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dynamic behavior of tunneling triboelectric charges in two-dimensional materials

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International Journal of Minerals,Metallurgy and Materials 2023年第9期30卷 1801-1808页

作者： Xuan Zhao Liangxu Xu Xiaochen Xun Fangfang Gao Qingliang Liao Yue Zhang Academy for Advanced Interdisciplinary Science and Technology School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Advanced Energy Materials and TechnologiesUniversity of Science and Technology BeijingBeijing 100083China

Although the research history of triboelectrification has been more than 2000 years, there are still many problems to be solved so far.The use of scanning probe microscopy provides an important way to quantitatively study the transfer, accumulation, and dissipation of triboelectric charges in the process of triboelectrification. Two-dimensional materials are considered to be key materials for new electronic devices in the post-Moore era due to their atomic-scale size advantages. If the electrostatic field generated by triboelectrification can be used to replace the traditional gate electrostatic field, it is expected to simplify the structure of two-dimensional electronic devices and reconfigure them at any time according to actual needs. Here, we investigate the triboelectrification process of various two-dimensional materials such as MoS_(2), WSe_(2),and ZnO. Different from traditional bulk materials, after two-dimensional materials are rubbed, the triboelectric charges generated may tunnel through the two-dimensional materials to the underlying substrate surface. Because the tunneling triboelectric charge is protected by the twodimensional material, its stable residence time on the substrate surface can reach more than 7 days, which is more than tens of minutes for the traditional triboelectric charge. In addition, the electrostatic field generated by the tunneling triboelectric charge can effectively regulate the carrier transport performance of two-dimensional materials, and the source–drain current of the field effect device regulated by the triboelectric floating gate is increased by nearly 60 times. The triboelectric charge tunneling phenomenon in two-dimensional materials is expected to be applied in the fields of new two-dimensional electronic devices and reconfigurable functional circuits.

关键词： two-dimensional materials triboelectric charge dynamic behavior reconfigurable electronics

dynamic behavior Analysis of Finger Seal Based on Equivalent dynamic Model

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Chinese Journal of Mechanical Engineering 2010年第5期23卷 590-599页

作者： SU Hua CHEN Guoding School of Mechatronics Northwestern Polytechnical University Xi ＇an 710072 China

Finger seal is a new technology developed for gas path sealing in gas turbine engine.It has been paid attention to its good sealing performance and lower manufacture cost.The vibration behavior of finger seal is not be considered in performance analysis for the contact finger seal with compliant geometric configuration,then this will influence the reliability of the performance analysis and the parametric design of a finger seal.According to the dynamic character of finger seal,the harmonic vibration and free vibration models of a repetitive section of a two-layer finger seal that contains one high and one low finger seal are established separately.The dynamic behavior of finger seal in different working conditions is obtained based on the dynamic response analysis of finger＇s vibrations.The dynamic low hysteresis and low wear terms based on the equivalent dynamic model of finger seal are put forward,which can be used to predict the dynamic behavior of finger seal.As an example,the dynamic behaviors of an 8-layer finger seal and a 10-layer finger seal were predicted,and the validity of the prediction was demonstrated by the leakage test results of these two finger seals.The work presented here not only could make the dynamic analysis of finger seal with complicated structure simple and easy especially for multi-layer finger seal system,but also suggest a useful method for designing the finger seal with good dynamic behavior by means of different seal layers assembly.

关键词： finger seal dynamic behavior vibration

dynamic behavior OF PILES EMBEDDED IN TRANSVERSELY ISOTROPIC LAYERED MEDIA

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Acta Mechanica Sinica 1997年第3期13卷 241-252页

作者：郑铁生 Department of Engineering Mechanics Xi'an Jiaotong UniversityXi'an710049China

dynamic behavior of single pile embedded in transversely isotropic layered media is investigated using the finite element method combined with dynamic stiffness matrices of the soil derived from Green's function for ring loads. The influence of soil anisotropy on the dynamic behavior of piles is examined through a series of parametric studies.

