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Wear mechanism and debris analysis of PEEK as an alternative to CoCrMo in the femoral component of total knee replacement

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Friction 2023年第10期11卷 1845-1861页

作者： Xinyue zhang Tao zhang Kai CHEN Handong XU Cunao FENG Dekun ZHANG School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China

The polyetheretherketone(PEEK)-highly cross-linked polyethylene(XLPE),all-polymer knee prosthesis has excellent prospects for replacing the traditional metal/ceramic-polyethylene joint prosthesis,improving the service life of the joint prosthesis and the quality of patients’life.The long-term wear mechanism of PEEK-XLPE knee joint prosthesis is comprehensively evaluated from wear amount,wear morphology,and wear debris compared to that of CoCrMo-XLPE joint prosthesis.After 5 million cycles of in vitro wear,the wear loss of XLPE in PEEK-XLPE(30.9±3.2 mg)is lower than that of XLPE in CoCrMo-XLPE(32.1±3.1 mg).Compared to the XLPE in CoCrMo-XLPE,the plastic deformation of XLPE in PEEK-XLPE is more severe in the early stage,and the adhesive peeling and adhesion are lighter in the later stage.The size distribution of XLPE wear debris in PEEK-XLPE is relatively dispersed,which in CoCrMo-XLPE is relatively concentrated.Wear debris is mainly flake and block debris,and the wear mechanism of XLPE was abrasive wear.The wear volume per unit area of PEEK femoral condyle(10.45×10^(5)μm^(3)/mm^(2))is higher than that of CoCrMo(8.32×10^(5)μm^(3)/mm^(2)).The PEEK surface is mainly furrows and adhesions,while the CoCrMo surface is mainly furrows and corrosion spots.The PEEK wear debris is mainly in flakes and blocks,and the CoCrMo wear debris is mainly in the shape of rods and blocks.The wear mechanism of PEEK is abrasive wear and adhesion,and that of CoCrMo is abrasive wear and corrosion.

关键词： polyetheretherketone(PEEK)-highly cross-linked polyethylene(XLPE) cobalt-chromium-molybdenum(CoCrMo)-XLPE wear debris wear mechanism

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A Facile Modifier-free Approach to Fabricate Antistatic Superhydrophobic Composite Coatings with Remarkable Thermal Stability and Corrosion Resistance

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Journal of Bionic Engineering 2020年第3期17卷 421-435页

作者： Xiang Liu Dekun ZHANG Zhiguang Guo School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China School of Materials Science and Engineering China University of Mining and TechnologyXuzhou 221116China Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials Hubei UniversityWuhan 430062China

Research on antistatic superhydrophobic surfaces has attracted widespread attention in some fields.However,in the application of superhydrophobic materials,fabricating stable and practical superhydrophobic surfaces through facile and low-cost approaches still faces considerable challenges.Herein,a polyphenylene sulfide(PPS)-based antistatic superhydrophobic composite coating with a high water contact angle(166°)and a low sliding angle(2°)was fabricated on a Q345 steel surface through a simple spray-coating method without any modifier.Furthermore,the as-prepared superhydrophobic coating also displayed excellent superhydrophobicity for water droplets at different pH values,as well as self-cleaning,anti-fouling and anti-icing properties.Importantly,the superhydrophobic coating still exhibited superhydrophobicity after calcination at 350°C for 1 h,indicating its outstanding thermal stability.Excellent antistatic and anticorrosion properties were obtained on the prepared coating surface,which allows the coating to be applied under harsh conditions.Benefiting from the above characteristics,compared with the commercial coating,the as-obtained antistatic superhydrophobic coating may be applied more widely in related fields.

关键词： no-modifier superhydrophobicity thermal stability antistatic property anticorrosion

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(Parallel) kinetic resolution of 3,3-disubstituted indolines via organocatalyzed reactions with azodicarboxylates

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Science China Chemistry 2024年第3期67卷 973-980页

作者： Qianwen Jiang Dekun ZHANG Mengyao Tang Hua Liu Xiaoyu Yang School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China

A novel kinetic resolution(KR) method has been developed for 3,3-disubstituted indolines, whose catalytic asymmetric synthesis remains a significant challenge in organic synthesis. The key to the success of this KR protocol lies in the utilization of chiral phosphoric acid-catalyzed triazane formation reaction with azodicarboxylates, which enables the enantioselective synthesis of various substituted indolines bearing C3-quaternary stereocenters with good to high enantioselectivities(with sfactors up to 70). Moreover, an intriguing parallel kinetic resolution(PKR) has been developed by combining triazane formation and dehydrogenation reactions using different azodicarboxylates. Experimental studies have provided insight into the mechanism of this PKR reaction, demonstrating stereoselectivity in both triazane formation and dehydrogenation steps, favoring the opposite enantiomers. The large-scale synthesis and diverse derivatizations of the products, particularly the imine groupcontaining 3H-indoles, demonstrate the value of these(P)KR methods.

