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Pressure stimulated current in progressive failure process of combined coal-rock under uniaxial compression:Response and mechanism

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International Journal of Mining Science and technology 2024年第2期34卷 227-243页

作者： Tiancheng Shan Zhonghui Li Xin Zhang Haishan Jia Xiaoran Wang Enyuan Wang Yue Niu Dong Chen Weichen Sun Dongming Wang State Key Laboratory of Coal Mine Disaster Prevention and Control China University of Mining and TechnologyXuzhou 221116China National Engineering Research Center for Coal Gas Control China University of Mining and TechnologyXuzhou 221116China School of Safety Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory for Fine Exploration and Intelligent Development of Coal Resources China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China

Effective monitoring of the structural health of combined coal-rock under complex geological conditions by pressure stimulated currents(PSCs)has great potential for the understanding of dynamic disasters in underground *** reveal the effect of this way,the uniaxial compression experiments with PSC monitoring were conducted on three types of coal-rock combination samples with different strength *** mechanism explanation of PSCs are investigated by resistivity test,atomic force microscopy(AFM)and computed tomography(CT)methods,and a PSC flow model based on progressive failure process is *** influence of strength combinations on PSCs in the progressive failure process are *** results show the PSC responses between rock part,coal part and the two components are different,which are affected by multi-scale fracture characteristics and electrical *** the rock strength decreases,the progressive failure process changes obviously with the influence range of interface constraint effect decreasing,resulting in the different responses of PSC strength and direction in different parts to fracture *** PSC flow model is initially validated by the relationship between the accumulated charges of different *** results are expected to provide a new reference and method for mining design and roadway quality assessment.

关键词： Combined coal-rock Pressure stimulated current Progressive failure process Mechanism Flow model

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Femtosecond laser controllable annealing for color centers based on ion-implanted silicon carbide substrate

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Ceramics International 2024年第22期50卷 46566-46578页

作者： Wang, Jianshi Song, Ying Dong, Bing Zhao, Yukun Sun, Qingqing Yan, Mengzhi Yao, Chengqi Du, Quanbin Xu, Zongwei State Key Laboratory of Precision Measuring Technology & Instruments Laboratory of Micro/Nano Manufacturing Technology Tianjin University Tianjin300072 China Henan Key Laboratory of Intelligent Manufacturing Equipment Integration for Superhard Materials Zhengzhou451191 China

As a representative of third-generation semiconductors, silicon carbide serves as a new platform for quantum nano-optics with readable paramagnetic color centers such as silicon vacancies. The potential applications include biomedical imaging, quantum sensing and micro/nano environment detection. Color centers are usually prepared based on ion-irradiated substrates, then annealed at high temperature to increase the yield. Currently, annealing furnaces have been the main method to heat the substrate and achieve annealing of the whole sample. However, further exploration is still necessary for fine processing requirements such as specialized annealing regions with certain shapes. In this work, we applied femtosecond laser to achieve controllable annealing at micron scale, based on silicon carbide substrate after ion injection. The whole process of point, line and pattern annealing was realized. The annealing area demonstrates enhanced photoluminescence, attributed to silicon vacancy color centers. Raman and photoluminescence spectra reveal that the annealing effect is primarily influenced by the number of pulses per unit area. The mechanism of femtosecond laser annealing was introduced. Finally, the controllable annealing areas with various shapes were prepared based on the comprehensive optimal parameters (100 kHz pulse repetition frequency, 105 point annealing pulses, 10 μm/s line scanning speed). This annealing strategy demonstrates excellent stability and uniformity, as well as micron scale accuracy. Additionally, the excited state lifetime of silicon vacancy was extracted and quantified. The result means that femtosecond laser annealing enhances the optical properties and quantum application potential of color centers. This work can be further extended to other semiconductors as well as patterned modification of local surface/planes at some depth, and helpful to explore the mechanism and applications of femtosecond laser annealing. © 2024

关键词： Color centers

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Distributed Robust Safety-Critical Predefined-Time Control for Target Spherical Surrounding of UAVs

