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Entropy regulation in LaNbO_(4)-based fergusonite to implement high-temperature phase transition and promising dielectric properties

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Journal of Advanced Ceramics 2023年第5期12卷 1067-1080页

作者： Deqin Chen Na Yan Xuefeng Cao Fengrong Li Laijun Liu Qinghua Shen Huanfu Zhou Chunchun Li Guangxi University Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and Devices College of Material Science and EngineeringGuilin University of TechnologyGuilin 541004China Guangxi Key Laboratory of Embedded Technology and Intelligent System Guilin University of TechnologyGuilin 541004China

High-entropy effect is a novel design strategy to optimize properties and explore novel *** this work,(La_(1/5)Nd_(1/5)Sm_(1/5)Ho_(1/5)Y_(1/5))NbO_(4)(5RNO)high-entropy microwave dielectric ceramics were successfully prepared in the sintering temperature(S.T.)range of 1210–1290℃via a solid-phase reaction route,and medium-entropy(La_(1/3)Nd_(1/3)Sm_(1/3))NbO_(4) and(La_(1/4)Nd_(1/4)Sm_(1/4)Ho_(1/4))NbO_(4)(3RNO and 4RNO)ceramics were *** effects of the entropy(S)on crystal structure,phase transition,and dielectric performance were *** entropy increase yields a significant increase in a phase transition temperature(from monoclinic fergusonite to tetragonal scheelite structure).Optimal microwave dielectric properties were achieved in the high-entropy ceramics(5RNO)at the sintering temperature of 1270℃for 4 h with a relative density of 98.2%and microwave dielectric properties of dielectric permittirity(ε_(r))=19.48,quality factor(Q×f)=47,770 GHz,and resonant frequency temperature coefficient(τ_(f))=–13.50 ppm/℃.This work opens an avenue for the exploration of novel microwave dielectric material and property optimization via entropy engineering.

关键词： high-entropy ceramics microwave dielectric property ion disorder far-infrared

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Femtosecond laser fabrication of 3D vertically aligned micro-pore network on thick-film Li_(4)Ti_(5)O_(12)electrode for high-performance lithium storage

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Journal of Energy Chemistry 2024年第8期95卷 250-262,I0006页

作者： Quansheng Li Xiaofei Sun Xuesong Mei Lingzhi Wang Minxing Yang Jianlei Cui Wenjun Wang State Key Laboratory for Manufacturing System Engineering Xi'an Jiaotong UniversityXi'an 710049ShaanxiChina Shaanxi Key Laboratory of Intelligent Robots Xi'an Jiaotong UniversityXi'an 710049ShaanxiChina School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049ShaanxiChina

The development of energy storage devices with high energy density relies heavily on thick film electrodes,but it is challenging due to the limited ion transport kinetics inherent in thick ***,we report on the preparation of a directional vertical array of micro-porous transport networks on LTO electrodes using a femtosecond laser processing strategy,enabling directional ion rapid transport and achieving good electrochemical performance in thick film *** three-dimensional(3D)vertically aligned micro-pore networks are innovatively designed,and the structure,kinetics characteristics,and electrochemical performance of the prepared ion transport channels are analyzed and discussed by multiple characterization and testing ***,the rational mechanisms of electrode performance improvement are studied experimentally and simulated from two aspects of structural mechanics and transmission *** ion diffusion coefficient,rate performance at 60 C,and electrode interface area of the laser-optimized 60-15%micro-porous transport network electrodes increase by 25.2 times,2.2 times,and 2.15 times,respectively than those of untreated ***,the preparation of 3D micro-porous transport networks by femtosecond laser on ultra-thick electrodes is a feasible way to develop high-energy *** addition,the unique micro-porous transport network structure can be widely extended to design and explore other high-performance energy materials.

关键词： Femtosecond laser Micro-porous transport networks Laser processing Thick film electrodes Ion transport kinetics

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Temperature field characteristics of CF/PEEK thermoplastic composites formed by automated fiber placement using hot gas torch with slit structure nozzle

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Chinese Journal of Aeronautics 2024年第6期37卷 392-409页

作者： Ziang JIN Shouzheng SUN Sunil Chandrakant JOSHI Zhenyu HAN Hongya FU State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore 639798Singapore

In-situ consolidation forming of high-performance thermoplastic composites by Automated Fiber Placement(AFP)is of significant interest in *** the laying process,the heating temperature has a great influence on the quality of the formed components.A threedimensional heat transfer finite element model of Carbon Fiber(CF)/Polyether Ether Ketone(PEEK)heated by Slit Structure Nozzle Hot Gas Torch(SSNHGT)assisted AFP is *** influence of gas flow rate,heat transfer distance,and laying speed on heating temperature is *** results show that the overall temperature increases and then decreases as the gas flow rate *** the increase in heat transfer distance and laying speed,the overall temperature ***,the gas flow rate has the greatest influence on the temperature of CF/PEEK being heated,followed by the laying speed and finally the heat transfer ***,the model can also be extended to other fiber-reinforced polymer composites formed by hot gas torch assisted AFP,which can guide the optimization of process parameters for subsequent heating temperature control.

