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Analysis of Vibration Characteristics of Electro-hydraulic Driven 3-UPS/S Parallel Stabilization Platform

Chinese Journal of Mechanical Engineering 2024年第6期37卷 212-224页

作者： Xiaoming Yuan Weiqi Wang Haodong Pang Lijie Zhang Hebei Key Laboratory of Heavy Machinery Fluid Power Transmission and Control Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging&Stamping Technology and Science Ministry of EducationYanshan UniversityQinhuangdao 066004China

With the development of fluid-power transmission and control technology,electro-hydraulic-driven technology can significantly improve the load-carrying capacity,stiffness,and control accuracy of stabilization ***,compared with mechanically driven platforms,the stiffness and damping of the fluid,as well as the coupling effect between the fluid and the structure need to be considered for electro-hydraulic-driven parallel stabilization platforms,making the modal and dynamic response characteristics of the mechanism more *** the aim of solving the aforementioned issues,we research the electro-hydraulic driven 3-UPS/S parallel stabilization platform considering the hinge ***,the characteristic vibration equation of the mechanism is established using the virtual work ***,the variation characteristics of the natural frequency and the vibration response according to the position of the mechanism are analyzed based on the dynamic ***,the correctness of the model is verified by a modal test and Runge-Kutta *** study provides a theoretical basis for the dynamic design of electrohydraulic-driven parallel mechanisms.

关键词： Electro-hydraulic driven 3-UPS/S parallel stabilization platform Kinetic equation Vibration mode Vibration response Modal test

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Evaluation on Configuration Stiffness of Overconstrained 2R1T Parallel Mechanisms

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Chinese Journal of Mechanical Engineering 2024年第3期37卷 62-82页

作者： Xuejian Ma Zhenghe Xu Yundou Xu Yu Wang Jiantao Yao Yongsheng Zhao Parallel Robot and Mechatronic System Laboratory of Hebei Province Yanshan UniversityQinhuangdao 066004China Key Laboratory of Advanced Forging and Stamping Technology and Science of Ministry of National Education Yanshan UniversityQinhuangdao 066004China

Currently,two rotations and one translation(2R1T)three-degree-of-freedom(DOF)parallel mechanisms(PMs)are widely applied in five-DOF hybrid machining ***,there is a lack of an effective method to evaluate the configuration stiffness of mechanisms during the mechanism design *** is a challenge to select appropriate 2R1T PMs with excellent stiffness performance during the design *** the operational status of 2R1T PMs,the bending and torsional stiffness are considered as indices to evaluate PMs'configuration ***,a specific method is proposed to calculate these stiffness ***,the various types of structural and driving stiffness for each branch are assessed and their specific values ***,a rigid-flexible coupled force model for the over-constrained 2R1T PM is established,and the proposed evaluation method is used to analyze the configuration stiffness of the five 2R1T PMs in the entire ***,the driving force and constraint force of each branch in the whole working space are calculated to further elucidate the stiffness evaluating results by using the proposed method *** obtained results demonstrate that the bending and torsional stiffness of the 2RPU/UPR/RPR mechanism along the x and y-directions are larger than the other four mechanisms.

关键词： Parallel mechanism Stiffness Over-constrained Three degrees of freedom

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Electronic structure engineering of transition metal dichalcogenides for boosting hydrogen energy conversion electrocatalysts

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Chinese Physics B 2024年第9期33卷 13-28页

作者： Bing Hao Jingjing Guo Peizhi Liu Junjie Guo Key Laboratory of Interface Science and Engineering in Advanced Materials Ministry of EducationTaiyuan University of TechnologyTaiyuan 030024China

Electrocatalytic water splitting for hydrogen production is an appealing strategy to reduce carbon emissions and generate renewable *** promising process,however,is limited by its sluggish reaction kinetics and high-cost *** two-dimensional(2D)transition metal dichalcogenides(TMDCs)have presented great potential as electrocatalytic materials due to their tunable bandgaps,abundant defective active sites,and good chemical ***,phase engineering,defect engineering and interface engineering have been adopted to manipulate the electronic structure of TMDCs for boosting their exceptional catalytic ***,it is essential to clarify the local structure of catalytically active sites of TMDCs and their structural evolution in catalytic reactions using atomic resolution electron microscopy and the booming in situ technologies,which is beneficial for exploring the underlying reaction *** this review,the growth regulation,characterization,particularly atomic configurations of active sites in TMDCs are *** significant role of electron microscopy in the understanding of the growth mechanism,the controlled synthesis and functional optimization of 2D TMDCs are *** review will shed light on the design and synthesis of novel electrocatalysts with high performance,as well as prompt the application of advanced electron microscopy in the research of materials science.

