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Arch formation mechanism and discharge process of cohesive fine powder in a vibrated silo

Particuology 2024年第11期94卷 373-385页

作者： Jingzhen Zhu Kun Wang Yu Ma Wentao Xu Jiecai Long Xiwen Li State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan430074China State Key Laboratory of Precision Electronic Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou510006China

The arch formation mechanism and discharge process of a very cohesive fine powder(calcium carbonate)in a vibrated silo was investigated by experiments and discrete element method(DEM)*** experimental setup is built to study the flow behaviors with the proposed image-based flow rate measurement method.A cohesive DEM model is used to investigate the dynamic behaviors of the powder *** indicate that the arch formation depends on the vibration acceleration amplitude and is slightly affected by the *** powder discharge flow rate increases with vibration acceleration amplitude and decreases with *** the acceleration amplitude exceeds 15 g,the flow rate tends to *** the acceleration amplitude exceeds 1 g,there is separation and collision between the powder bed and the silo *** collision leads to a significant increase in the contact force.

关键词： Cohesive fine powder Silo discharge Vertical vibration Arch formation Flow rate Discrete element method

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In vivo whole brain photoacoustic microscopy through a transparent ultrasound transducer

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Chinese Optics Letters 2025年第2期23卷 38-43页

作者： Chen Liang Junwei Wu Hangbing Peng Ljun Deng Yiqin Lin Zhongwen Cheng Luming Zeng Xuanrong Ji Jiangxi Provincial Key Laboratory of Advanced Electronic Materials and Devices Jiangxi Science and Technology Normal University Nanchang 33038China State Key Laboratory of Precision Electronics Manufacturing Technology and Equipment Guangdong University of TechnologyGuangzhou 510006China

Brain imaging techniques provide in vivo insight into structural and functional phenotypes that are physiologically and clinically ***,most existing brain imaging techniques suffer from balancing trade-offs among the temporal and spatial resolutions as well as the field of view(FOV).Here,we proposed a high-resolution photoacoustic microscopy(PAM)system based on a transparent ultrasound transducer(TUT).The system not only retains the advantage of the fast imaging speed of pure optical scanning but also has an imaging FOV of up to 20 mm×20 mm,which can easily enable rapid imaging of the whole mouse brain in *** on experimental validation of brain injury,glioma,and cerebral hemorrhage in mice,the system has the capability to visualize the vascular structure and hemodynamic changes in the cerebral ***-based PAM provides an important research tool for rapid multi-parametric brain imaging in small animals,providing a solid foundation for the study of brain diseases.

关键词： photoacoustic microscopy transparent ultrasound transducer whole brain imaging.

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Digital Transformation of Labor-Intensive Measurement Centers

Digital Transformation of Labor-Intensive Measurement Center...

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2024 Academic Conference of China Instrument and Control Society, ACCIS 2024

作者： Li, Canwei Luan, Lei Cui, Xiao Beijing Precision Engineering Institute for Aircraft Industry Aviation Key Laboratory of Science and Technology on Precision Manufacturing Technology Beijing China

ISBN: (纸本)9798350350326

With the deep integration of new-generation information technology and the equipment manufacturing industry, labor-intensive inspection centers face numerous development opportunities and challenges. It is imperative to upgrade digitally to enhance inspection efficiency and the integrity of inspection data. This study explores the design and implementation of a digital inspection system aimed at streamlining inspection processes through automated data capture, facilitating real-time monitoring of production process data, and promoting a paperless environment through equipment networking and comprehensive data aggregation. The proposed system acts as a catalyst for improving production efficiency and enhancing quality management practices. The core of this research is to investigate methodologies for data acquisition, automated data entry, and real-time equipment monitoring, leveraging network technology, automation frameworks, and paperless workflows. The study further delves into modular system design principles, effective database management strategies, and intuitive user interfaces to ensure system scalability and operational simplicity. Through practical field deployment and in-depth data analysis, the system's performance was rigorously evaluated, verifying its proficiency and effectiveness. Additionally, this paper discusses the challenges encountered during implementation and outlines practical solutions to overcome these obstacles. © 2024 IEEE.