关键词： Fiber reinforced plastics Thermoplastics Heating temperature Automated fiber placement CF/PEEK

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Trajectory planning and base attitude restoration of dual-arm free-floating space robot by enhanced bidirectional approach

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Frontiers of Mechanical Engineering 2022年第1期17卷 2-17页

作者： Zongwu XIE Xiaoyu ZHAO Zainan JIANG Haitao YANG Chongyang LI State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Robotic System Department Jiangsu Jitri-Hust Intelligent Equipment TechnologyWuxi 214000China

When free-floating space robots perform space tasks,the satellite base attitude is disturbed by the dynamic *** disturbance of the base orientation may affect the communication between the space robot and the control center on *** this paper,the enhanced bidirectional approach is proposed to plan the manipulator trajectory and eliminate the final base attitude variation.A novel acceleration level state equation for the nonholonomic problem is proposed,and a new intermediate variable-based Lyapunov function is derived and solved for smooth joint trajectory and restorable base *** the method,the state equation is first proposed for dual-arm robots with and without end constraints,and the system stability is analyzed to obtain the system *** input modification further increases the system stability and simplifies the calculation *** are carried out in the end,and the proposed method is validated in minimizing final base attitude change and trajectory ***,the minute internal force during the coordinated operation and the considerable computing efficiency increases the feasibility of the method during space tasks.

关键词： free-floating space robot dual arm coordinated operation base attitude restoration bidirectional approach

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A Bio-inspired Mutual-hook Strategy for the Soft Finger to Improve Load-bearing Capacity and Grasping Stability

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Journal of Bionic Engineering 2024年第3期21卷 1290-1304页

作者： Jie Huang Lingjie Gai Xiaofeng Zong Yunquan Li School of Automation China University of GeosciencesWuhan430074China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan430074China The Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou510641China

Soft grippers have great potential applications in daily life,since they can compliantly grasp soft and delicate ***,the highly elastic fingers of most soft grippers are prone to separate from each other while grasping objects due to their low stiffness,thus reducing the grasping stability and load-bearing *** tackle this problem,inspired from the venus flytrap plant,this work proposes a mutual-hook mechanism to restrain the separation and improve the grasping performance of soft *** novel soft gripper design consists of three modules,a soft finger-cot,two Soft Hook Actuators(SHAs)and two sliding ***,the soft finger-cot covers on the soft finger,increasing the contact area with the target object,two SHAs are fixed to the left and right sides of the finger-cot,and the sliding mechanisms are designed to make SHAs stretch *** demonstrate that the proposed design can restrain the separation of soft fingers substantially,and the soft fingers with the finger-cots can grasp objects three times heavier than the soft fingers without the proposed *** proposed design can provide invaluable insights for soft fingers to restrain the separation while grasping,thus improving the grasping stability and the load-bearing capacity.

关键词： Soft robotics Soft bionic finger-cot Soft hook actuator Grasping stability Load-bearing capacity

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Cascaded chiral birefringent media enabled planar lens with programable chromatic aberration

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PhotoniX 2024年第1期5卷 411-423页

作者： Dewei Zhang Chun-Ting Xu Quan-Ming Chen Han Cao Hong-Guan Yu Qing-Gui Tan Yan-qing Lu Wei Hu National Laboratory of Solid State Microstructures Key Laboratory of Intelligent Optical Sensing and ManipulationCollege of Engineering and Applied SciencesNanjing UniversityNanjing 210023China National Key Laboratory of Science and Technology on Space Microwave China Academy of Space TechnologyXi‘anChina

Wavefront control is the fundamental requirement in optical *** optics have drawn intensive attention due to the merits of compactness and light ***,it remains a challenge to freely manipulate the dispersion,hindering practical applications,especially in ***,we propose the concept of frequencysynthesized phase engineering to solve this problem.A phasefront-frequency matrix is properly designed to encode different spatial phases to separate frequencies,thus makes arbitrary dispersion tailoring and even frequency-separated functionalization *** periodically rotated director endows cholesteric liquid crystal with a spin and frequency selective ***,via presetting the local initial orientation of liquid crystal,geometric phase is encoded to the reflected *** verify the proposed strategy by cascading the chiral anisotropic optical media of specifically designed helical pitches and initial director *** this means,planar lenses with RGB achromatic,enhanced chromatic aberration and color routing properties are ***-sized and high-efficient lenses are fabricated with low crosstalk among *** releases the freedom of dispersion control of planar optics,and even enables frequency decoupled phase *** work brings new insights to functional planar optics and may upgrade the performance of existing optical apparatuses.