关键词： pile-soil system soil anisotropy transversely isotropic layered media dynamic behavior finite element method

dynamic behavior of bridge-erecting machine subjected to moving mass suspended by wire ropes

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Applied Mathematics and Mechanics(English Edition) 2016年第6期37卷 741-748页

作者： Shaopu YANG Xueqian FANG Jianchao ZHANG Dujuan WANG School of Mechanical Engineering Shijiazhuang Tiedao University China Railway Engineering Equipment Group Co. Ltd.

The dynamic behavior of a bridge-erecting machine, carrying a moving mass suspended by a wire rope, is investigated. The bridge-erecting machine is modelled by a simply supported uniform beam, and a massless equivalent ＂spring-damper＂ system with an effective spring constant and an effective damping coefficient is used to model the moving mass suspended by the wire rope. The suddenly applied load is represented by a unitary Dirac Delta function. With the expansion method, a simple closed-form solution for the equation of motion with the replaced spring-damper-mass system is formulated. The characters of the rope are included in the derivation of the differential equation of motion for the system. The numerical examples show that the effects of the damping coefficient and the spring constant of the rope on the deflection have significant variations with the loading frequency. The effects of the damping coefficient and the spring constant under different beam lengths are also examined. The obtained results validate the presented approach, and provide significant references in the design process of bridgeerecting machines.

关键词： bridge-erecting machine wire rope dynamic behavior equivalent ＂spring-damper＂ system

dynamic behavior of Two Part Towing Cable System During Turning

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Journal of Shanghai Jiaotong university(Science) 2018年第3期23卷 444-455页

作者：高慧王志博 Jiangsu University of Science and Technology Zhangjiagang 215600 Jiangsu China Shanghai Ship and Shipping Research Institute Shanghai 200135 China

An improved numerical method is used to simulate the dynamic behavior of a two part towing cable systems during turnings. In U turns and full turns, periodical heave motions are found both for the towed vehicle and for the depressor. Periodic motions of the subsea units and of the cable surface tension are closely related to the turning parameters, such as turning velocity and turning radius. System parameters, such as length of the second cable and the vehicle hydrodynamics, also damp turning instability.

关键词： towing cable systems dynamic behavior periodic motion turning operation

Computational and experimental study on dynamic behavior of underwater robots propelled by bionic undulating fins

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Science China(Technological Sciences) 2010年第11期53卷 2966-2971页

作者： ZHOU Han HU TianJiang XIE HaiBin ZHANG DaiBing SHEN LinCheng College of Mechatronic Engineering and Automation National University of Defense TechnologyChangsha 410073China

Bionic undulating fins, inspired by undulations of the median and/or paired fin (MPF) fish, have a bright prospective for un-derwater missions with higher maneuverability, lower noisy, and higher efficiency. In the present study, a coupled computa-tional fluid dynamics (CFD) model was proposed and implemented to facilitate numerical simulations on hydrodynamic ef-fects of the bionic undulating robots. Hydrodynamic behaviors of underwater robots propelled by two bionic undulating fins were computationally and experimentally studied within the three typical desired movement patterns, i.e., marching, yawing and yawing-while-marching. Moreover, several specific phenomena in the bionic undulation mode were unveiled and dis-cussed by comparison between the CFD and experimental results under the same kinematics parameter sets. The contributed work on the dynamic behavior of the undulating robots is of importance for study on the propulsion mechanism and control algorithms.

关键词： bionic underwater robot CFD dynamic behavior undulating fins

Life-Inspired Endogenous dynamic behavior of Lipid Droplet-like Microcompartments in Artificial Adipocyte-like Structures

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CCS Chemistry 2021年第11期3卷 2782-2794页

作者： Xiaoliang Wang Yan Huang Youping Lin Haixu Chen Junbo Li Chunyu Zhao Xiaoman Liu Li Yang Xin Huang MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage School of Chemistry and Chemical EngineeringHarbin Institute of TechnologyHarbin 150001

