one-dimensional model for the inlet-exhaust system and conducts experimental ***,a mechanism-data fusion adaptive modeling scheme using an Extreme Learning Machine based on the Salp Swarm Algorithm(SSA-ELM)is *** study reveals the inlet model’s efficacy in reflecting installed performance,flow matching,and mitigating pressure distortion,while the nozzle model accurately predicts flow coefficients and thrust coefficients,and identifies various operational *** model’s output closely aligns with typical experimental *** combining offline optimization and online adaptive correction,the mechanismdata fusion adaptive model substantially reduces output errors during regular flights and varying levels of degradation,and effectively handles gradual degradation within a single flight ***,the mechanism-data fusion adaptive model holistically addresses total pressure errors within the inlet-exhaust system and normal shock location *** approach significantly curbs performance deviations in supersonic *** example,at Ma=2.0,the system error impressively drops from 34.17%to merely 6.54%,while errors for other flight conditions consistently stay below the 2.95%*** findings underscore the clear superiority of the proposed method.

关键词： Aero-propulsion system Integrated inlet-enginenozzle Component-level model On-board adaptive model Mechanism-data fusion Extreme learning machine

Methane activation by[LnO]^(+):the 4f orbital matters

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Science China Chemistry 2024年第1期67卷 330-335页

作者： Bowei yuan Jingxiang zou Mincheng yu Shaodong Zhou College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027China Zhejiang Provincial Innovation Center of Advanced Chemicals Technology Institute of Zhejiang University–QuzhouQuzhou 324000China Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005China

Gas-phase reactions of[LnO]^(+)with methane have been studied by using inductively coupled plasma-mass spectrometer(ICP-MS)combined with quantum chemical *** indicate that the[LnO]^(+)(Ln=Sm-Lu)ions are able to activate methane to generate methyl *** particular,[EuO]^(+)and[YbO]^(+)exhibit the highest ***,ab initio computations reveal a novel HAT process operating in the absence of a terminal oxygen radical,as mediated by[EuO]^(+)and[YbO]^(+).Such a process diverges from previous findings on the methane activation by metal oxide clusters,not only on the electronic pattern during the course of hydrogen transfer,but also on the important role that 4f electrons *** associated electronic origins have been discussed,and the well-designed 4f electron occupation may turn to be a promising approach in constructing lanthanide involved catalysts.

关键词： lanthanide oxides methane activation 4f orbitals quantum chemical calculation ion-molecule reaction

Limit Theorems for Critical Galton-Watson Processes with Immigration Stopped at Zero

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Acta Mathematica Sinica,English Series 2024年第2期40卷 435-450页

作者： Dou Dou LI Mei ZHANG xian yu ZHANG College of Statistics and Data Science Faculty of ScienceBeijing University of TechnologyBeijing 100124P.R.China Laboratory of Mathematics and Complex Systems(Ministry of Education) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875P.R.China

In this paper,we consider a critical Galton-Watson branching process with immigration stopped at zero *** precise estimation on the probability generating function of the n-th population are obtained,and the tail prob... 详细信息

关键词： Branching immigration critical life period limit theorems

Controlled flight of a self-powered micro blimp driven by insect-sized flapping-wing thrusters

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Chinese Journal of Aeronautics 2024年第6期37卷 127-136页

作者： xian yu Zhiwei LIU Jiaming LENG Mingjing QI Xiaojun YAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Collaborative Innovation Center of Advanced Aero-Engine Beijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-thermodynamics Beihang UniversityBeijng 100191China Beijing Key Laboratory of Aero-Engine Structure and Strength Beihang UniversityBeijing 100191China

Micro aerial platforms face significant challenges in achieving long controlled endurance as most of the energy is consumed to overcome the weight of the *** this study,we present a controllable micro blimp that addresses this issue through the use of a helium-filled *** micro blimp has a long axis of 23 cm and is propelled by four insect-sized flapping-wing thrusters,each weighing 80 mg and with a wingspan of 3.5 *** distributed thrusters enable controlled motions and provide the micro blimp with an advantage in flight endurance compared to multirotors or flapping-wing micro aerial vehicles at the same size *** enhance the performance of the controlled flight,we propose a wireless control module that enables manipulation from a distance of up to 100 ***,a smartphone application is developed to send instructions to the circuit board,allowing the blimp to turn left and right,ascend and descend,and achieve a combination of these movements *** findings demonstrate that this micro blimp is one of the smallest controlled self-powered micro blimps to date.

