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A review of the bio-tribology of medical devices

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Friction 2022年第1期10卷 4-30页

作者： xiaogang zhang Yali zhang Zhongmin JIN School of Mechanical Engineering Southwest Jiaotong UniversityChengdu 610031China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710049China School of Mechanical Engineering University of Leeds.Leeds LS29JTUK

Numerous medical devices have been applied for the treatment or alleviation of various *** issues widely exist in those medical devices and play vital roles in determining their performance and service *** this review,the bio-tribological issues involved in commonly used medical devices are identified,including artificial joints,fracture fixation devices,skin-related devices,dental restoration devices,cardiovascular devices,and surgical *** current understanding of the bio-tribological behavior and mechanism involved in those devices is *** advances in the improvement of tribological properties are *** and future developments for the prospective of bio-tribological performance are highlighted.

关键词： bio-tribology medical devices wear friction

基于OpenSim预测青少年跖屈肌无力的下肢生物力学行为

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中国组织工程研究 2025年第9期29卷 1789-1795页

作者：付恩洪杨行梁成张小刚张亚丽靳忠民西南交通大学机械工程学院四川省成都市610031

背景:跖屈肌无力是痉挛型脑瘫和腓骨肌萎缩症患者的常见肌肉缺陷,临床上会表现出异常步态,而跖屈肌无力与异常步态间的关系尚不明晰。目的:探讨跖屈肌无力单因素作用时对下肢生物力学行为的影响,以揭示跖屈肌无力诱发异常步态的机制,为... 详细信息

背景:跖屈肌无力是痉挛型脑瘫和腓骨肌萎缩症患者的常见肌肉缺陷,临床上会表现出异常步态,而跖屈肌无力与异常步态间的关系尚不明晰。目的:探讨跖屈肌无力单因素作用时对下肢生物力学行为的影响,以揭示跖屈肌无力诱发异常步态的机制,为跖屈肌无力患者康复训练提供指导。方法:基于OpenSim Moco建立矢状面内骨肌多体动力学预测框架,预测正常受试者下肢关节角和肌肉激活变化,结合实验数据逆运动学和肌电图激活时间,验证框架有效性。减小等距肌肉力进行跖屈肌无力建模并将预测得到的下肢关节角、关节力矩和肌肉能量消耗,与正常受试者对比,以分析跖屈肌无力对下肢生物力学的影响。结果与结论:①基于Moco的预测框架较真实地预测了正常受试者步行过程中的下肢生物力学变化(关节角归一化相关系数≥0.73,均方根误差≤7.10°);②跖屈肌无力时模型采用小步幅且支撑相上升的“脚跟行走”步态,当跖屈肌无力达到80%时,肌肉能量消耗为5.6914 J/(kg·m),腓肠肌和比目鱼肌激活度最大分别为0.72,0.53,可能致使跖屈肌无力患者步行时更易疲劳;③当跖屈肌无力超过40%时,肌肉能量消耗显著升高;跖屈肌无力超过60%时,下肢关节角和关节力矩出现较明显恶化,说明跖屈肌无力对步态的影响可能存在“阈值”,这或许对应于医护人员进行临床干预的时间点。

关键词：下肢跖屈肌无力生物力学步态预测肌肉能量消耗肌肉激活 OpenSimMoco

Information compression and speckle reduction for multifrequency polarimetric SAR images based on kernel PCA

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Journal of Systems Engineering and Electronics 2008年第3期19卷 493-498页

作者： Li Ying Lei xiaogang Bai Bendu zhang Yanning Dept. of Computer Science and Engineering Northwest Polytechnical Univ. Xi'an 710072 P. R. China

Multifrequency polarimetric SAR imagery provides a very convenient approach for signal processing and acquisition of radar image. However, the amount of information is scattered in several images, and redundancies exist between different bands and polarizations. Similar to signal-polarimetric SAR image, multifrequency polarimetric SAR image is corrupted with speckle noise at the same time. A method of information compression and speckle reduction for multifrequency polarimetric SAR imagery is presented based on kernel principal component analysis （KPCA）. KPCA is a nonlinear generalization of the linear principal component analysis using the kernel trick. The NASA/JPL polarimetric SAR imagery of P, L, and C bands quadpolarizations is used for illustration. The experimental results show that KPCA has better capability in information compression and speckle reduction as compared with linear PCA.

关键词： kernel PCA multifrequency polarimetric SAR imagery information compression despeckling.