Chemical systems that can replicate cellular behaviors are gaining increasing attention and are being used to study various biological processes.Here,a protein-or amylose-based assembly at an oil/water interface was employed to construct a large compartmentalized adipocyte-like structure,and a lipid droplet-like microcompartment(amylose-polymerstabilized 2-ethyl-1-hexanol microcompartment),which exhibits floating behaviors driven by the amylose-polymer micelle solubilization,was introduced inside these adipocyte-like structures.When the lipase-based catalytic reaction and the external oil composition were controlled and another lipid droplet-like microcompartment(lipase-stabilized tributyrin microcompartment)was introduced,then a series of dynamic behaviors were exhibited by the two types of lipid droplet-like microcompartments,including growth,self-sorting,and fusion within the adipocyte-like structures.Therefore,it is anticipated that this autonomous generation of hierarchical multicompartments represents a breakthrough compared to the traditional bottom-up strategies,and the artificial life systems we studied could contribute a chemical-based strategy of understanding the process of lipid droplet growth and fusion inside a living adipocyte cell.

关键词： artificial adipocyte-like structures lipid droplet-like microcompartments selfsorting endogenous growth dynamic behavior

Systematic Evaluation of Deep Neural Network based dynamic Modeling Method for AC Power Electronic System

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CES Transactions on Electrical Machines and Systems 2023年第2期7卷 137-143页

作者： Yunlu Li Guiqing Ma Junyou Yang Yan Xu the School o Electrical Engineering Shenyang University of Technology110870China IEEE

Since the high penetration of renewable energy complicates the dynamic characteristics of the AC power electronic system(ACPES),it is essential to establish an accurate dynamic model to obtain its dynamic behavior for ensure the safe and stable operation of the system.However,due to the no or limited internal control details,the state-space modeling method cannot be realized.It leads to the ACPES system becoming a black-box dynamic system.The dynamic modeling method based on deep neural network can simulate the dynamic behavior using port data without obtaining internal control details.However,deep neural network modeling methods are rarely systematically evaluated.In practice,the construction of neural network faces the selection of massive data and various network structure parameters.However,different sample distributions make the trained network performance quite different.Different network structure hyperparameters also mean different convergence time.Due to the lack of systematic evaluation and targeted suggestions,neural network modeling with high precision and high training speed cannot be realized quickly and conveniently in practical engineering applications.To fill this gap,this paper systematically evaluates the deep neural network from sample distribution and structural hyperparameter selection.The influence on modeling accuracy is analyzed in detail,then some modeling suggestions are presented.Simulation results under multiple operating points verify the effectiveness of the proposed method.

关键词： AC power electronic system dynamic behavior Neural network Systematic evaluation

dynamic Analysis and Optimal Parameter Design of FlexibleComposite Structures via Absolute Nodal Coordinate Formulation

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Journal of Shanghai Jiaotong university(Science) 2023年第5期28卷 621-629页

作者：杨丹余海东林张鹏 Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures Shanghai 200240China

The composite structure with the dielectric elastomer and soft materials is the main form of theactuators in soft robots. However, the theoretical model is hard to obtain due to the nonlinear large deformationof materials. In this paper, a new composite element model is established based on the absolute nodal coordinateformulation. The consistent deformation conditions at the contact interface between two thin plates are deduced.The hyperelastic constitutive model and the dielectric elastomer constitutive model are introduced for the twothin plates. Then the dynamic model is established to study the dynamic behaviors of the composite flexiblestructure with various parameters. The results show that the nonlinear deformation appears obviously whenthe flexible composite plate structure is driven by various voltages, and the warping deformation becomes moreobvious with the increase of the voltage. The width and thickness of the driven thin plate influence the stabilityof the whole structure. With the decrease of the width or thickness, the deformation of the structure is moreconsistent with obvious periodicity, and the control performance is improved. Finally, the structural parametersof the composite structures are optimized to improve the control performance based on the dynamic performance.Additionally, smaller width and thickness parameters are preferred to obtain better performance in the design offlexible actuator of soft robot.

关键词： flexible composite structure absolute nodal coordinate formulation dynamic behavior deformation compatibility optimal design