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Electro-lubrication in Janus transition metal dichalcogenide bilayers

Friction 2022年第11期10卷 1851-1858页

作者： Hao LI Yufeng GUO Wanlin GUO State Key Laboratory of Mechanics and Control of Mechanical Structures MOE Key Laboratory for Intelligent Nano Materials and DevicesCollege of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

Lubrication induced by a vertical electric field or bias voltage is typically not applicable to twodimensional(2D)van der Waals(vdW)*** performing extensive first-principles calculations,we reveal that the interlayer friction and shear resistance of Janus transition metal dichalcogenide(TMD)MoXY(X/Y=S,Se,or Te,and X≠Y)bilayers under a constant normal force mode can be reduced by applying vertical electric *** maximum interlayer sliding energy barriers between AA and AB stacking of bilayers MoSTe,MoSeTe,and MoSSe decrease as the positive electric field increases because of the more significant counteracting effect from the electric field energy and the more significant enhancement in interlayer charge transfer in AA ***,the presence of negative electric fields decreases the interlayer friction of bilayer MoSTe,because the electronegativity difference between Te and S atoms reduces the interfacial atom charge differences between AA and AB *** results reveal an electro-lubrication mechanism for the heterogeneous interfaces of 2D Janus TMDs.

关键词： Janus transition metal dichalcogenide(TMD) electro-lubrication electric field tuning first-principles calculations

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Modeling the Efficiency of an Edge Coupler with a Si3N4-based Taper 25

Modeling the Efficiency of an Edge Coupler with a Si3N4-base...

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25th IEEE International Conference of Young Professionals in Electron Devices and Materials, EDM 2024

作者： Barbin, Evgenij S. Nesterenko, Tamara G. Koleda, Aleksej N. Myrzakhmetov, Ayan Kulinich, Ivan V. Mokhovikov, Denis M. Laboratory of microsystems engineering Tomsk State University of Control Systems and Radioelectronics Laboratory of Radiophotonics V.E. Zuev Institute of Atmospheric Optics of SB RAS Tomsk Russia Laboratory of microsystems engineering Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Radiophotonics Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Photonic Integrated Circuits Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Radiophotonics Tomsk State University of Control Systems and Radioelectronics Laboratory of Intelligent Computer Systems V.E. Zuev Institute of Atmospheric Optics of SB RAS Tomsk Russia

ISBN: (纸本)9798350389234

The article studies the efficiency of optical radiation input/output between a photonic integrated circuit (PIC) and an edge-coupled tapered silicon nitride waveguide with dimensions 350 nm x 850 nm at a wavelength of 1550 nm. The work determines the losses by radiation for transverse electric and transverse magnetic modes at different taper width and input mode diameter for direct (edge width more than 850 nm) and inverted tapers (edge width less than 850 nm). The results show that the admissible width of the inverted taper edge lies within 150–300 nm with losses by input/output of up to 2 dB and low sensitivity to optical polarization. For the direct taper, the highest input efficiency (losses amounted to 3-6 dB) belongs to the optical fibers with a beam waist diameter of 2–3 μm and taper edge width of 2–3 μm. For both types of edge couplers, the effect of the waist diameter of lensed fiber is more important: the spread should be within 150 nm. © 2024 IEEE.

关键词： Silicon nitride

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Temperature Effect on the Optical Characteristics of a Microoptoelectromechanical Accelerometer 25

Temperature Effect on the Optical Characteristics of a Micro...

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25th IEEE International Conference of Young Professionals in Electron Devices and Materials, EDM 2024

作者： Barbin, Evgenij S. Nesterenko, Tamara G. Koleda, Aleksej N. Talovskaia, Alena A. Kulinich, Ivan V. Mokhovikov, Denis M. Laboratory of Microsystems Engineering Tomsk State University of Control Systems and Radioelectronics Laboratory of Radiophotonics V.E. Zuev Institute of Atmospheric Optics of SB RAS Tomsk Russia Laboratory of Microsystems Engineering Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Radiophotonics Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Radiophotonics Tomsk State University of Control Systems and Radioelectronics Laboratory of Intelligent Computer Systems V.E. Zuev Institute of Atmospheric Optics of SB RAS Tomsk Russia