关键词： Inspection equipment

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Study on the Stability of the Displacement Sensing Actuator Under Oil Conditions 7th

Study on the Stability of the Displacement Sensing Actuator ...

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7th China Aeronautical science and technology Conference, CASTC 2024

作者： Li, Xingliang Fan, Ya Zhao, Hongxin Zhang, Bin Liu, Yong Xu, Changyu Aviation Key Laboratory of Science and Technology on Precision Manufacturing Beijing Institute of Aeronautical Precision Machinery Beijing100076 China

ISBN: (纸本)9789819797677

The new aircraft is facing the development needs of integration and intelligence, and the actuator, as the actuator for aircraft actions, is worthy of in-depth study of its integrated displacement perception method and signal stability under working conditions. Taking a certain type of landing gear steering mechanism actuator as the research object, aiming at the phenomenon of zero point and amplitude drift of the existing capacitive integrated displacement sensor under oil conditions, this paper proposes to use the drag increase and deceleration effect of the surface microstructure to homogenize the oil film and abrasive debris between the capacitive plates. The finite element simulation technology was used to design and optimize the form and parameters of the microstructure, the ultra-precision machining technology was used to process the microstructure on the surface of the plane sample and the actuator shaft, the tribological properties of the microstructure with different parameters were tested by the UMT friction and wear testing machine, and the capacitance signal change law before and after the processing of the microstructure on the surface of the actuator shaft was compared by the self-made capacitance signal detection platform. The results show that the resistance increase and deceleration efficiency of the surface microstructure can achieve the homogenization of the oil film between the capacitor plates, and then ensure the stability of the capacitive signal under the oil condition, thus the research results can promote the engineering application of the integrated displacement sensing actuator. © Chinese Society of Aeronautics and Astronautics 2025.

关键词： Tribology

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Enhancing microwave absorption performance of MoS_(2)by synergistic effect of Fe doping

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Journal of Advanced Ceramics 2025年第3期14卷 79-90页

作者： Yuefeng Yan Guangyu Qin Kaili Zhang Boshi Gao Guansheng Ma Xiaoxiao Huang Yu Zhou National Key Laboratory of Precision Welding&Joining of Materials and Structures Harbin Institute of Technology Harbin 150001China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001China MIIT Key Laboratory of Advanced Structural-Functional Integration Materials&Green Manufacturing TechnologyHarbin Institute of TechnologyHarbin 150001China

Owing to its unique two-dimensional structure and tunable electronic properties,MoS_(2)has emerged as a promising electromagnetic wave(EMW)-absorbing material that can be extensively combined with various other substances to construct effective EMW ***,research on cation substitution doping in MoS_(2)remains relatively limited,which impedes the design and development of high-performance MoS_(2)-based EMW absorbing *** this study,MoS_(2)was synthesized with various concentrations of doped Fe via a facile hydrothermal *** thoroughly investigated the effects of Fe doping,which induced lattice distortion and collapse,triggered a 1T‒2H phase transition,and led to the formation and evolution of second *** modulation of phase transitions,coupled with doping-induced lattice defects that enhance polarization and interfacial polarization from second phases,enabled the Fe-doped MoS_(2)samples to exhibit remarkable EMW absorption ***,the sample FM3 achieved an effective absorption bandwidth(EAB)of 5.1 GHz and a minimum reflection loss(RLmin)of−60.6 dB,underscoring the critical role of Fe doping in increasing the EMW absorption *** research provides valuable pathways and unique insights for the advancement of transition metal dichalcogenides(TMDs)as high-performance EMW-absorbing materials.

关键词： microwave absorption Fe-doped MoS_(2) dielectric property impedance characteristic second phase

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The dynamic performance of the spindle in ultra-precision machine tools under different drive systems 8

The dynamic performance of the spindle in ultra-precision ma...