Overlying strata movement rules and safety mining technology for the shallow depth seam proximity beneath a room mining goaf

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International Journal of Mining Science and Technology 2015年第1期25卷 139-143页

作者： Wang Fangtian zhang Cun zhang xiaogang Song Qi School of Mines China University of Mining and Technology Key Laboratory of Deep Coal Resource Mining Ministry of Education of China China University of Mining and Technology State Key Laboratory of Coal Resources and Mine Safety China University of Mining and Technology

Aiming at the shallow depth seam proximity beneath a room mining goaf, due to that the shallow depth seam is exploited using the longwall mining and overlain by thin bedrock and thick loose sands, many accidents are likely to occur, including roof structure instability, roof step subsidence, damages of shield supports, and the face bumps triggered by the large area roof weighting, resulting in serious threats to the safety of underground miners and equipment. This paper analyses the overlying strata movement rules for the shallow seams using the physical simulation, the 3DEC numerical simulation and the field mea- surements. The results show that, in shallow seam mining, the overburden movement forms caved zone and fractured zone, the cracks develop continuously and reach the surface with the face advancing, and the development of surface cracks generally goes through four stages. With the application of loose blast- ing of residual pillars, reasonable mining height, and roof support and management, the safe, efficient and high recovery rate mining has been achieved in the shallow depth seam proximity beneath a room min ing goal.

关键词： Shallow depth seamRoom mining goafClosely-separated coal seamsLongwall miningOverlying strata movement roles

Niobium Tungsten Oxide in a Green Water‑in‑Salt Electrolyte Enables Ultra‑Stable Aqueous Lithium‑Ion Capacitors

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Nano-Micro Letters 2020年第12期12卷 106-116页

作者： Shengyang Dong Yi Wang Chenglong Chen Laifa Shen xiaogang zhang School of Chemistry and Materials Science Institute of Advanced Materials and Flexible Electronics(IAMFE)Nanjing University of Information Science and TechnologyNanjing 210044People’s Republic of China Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016People’s Republic of China Max Planck Institute for Solid State Research Heisenbergstrasse 170569 StuttgartGermany

Aqueous hybrid supercapacitors are attracting increasing attention due to their potential low cost,high safety and ***,the narrow operating potential window of aqueous electrolyte and the lack of suitable negative electrode materials seriously hinder its future ***,we explore high concentrated lithium acetate with high ionic conductivity of 65.5 mS cm−1 as a green“water-in-salt”electrolyte,providing wide voltage window up to 2.8 *** facilitates the reversible function of niobium tungsten oxide,Nb18W16O93,that otherwise only operations in organic electrolytes *** Nb18W16O93 with lithium-ion intercalation pseudocapacitive behavior exhibits excellent rate performance,high areal capacity,and ultra-long cycling *** aqueous lithium-ion hybrid capacitor is developed by using Nb18W16O93 as negative electrode combined with graphene as positive electrode in lithium acetate-based“water-in-salt”electrolyte,delivering a high energy density of 41.9 W kg−1,high power density of 20,000 W kg−1 and unexceptionable stability of 50,000 cycles.

关键词： Aqueous hybrid capacitors Water-in-salt electrolyte Niobium tungsten oxide Ultra-stability High power density

Solvation Engineering via Fluorosurfactant Additive Toward Boosted Lithium-Ion Thermoelectrochemical Cells

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Nano-Micro Letters 2024年第4期16卷 253-268页

作者： Yinghong Xu Zhiwei Li Langyuan Wu Hui Dou xiaogang zhang Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies College of Material Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 211106People’s Republic of China

Lithium-ion thermoelectrochemical cell(LTEC), featuring simultaneous energy conversion and storage, has emerged as promising candidate for low-grade heat harvesting. However, relatively poor thermosensitivity and heat-to-current behavior limit the application of LTECs using LiPF_6 electrolyte. Introducing additives into bulk electrolyte is a reasonable strategy to solve such problem by modifying the solvation structure of electrolyte ions. In this work, we develop a dual-salt electrolyte with fluorosurfactant(FS) additive to achieve high thermopower and durability of LTECs during the conversion of low-grade heat into electricity. The addition of FS induces a unique Li~+ solvation with the aggregated double anions through a crowded electrolyte environment,resulting in an enhanced mobility kinetics of Li~+ as well as boosted thermoelectrochemical performances. By coupling optimized electrolyte with graphite electrode, a high thermopower of 13.8 mV K^(-1) and a normalized output power density of 3.99 mW m^(–2) K^(–2) as well as an outstanding output energy density of 607.96 J m^(-2) can be *** results demonstrate that the optimization of electrolyte by regulating solvation structure will inject new vitality into the construction of thermoelectrochemical devices with attractive properties.