关键词： Microairvehicle Aircraft control Self-powered micro blimp Flapping-wing thruster Wireless flight

Progress of Proximity Sensors for Potential Applications in Electronic Skins

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Transactions of Tianjin University 2024年第1期30卷 40-62页

作者： Runnan zou Yanhong Tong Jiayi Liu Jing Sun Da xian Qingxin Tang Center for Advanced Optoelectronic Functional Materials Research Key Lab of UV-Emitting Materials and Technology of Ministry of EducationNortheast Normal UniversityChangchun 130024China

Recently,electronic skins and fl exible wearable devices have been developed for widespread applications in medical monitoring,artifi cial intelligence,human–machine interaction,and artifi cial *** proximity sensors can accurately perceive external objects without contact,introducing a new way to achieve an ultrasensitive perception of *** article reviews the progress of fl exible capacitive proximity sensors,fl exible triboelectric proximity sensors,and fl exible gate-enhanced proximity sensors,focusing on their applications in the electronic skin fi ***,their working mechanism,materials,preparation methods,and research progress are discussed in ***,we summarize the future challenges in developing fl exible proximity sensors.

关键词： Capacitive proximity sensors Triboelectric proximity sensors Gate-enhanced proximity sensors Flexible wearable devices Electronic skins

Bifunctional interstitial phosphorous doping strategy boosts platinum-zinc alloy for efficient ammonia oxidation reaction and hydrogen evolution reaction

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Nano Research 2024年第3期17卷 1182-1189页

作者： Tianqi yu Kexin Tan Jia Wu Yongjin zou Shibin Yin Guangxi Key Laboratory of Electrochemical Energy Materials School of Chemistry and Chemical EngineeringGuangxi UniversityNanning 530004China Guangxi Key Laboratory of Information Materials Guilin University of Electronic TechnologyGuilin 541004China

It is still a lack of bifunctional catalysts for ammonia oxidation reaction(AOR)and hydrogen evolution reaction(HER)due to their different reaction *** this work,P is doped into PtZn alloy by calcination with NaH_(2)PO_(2) as P source to induce the lattice tensile strain of Pt and the electronic interaction between P and Zn,which optimizes the AOR and HER activity *** sample with the optimal P content can drive the AOR peak current density of 293.6 mA·mgPt^(-1),which is almost 2.7 times of *** HER,the overpotential at^(-1)0 mA·cm^(-2) is only 23 mV with Tafel slope of 34.1 mV·dec^(-1).Furthermore,only 0.59 V is needed to obtain 50 mA·mgPt^(-1) for ammonia electrolysis under a two-electrode ***,this work shows an ingenious method to design bifunctional catalysts for ammonia electrolysis.

关键词： PtZn alloy phosphorous doping ammonia oxidation reaction hydrogen evolution reaction bifunctional catalyst

CCM-FL:Covert communication mechanisms for federated learning in crowd sensing IoT

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Digital Communications and Networks 2024年第3期10卷 597-608页

作者： Hongruo Zhang Yifei zou Haofei Yin Dongxiao yu Xiuzhen Cheng Institute of Intelligent Computing School of Computer Science and TechnologyShandong UniversityQingdao266237China