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8th Asia Pacific Conference on Optics Manufacture, APCOM 2023 and 3rd International Forum of Young Scientists on Advanced Optical manufacturing, YSAOM 2023

作者： Wu, Hailiang Yang, Hui Lu, Chaowei Zhang, Yang Aviation Key Laboratory of Science and Technology on Precision Manufacturing Technology Beijing Precision Engineering Institute for Aircraft Industry Beijing100076 China

ISBN: (纸本)9781510672673

In order to analyze the influence of servo drives on the dynamic performance of multi-Axis coordinated ultra-precision machine tools, this study employs Simulink modeling and simulation of the control system for a domestic ultra-precision machine tool with gas-static spindle, followed by conducting position control experiments. The dynamic response of the spindle under different drives in ultra-precision machine tools is modeled based on the dynamic characteristic equation of the spindle motor. Waveforms of current, torque, and speed response of the spindle motor under different drives are simulated and analyzed. Control laws between the controlled object and the drive system are derived from the analysis of simulation data. Based on this, a dynamic performance testing platform for the spindle in ultra-precision machine tools is established, with the repeatability of positioning accuracy as the dynamic performance parameter. The linear correlation analysis between the experimental data of repeatability of positioning accuracy and the simulation results is conducted to quantitatively evaluate their correlation. Finally, it is determined that the gas-static spindle under the control of a linear amplifier exhibits the best dynamic performance. Moreover, as the PWM frequency increases under the control of PWM-Type drives at 100 kHz, 50 kHz, and 16 kHz, the dynamic performance of the spindle also improves. This study provides reference for the selection of drives in the design and selection stage of control systems for ultra-precision machine tools. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Machine tools

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Research on the high-quality, low-wear single point diamond turning process of single crystal germanium 2

Research on the high-quality, low-wear single point diamond ...

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Advanced Optical manufacturing Technologies and Applications 2022, AOMTA 2022 and 2nd International Forum of Young Scientists on Advanced Optical manufacturing, YSAOM 2022

作者： Hongxin, Zhao Bin, Zhang Shanyi, Ma Deqing, Zhu Aviation Key Laboratory of Science and Technology on Precision Manufacturing Technology Beijing Precision Engineering Institute for Aircraft Industry Beijing100076 China

ISBN: (纸本)9781510661264

Single crystal germanium, which is a typical infrared optical crystal used for aerospace and astronomy applications due to their excellent mechanical, optical, and chemical property is difficult to obtain super smooth surface in ultra-precision turning and easy to cause tool wear owing to its inherent brittleness and hardness. In the processing process of single crystal germanium optical elements, good surface roughness is beneficial to improve the diffraction efficiency of single crystal germanium, while small cutting force can effectively lower the diamond tool wear caused by high hardness of germanium. In this paper, the single variable method is used to study the influence of the main factors in the single point diamond turning process on the surface roughness and cutting force of single crystal germanium, including spindle speed back cutting depth and feed. The experimental results are used to guide the machining process of the single crystal germanium diffraction surface, and the appropriate process parameters are selected to perform ultra-precision turning on the single crystal germanium with a very small cutting force to obtain a sub-nanometer ultra-smooth surface to improve the diffraction efficiency and reducing tool wear. © 2023 SPIE. All rights reserved.

关键词： Surface roughness

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Research on key technology of compound polishing of off-axis Parabolic Mirror 2

Research on key Technology of compound polishing of off-axis...

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Advanced Optical manufacturing Technologies and Applications 2022, AOMTA 2022 and 2nd International Forum of Young Scientists on Advanced Optical manufacturing, YSAOM 2022

作者： Zhu, Deqing Fan, Chuyi Fang, Jianguo Guo, Xiaoyue Li, Yang Aviation Key Laboratory of Science and Technology on Precision Manufacturing Technology Beijing Precision Engineering Institute for Aircraft Industry Beijing100076 China

ISBN: (纸本)9781510661264

Off-axis aspherical surface have the advantages of excellent optical performance and simplified system structure. In order to satisfy the requirements of high-precision off-axis aspheric mirror in the telescopic system of some equipment, the research on ultra-precision manufacturing technology of off-axis aspheric mirror is carried out, and a composite polishing and detection technology based on robot-controlled optical surfacing and ion beam figuring is proposed. In the processing stage, the robotic flexible polishing and gadget polishing are used to quickly grind and polish the aspheric surface, and then the pitch lap is used to smooth the mid-spatial-frequency errors. Finally the aspheric surface is machined to the final requirement by ion beam figuring. In the detection stage, the coordinate measuring machine is used to detect the surface shape in the grinding stage, and the stigmatic null test is used to detect the aspheric shape in the fine polishing stage. Using the proposed method, the off-axis aspheric surface of a caliber 408mm is machined and tested, and the final surface figure error was 0.015 λ (λ = 632.8nm), which meets the requirements of the index. © 2023 SPIE.