关键词： Solvation engineering Fluorosurfactant Ionic thermoelectric Lithium-ion thermoelectrochemical cell Low-grade heat

Supercritical CO_2-based solvents in next generation microelectronics processing

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Chinese Science Bulletin 2007年第1期52卷 27-33页

作者： zhang xiaogang Keith P. JOHNSTON Department of Chemistry Renmin University of China Beijing 100872 China Department of Chemical Engineering Center for Nano and Molecular Science and Technology University of Texas at Austin Austin TX 78712 USA

Large amount of chemicals and highly purified-water are needed in microelectronic manufacture. The ability of solutions to penetrate tiny spaces will become significantly more challenging as the feature size of semiconductor devices decreases to nanoscale dimensions and the functional complexity of integrated circuitries (ICs) ever increases. Supercritical fluids (SCFs) possess a unique combination of properties (no surface tension and gas-like viscosity) that can potentially be exploited for application in microelectronics manufacturing and processing in response to needs for material-compatible cleaning systems, small-dimension developing solvents, and low chemical-use processes. Recent microelec- tronics processes for cleaning and rinsing of patterned porous low-k dielectrics and drying of photo- resist in CO2-based solvents are the main focus of this review. Additional topics in supercritical fluid processing include spin coating of photoresists, development with nanoscale dimensions, metal deposition and silylation.

关键词：微电子学二氧化碳溶解性深冷分离

Targeted Deposition in a Lithiophilic Silver-Modified 3D Cu Host for Lithium-Metal Anodes

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Energy & Environmental Materials 2023年第5期6卷 355-363页

作者： Weiyi Chen Shaopeng Li Chenhui Wang Hui Dou xiaogang zhang Jiangsu Key Laboratory of Electrochemical Energy Storage Technologies College of Materials Science and TechnologyNanjing University of Aeronautics and AstronauticsNanjing 210016China

Lithium-metal batteries are regarded as the"Holy Grail"of next-generation ***,lithium dendrite and anode volume expansion in cycles seriously hinders lithium-metal battery ***,we propose a precise and efficient strategy for stabilizing lithium-metal batteries via a lithiophilic Ag-modified Cu current host(Li@CuM/Ag).By applying the magnetron sputtering method,the lithiophilic silver layer can be anchored homogeneously on the Cu *** lithiophilic silver layer effectively guides uniform Li deposition in the 3D host and realizes spatial control over Li *** addition,a dendrite-free lithium anode is successfully realized,which has been proven by in situ optical dynamic tests and Li deposition *** symmetrical cell can maintain a low overpotential(230 mV)and long cycle life(90 h)at a large current of 10 mA cm^(-2)for a plating amount of 3 mAh cm^(-2).Furthermore,Li@CuM/Ag||LiCoO2 cells exhibited a high-capacity retention rate(86.39%)after 150 cycles at 2 *** hosts based on magnetron sputtering provide a feasible strategy for applications of lithium-metal batteries.

关键词： lithiophilic modification lithium-metal battery lithium-metal host magnetron sputtering targeted deposition

Improved flexible Li-ion hybrid capacitors： Techniques for superior stability

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Nano Research 2017年第12期10卷 4448-4456页

作者： Shengyang Dong Hongsen Li Junjun Wang xiaogang zhang Xiulei Ji Jiangsu Key Laboratory of Materials and Technology for Energy Conversion College of Material Science and Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China Department of Chemistry Oregon State University Corvallis Oregon 97331-4003 USA

Flexible power devices play an increasingly crucial role in emerging flexible electronics. To improve the electrochemical performance of flexible power devices, novel electrode structures and new energy-storage systems should be designed. Herein, a novel flexible Li-ion hybrid capacitor （LIC） is designed based on an anode comprising Li4TisO12 nanoplate arrays coated on carbon textile （LTO/CT） and a cathode comprising a flexible N-doped graphene/carbon-nanotube composite （NGC） film. The LTO/CT anode is fabricated by directly growing Li4TisO12 nano- plates on CT with robust adhesion using a simple one-pot hydrothermal reaction. Considering the volume of a real-device flexible LIC, the NGC//LTO/CT con- figuration delivers high volumetric energy and power densities of 2 mWh·cm-3 and 185 mW·cm-3, respectively. Furthermore, the flexible LIC shows excellent flexibility and electrochemical stability, with extremely small capacity fluctuation under different bending states. This work demonstrates a scalable route to assemble flexible LICs as high-performance power devices.

关键词： flexible devices Li-ion hybrid capacitors Li4TisO^2 nanoplates graphene carbon nanotube