关键词： TMDCs STEM hydrogen energy conversion active site identification

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Excellent high-temperature strength of(HfZrTiTaNb)C high-entropy carbide diffusion-bonded joint via in-situ alloying of Ni/Nb/Ni composite interlayer

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Journal of advanced Ceramics 2025年第1期14卷 127-133,136-139页

作者： Ruijie Mu Ying Wang Shiyu Niu Kongbo Sun Zhenwen Yang Tianjin Key Laboratory of Advanced Joining Technology School of Materials Science and EngineeringTianjin UniversityTianjin 300350China Key Laboratory of Advanced Ceramics and Machining Technology Ministry of EducationTianjin 300350China

To obtain high-entropy carbide(HEC)joints with excellent high-temperature performance,a(HfZrTiTaNb)C HEC joint featuring a direct diffusion-bonded interface with a Nb-based interlayer was successfully fabricated at relatively low temperatures of 1150–1250℃for 60 min under 10 *** from a modified Ni/Nb/Ni composite interlayer with a Nb content of>64 at%,an alloyed Nb_(2)Ni layer was constructed in situ by accelerating the directional diffusion of Ni atoms from the high-entropy interface into the remaining pure Nb through the Ni‒Nb eutectic ***,the excess liquid phase was squeezed out of the bonding region,ensuring the absence of Ni-based *** the intrinsic interfacial stability and sluggish diffusion effect,the HEC with its original lattice structure,was capable of developing diffusion bonding with the Nb_(2)Ni layer instead of interacting with the liquid *** high reliability of the HEC/Nb_(2)Ni bonded interface was confirmed by the coherence of(11¯3)_(HEC)//(141)_(Nb_(2))Ni and a calculated lattice misfit of *** HEC joint had a high room-temperature strength of 174 MPa because of the homogenous Nb_(2)Ni layer,which exhibited nanohardness(15.2±1.5 GPa)and an elastic modulus of 219.9±17.5 ***,the strength of the HEC joint did not decrease at 1000℃,increasing by~49%over that of HEC/Ni/HEC diffusion-bonded joints,which have stringent surface flatness *** suggested that the HEC/Nb_(2)Ni interface had excellent resistance to high-temperature softening,even though it was invariably the initial failure *** work is informative for designing bonding structures and preparing HEC components.

关键词： high-entropyceramic diffusion bonding in situ alloyed interlayer mechanical properties

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Synergistic Enhancement of Mechanical Properties and Electrical Conductivity of Immiscible Bimetal:A Case Study on W–Cu

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Engineering 2025年第3期46卷 224-235页

作者： Qixiang Duan Chao Hou Tielong Han Yurong Li Haibin Wang Xiaoyan Song Zuoren Nie Key Laboratory of Advanced Functional Materials Ministry of EducationCollege of Materials Science and EngineeringBeijing University of TechnologyBeijing 100124China

Immiscible bimetal systems,of which tungsten–copper(W–Cu)is a typical representative,have crucial applications in fields requiring both mechanical and physical ***,it is a major challenge to determine how to give full play to the advantages of the two phases of the bimetal and achieve outstanding comprehensive *** this study,an ultrafine-grained W–Cu bimetal with spatially connected Cu and specific Wislands was fabricated through a designed powder-mixing process and subsequent rapid low-temperature *** prepared bimetal concurrently has a high yield strength,large plastic strain,and high electrical *** stress distribution and strain response of individual phases in different types of W–Cu bimetals under loading were quantified by means of a *** high yield strength of the reported bimetal results from the microstructure refinement and high contiguity of the grains in the W islands,which enhance the contribution of W to the total plastic deformation of the *** high electrical conductivity is attributed to the increased mean free path of the Cu and the reduced proportion of phase boundaries due to the specific phase combination of W islands and *** work provides new insight into modulating phase configuration in immiscible metallic composites to achieve high-level multi-objective properties.