ISBN: (纸本)9798350389234

The treatise studies the temperature sensitivity of the optical transmission coefficient of an microoptoelectromechanical accelerometer (MOEMA) based on the optical tunneling effect in a temperature range from minus 40 °C to plus 100 °C. Two types of optical measuring transducers are studied: based on a directional coupler or a resonator. It is shown that the major contribution to the temperature error of the MOEMA’s transmission coefficient is made by the alteration of the optical transmission coefficient (OTC). For a measuring transducer based on a directional coupler, the temperature sensitivity of the OTC amounted to 0.00058 °C-1. That for a transducer based on a resonator amounted to 0.33 °C-1, which definitely speaks of its inability to operate without a thermostatic system. Following the results, the contribution of the refraction index alteration depending on temperature more than 5 times exceeds that of the MOEMA's mechanical parameters for optical measuring transducers based on the directional coupler and more than 3000 times for the resonator. © 2024 IEEE.

关键词： Accelerometers

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state estimation for delayed switched positive systems: delayed radius approach

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Science China(Information Sciences) 2024年第8期67卷 190-205页

作者： Weizhong CHEN Zhongyang FEI Xudong ZHAO Zheng-Guang WU School of Electronics and Information Xi'an Polytechnic University Research Institute of Intelligent Control and Systems Harbin Institute of Technology Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of Technology School of Control Science and Engineering Dalian University of Technology State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang University

In this paper, an interval estimation scheme is developed for delayed switched positive systems（DSPS） with mode-dependent average dwell time switching. A lossless zonotopic estimation approach is proposed for the delayed intersection zonotope with the positive generator matrix. First, considering the existence of asynchronism between the system mode and the correction matrix mode, the mismatched intersection zonotope is constructed for DSPS to verify the consistency between the system model and ***, by utilizing the introduced radius definitions, the ?∞performance is addressed to optimize the size of delayed intersection zonotopes. Subsequently, we present a joint-design approach of switching signals and the mode-dependent correction matrix by constructing positive generator matrix-based delayed radius functions. Furthermore, guaranteed nonnegative state bounds are derived for the considered DSPS based on the proposed lossless zonotopic estimation criteria. Finally, detailed simulations are conducted to validate the feasibility and superiority of the developed methods.

关键词： delayed switched positive systems interval estimation asynchronous correction matrix zonotopes mode-dependent average dwell time

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Asymptotic Output Tracking control of a Class of Linear systems by Finite-and-Quantized Output Feedback

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无人系统（英文） 2024年第2期12卷 249-260页

作者： Jian Guo Yanjun Zhang Ji-Feng Zhang Key Lab of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematics Sciences University of Chinese Academy of SciencesBejing 100149China School of Automation Beijing Institute of TechnologyBeijing 100081China State Key Lab of Autonomous Intelligent Unmanned Systems Beijing Institute of TechnologyBeijing 100081China

This paper presents a novel finite-and-quantized output feedback asymptotic tracking control method for a general class of continuous-time linear time-invariant ***,we construct a finite quantizer with time-varying thresholds and design a pole placement control law that exclusively utilizes the finite-and-quantized output signal and an external reference ***,we establish the boundedness of all closed-loop signals and prove the asymptotic convergence of the output tracking error to *** proposed method combines the advantages of classical pole placement control technique and finite quantization feedback *** not only reduces the requirement for feedback information compared with existing tracking control methods but also effectively handles unstable poles and zeros in controlled systems,thereby achieving asymptotic output ***,we provide a representative example to validate the effec-tiveness and new features of our proposed method.

关键词： Continuous-time asymptotic output tracking pole placement control quantized-output feedback

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GaitFormer: Two-Stream Transformer Gait Recognition Using Wearable IMU Sensors in the Context of Industry 5.0

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IEEE Sensors Journal 2025年第11期25卷 19947-19956页

作者： Lu, Zhangli Zhou, Huiying Wang, Longqiang Kong, Depeng Lyu, Honghao Wu, Haiteng Chen, Bing Chen, Fuguo Dong, Na Yang, Geng Zhejiang University State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical Engineering Hangzhou310058 China Innovation Institute Co. Ltd China Hangzhou Shenhao Technology Key Laboratory of Intelligent Robot for Operation and Maintenance of Zhejiang province Hangzhou China

