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Recent advancements of nonlinear dynamics in mode coupled microresonators:a review

Applied Mathematics and Mechanics(English Edition) 2025年第2期46卷 209-232页

作者： Xuefeng WANG Zhan SHI Qiqi YANG Yuzhi CHEN Xueyong WEI Ronghua HUAN Department of Engineering Mechanics MIIT Key Laboratory of Dynamics and Control of Complex SystemsNorthwestern Polytechnical UniversityXi’an 710129China Department of Mechanics Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang UniversityHangzhou 310027China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710054China

Due to scale effects,micromechanical resonators offer an excellent platform for investigating the intrinsic mechanisms of nonlinear dynamical phenomena and their potential *** review focuses on mode-coupled micromechanical resonators,highlighting the latest advancements in four key areas:internal resonance,synchronization,frequency combs,and mode *** origin,development,and potential applications of each of these dynamic phenomena within mode-coupled micromechanical systems are investigated,with the goal of inspiring new ideas and directions for researchers in this field.

关键词： mode coupling micro-electro-mechanical system(MEMS)resonator nonlinear dynamics

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Dynamics and experiments of a tendon-actuated flexible robotic arm for capturing a floating target

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Defence Technology(防务技术) 2025年第5期47卷 216-241页

作者： Xin Xia Yunpeng Sun Jialiang Sun State Key Laboratory of Mechanics and Control for Aerospace Structures College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing210016China College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016China

Reusable and flexible capturing of space debris is highly required in future aerospace technologies.A tendon-actuated flexible robotic arm is therefore proposed for capturing floating targets in this ***,an accurate dynamic model of the flexible robotic arm is established by using the absolute nodal coordinate formulation(ANCF)in the framework of the arbitrary Lagrangian-Eulerian(ALE)description and the natural coordinate formulation(NCF).The contact and self-contact dynamics of the flexible robotic arm when bending and grasping an object are considered via a fast contact detection ***,the dynamic simulations of the flexible robotic arm for capturing floating targets are carried out to study the influence of the position,size,and mass of the target object on the grasping ***,a principle prototype of the tendon-actuated flexible robotic arm is manufactured to validate the dynamic *** corresponding grasping experiments for objects of various shapes are also conducted to illustrate the excellent performance of the flexible robotic arm.

关键词： Tendon-actuated flexible robotic arm Dynamic modeling Contact dynamics ALE-ANCF variable-length cable element Capturing experiments

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3D FE cutting simulations of Nomex honeycomb composites in rotary ultrasonic machining process

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International Journal of Machining and Machinability of Materials 2024年第1期26卷 58-84页

作者： Ahmad, Shahzad Zhang, Jianfu Wang, Jianjian Feng, Pingfa Zhang, Xiangyu Beijing Key Laboratory of Precision/ Ultra-Precision Manufacturing Equipment and Control Department of Mechanical Engineering Tsinghua University Beijing100084 China Multan60600 Pakistan State Key Laboratory of Tribology Department of Mechanical Engineering Tsinghua University Beijing100084 China

In this research a 3D FE rotary ultrasonic cutting simulation model of NHCs core material was developed based on Hashin failure criterion and novel ultrasonic circular saw blade cutter system. Further, 3D FE cutting simulation model was validated by performing RUM experiments on ultrasonic machine tool and explored. Cutting force exhibits inverse relation with vibration amplitude and spindle speed of ultrasonic circular saw blade tool, whereas it shows direct relation with feed rate. Finally, an optimised set of processing parameters was obtained by performing series of cutting simulations and verified by experimental work with a novel ultrasonic circular saw blade cutting tool at resonant frequency of 22,050 Hz, spindle speed 3,000 rpm, feed rate 500 mm/min, cutting width 8 mm, cutting depth 2 mm, and vibration amplitude 25 µm. Moreover, this study provides systematic guideline for RUM process optimisation and improvements of surface quality. © 2024 Inderscience Publishers. All rights reserved.

关键词： Natural frequencies

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MATD3-Based End-Edge Collaborative Resource Optimization for NOMA-Assisted Industrial Wireless Networks

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Computers, Materials & Continua 2025年第2期82卷 3203-3222页

作者： Ru Hao Chi Xu Jing Liu College of Information Engineering Shenyang University of Chemical TechnologyShenyang110142China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang110016China Key Laboratory of Networked Control Systems Chinese Academy of SciencesShenyang110016China

Non-orthogonal multiple access (NOMA) technology has recently been widely integrated into multi-access edge computing (MEC) to support task offloading in industrial wireless networks (IWNs) with limited radio resources. This paper minimizes the system overhead regarding task processing delay and energy consumption for the IWN with hybrid NOMA and orthogonal multiple access (OMA) schemes. Specifically, we formulate the system overhead minimization (SOM) problem by considering the limited computation and communication resources and NOMA efficiency. To solve the complex mixed-integer nonconvex problem, we combine the multi-agent twin delayed deep deterministic policy gradient (MATD3) and convex optimization, namely MATD3-CO, for iterative optimization. Specifically, we first decouple SOM into two sub-problems, i.e., joint sub-channel allocation and task offloading sub-problem, and computation resource allocation sub-problem. Then, we propose MATD3 to optimize the sub-channel allocation and task offloading ratio, and employ the convex optimization to allocate the computation resource with a closed-form expression derived by the Karush-Kuhn-Tucker (KKT) conditions. The solution is obtained by iteratively solving these two sub-problems. The experimental results indicate that the MATD3-CO scheme, when compared to the benchmark schemes, significantly decreases system overhead with respect to both delay and energy consumption.