IEEE Transactions on Intelligent Vehicles

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IEEE Transactions on intelligent Vehicles 2024年 1-10页

作者： Huang, Yanting Han, Honggui Zhu, Ming Faculty of Information Technology Beijing Key Laboratory of Computational Intelligence and Intelligent System Engineering Research Center of Digital Community Ministry of Education Beijing University of Technology Beijing China Institute of Unmanned System Beihang University Beijing China

This paper develops a distributed safety-critical predefined-time control method for the 3-dimensional (3D) moving target surrounding problem of multiple UAVs. A new 3D surrounding shape is first formulated for multiple UAVs to distribute on a moving spherical surface around the target. To reduce the communication and load burden, a predefined-time distributed estimator is designed for a subset of UAVs without any access to the target, so that the target's motion information can be accurately estimated within a predefined time. Subsequently, a robust safety-constrained predefined-time control law is designed with a twofold structure, where the nominal control term guarantees the predefined-time convergence under the safety constraints, and the adjunctive control term overcomes the influence of disturbances. A new dynamic parameter-based predefined-time control method is proposed, which can relax the unnecessary requirement of control design for achieving predefined-time convergence. The corresponding dynamic parameter-based predefined-time control Lyapunov function (DPP-CLF) is constructed together with second-order control barrier function (SCBF) to map the convergence requirement and safety constraints on states to constraints on control inputs. The nominal control term is obtained by minimizing the control inputs under constraints with linear programming. The adjunctive control term is acquired by combining a filter-based estimator and an integral sliding mode surface design, providing an accurate compensation for the disturbances. The theoretical analysis and simulation results demonstrate the predefined-time stability and collision avoidance performance of the multi-UAV system. IEEE

关键词： Unmanned aerial vehicles (UAV)

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Mechanical Properties Inside Origami-Inspired Structures: An Overview

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Applied Mechanics Reviews 2025年第1期77卷 011001页

作者： Yan, Peng Huang, Hailin Meloni, Marco Li, Bing Cai, Jianguo Department of Mechanical Engineering and Automation Harbin Institute of Technology Shenzhen518052 China Harbin Institute of Technology Shenzhen518052 China Key Laboratory of C & PC Structures of Ministry of Education National Prestress Engineering Research Center Southeast University Nanjing211189 China State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Guangdong Provincial Key Laboratory of Intelligent Morphing Mechanisms and Adaptive Robotics Harbin Institute of Technology Shenzhen518052 China Key University Laboratory of Mechanism Machine Theory and Intelligent Unmanned Systems of Guangdong Habin Institute of Technology Shenzhen518052 China

In recent decades, origami has transitioned from a traditional art form into a systematic field of scientific inquiry, characterized by attributes such as high foldability, lightweight frameworks, diverse deformation modes, and limited degrees-of-freedom. Despite the abundant literature on smart materials, actuation methods, design principles, and manufacturing techniques, comprehensive reviews focusing on the mechanical properties of origami-inspired structures are relatively rare and unsystematic. This review aims to fill this void by analyzing and summarizing the significant studies conducted on the mechanical properties of origami-inspired structures from 2013 to 2023. We begin with an overview that includes essential definitions of origami, classical origami patterns, and their associated tessellated or stacked structures. Following this, we delve into the principal dynamic modeling method for origami and conduct an in-depth analysis of the key mechanical properties of origami-inspired structures. These properties include tunable stiffness, bistability and multistability, metamechanical properties demonstrated by origami-based metamaterials, and bio-inspired mechanical properties. Finally, we conclude with a comprehensive summary that discusses the current challenges and future directions in the field of origami-inspired structures. Our review provides a thorough synthesis of both the mechanical properties and practical applications of origami-inspired structures, aiming to serve as a reference and stimulate further research. © 2025 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Degrees of freedom (mechanics)

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Hybrid Mapping Method:from Human to Robotic Hands with Dissimilar Kinematics