The rising attention to human-centricity, a core value of Industry 5.0, makes researchers propose various methods to place humans in the center of production, such as the Human Digital Twin (HDT) and gait identity recognition. However, previous HDT applications in the Industry 5.0 era have less consideration of identity recognition, the vital way to link physical signals to personal archives in cyber systems. Herein GaitFormer, a Two-Stream Transformer gait recognition method is proposed for application with the wearable inertial measurement unit (IMU) motion capture system. GaitFormer consists of Temporal and Channel Modules enclosing Gaussian Range Encoding, multi-head Auto-Correlation mechanism, and multi-scale as convolutional neural network (CNN) layers. It outperforms state-of-the-art architectures with extensive experiments over publicly available IMU-based datasets respectively: whuGait and OU-ISIR. Then the study intends to combine the motion capture system and gait identity recognition algorithm to propose an application of personal monitoring in the Human-Cyber-Physical-System (HCPS), which uses GaitFormer to recognize the identity of the user with motion capture system and show their corresponding customized HDT. This work may contribute to making a connection between gait identity recognition and HDT, constructing personal working profiles in the environment of Industry 5.0. © 2001-2012 IEEE.

关键词： Convolutional neural networks

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Enhancing rheology and mechanical properties of DLP 3D-printed Si_(3)N_(4) materials via composition optimization and gas-pressure sintering

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International Journal of Minerals,Metallurgy and Materials 2025年第5期32卷 1220-1233页

作者： Qing Qin Gang Xiong Lin Han Yujuan Zhang Zhen Shen Changchun Ge Institute of Powder Metallurgy and Advanced Ceramics School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of Multimodal Artificial Intelligence Systems Beijing Engineering Research Center of Intelligent Systems and TechnologyInstitute of AutomationChinese Academy of SciencesBeijing 100190China

Digital light processing(DLP)is a crucial additive manufacturing(AM)technique for producing high-precision ceramic *** study aims to optimize the formulation of Si_(3)N_(4)slurry to enhance both its performance and manufacturability in the DLP process,and investigate key factors such as particle size distribution,photopolymer resin monomer ratios,and dispersant types to im-prove the slurry’s rheological *** these optimizations,a photosensitive Si_(3)N_(4)slurry with 50vol%solid content was de-veloped,exhibiting excellent stability,and low viscosity(2.48 Pa·s at a shear rate of 12.8 s^(-1)).The effects of gas-pressure sintering on the material’s phase composition,microstructure,and mechanical properties were further explored,revealing that this technique significantly increases the flexural strength of the green sample from(109±10.24)to(618±42.15)*** sintered ceramics exhibited high hard-ness((16.59±0.05)GPa)and improved fracture toughness((4.45±0.03)MPa·m^(1/2)).Crack trajectory analysis revealed that crack deflec-tion,crack bridging,and the pull-out of rod-likeβ-Si_(3)N_(4)grains,are the main toughening mechanisms,which could effectively mitigate crack *** these mechanisms,crack deflection and bridging were particularly influential,significantly enhancing the frac-ture toughness of the Si_(3)N_(4)***,this research highlights how monomer formulation and gas-pressure sintering strengthen the performance of Si_(3)N_(4)slurry in the DLP three-dimensional printing *** work is expected to provide new insights for fabricat-ing complex Si_(3)N_(4)ceramic components with superior mechanical properties.

关键词： additive manufacturing Si_(3)N_(4)slurry low viscosity pressure sintering

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Temperature Effect on the Mechanical Transmission Coefficient of a Microoptoelectromechanical Accelerometer 25

Temperature Effect on the Mechanical Transmission Coefficien...

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25th IEEE International Conference of Young Professionals in Electron Devices and Materials, EDM 2024

作者： Barbin, Evgenij S. Nesterenko, Tamara G. Koleda, Aleksej N. Talovskaia, Alena A. Kulinich, Ivan V. Mokhovikov, Denis M. Laboratory of microsystems engineering Tomsk State University of Control Systems and Radioelectronics Laboratory of Radiophotonics V.E. Zuev Institute of Atmospheric Optics of SB RAS Tomsk Russia Laboratory of microsystems engineering Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Radiophotonics Tomsk State University of Control Systems and Radioelectronics Tomsk Russia Laboratory of Radiophotonics Tomsk State University of Control Systems and Radioelectronics Laboratory of Intelligent Computer Systems V.E. Zuev Institute of Atmospheric Optics of SB RAS Tomsk Russia

