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Inter-well internal resonance analysis of rectangular asymmetric cross-ply bistable composite laminated cantilever shell under transverse foundation excitation

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1353-1370页

作者： Lele REN Wei ZHANG Yufei ZHANG State Key Laboratory of Mechanical system and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Department of Mechanics Guangxi UniversityNanning 530004China beijing Key Laboratory of Nonlinear Vibrations and Strength of Mechanical Structures College of Mechanical EngineeringBeijing University of TechnologyBeijing 100124China

The chaotic dynamic snap-through and complex nonlinear vibrations are investigated in a rectangular asymmetric cross-ply bistable composite laminated cantilever shell,in cases of 1:2 inter-well internal resonance and primary *** transverse foundation excitation is applied to the fixed end of the structure,and the other end is in a free *** first-order approximate multiple scales method is employed to perform the perturbation analysis on the dimensionless two-degree-of-freedom ordinary differential motion control *** four-dimensional averaged equations are derived in both polar and rectangular coordinate *** from the obtained frequency-amplitude and force-amplitude response curves,a detailed analysis is conducted to examine the impacts of excitation amplitude,damping coefficient,and tuning parameter on the nonlinear internal resonance characteristics of the *** nonlinear softening characteristic is exhibited in the upper stable-state,while the lower stable-state demonstrates the softening and linearity *** simulation is carried out using the fourth-order Runge-Kutta method,and a series of nonlinear response curves are *** the excitation amplitude further elucidates the global bifurcation and chaotic dynamic snap-through characteristics of the bistable cantilever shell.

关键词： bistable composite laminated cantilever shell inter-well internal resonance primary resonance chaotic dynamic snap-through complex nonlinear vibration

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Technologies and studies of gas exchange in two-stroke aircraft piston engine:A review

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Chinese Journal of Aeronautics 2024年第1期37卷 24-50页

作者： Yu ZHOU Xueyu LI Shuiting DING Shuai ZHAO Kun ZHU Longtao SHAO Farong DU Gerui WANG Zheng XU Research Institute of Aero-Engine Beihang UniversityBeijing 100191China Aircraft/Engine Integrated system Safety beijing Key Laboratory Beijing 100191China School of Transportation Science and engineering Beihang UniversityBeijing 100191China Civil Aviation University of China Tianjin 300300China Aero Engine Academy of China Beijing 101304China School of Energy and Power engineering Beihang UniversityBeijing 100191China Beihang Hangzhou Innovation Institute Yuhang Hangzhou 310052China

The in-cylinder gas exchange process is crucial to the power performance of two-stroke aircraft piston engines,which is easily influenced by complex factors such as high-altitude performance variation and in-cylinder flow *** paper reviews the development history and characteristics of gas exchange types,as well as the current state of theory and the validation methods of gas exchange technology,while also discusses the trends of cutting-edge technologies in the *** paper provides a theoretical foundation for the optimization and engineering design of gas exchange systems and,more importantly,points out that the innovation of gas exchange types,the modification of theoretical models,and the technology of variable airflow organization are the key future research directions in this field.

关键词： Aircraft piston engine Aircraft power systems Gas exchange High-altitude performance In-cylinder flow Two-stroke Unmanned Aerial Vehicles(UAVs)

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Building Semantic Communication system via Molecules:An End-to-End Training Approach

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China Communications 2024年第7期21卷 113-124页

作者： Cheng Yukun Chen Wei Ai Bo School of Electronic and Information engineering Beijing Jiaotong UniversityBeijing 100091China Frontiers Science Center for Smart High-speed Railway system Beijing Jiaotong UniversityBeijing 100091China Key Laboratory of Railway Industry of Broadband Mobile Information Communications Beijing Jiaotong UniversityBeijing 100091China beijing engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing Jiaotong UniversityBeijing 100091China School of Information engineering Zhengzhou UniversityZhengzhou 450001China

The concept of semantic communication provides a novel approach for applications in scenarios with limited communication *** this paper,we propose an end-to-end(E2E)semantic molecular communication system,aiming to enhance the efficiency of molecular communication systems by reducing the transmitted ***,following the joint source channel coding paradigm,the network is designed to encode the task-relevant information into the concentration of the information molecules,which is robust to the degradation of the molecular communication ***,we propose a channel network to enable the E2E learning over the non-differentiable molecular *** results demonstrate the superior performance of the semantic molecular communication system over the conventional methods in classification tasks.