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Journal of Bionic Engineering 2022年第4期19卷 935-952页

作者： Bingchen Liu Li Jiang Shaowei Fan State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150080China

Mapping grasps from human to anthropomorphic robotic hands is an open issue in research,because the master hand and the slave hand have dissimilar *** paper proposes a hybrid mapping method to solve this *** the proposed method,fingers in the master and the slave hands are divided into vital and synergic fingers according to their contribution to the grasping *** tip of the vital finger of the master hand is first mapped to that of the slave hand while ensuring that both are in simultaneous contact with the object to be *** postural synergy theory,joints of the other synergic fingers of the slave hand are then used to generate an anthropomorphic grasping configuration according to the shape of the object to be *** this,a human-guided impedance controller is used to reduce the pre-grasping error and realize compliant interaction with the *** proposed hybrid mapping method can not only generate the posture of the humanoid envelope but can also carry out impedance-adaptive *** was evaluated using simulations and an experiment involving an anthropomorphic robotic slave hand.

关键词： Robotic hand Human-in-the-loop Grasping Postural synergy Impedance control

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Experimental and modeling study of surface topography generation considering tool-workpiece vibration in high-precision turning

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Chinese Journal of Aeronautics 2023年第7期36卷 194-212页

作者： Xingying ZHOU Henan LIU Tianyu YU Ruiyang GUO Guangzhou WANG Yazhou SUN Mingjun CHEN State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechatronics Engineering Harbin Institute of TechnologyHarbin 150001China

High-precision turning(HPT)is a main processing method for manufacturing rotary high-precision components,especially for metallic ***,the generated vibration between tool tip and workpiece during turning may seriously deteriorate the surface ***,exploring the effect of vibration on turning surface morphology and quality of copper parts using 3D surface topography regeneration model is crucial for predicting HPT *** developed model can update the machined surface topology in real *** this study,the effects of tool arc radius,feed rate,radial vibration,axial vibration and tangential vibration on the surface topography and surface roughness were *** results show that the effect of radial vibration on surface topography is greater than that of axial vibration and tangential *** radial vibration frequency is also *** vibration frequency changes,the surface topography profile presents three different types:the standard sinusoidal curve,the sinusoidal curve whose lowfrequency signal envelopes high-frequency signal,and the oscillation curve whose low-frequency signal superimposes high-frequency *** addition,HPT experiment was carried out to validate the developed *** surface roughness obtained in the experiment was Ra=53 nm,while the roughness obtained by the simulation was Ra=46 nm,achieving a prediction accuracy of 86.7%.Received 4 September 2022;revised 3 October 2022;accepted 17 October 2022.

关键词： High-precision turning Machining vibration Modeling Surface roughness Surface topography

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Ultra-fast light-field microscopy with event detection

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Light(Science & Applications) 2024年第12期13卷 2868-2871页

作者： Liheng Bian Xuyang Chang Hanwen Xu Jun Zhang State Key Laboratory of CNS/ATM&MIIT Key Laboratory of Complex-field Intelligent Sensing Beijing Institute of TechnologyNo 5 Zhongguancun South StreetHaidian District100081 BeijingChina

The event detection technique has been introduced to light-field microscopy,boosting its imaging speed in orders of magnitude with simultaneous axial resolution enhancement in scattering medium.

关键词： field light orders

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Dual-band dynamic reconfigurable intelligent surface for signal enhancement in millimeter wave

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Science China(Technological Sciences) 2024年第4期67卷 1133-1138页

作者： YAO HuiMing DU XinRun WANG HengBin GAO Song PANG YaChen ZHENG HaiRong GONG HuiWen LI Yi XU JianChun ZHANG JianHua BI Ke State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China Beijing Key Laboratory of Intelligent Telecommunications Software and Multimedia Beijing University of Posts and TelecommunicationsBeijing 100876China State Key Laboratory of Networking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing 100876China

