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State of the art in movement around a remote point:a review of remote center of motion in robotics

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Frontiers of Mechanical Engineering 2024年第2期19卷 1-28页

作者： Wuxiang ZHANG Zhi WANG Ke MA Fei LIU Pengzhi CHENG xilun ding School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Ningbo Institute of Technology Beihang UniversityNingbo 315832China Intelligent Aerospace Manufacturing Engineering Technology Co. Ltd.Beijing 100191China

The concept of remote center of motion(RCM)is pivotal in a myriad of robotic applications,encompa-ssing areas such as medical robotics,orientation devices,and exoskeletal systems.The efficacy of RCM technology is a determining factor in the success of these robotic domains.This paper offers an exhaustive review of RCM technologies,elaborating on their various methodologies and practical implementations.It delves into the unique characteristics of RCM across different degrees of freedom(dOFs),aiming to distill their fundamental principles.In addition,this paper categorizes RCM approaches into two primary classifications:design based and control based.These are further organized according to their respective dOFs,providing a concise summary of their core methodologies.Building upon the understanding of RCM’s versatile capabilities,this paper then transitions to an in-depth exploration of its applications across diverse robotic fields.Concluding this review,we critically analyze the existing research challenges and issues that are inherently present in both RCM methodologies and their applications.This discussion is intended to serve as a guiding framework for future research endeavors and practical deployments in related areas.

关键词： remote center of motion mechanism robotics medical robot orientation device exoskeleton

Recent Advances in Biomass-derived Porous Carbon Materials:Synthesis,Composition and Applications

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Chemical Research in Chinese Universities 2024年第1期40卷 3-19页

作者： ZHAI Ziqi LU Yumiao LIU Guangyong ding Wei-Lu CAO Bobo HE Hongyan CAS Key Laboratory of Green Process and Engineering State Key Laboratory of Mesoscience and EngineeringBeijing Key Laboratory of Ionic Liquids Clean ProcessInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China Longzihu New Energy Laboratory Zhengzhou Institute of Emerging Industrial TechnologyZhengzhou 450000P.R.China

Porous carbon materials(PCMs)play a pivotal role in diverse applications,such as energy storage,adsorption,catalysis,environmental remediation,and microwave adsorption.The selection of carbon precursors,in particular,is crucial for tailoring porous structures with specific functionalities.Biomass,with its rich carbon feedstock,abundant availability,renewability,and versatile structures,has emerged as a promising precursor for porous carbon material synthesis.This review comprehensively summarizes the recent advances in biomass-derived porous carbon materials(BPCMs)encompassing synthetic strategy,morphology,structural composition,and multiple applications.We first review synthetic approaches aiming at regulating porosity,followed by morphological and composition features of BPCMs,with a special emphasis on elucidating the dimensional clarification and heteroatom doping effects.The discussion then extends to the wide-ranging applications of BPCMs,covering energy-related applications and CO_(2) adsorption to environmental remediation.Finally,the review outlines the existing challenges and prospects in the field.In summary,this review systematically describes BPCMs and provides valuable guidance for researchers to select and synthesize BPCMs that meet specific functional requirements.

关键词： Biomass Porous carbon Pyrolysis Heteroatom-doping Supercapacitor CO_(2)adsorption

Human umbilical cord mesenchymal stem cell-derived exosomes loaded into a composite conduit promote functional recovery after peripheral nerve injury in rats

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Neural Regeneration Research 2024年第4期19卷 900-907页

作者： Haoshuai Tang Junjin Li Hongda Wang Jie Ren Han ding Jun Shang Min Wang Zhijian Wei Shiqing Feng department of Othopaedics Tianjin Medical University General Hospital International Science and Technology Cooperation Base of Spinal Cord Injury Tianjin Key Laboratory of Spine and Spinal Cord InjuryDepartment of OrthopedicsTianjin Medical University General Hospital Tianjin Key Laboratory of Lung Cancer Metastasis and Tumor Microenvironment Tianjin Lung Cancer InstituteTianjin Medical University General Hospital department of Othopaedics Qilu Hospital of Shandong UniversityShandong University Centre for OthopedicsAdvanced Medical Research InstituteShandong University Orthopedic Research Center of Shandong University&Advanced Medical Research Institute Cheeloo College of MedicineShandong University