关键词： Industrial wireless networks(IWNs) multi-access edge computing(MEC) non-orthogonal multiple access(NOMA) task offloading resource allocation

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Improved Residual Reinforcement Learning for Dynamic Obstacle Avoidance of Robotic Arm 13

Improved Residual Reinforcement Learning for Dynamic Obstacl...

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13th IEEE Data Driven control and Learning Systems Conference, DDCLS 2024

作者： Liu, Zhenting Liu, Shan College of Control Science and Engineering Zhejiang University State Key Laboratory of Industrial Control Technology Hangzhou310027 China

ISBN: (纸本)9798350361674

This paper proposes an improved residual deep reinforcement learning method for robot arm dynamic obstacle avoidance and position servo. The proposed method first simplifies the state space by constructing key points and pre-trains a model capable of completing obstacle avoidance tasks using the simplified state. Then, when training with real state information, a guiding network is used to help accumulate good samples, which improves the training efficiency. To overcome the convergence difficulty of residual DQN in robot arm obstacle avoidance, this paper incorporates the action of the feedback controller into the action space and uses incremental reward values to evaluate the actions. Simulation results demonstrate that the proposed method can effectively achieve robot arm dynamic obstacle avoidance and position servo. © 2024 IEEE.

关键词： Deep reinforcement learning

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Ambient particle composition and toxicity in 31 major cities in China

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Fundamental Research 2024年第3期4卷 505-515页

作者： Lu Zhang Maosheng Yao State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking UniversityBeijing 100871China

Current assessment of air quality or control effectiveness is solely based on particulate matter(PM)mass levels,without considering their toxicity differences in terms of health ***,we collected a total of 465 automo-bile air conditioning filters from 31 major Chinese cities to study the composition and toxicity of PM at a national *** assay showed that normalized PM toxicity(NIOG)in different Chinese cities varied greatly from the highest 4.99×10^(-3)for Changsha to the lowest 7.72×10^(-4)for ***0G values were observed to have significant correlations with annual PM_(10) concentration(r=-0.416,p=0.020)and some PM components(total fungi,so.2-and calcium element).The concentrations of different elements and water-soluble ions in PM also varied by several orders of magnitude for 31 cities in *** concentrations in PM analyzed using limulus amebocyte lysate assay ranged from 2.88 EU/mg PM(Hangzhou)to 62.82 EU/mg PM(Shijiazhuang)among 31 Chinese ***,real-time qPCR revealed 10~100-fold differences in total bacterial and fungal levels among 31 Chinese *** concentrations of chemical(water soluble ions and trace elements)and bi-ological(fungi,bacteria and endotoxin)components in PM were found to be significantly correlated with some meteorological factors and gaseous pollutants such as SO_(2).Our results have demonstrated that PM toxicity from 31 major cities varied greatly up to 6.5 times difference;and components such as fungi and SO_(4)^(2-)in PM could play important roles in the observed PM *** city-specific air pollution control strategy that integrates toxicity factors should be enacted in order to maximize health and economic *** work also provides a comprehensive view on the overall PM pollution situation in China.

关键词： PM toxicity Oxidative potential Biologicals Chemical components Endotoxin

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Design and fabrication of self-suspending aluminum-plastic/semiconductor photocatalyst devices for solar energy conversion

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Journal of Environmental Sciences 2024年第2期136卷 615-625页

作者： Zhi-Ang Zhao Jingyun Mao Chengjing Lu Shuangqiao Yang Qingrong Qian Qinghua Chen Hun Xue Xiaoli Sun Min-Quan Yang College of Environmental and Resource Sciences College of Carbon Neutral Modern IndustryFujian Key Laboratory of Pollution Control and Resource ReuseFujian Normal UniversityFuzhou 350007China State Key Laboratory of Polymer Materials Engineering Polymer Research Institute of Sichuan UniversityChengdu 610065China

The design and synthesis of self-suspending photocatalyst device with easy recyclability is important for practical ***,this work utilizes aluminum-plastic package waste as raw material to prepare an aluminum-plastic supported TiO_(2)(AP-TiO_(2))photocatalyst device through 3D printing design and surface deposition method.A series of characterizations were carried out to explore the structure,morphology and performance of the AP-TiO_(2)*** UV light illumination,the AP-TiO_(2)-50 efficiently degrade 93.6%tetracycline hydrochloride(THC)after 4 hr,which increases by 8.3%compared with that of TiO_(2)powder suspension system with the same catalyst *** on it,AP-ZnO,AP-CdS,AP-g-C_3N_4and AP-Pt-TiO_(2)are also fabricated,and applied in photocatalytic degradation and hydrogen evolution,which all exhibit higher photoactivities than powder suspension *** work provides a new avenue for the fabrication of advanced recyclable photocatalyst ***,the work offers a novel sight for the high-value utilization of aluminum-plastic package waste,which has positive implications for environmental protection.