关键词： Immiscible bimetal Phase configuration Mechanical property Electrical conductivity Strain response

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Temperature-sensitive Micelles as Artificial Chaperones for Insulin Protection

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Chinese Journal of Polymer science 2025年第2期43卷 350-359页

作者： Jia-Wen Chen Yan Xiao Mei-Dong Lang Shanghai Key Laboratory of Advanced Polymeric Materials Key Laboratory for Ultrafine Materials of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Insulin is an essential and versatile protein taking part in the control of blood glucose levels and protein ***,under prolonged storage or high temperature stress,insulin tends to unfold and aggregate into toxic amyloid fibrils,leading to loss of physiological *** by natural chaperones,a series of temperature-sensitive polycaprolactone-based micelles were designed to prevent insulin from *** micelles were fabricated through the self-assembly of amphiphilic copolymers of methoxy poly(ethylene glycol)-poly(4-diethylformamide caprolactone-co-caprolactone)(mPEG_(17)-P(DECL-co-CL)),which had a regular spherical morphology with particle sizes of about 100 *** addition,the lower critical solution temperature(LCST)of the micelles could be tuned to 9 and 29℃by changing the ratio of DECL to *** from the temperature-sensitivity of DECL segment,the binding ability of micelles to insulin could be modulated by changing the *** LCST,micelles effectively inhibited insulin aggregation and protected it from thermal inactivation due to the strong binding ability between the hydrophobic segment DECL and *** LCST,DECL segment returned to hydrophilic and bound weakly with insulin,leading to the release of insulin and assisting in its recovery of secondary ***,these temperature-sensitive micelles provided an effective strategy for insulin protection.

关键词： Temperature-sensitive Insulin Micelles Chaperones

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Automatic Control of Magnetic Helical Microrobots Docking with Target Objects in Liquid Environments

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Journal of Bionic Engineering 2025年第2期22卷 574-584页

作者： Fu Zhao Haoran Rong Lefeng Wang State Key Laboratory of Robotics and Systems Harbin Institute of TechnologyHarbin150080China Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin150080China

Bio-inspired magnetic helical microrobots have great potential for biomedical and micromanipulation applications. Precise interaction with objects in liquid environments is an important prerequisite and challenge for helical microrobots to perform various tasks. In this study, an automatic control method is proposed to realize the axial docking of helical microrobots with arbitrarily placed cylindrical objects in liquid environments. The docking process is divided into ascent, approach, alignment, and insertion stages. First, a 3D docking path is planned according to the positions and orientations of the microrobot and the target object. Second, a steering-based 3D path-following controller guides the helical microrobot to rise away from the container bottom and approach the target along the path. Third, based on path design with gravity compensation and steering output limits, alignment of position and orientation can be accomplished simultaneously. Finally, the helical microrobot completes the docking under the rotating magnetic field along the target orientation. Experiments verified the automatic docking of the helical microrobot with static targets, including connecting with micro-shafts and inserting into micro-tubes. The object grasping of a reconfigurable helical microrobot aided by 3D automatic docking was also demonstrated. This method enables precise docking of helical microrobots with objects, which might be used for capture and sampling, in vivo navigation control, and functional assembly of microrobots.

关键词： Magnetic actuation Helical microrobots Visual servo Motion control Docking

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Lightweight and large-scale rGO reinforced SiBCN aerogels with hierarchical cellular structures exposed to high-temperature environments

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Journal of Materials science & technology 2024年第12期179卷 145-154页

作者： Huijie Wang Zhiwei Chen Dong Su Key Laboratory of Advanced Ceramics and Machining Technology of Ministry of Education School of Materials Science and EngineeringTianjin UniversityTianjin 300350China