Complete transverse injury of peripheral nerves is challenging to treat.Exosomes secreted by human umbilical cord mesenchymal stem cells are considered to play an important role in intercellular communication and regulate tissue regeneration.In previous studies,a collagen/hyaluronic acid sponge was shown to provide a suitable regeneration environment for Schwann cell proliferation and to promote axonal regeneration.This three-dimensional(3d)composite conduit contains a collagen/hyaluronic acid inner sponge enclosed in an electrospun hollow poly(lactic-co-glycolic acid)tube.However,whether there is a synergy between the 3d composite conduit and exosomes in the repair of peripheral nerve injury remains unknown.In this study,we tested a comprehensive strategy for repairing long-gap(10 mm)peripheral nerve injury that combined the 3d composite conduit with human umbilical cord mesenchymal stem cell-derived exosomes.Repair effectiveness was evaluated by sciatic functional index,sciatic nerve compound muscle action potential recording,recovery of muscle mass,measuring the cross-sectional area of the muscle fiber,Masson trichrome staining,and transmission electron microscopy of the regenerated nerve in rats.The results showed that transplantation of the 3d composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes promoted peripheral nerve regeneration and restoration of motor function,similar to autograft transplantation.More Cd31-positive endothelial cells were observed in the regenerated nerve after transplantation of the loaded conduit than after transplantation of the conduit without exosomes,which may have contributed to the observed increase in axon regeneration and distal nerve reconnection.Therefore,the use of a 3d composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes represents a promising cell-free therapeutic option for the treatment of peripheral nerve injury.

关键词： axon growth collagen exosome human umbilical cord mesenchymal stem cells hyaluronic acid muscular atrophy nerve guidance conduits peripheral nerve regeneration

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First-principles study of the relationship between the formation of single atom catalysts and lattice thermal conductivity

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Chinese Chemical Letters 2024年第6期35卷 502-506页

作者： Chaozheng He Pei Shi donglin Pang Zhanying Zhang Long Lin Yingchun ding department of Chemistry and Chemical Engineering Liaocheng UniversityLiaocheng 252059China Henan Key Laboratory of Materials on deep-Earth Engineering School of Materials Science and EngineeringHenan Polytechnic UniversityJiaozuo 454000China School of Materials Science and Engineering Henan Polytechnic UniversityJiaozuo 454000China department of Basic Medicine North Sichuan Medical CollegeNanchong 637000China

Single atom catalysts(SACs)have been in the forefront of catalysts research because of their high efficiency and low cost and provide new ideas for development of renewable energy conversion and storage technologies.However,the relationship between the intrinsic properties of materials such as lattice thermal conductivity and catalysis remains to be explored.In this work,the lattice thermal conductivity of BN and graphene was calculated by Sheng BTE.In addition,the adsorption properties of 3d-TM(TM=V,Cr,Mn,Fe,Co,Ni)on BN and graphene were investigated using first-principles methods,and it was found that Ni atom can form relatively stable SACs compared to other TMs.The molecular dynamics(Md)simulation and migration barrier of Ni loaded on BN and graphene were calculated.Our study found that graphene has higher thermal conductivity and is easier to form SACs than BN,but the SACs formed on BN surface have higher thermodynamic stability.

关键词： First-principles calculation Thermal conductivity Single atom catalysts Graphene BN

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Microstructure evolution and phase transformation of the mushy zone in a quenchedβ-solidifying TiAl alloy

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Journal of Materials Science & Technology 2024年第2期169卷 28-41页

作者： Fuqiang Zhang xianfei ding Leming xu xin Feng Hai Nan Jianping He Yongfeng Liang Junpin Lin State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China Cast Titanium Alloy R&d Center Beijing Institute of Aeronautical MaterialsBeijing 100095China

This study investigates the phase constitutions and transformations that occur in the mushy zone and in the adjacent phase fields of a directionally solidified Ti-44Al-8Nb-1Cr alloy via quenching technique.The results indicate that the mushy zone consists of unmeltedβdendrites and interdendritic liquid,whose formation can be attributed to the difference in melting point aroused by local heterogeneity in solutecontent.Theβdendrite is composed of numerous subgrains with various orientations.during quenching,theβdendrite transforms into Widmanstättenαvia a precipitation reaction,owing to the decreasing cooling rate caused by heat transfer from the surrounding liquid.Additionally,after quenching,the interdendritic liquid is transformed intoγplates.Within the singleβphase field and the lower part of the mushy zone,a massive transformation ofβtoγoccurs.Conversely,in theβ+αphase field,bothβandαphases are retained to ambient temperature.during the heating process,the transformation ofα→βgives rise to the formation ofβvariants,which affects the orientation ofβdendrites in the mushy zone.The growth kinematics of theα→βtransformation was elucidated,revealing the preferential growth directions of111and112forβvariants.Furthermore,this study presents an illustration of the formation process of the mushy zone and the microstructural evolution during the heating and quenching process.