关键词： Liquid crystals Planar lens Dispersion programmable Spatial light modulation

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Applications of mercury stable isotopes for tracing volcanism in the geologic record

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Science China Earth Sciences 2024年第5期67卷 1436-1458页

作者： Qing GONG Ming-Xing LING Wang ZHENG State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth System Science Institute of Surface-Earth System ScienceTianjin UniversityTianjin 300072China

Mercury(Hg)enrichments in ancient sediments have been used as a proxy of volcanism,especially large igneous province(LIP)***,considering the existence of other potential Hg sources besides volcanoes and the diverse factors(e.g.,organic matters,clay minerals,sulfide minerals and Fe oxides)that can affect Hg sequestration,there are considerable uncertainties to simply regard sedimentary Hg anomalies as signatures of volcanic *** stable isotopes,a promising tool for tracing the origins and transformations of Hg,have been increasingly used for determining the causes of Hg spikes and understanding the geochemical behavior of Hg in the geologic *** date,lots of researches have applied Hg concentrations and Hg isotopes to identify LIP volcanisms linking with significant geological events such as mass extinctions,ocean anoxic events and other environmental perturbations that mainly occurred in the ***,the results in previous studies clearly show that not all Hg enrichments are derived from volcanic inputs,which emphasize the need for more caution in using Hg as a fingerprint of *** a better understanding of Hg isotopes in the future,there will be important implications for Hg isotopes to reconstruct volcanic activities in the rock records and their impacts on biological evolution.

关键词： Mercury stable isotopes Large igneous province Mass extinction event Ocean anoxic event

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LSF-planner: a visual local planner for legged robots based on ground structure and feature information

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Autonomous Robots 2025年第2期49卷 1-17页

作者： Zhang, Teng Wang, Xiangji Zha, Fusheng Liu, Fucheng Harbin Institute of Technology The State Key Laboratory of Robotics and System Harbin150006 China Lanzhou University of Technology Lanzhou730050 China

Three-dimensional navigation of legged robots is crucial for field exploration and post-disaster rescue. Existing optimization-based local trajectory planners predominantly focus on obstacle avoidance, neglecting negative obstacles (e.g., pits) and varying ground features (e.g., different terrain types). Additionally, non-overlapping areas between the planned space in three-dimensional trajectory planning and the robot’s actual reachable space lead to decision-making issues between crossing and obstacle avoidance, making it challenging to differentiate between passable and hazardous areas, thus impacting navigation safety and stability. To address these limitations, we propose a novel visual local planner, LSF-Planner (Visual Local Planner for Legged Robots Based on Ground Structure and Feature Information). The LSF-Planner employs a multi-layer local perception map that integrates ground feature semantics, sensor range, and negative obstacles (e.g., voids detected by depth sensors) to construct a ground reliability representation. The Label2Grad method is introduced to convert this representation into gradient layers, incorporating a ground reliability penalty function into trajectory optimization. By incorporating constraints on the center of mass height and crossing angles, LSF-Planner effectively differentiates between traversable and hazardous areas. Experimental results show that LSF-Planner significantly outperforms existing methods in 3D trajectory planning, enhancing the navigation performance of legged robots in unstructured environments. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2025.

关键词： Emergency services

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Development of High-Speed On-Of Valves and Their Applications

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 21-41页

作者： He Wang Zhen Chen Jiahai Huang Long Quan Bin Zhao Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic *** of the hydraulic components is critical in the digital hydraulic ***-speed on-of valves(HSVs)which convert a train of input pulses into the fast and accurate switching between the on and of states belong to widely used basic digital hydraulic *** some ways,the characteristics of the HSVs determine the performance of the digital hydraulic *** paper discusses the development of HSVs and their ***,the HSVs with innovative structures which is classifed into direct drive valves and pilot operated valves are discussed,with the emphasis on their ***,an overview of HSVs with intelligent materials is presented with considering of the switching frequency and fow ***,the applications of the HSVs are reviewed,including digital hydraulic components with the integration of the HSVs and digital hydraulic systems controlled by the HSVs.

关键词： High-speed on-of valve Digital hydraulic component Switching frequency Flow rate Innovative structure intelligent material

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A Rhythmic Motion Control Method Inspired by Board Shoe Racing for a Weight-Bearing Exoskeleton

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Journal of Bionic Engineering 2022年第2期19卷 403-415页

作者： Tianshuo Wang Jie Zhao Dongbao Sui Sikai Zhao Yanhe Zhu State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China

To ensure the flexible walking of the weight-bearing exoskeleton robot,most researchers control the exoskeleton to follow the wearer’s movements and provide force to maintain the current dynamic ***,due to the limitation of sensing information and computing power,it is difficult for the exoskeleton to provide the wearer reasonable and stable force only based on the dynamic model,especially in switching between swing phase and stance *** by China’s traditional sport named board shoe racing,a walking control method based on the cooperation of the human and the exoskeleton is proposed in this paper for a lower-limb exoskeleton named *** certain conditions,the exoskeleton itself can walk stably depending on the rhythm signals generated by the Central Pattern Generator(CPG).With certain initiative during walking,it can make proper adjustments according to the human *** the help of dynamic simulation software and Genetic Algorithm(GA),the optimized CPG parameters are *** control is introduced to increase the comfort of the *** impedance parameters as well as the CPG parameters are tuned in real time based on *** experiments were conducted with *** results demonstrate that PALExo can effectively assist the wearer walking with a 45-kg payload benefiting from the proposed method.

关键词： Exoskeleton robot Central pattern generator Walking control method

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