SiBCN ceramic aerogel is an ideal potential candidate for ultra-high temperature thermal insulation due to its unique microscopic pore structure combined with the excellent thermal stability of SiBCN ***,reduced graphene oxide(rGO)modified SiBCN aerogels(rGO/SiBCN)were prepared through solvothermal,freeze-casting and pyrolysis,and the dimension of the aerogel is up toΦ130 mm×28 *** density of the rGO/SiBCN aerogel is as low as 0.024 g/cm^(3) and the microstructural regulation is achieved by controlling the rGO content in the *** hierarchical cellular structure endows the aerogel with a high specific surface area(148.6 m^(2)/g)and low thermal conductivity(0.057 W m^(-1) K^(-1)).The 10 mm-thick sample exhibits excellent thermal insulation and ablation resistance,as evidenced by its ability to reduce the temperature from~1100℃to~180℃under the intense heat of a butane ***,benefiting from the ultrahigh-temperature stability of SiBCN,the rGO/SiBCN aerogel exhibits good thermal stability up to 1200℃in argon and short-oxidation resistance at 800℃in ***-fore,the rGO/SiBCN aerogel with superior overall performance could expand its practical application in high-temperature thermal insulation under extreme environments.

关键词： rGO/SiBCN Lightweight Large size Hierarchical cellular structure Thermal insulation

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Data-physics collaborativige fusion prediction method for tool remaining useful life based on Mamba state space and physical description

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Journal of Manufacturing Systems 2025年 81卷 1-15页

作者： Yue, Caixu Qin, Yiyuan Liu, Xianli Gu, Hao Sun, Shaocong Key Laboratory of Advanced Manufacturing and Intelligent Technology Ministry of Education Harbin University of Science and Technology Harbin150080 China

Tool wear is an inherent phenomenon of the metal cutting process, the traditional replacement strategy relies on experience or a fixed cycle easily leads to waste of resources or workpiece damage, accurate prediction of the tool's remaining useful life (RUL) has become a key issue in the field of intelligent manufacturing urgently need to break through. Aiming at the problems of insufficient nonlinear processing capability of physical models and weak interpretability of data-driven models in the existing RUL prediction, this study proposes a data-physics collaborative fusion prediction method for tool remaining useful life based on Mamba state space and physical description. The method breaks through the traditional single-model paradigm and achieves in-depth characterization of the cutting process through a dual modeling mechanism: firstly, a time-series feature extraction network based on the Mamba state space is constructed, and a selective memory mechanism is adopted to achieve the screening of degradation features and non-linear characterization;secondly, a two-stage piecewise physical degradation model is established. The explicit mathematical expressions are deduced based on the geometrical features of the tool wear curve, and the prior distributions of the model parameters are estimated from historical data. The Particle Filter (PF) algorithm is introduced to establish a collaborative optimization mechanism for the dual models, and the physical parameters are dynamically updated through importance sampling to achieve tool RUL prediction under Data-physics collaborative fusion (DPCF). The experimental results show that the method can achieve accurate monitoring of tool RUL and has a certain reference value for efficient tool change in the metal-cutting process. © 2025 The Society of Manufacturing Engineers

关键词： Metal cutting

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Numerical simulation on directional solidification and heat treatment processes of turbine blades

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China Foundry 2024年第5期21卷 476-490页

作者： Ye-yuan Hu Ju-huai Ma Qing-yan Xu School of Materials Science and Engineering Tsinghua UniversityKey Laboratory for Advanced Materials Processing TechnologyMinistry of EducationBeijing 100084China

Study on turbine blades is crucial due to their critical role in ensuring the efficient and reliable operation of aircraft ***-based single crystal superalloys are extensively used in the hot manufacturing of turbine blades due to their exceptional high-temperature mechanical *** hot manufacturing of single crystal blades involves directional solidification and heat *** manufacturing of these blades is time-consuming,capital-intensive,and often insufficient to meet industrial *** simulation techniques have gained widespread acceptance in blade manufacturing research due to their low energy consumption,high efficiency,and rapid turnaround *** article introduces the modeling and simulation of hot manufacturing in single crystal *** discussion outlines the prevalent mathematical models employed in numerical simulations related to blade hot *** encapsulates the advancements in research concerning macro to micro-level numerical simulation techniques for directional solidification and heat treatment ***,potential future trajectories for the numerical simulation of single crystal blade hot manufacturing are also discussed.

关键词： single crystal blades Ni-based superalloy directional solidification heat treatment numerical simulation

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