关键词： TiO_(2) Self-suspending Photocatalyst device Aluminum plastic

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An improved adaptive minimum entropy deconvolution method in bearing fault detection 4

An improved adaptive minimum entropy deconvolution method in...

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4th International Conference on Mechanical, Electronics, and Electrical and Automation control, METMS 2024

作者： Liao, Zihao Xu, Jinglun Jin, Minglv Cao, Yuqi Cao, Yunqi Hou, Dibo Huang, Pingjie State Key Laboratory of Industrial Control Technology College of Control Science and Engineering Zhejiang University Hangzhou310027 China

ISBN: (数字)9781510679887

ISBN: (纸本)9781510679870

Bearings, a crucial element in rotating machinery, are most susceptible to failure during operation, making up over half of all malfunctions. Detecting bearing faults in a timely manner can be quite challenging due to the frequent influence of strong noise on the fault features. To address the issue, an adaptive parameter optimization based on Minimum Entropy Deconvolution (MED) method in conjunction with Infogram is proposed. First, the Infogram is created through spectral negentropy, followed by the construction of a filter that utilizes the center frequency and the frequency band exhibiting the highest spectral negentropy. This filter is then applied to the original vibration signal in order to isolate the frequency band that contains the most significant bearing fault information. Then, based on MED method, the autocorrelation function and L1 norm are introduced to evaluate the filtered signal to realize the adaptive search of deconvolution filter length. Finally, the characteristic frequency components are extracted by envelope spectrum analysis. The validation of the effectiveness of the proposed method is conducted on a public dataset across various bearing operating conditions. The verification results show that this method can accurately detect the conditions of bearings, and extract more distinctive characteristic frequency components compared with some relevant techniques. © 2024 SPIE.

关键词： Spectrum analysis

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Numerical study on the dynamic fracture of explosively driven cylindrical shells

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Defence Technology（防务技术） 2023年第9期27卷 154-168页

作者： Zhi-yong Yin Xiao-wei Chen State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing100081China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing100081China Advanced Research Institute of Multidisciplinary Sciences Beijing Institute of TechnologyBeijing100081China

Research on the expansion and fracture of explosively driven metal shells has been a key issue in weapon development and structural *** is important to study and predict the failure mode,fracture mechanism,and fragment distribution characteristics of explosively driven metal *** this study,we used the finite element-smoothed particle hydrodynamics(FE-SPH)adaptive method and the fluid-structure interaction method to perform a three-dimensional numerical simulation of the expansion and fracture of a metal cylindrical *** method combined the advantages of the FEM and SPH,avoiding system mass loss,energy loss,and element distortion;in addition,the proposed method had a good simulation effect on the interaction between detonation waves and the cylindrical *** simulated detonation wave propagation,shell damage morphology,and fragment velocity distribution were in good agreement with theoretical and experimental *** divided the fragments into three regions based on their shape *** analyzed the failure mode and formation process of fragments in different *** numerical results reproduced the phenomenon in which cracks initiated from the inner surface and extended to the outer surface of the cylindrical shell along the 45°or 135°shear *** addition,fragments composed of elements are identified,and the mass and characteristic lengths of typical fragments at a stable time are ***,the mass and size distribution characteristics of the fragments were explored,and the variation in the fitting results of the classical distribution function under different explosion pressures was ***,based on mathematical derivation,the distribution formula of fragment velocity was *** improved formula provided higher accuracy and could be used to analyze any metal cylindrical shells with different length-to-diameter ratios.

关键词： Metal cylindrical shell Shear failure Fragment distribution Numerical simulation Fragment velocity

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Experimental study on the DC response of parallel NTC thermistors to sensitive semiconductor bridge transducers 4

Experimental study on the DC response of parallel NTC thermi...

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4th International Conference on Defence Technology, ICDT 2024

作者： Jin, Hao-Jie Niu, Hui-Yuan Ren, Wei Ji, Xiang-Fei Wang, Li Li, Hui An, Cheng-Yuan National Key Laboratory of Transient Chemical Effects and Control Shaanxi Applied Physics and Chemistry Research Institute Xi’an China School of Mechatronical Engineering Beijing Institute of Technology Beijing China

The application of parallel thermistor is an essential method for improving the critical fusing current of semiconductor bridge (SCB). In this paper, constant current power supply and infrared test system are employed to experimentally investigate the effect of parallel negative temperature coefficient (NTC)thermistor on the response of semiconductor bridge under various DC excitations. The test results demonstrate a comparison between the SCB (NTC-SCB) with negative temperature coefficient thermistor in parallel and the SCB without NTC. The temperature in the bridge region can be reduced by 68% with a more than one-fold increase in the critical fusing current. And the shunt effect of NTC thermistor is 34.4%-74.4%. © 2024 Institute of Physics Publishing. All rights reserved.

关键词： Thermistors

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