关键词： deep learning end-to-end learning molecular communication semantic communication

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Meter-Scale Thin-Walled Structure with Lattice Infill for Fuel Tank Supporting Component of Satellite:Multiscale Design and Experimental Verification

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工程与科学中的计算机建模(英文) 2024年第1期138卷 201-220页

作者： Xiaoyu Zhang Huizhong Zeng Shaohui Zhang Yan Zhang Mi Xiao Liping Liu Hao Zhou Hongyou Chai Liang Gao beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures Beijing Institute of TechnologyBeijing100081China beijing Key Laboratory of Intelligent Space Robotic systems Technology and Applications Beijing Institute of Spacecraft System EngineeringChina Academy of Space TechnologyBeijing100094China Key Laboratory of Metallurgical Equipment and Control Technology Ministry of EducationWuhan University of Science and TechnologyWuhan430081China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China

Lightweight thin-walled structures with lattice infill are widely desired in satellite for their high stiffness-to-weight ratio and superior buckling strength resulting fromthe sandwich *** structures can be fabricated bymetallic additive manufacturing technique,such as selective laser melting(SLM).However,the maximum dimensions of actual structures are usually in a sub-meter scale,which results in restrictions on their appliance in aerospace and other *** this work,a meter-scale thin-walled structure with lattice infill is designed for the fuel tank supporting component of the satellite by integrating a self-supporting lattice into the thickness optimization of the *** designed structure is fabricated by SLM of AlSi10Mg and cold metal transfer welding ***-static mechanical tests and vibration tests are both conducted to verify the mechanical strength of the designed large-scale lattice thin-walled *** experimental results indicate that themeter-scale thin-walled structure with lattice infill could meet the dimension and lightweight requirements of most spacecrafts.

关键词： Thin-walled structure lattice infill supporting component selective laser melting satellite

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Cyber-physical Collaborative Restoration Strategy for Power Transmission system Considering Maintenance Scheduling

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CSEE Journal of Power and Energy systems 2024年第3期10卷 1331-1341页

作者： Baozhong Ti Chuanyun Zhang Jingfei Liu Zhaoyuan Wu Ziyang Huang North China Branch of State Grid Corporation of China Beijing 100053China State Grid beijing Electric Power Company Beijing 100031China State Key Laboratory of Alternate Electrical Power system with Renewable Energy Sources School of Electrical and Electronic EngineeringNorth China Electric Power UniversityBeijing 102206China IEEE CSEE

In order to improve the ability of power transmission system to cope with compound faults on the communication side and power side,a cyber-physical collaborative restoration strategy is ***,according to the information system’s role in fault diagnosis,remote control of equipment maintenance and automatic output adjustment of generator restoration,a cyber-physical coupling model is *** this basis,a collaborative restoration model of power transmission system is established by studying interactions among maintenance schedule paths,information system operation,and power system *** on power flow linearization and the large M-ε method,the above model is transformed into a mixed integer linear programming model,whose computational burden is reduced further by the clustering *** to the parameters of IEEE39 New England system,the geographic wiring diagram of the cyber-physical system is *** results show the proposed restoration strategy can consider the support function of the information system and space-time coordination of equipment maintenance at both sides comprehensively to speed up load recovery progress.