关键词： asymmetric organocatalysis kinetic resolution 3 3-disubstituted indolines azodicarboxylate triazanes

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Tribo-corrosion interaction of the parallel steel wires in the suspension bridges

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摩擦:英文版 2023年第12期11卷 2221-2237页

作者： Bo WANG Dagang WANG Hailang CHONG Guozheng XIE Dekun ZHANG Shirong GE School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China College of Mechatronic Engineering China University of Mining and Technology(Beijing)Beijing 100083China

The effect of contact load and relative displacement on tribo-corrosion interaction of parallel steel wires of main cable in the suspension bridge was investigated in this study.A self-made tribo-corrosion test bench was employed to conduct tribo-corrosion tests of parallel steel wires in 3.5%(wt%)NaCl solution and deionized water under different contact loads and different relative displacements.The friction coefficient and wear coefficient of wires were presented.Electrochemical corrosion behavior(Tafel polarization curves,Nyquist diagram,and equivalent circuit diagram)was characterized by electrochemical analyzer.Wear morphology was observed by scanning electron microscope.Wear volume loss and corrosion‒wear interaction were quantitatively demonstrated by high-precision weighing balance.The results show that the electrochemical corrosion ability of the steel wires increases with the increase of the contact load or relative displacement.The increased contact load or relative displacement increases the volume loss of corrosion‒wear and pure wear,but decreases the wear coefficient.The wear mechanisms in 3.5%NaCl solution are adhesive wear,abrasive wear,and corrosive wear as compared to adhesive wear and abrasive wear in deionized water under different contact loads.The wear mechanisms of parallel steel wires are slightly different under different relative displacements.But the main wear mechanisms are similar to that under different contact loads.The interaction effects of corrosion and wear produced by the contact load and relative displacement are all the synergistic effects.

关键词： main cable parallel steel wires friction corrosion‒wear interaction

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Kinetic Resolution of 1,2-Diamines via Organocatalyzed Asymmetric Electrophilic Aminations of Anilines

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Chinese Journal of Chemistry 2022年第24期40卷 1674-1680页

作者： Jinglei Xie Zheng Guo Wei Liu Dekun ZHANG Yu-Peng He Xiaoyu Yang School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Key Laboratory of Petrochemical Catalytic Science and Technology Liaoning Shihua UniversityFushunLiaoning 113001China Universityof Chinese Academy of Sciences Bejing 100049China State Key Laboratory of Fine Chemicals Ningbo Institute of Dalian University of TechnologyNingboZhejiang 315016China

An efficient kinetic resolution(KR)protocol for 1,2-diamines has been developed through asymmetric electrophilic aminations of anilines enabled by chiral phosphoric acid catalysis.A wide array of substituted 1,2-diamines were compatible with this method,generating both the recovered staring materials and the amination products with high enantioselectivities(with s-factor up to 218).Notably,this method is amenable to the kinetic resolution of 1,2-diamines bearingα-tertiary amine moieties,which represents the first KR of this type of 1,2-diamines.Facile removal of the introduced hydrazine group and oxidative cleavage of the N-aryl group to release the free primary amine demonstrate the value of this method.

关键词： Asymmetric catalysis 1,2-Diamines Kinetic resolution Chiral phosphoric acids Amination

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Cartilage-bone inspired the construction of soft-hard composite material with excellent interfacial binding performance and low friction for artificial joints

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Friction 2023年第7期11卷 1177-1193页

作者： Qin CHEN Xinyue zhang Siyu LIU Kai CHEN Cunao FENG Xiaowei LI Jianwei QI Yong LUO Hongtao LIU Dekun ZHANG School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China School of Chemical Engineering and Technology China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

Inspired by the cartilage-bone structure in natural joints,soft-hard integrated materials have received extensive attention,which are the most promising candidates for artificial joints due to their combination of excellent load-bearing properties and lubricating properties.The latest progress showed that the combination of hydrogel and titanium alloy can realize a bionic natural joint lubrication system on the surface of titanium alloy.However,obtaining a tough interface between the hydrogel(soft and wet)and the titanium substrate(hard and dry)is still a great challenge.Here,we designed a"soft(hydrogel)-hard(Ti6Al4V)"integrated material with outstanding combination,which simulates the structure and function of cartilage-bone in the natural joint.The load-bearing properties,binding performance,and tribological behaviors for different forms of the soft-hard integrated materials were investigated.The results showed that the hydrogel layer and Ti6Al4V substrate possess ultra-high interfacial toughness(3,900 J/m^(2)).In addition,the combination of the hydrogel layer and Ti6Al4V substrate provided a good lubrication system to endow the"soft(hydrogel)-hard(Ti6Al4V)"integrated material with high load-bearing and excellent tribological properties.Therefore,this study provided an effective strategy for prolonging the service life of Ti6Al4V in the biomedical field.