关键词： Titanium aluminides Mushy zone Quenching Electron backscattering diffraction Phase transformation

Recovery of Li, Ni, Co and Mn from spent lithium-ion batteries assisted by organic acids: Process optimization and leaching mechanism

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International Journal of Minerals,Metallurgy and Materials 2024年第3期31卷 518-530页

作者： Liuyi Ren Bo Liu Shenxu Bao Wei ding Yimin Zhang xiaochuan Hou Chao Lin Bo Chen School of Resources and Environmental Engineering Wuhan University of TechnologyWuhan 430070China State Environmental Protection Key Laboratory of Mineral Metallurgical Resources Utilization and Pollution Control Wuhan University of Science and TechnologyWuhan 430081China Zhejiang New Era Zhongneng Recycling Technology Co. LtdShaoxing 312000China Shenzhen Water Planning&design Institute Co. LtdShenzhen 518000China

The proper recycling of spent lithium-ion batteries(LIBs)can promote the recovery and utilization of valuable resources,while also negative environmental effects resulting from the presence of toxic and hazardous substances.In this study,a new environmentally friendly hydro-metallurgical process was proposed for leaching lithium(Li),nickel(Ni),cobalt(Co),and manganese(Mn)from spent LIBs using sulfuric acid with citric acid as a reductant.The effects of the concentration of sulfuric acid,the leaching temperature,the leaching time,the solid-liquid ratio,and the reducing agent dosage on the leaching behavior of the above elements were investigated.Key parameters were optimized using response surface methodology(RSM)to maximize the recovery of metals from spent LIBs.The maxim-um recovery efficiencies of Li,Ni,Co,and Mn can reach 99.08%,98.76%,98.33%,and 97.63%.under the optimized conditions(the sulfuric acid concentration was 1.16 mol/L,the citric acid dosage was 15wt%,the solid-liquid ratio was 40 g/L,and the temperature was 83℃ for 120 min),respectively.It was found that in the collaborative leaching process of sulfuric acid and citric acid,the citric acid initially provided strong reducing CO_(2)^(-),and the transition metal ions in the high state underwent a reduction reaction to produce transition metal ions in the low state.Additionally,citric acid can also act as a proton donor and chelate with lower-priced transition metal ions,thus speeding up the dissolution process.

关键词： spent lithium-ion batteries leaching response surface methodology sulfuric acid citric acid

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Research on the mechanism of the two-dimensional ultrasonic surface burnishing process to enhance the wear resistance for aluminum alloy

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Friction 2024年第3期12卷 490-509页

作者： Zhen-Yu ZHOU Qiu-Yang ZHENG Yu LI Cong ding Guang-Jian PENG Zhong-Yu PIAO College of Mechanical Engineering Zhejiang University of TechnologyHangzhou 310023China Key Laboratory of Special Purpose Equipment and Advanced Processing Technology Ministry of Education and Zhejiang ProvinceZhejiang University of TechnologyHangzhou 310014China

The gradient nanostructure is machined on the aluminum(Al)alloy by the two-dimensional ultrasonic surface burnishing process(2d-USBP).The mechanism of why the gradient nanostructure enhances wear resistance is investigated.The mechanical properties and microstructure characterization for the gradient nanostructure are performed by operating a nanoindenter,transmission electron microscopy(TEM),and electron backscattered diffraction(EBSd).dry wear tests are performed on the samples before and after machining to evaluate the wear resistance and mechanisms.The effect of the gradient nanostructure on the wear resistance is explored by developing the crystal plasticity(CP)finite element and molecular dynamics(Md)models.The characterization results show that the 2d-USBP sample prepared a gradient structure of~600μm thick on the aluminum surface,increasing the surface hardness from 1.13 to 1.71 GPa and reducing the elastic modulus from 78.84 to 70.14 GPa.The optimization of the surface microstructure and the increase of the mechanical properties effectively enhance the wear resistance of the sample,with 41.20%,39.07%,and 54.58% of the wear scar areas for the 2d-USBP treated samples to the original samples under 5,10,and 15 N loads,respectively.The gradient nanostructure hinders the slip of dislocations inside the sample during the wear process and reduces the size and scope of plastic deformation;meanwhile,the resistance to deformation,adhesion,and crack initiation and propagation of the sample surface is improved,resulting in enhanced wear resistance.