关键词： Clustering method collaborative restoration cyber-physical power system maintenance scheduling power transmission system restoration

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Experimental Study on the Molten Salt at Micron Scale during the Melting Process

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Journal of Thermal Science 2024年第1期33卷 70-85页

作者： TIAN Ziqian LIAO Zhirong XU Chao FANG Yongzhe JIANG Kaijun YUAN Mengdi Key Laboratory of Power Station Energy Transfer Conversion and system Ministry of Education of ChinaSchool of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

The investigation of the melting behaviors of the molten salt at micron scale during the melting process is critical for explaining the solid-liquid phase transition *** this paper,a novel experimental system and analysis method were proposed to study the melting process with three heating rates in the range of1-10℃/min of the solar salt at micron *** solid-liquid boundary morphology and phase transition kinetics of molten salt particles were focused ***,the correlations between liquid fraction,temperature and time under different heating rates were *** solid-liquid boundary morphology was depicted by the visualized experimental set-up,and the instantaneous liquid volume fraction during the non-isothermal phase transition was ***,the correlation between temperature and liquid volume fraction was proposed to reveal the evolution of the solid-liquid boundary with temperature at different heating ***,the non-isothermal phase transition kinetic equation was established by introducing a constant parameter(V_(a,b)),and more kinetic parameters such as 1g V_(a,b) and-lg V_(a,b)/b were *** results showed that the exponent b is not sensitive to the heating rate with a range of 3-5 for solar salt ***,the heating rate influences the value of V_(a,b) and presents a positive ***,the non-isothermal phase transition kinetic equations at different heating rates in the range of 1-10℃/min can be quickly predicted by the proposed improved experimental test *** study could fill the research insufficiency and provide significant guidance for future research on the solid-liquid transition mechanism of molten salts at micron scale.

关键词： molten salt non-isothermal phase transition solid-liquid boundary morphology liquid volume fraction micron scale melting process

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How does supergravity affect combustion?

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Acta Mechanica Sinica 2024年第6期40卷 39-40页

作者： Wenjun Kong Zheng Chen School of Astronautics Beihang UniversityBejing 102206China State Key Laboratory of Turbulence and Complex system Cllege of EngineeringPeking Universy Beijing 100871Chin

It is well known that gravity may have a profound impact on the combustion process under certain conditions[1].The densities of the gaseous combustion products are typically 5-12 times lower than those of *** normal gravity conditions,the density difference generates buoyant forces that drive the flow,which affects the combustion process through flow-transport-chemistry *** example,the buoyant convection in normal gravity causes the candle flame to be shaped like a teardrop while spherical candle flame is observed in ***,microgravity combustion has drawn great attention.A series of combustion experiments have been and will be conducted in the International Space Station and Chinese Space *** fact,significant progress has been made in microgravity *** example,the discovery of steadily burning cool flames[2]in microgravity experiments was regarded as one of the"20 Breakthroughs from 20 Years of Science aboard the International Space Station".

关键词： interaction. reactant typically

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Microphase Separation of Semiflexible Ring Diblock Copolymers

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Chinese Journal of Polymer Science 2024年第2期42卷 267-276,I0011页

作者： Dan-Yan Qin Sheng-Da Zhao Zhi-Xin Liu Jing Zhang Xing-Hua Zhang School of Physical Science and engineering Beijing Jiaotong UniversityBeijing100044China

Aiming at the difficult problem of solving the conformation statistics of complex polymers, this study presents a novel and concise conformation statistics theoretical approach based on Monte Carlo and Neural Network method. This method offers a new research idea for investigating the conformation statistics of complex polymers, characterized by its simplicity and practicality. It can be applied to more complex topological structure, more higher degree of freedom polymer systems with higher dimensions, theory research on dynamic self-consistent field theory and polymer field theory, as well as the analysis of scattering experimental data. The conformation statistics of complex polymers determine the structure and response properties of the system. Using the new method proposed in this study, taking the semiflexible ring diblock copolymer as an example, Monte Carlo simulation is used to sample this ring conformation to construct the dataset of polymer. The structure factor describing conformation statistics are expressed as continuous functions of structure parameters by neural network supervised learning. This is the innovation of this work. As an application, the structure factors represented by neural networks were introduced into the random phase approximation theory to study the microphase separation of semiflexible ring diblock copolymers. The influence of the ring's topological properties on the phase transition behavior was pointed out.