Millimeter wave with large bandwidth,high transmission rate,and low delay is considered a reliable alternative to cope with the spectrum ***,the fast attenuation and narrow beam characteristics make it difficult to achieve long-distance or wide-range ***,a 1-bit dual-band reflective reconfigurable intelligent surface(RIS)for signal enhancement in millimeter wave with 16×16 elements is designed,fabricated,and *** from most existent RIS,dynamic programming is realized at two separate frequency bands by integrating the PIN diodes and field-programmable gate array(FPGA).Particularly,the beam deflection,dual-beam,and multi-beam are created based on the coding theory and convolution operation,proving the effectiveness of wavefront ***,the far-field patterns and signal power with different coding sequences are measured and *** is indicated that the received signal power is 6–7 dB stronger than that without coding,which shows good agreement with the desired *** proposed reconfigurable metasurface exhibits great potential in beam forming,making it a promising candidate for progressive wireless communication applications.

关键词： dual-band millimeter wave reconfigurable intelligent surface signal enhancement

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A novel method of water bath heating assisted small ball-end magnetorheological polishing for hemispherical shell resonators

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Chinese Journal of Aeronautics 2023年第12期36卷 451-460页

作者： Jinchuan TIAN Mingjun CHEN Jian CHENG Henan LIU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Center for Precision Engineering Harbin Institute of TechnologyHarbin 150001China

Hemispherical shell resonator(HSR)is the core component of hemispherical resonator *** is aφ-shaped small-bore complex component with minimum curvature radius less than 3 ***,traditional polishing methods are difficult to polish *** ball-end magnetorheological polishing method can polish the small components with complicated three-dimensional surface and obtain non-destructive ***,this method is suitable for polishing ***,the material removal rate of the ordinary small ball-end magnetorheological polishing is low,leading to long polishing time and low output of *** solve this problem,a water bath heating assisted small ball-end magnetorheological polishing method is proposed in this *** influence rule of processing parameters on the material removal rate is studied experimentally.A set of optimal processing parameters is obtained to maximize the material removal *** with the ordinary method,the material removal rate of the new method can be improved by 143%.Subsequently,an HSR is polished by the new *** results show that the polishing time can be reduced by 55%,and the polished surface roughness can reach 7.7 *** new method has the great potential to be used in actual production to improve the polishing efficiency of HSR.

关键词： Hemispherical shell resonator Magnetorheological fluid temperature Material removal rate Optimization Small ball-end magnetorheological polishing

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Design and performance evaluation of a novel ranging signal based on an LEO satellite communication constellation

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Geo-Spatial Information Science 2023年第1期26卷 107-124页

作者： Jingfang Su Jia Su Qingwu Yi Cailun Wu Weimin Hou School of Information Science and Engineering Hebei University of Science and TechnologyShijiazhuangChina The State Key Laboratory of Satellite Navigation System and Equipment Technology ShijiazhuangChina

Driven by improvements in satellite internet and Low Earth Orbit(LEO)navigation augmenta-tion,the integration of communication and navigation has become increasingly common,and further improving navigation capabilities based on communication constellations has become a significant *** the context of the existing Orthogonal Frequency Division Multiplexing(OFDM)communication systems,this paper proposes a new ranging signal design method based on an LEO satellite communication *** LEO Satellite Communication Constellation Block-type Pilot(LSCC-BPR)signal is superimposed on the com-munication signal in a block-type form and occupies some of the subcarriers of the OFDM signal for transmission,thus ensuring the continuity of the ranging pilot signal in the time and frequency *** estimation in the time and frequency domains is performed to obtain the relevant distance value,and the ranging accuracy and communication resource utilization rate are *** characterize the ranging performance,the Root Mean Square Error(RMSE)is selected as an evaluation *** show that when the number of pilots is 2048 and the Signal-to-Noise Ratio(SNR)is 0 dB,the ranging accuracy can reach 0.8 m,and the pilot occupies only 50%of the communication subcarriers,thus improving the utilization of communication resources and meeting the public demand for communication and location services.

关键词： Integration of communication and navigation LEO communication constellation ranging LEO navigation augmentation satellite internet

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