ISBN: (纸本)9798350389234

The treatise studies a temperature effect on the microoptoelectromechanical (MOEMS) accelerometer with an optical measuring transducer based on evanescent wave coupling. The work investigates the temperature sensitivity of the mechanical part of the accelerometer in a temperature range from minus 65 °C to plus 125 °C. The temperature alteration induces stresses in the mechanical structure. Maximum mechanical stresses emerging in the structure at a temperature of minus 65 °C reach 556.61 MPa for the layer of aluminum that can be used for in-package wire bonding. However, these stresses are smaller than the admissible value for aluminum (690 MPa). The maximum stresses in residual layers of the mechanical structure are several times smaller than those in the aluminum layer. At different temperatures, the eigenfrequency of the accelerometer also changes, which alters its mechanical transmission coefficient. The temperature sensitivity of normalized mechanical transmission coefficient per 1 °C amounts to 0.00012 °C-1. To compensate the temperature effect on the mechanical transmission coefficient, various design schemes can be used and the output signal can be adjusted according to the temperature sensor readings. © 2024 IEEE.

关键词： Accelerometers

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A Novel Trajectory Planning Method Based on Trust Region Policy Optimization

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on intelligent Vehicles 2024年 1-15页

作者： Ye, Bao-Lin Zhang, Jiajie Li, Lingxi Wu, Weimin Jiaxing Key Laboratory of Smart Transportations the School of Information Science and Engineering Jiaxing University China Elmore Family School of Electrical and Computer Engineering Purdue University Indianapolis USA State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and Control Zhejiang University Hangzhou China

Trajectory planning method is a research hotspot in autonomous driving. Existing reinforcement learning-based trajectory planning methods suffer from unstable performance due to the strong randomness of network weight parameter updates during the training process. Therefore, this paper proposes a novel trajectory planning method based on deep reinforcement learning trust region policy optimization (TRPO). Firstly, in order to enhance the robustness of the trajectory planning method based on deep reinforcement learning TRPO, a TRPO-LSTM based decision model was proposed. More specifically, a long short term memory (LSTM) based state feature extraction network was designed and embeded into a TRPO-based decision model to enhance the ability of TRPO to extract information from the environmental state space. Secondly, in order to make the planned trajectory adaptive to the dynamic changes of traffic environment, we presented a novel TRPO-LSTM trajectory fitting algorithm. To the best of our knowledge, this is the first work aiming at applying the TRPO-LSTM based decision model in the trajectory fitting process to search the optimal longitudinal trajectory speed. Finally, the proposed trajectory planning method was implemented and simulated on the CARLA simulator. The experimental results show that, compared with existing trajectory planning methods based on deep reinforcement learning algorithms, our proposed method achieves a cumulative reward improvement of over 28.9% in the scenario of four lane highway, and has better robustness. Meanwhile, the proposed method can achieve a lower collision rate of 0.93% while improving the average speed and comfort of vehicle driving. IEEE

关键词： Heuristic algorithms

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Development of wet adhesion of honeybee arolium incorporated polygonal structure with three-phase composite interfaces

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Friction 2024年第2期12卷 215-230页

作者： Lulu LIANG Jieliang ZHAO Qun NIU Li YU Xiangbing WU Wenzhong WANG Shaoze YAN Zhenglei YU School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Division of Intelligent and Biomechanical Systems State Key Laboratory of TribologyDepartment of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key of Bionic Engineering Ministry of EducationJilin UniversityChangchun 130022China

Inspired by the dynamic wet adhesive systems in nature,various artificial adhesive surfaces have been developed but still face different ***,the theoretical mechanics of wet adhesives has never been sufficiently ***,we develop a novel adhesive mechanism for governing wet adhesion and investigate the biological models of honeybee arolium for reproducing the natural wet adhesive ***-nano structures of honeybee arolium and arolium-prints were observed by Cryogenic scanning electron microscopy(Cryo-SEM),and the air pockets were found in the contact interface ***,the adhesive models with a three-phase composite interface(including air pockets,liquid secretion,and hexagonal frames of arolium),were formed to analyze the wet adhesion of honeybee *** results of theoretical calculations and experiments indicated an enhanced adhesive mechanism of the honeybee by liquid self-sucking effects and air-embolism *** these effects,normal and shear adhesion can be adjusted by controlling the proportion of liquid secretion and air pockets in the contact ***,the air-embolism effects contribute to the optimal coupling of smaller normal adhesion with greater shear adhesion,which is beneficial for the high stride frequency of *** works can provide a fresh perspective on the development of bio-inspired wet adhesive surfaces.

关键词： honeybee arolium air pockets wet adhesion a three-phase interface self-sucking effects air-embolism effects

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