关键词： Ring copolymer Diblock copolymers Semiflexible The order-disorder transition

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Interface interaction between SiO_(2) and magnetite under high temperature:particle migration and inhibition mechanism

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Journal of Iron and Steel Research International 2024年第3期31卷 561-572页

作者： Yao-zu Wang Jian-liang Zhang Qiang Cheng Hui-qing Jiang Zheng-jian Liu Yu-bo Tan School of Intelligent Science and Technology University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological engineering University of Science and Technology BeijingBeijing 100083China School of Advanced engineering University of Science and Technology BeijingBeijing 100083China

Silicon is one of the main gangue components in iron ore,usually in the form of quartz and *** studies have shown that SiO_(2) has a two-sided effect on the consolidation of pellets during high-temperature oxidation roasting of ***,it is very difficult to capture the structural evolution and migration mechanisms during high-tem-perature roasting process by existing experimental ***,the influence of SiO_(2) on the consolidation behavior of magnetite was studied through a series of roasting experiments and molecular dynamic *** results show that the consolidation index and particle growth index decrease with the increase in SiO_(2) content in the *** 1573 K,the liquid phase promotes the recrystallization growth of hematite at high *** dynamic study shows that it is difficult for quartz SiO_(2) to form sintering neck with Fe_(2)O_(3).When the calcination temperature is higher than 1400 K,the Fe_(2)O_(3)-Fe_(2)SiO_(4) system produces a considerable sintering neck structure after *** atomic migration ability of Fe_(2)SiO_(4) is much higher than that of Fe_(2)O_(3).The higher atomic migration ability of Fe_(2)SiO_(4) is the main reason for the formation of the sintering neck.

关键词： Sintering neck Crystal growth Consolidation Molecular dynamics SiO_(2)

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Parallel system Based Quantitative Assessment and Self-evolution for Artificial Intelligence of Active Power Corrective Control

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CSEE Journal of Power and Energy systems 2024年第1期10卷 13-28页

作者： Tianyun Zhang Jun Zhang Feiyue Wang Peidong Xu Tianlu Gao Haoran Zhang Ruiqi Si School of Electrical engineering and Automation Wuhan UniversityWuhan 430072HubeiChina State Key Laboratory for Management and Control of Complex system Institute of AutomationChinese Academy of SciencesBeijing 100190China

In artificial intelligence(AI)based-complex power system management and control technology,one of the urgent tasks is to evaluate AI intelligence and invent a way of autonomous intelligence ***,there is,currently,nearly no standard technical framework for objective and quantitative intelligence *** this article,based on a parallel system framework,a method is established to objectively and quantitatively assess the intelligence level of an AI agent for active power corrective control of modern power systems,by resorting to human intelligence evaluation *** this basis,this article puts forward an AI self-evolution method based on intelligence assessment through embedding a quantitative intelligence assessment method into automated reinforcement learning(AutoRL)systems.A parallel system based quantitative assessment and self-evolution(PLASE)system for power grid corrective control AI is thereby constructed,taking Bayesian Optimization as the measure of AI evolution to fulfill autonomous evolution of AI under guidance of their intelligence assessment *** results exemplified in the power grid corrective control AI agent show the PLASE system can reliably and quantitatively assess the intelligence level of the power grid corrective control agent,and it could promote evolution of the power grid corrective control agent under guidance of intelligence assessment results,effectively,as well as intuitively improving its intelligence level through selfevolution.

关键词： AI quantitative intelligence assessment and self-evolution automated reinforcement learning Bayesian optimization corrective control parallel system

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