The past decades have witnessed a wide application of federated learning in crowd sensing,to handle the numerous data collected by the sensors and provide the users with precise and customized ***,how to protect the private information of users in federated learning has become an important research *** with the differential privacy(DP)technique and secure multiparty computation(SMC)strategy,the covert communication mechanism in federated learning is more efficient and energy-saving in training the ma-chine learning *** this paper,we study the covert communication problem for federated learning in crowd sensing Internet-of-Things *** from the previous works about covert communication in federated learning,most of which are considered in a centralized framework and experimental-based,we firstly proposes a centralized covert communication mechanism for federated learning among n learning agents,the time complexity of which is O(log n),approximating to the optimal ***,for the federated learning without parameter server,which is a harder case,we show that solving such a problem is NP-hard and prove the existence of a distributed covert communication mechanism with O(log logΔlog n)times,approximating to the optimal solution.Δis the maximum distance between any pair of learning *** analysis and nu-merical simulations are presented to show the performance of our covert communication *** hope that our covert communication work can shed some light on how to protect the privacy of federated learning in crowd sensing from the view of communications.

关键词： Covert communications Federated learning Crowd sensing SINR model

Shape estimation for a TPU-based multi-material 3D printed soft pneumatic actuator using deep learning models

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Science China(Technological Sciences) 2024年第5期67卷 1470-1481页

作者： HU yu TANG Wei QU Yang XU HuXiu KRAMARENKO yu.Elena zou Jun State Key Laboratory of Fluid Power and Mechatronic Systems Zhejiang UniversityHangzhou310058China School of Mechanical Engineering Zhejiang UniversityHangzhou310027China Institute of Process Equipment College of Energy EngineeringZhejiang UniversityHangzhou310027China Faculty of Physics Lomonosov Moscow State UniversityMoscow119991Russia Enikolopov Institute of Synthetic Polymeric Materials of Russian Academy of Sciences Moscow117393Russia

Real-time proprioception presents a significant challenge for soft robots due to their infinite degrees of freedom and intrinsic *** studies mostly focused on specific sensors and *** is still a lack of generalizable technologies for integrating soft sensing elements into soft actuators and mapping sensor signals to proprioception *** tackle this problem,we employed multi-material 3D printing technology to fabricate sensorized soft-bending actuators(SBAs)using plain and conductive thermoplastic polyurethane(TPU)*** designed various geometric shapes for the sensors and investigated their strain-resistive performance during *** address the nonlinear time-variant behavior of the sensors during dynamic modeling,we adopted a data-driven approach using different deep neural networks to learn the relationship between sensor signals and system states.A series of experiments in various actuation scenarios were conducted,and the results demonstrated the effectiveness of this *** sensing and shape prediction steps can run in real-time at a frequency of50 Hz on a consumer-level ***,a method is proposed to enhance the robustness of the learning models using data augmentation to handle unexpected sensor *** the methods are efficient,not only for in-plane 2D shape estimation but also for out-of-plane 3D shape *** aim of this study is to introduce a methodology for the proprioception of soft pneumatic actuators,including manufacturing and sensing modeling,that can be generalized to other soft robots.

关键词： shape estimation soft sensors and actuators 3D printing deep learning in robotics

An anti-icing scaling method for wind tunnel tests of aircraft thermal ice protection system

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Chinese Journal of Aeronautics 2024年第6期37卷 1-6页

作者： yu LIU Qiang WANG xian YI Ningli CHEN Jinghao REN Weihao LI Key Laboratory of Icing and Anti/de-icing China Aerodynamics Research and Development CenterMianyang 621000China State Key Laboratory of Aerodynamics Mianyang 621000China

The efficiency of the aircraft Ice Protection Systems(IPSs)needs to be verified through icing wind tunnel ***,the scaling method for testing the IPSs has not been systematically established yet,and further research is *** the present study,a scaling method specifically designed for thermal IPSs was derived from the governing equation of thin water *** scaling parameters were adopted to address the heat and mass transfer involved in the thermal anti-icing *** method validation,icing wind tunnel tests were conducted using a jet engine nacelle model equipped with a bleed air *** non-dimensional surface temperature and runback ice closely matched for both the reference and scaled *** validation confirms that the scaling method is capable of achieving the similarity of surface temperature and the runback ice *** anti-icing scaling method can serve as an important supplement to the existing icing similarity theory.

关键词： Scaling method Ice protection system Water film Anti-icing test Icing wind tunnel