关键词： Polishing

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Research on the influence of low frequency forced vibration on the surface quality of optical elements in ultra precision turning 8

Research on the influence of low frequency forced vibration ...

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8th Asia Pacific Conference on Optics Manufacture, APCOM 2023 and 3rd International Forum of Young Scientists on Advanced Optical manufacturing, YSAOM 2023

作者： Zhang, Yang Zhang, Bin Zhao, Hongxin Wu, Hailiang Aviation Key Laboratory of Science and Technology on Precision Manufacturing Technology Beijing Precision Engineering Institute for Aircraft Industry Beijing100076 China

ISBN: (纸本)9781510672673

Ultra precision turning technology is widely used in the manufacturing of optical precision components due to its excellent machining accuracy and production efficiency. In the actual turning process, various types of vibrations are superimposed and manifested as relative vibrations between the tool and the workpiece, resulting in specific shape texture features on the surface of the workpiece, seriously affecting the surface quality of the workpiece and reducing its efficiency. This article analyzes the impact of unfiltered low-frequency vibration in the ultra precision machining process environment on the machined surface morphology, achieving vibration error tracing based on workpiece surface morphology data analysis and texture features, and further improving the surface quality of ultra precision turning workpieces. A simulation model for ultra precision turning surface morphology was established based on the principle of tool contour mapping, taking into account the relative vibration in the circumferential, axial, and radial directions between the tool and the workpiece. Based on the deterministic and random factors obtained, the morphology prediction simulation was carried out in the model. Based on the comparative experimental method, single factor experimental method, and result oriented principle, the effect of different cutting parameters on the surface quality of the workpiece under the influence of low-frequency vibration was analyzed. The simulation results were compared with the actual surface morphology, and it was found that the simulation results had consistent layout rules with the measured morphology images. This study provides a reference for the establishment of ultra precision cutting models under external low-frequency forced vibration. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Surface morphology

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Phase transition of multi-component(TiZrVNb)C ceramics—Part II:From single phase to multiple phases via adjusting V content

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Journal of Advanced Ceramics 2024年第5期13卷 689-698页

作者： Qingyi Kong Lei Chen Sijia Huo Kunxuan Li Wenyu Lu Yujin Wang Yu Zhou Institute for Advanced Ceramics School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150080China Key Laboratory of Advanced Structure‒Function Integrated Materials and Green Manufacturing Technology Harbin Institute of TechnologyHarbin 150001China National Key Laboratory of Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China

To address the relatively mediocre mechanical properties of single-phase multi-component carbide ceramics,a phase transition from a single phase to multiple phases was proposed to achieve superior mechanical properties.A series of(TiZrV_(x)Nb)C_(0.8) ceramics with different V contents were fabricated by spark plasma sintering(SPS).The influence of the V content on the phase composition,microstructural evolution,and mechanical properties was investigated in *** transition behavior from a single phase to multiple phases is discovered and *** formation of the Zr-rich phase and Zr-poor phase can be attributed to the increase in lattice distortion and mixed enthalpy caused by the addition of V.A nanometer lamellar structure with a semi-coherent interface obtained via in situ decomposition is reported for the first time in multi-component carbide *** semi-coherent interfaces with high dislocation density and strain concentration effectively improve the mechanical properties,grain refinement,and multi-phase *** optimal comprehensive mechanical properties of the Vickers hardness(26.3 GPa),flexural strength(369 MPa),and fracture toughness(3.1 MPa·m^(1/2))were achieved for the sample with 20 mol%V.

关键词： multi-component ceramics multiple phases microstructure evolution phase decomposition mechanical properties

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