关键词： structural superlubricity lattice registry elastic deformation strained solitons crystal plasticity molecular dynamics simulations

Ultra-wide band gap and wave attenuation mechanism of a novel star-shaped chiral metamaterial

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1261-1278页

作者： Shuo WANG Anshuai WANG Yansen WU xiaofeng LI Yongtao SUN Zhaozhan ZHANG Qian ding G.d.AYALEW Yunxiang MA Qingyu LIN department of Mechanics Tianjin University Tianjin Key Laboratory of Nonlinear dynamics and Control Tianjin University State Key Laboratory of Metastable Materials Science and Technology Yanshan University

A novel hollow star-shaped chiral metamaterial(SCM) is proposed by incorporating chiral structural properties into the standard hollow star-shaped metamaterial, exhibiting a wide band gap over 1 500 Hz. To broaden the band gap,solid single-phase and two-phase SCMs are designed and simulated, which produce two ultra-wide band gaps(approximately 5 116 Hz and 6 027 Hz, respectively). The main reason for the formation of the ultra-wide band gap is that the rotational vibration of the concave star of two novel SCMs drains the energy of an elastic wave. The impacts of the concave angle of a single-phase SCM and the resonator radius of a two-phase SCM on the band gaps are studied. decreasing the concave angle leads to an increase in the width of the widest band gap, and the width of the widest band gap increases as the resonator radius of the two-phase SCM increases. Additionally,the study on elastic wave propagation characteristics involves analyzing frequency dispersion surfaces, wave propagation directions, group velocities, and phase velocities. Ultimately, the analysis focuses on the transmission properties of finite periodic structures. The solid single-phase SCM achieves a maximum vibration attenuation over 800, while the width of the band gap is smaller than that of the two-phase SCM. Both metamaterials exhibit high vibration attenuation capabilities, which can be used in wideband vibration reduction to satisfy the requirement of ultra-wide frequencies.

关键词： metamaterial ultra-wide band gap wave propagation vibration suppression O421 + .5 74H45

Molecular Engineering of Aptamer to Solubilize Hydrophobic Near-Infrared Photosensitizer for Enhanced Cancer Photodynamic Therapy

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CCS Chemistry 2024年第5期6卷 1240-1254页

作者： Rongjun Zhang ding-Kun Ji defan Yao Zeyu xiao Weihong Tan Institute of Molecular Medicine(IMM) Renji HospitalState Key Laboratory of Oncogenes and Related GenesShanghai Jiao Tong University School of MedicineShanghai 200240 department of Radiology Xinhua HospitalShanghai Jiao Tong University School of MedicineShanghai 200092 department of Pharmacology and Chemical Biology School of MedicineShanghai Jiao Tong UniversityShanghai 200025 Zhejiang Cancer Hospital Hangzhou Institute of Medicine(HIM)The Chinese Academy of SciencesHangzhouZhejiang 310022 Molecular Science and Biomedicine Laboratory(MBL) State Key Laboratory of Chemo/Biosensing and ChemometricsCollege of Chemistry and Chemical EngineeringCollege of BiologyAptamer Engineering Center of Hunan ProvinceHunan UniversityChangshaHunan 410082

Photodynamic therapy(PdT)is a clinically representative treatment strategy for cancer.However,conventional photosensitizers(PSs)are usually hampered by poor water solubility and low targeting capacity.Here,we report the precise molecular engineering of aptamer oligonucleotides to solubilize hydrophobic near-infrared(NIR)PSs for enhanced cancer PdT.Hydrophobic pyropheophorbide A(PA)is precisely conjugated to aptamer oligonucleotides by combing dNA solid-phase synthesis technology and Cu-free click chemistry.Precise coupling of insoluble PA to hydrophilic aptamer oligonucleotides vastly improves its solubility to as high as 750μM in water without any cosolvent,resulting in an enhanced NIR fluorescence property(quantum yield=23%)and photoactivity.Moreover,the targeting ability of aptamer oligonucleotides is not affected by our molecular engineering strategy.Abundant reactive oxygen species(ROS)are produced intracellularly with 660 nm laser irradiation,eliciting mitochondria damage and cell death.Tumor growth is effectively inhibited with a single dose of aptamer-PA conjugates without in vivo toxicity.Their therapeutic effect is more than 20-fold higher than that of PA.Compared with traditional formulation,using aptamer oligonucleotides as functional carriers to solubilize hydrophobic NIR PSs is more precise and operable.Our dNA molecular engineering strategy paves a way for the rational design of molecularly targeted medicine for future clinical cancer therapy.

关键词： aptamer aptamer-drug conjugates photosensitive drugs targeted photodynamic therapy cancer theranostics