关键词： Ti6Al4V alloy hydrogel soft-hard interface friction

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Optical properties of conductive silver-nanowire films with different nanowire lengths

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Nano Research 2017年第11期10卷 3706-3714页

作者： Xiaoming Yu Xuan Yu Jianjun zhang Liqiao Chen Yunqian Long Dekun ZHANG Innovation Application Institute Zhejiang Ocean University Zhoushan 316004 China College of Electronic Information and Optical Engineering Nankai University Tianjin 300071 China

Transparent electrodes made of silver nanowires （Ag NWs） exhibit a higher flexibility than conventional indium tin oxide electrodes.For this reason,Ag NWs may find applications in future flexible electronic and optoelectronic devices.However,different optoelectronic devices have different specific requirements for Ag NWs.For example,the optical transmittance haze is an important but rarely studied aspect of Ag NW films.In this study,the optical transmittance and optical scattering of long （5-50 μm,L-NWs） and short （1-20 μm,S-NWs） Ag NW films were investigated.The L-NWs exhibited better optical transmission than the S-NWs,whereas the S-NWs exhibited better light-scattering properties than the L-NWs.Our results indicate that the L-NWs are suitable for touch-screen displays,whereas the S-NWs are better suited as transparent conductive films for solar cells.We analyzed the scattering ratio of forward-scattered light to backscattered light for both the L-NWs and S-NWs and discovered that the mesh size affected the scattering ratio.For longer wavelengths,a larger mesh yielded a higher backscattering ratio,whereas a smaller mesh yielded a lower backscattering ratio.We formulated an equation for calculating the reflection haze using the total reflection （Ag NWs/glass）,R and the reflection of glass,R0.The reflection haze of the S-NWs and L-NWs exhibited different trends in the visible-near-infrared region.An omnidirectional scattering model for the Ag NWs was used to evaluate the Ag NW scattering properties.The results of this study have great significance for the evaluation of the performance of Ag NWs in optoelectronic devices.

关键词： transparent electrode,silver nanowires,transmittance haze factor,forward scattering and backscattering,reflection-haze factor

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Research on the Interstitial Fluid Load Support Characteristics and Start-Up Friction Mechanisms of PVA-HA-Silk Composite Hydrogel

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Journal of Bionic Engineering 2014年第3期11卷 378-388页

作者： Kai Chen Dekun ZHANG Zuming Dai Songquan Wang Shirong Ge School of Mechanical and Electrical Engineering China University of Mining and Technology Xuzhou 221116 P. R. China School of Materials Science and Engineering China University of Mining and Technology Xuzhou 221116 P. R. China

Hydrogel has been extensively studied as an articular cartilage repair and replacement material. PVA-HA-Silk composite hydrogel was prepared by freezing-thawing method in this paper. Mechanical properties were determined by experiments and the friction coefficient of PVA-HA-Silk composite hydrogel against steel ball was verified using micro-tribometer. Finite Element Method （FEM） was used to study the lubrication mechanism of PVA-HA-Silk composite hydrogel and the relation between the interstitial fluid load support and the start-up friction resistance. The results show that the elastic modulus and the permeability are 2.07 MPa and 10^-15m^4N^-1s^-1, respectively, and the start-up friction coefficients of PVA-HA-Silk composite hydrogel are in the range of 0.154）.2 at different contact loads, contact time and sliding speeds. The start-up friction resistance of PVA-HA-Silk composite hydrogel increases with the contact load and contact time. With the increase in sliding speed, the start-up friction resistance of PVA-HA-Silk composite hydrogel decreases. There is an inverse relation between the start-up friction resistance and the interstitial fluid load support. The change of fluid flow with the increase in sliding displacement has an important effect on the interstitial fluid load support and friction resistance. The interstitial fluid load support decreases with the increase in contact load and contact time, while the interstitial fluid load support reinforces with the increase in sliding speed. Moreover, PVA-HA-Silk composite hydrogel has mechanical properties of recovery and self-lubricating.

关键词： PVA-HA-Silk composite hydrogel friction FEM the interstitial fluid load support lubrication

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Friction reactions induced by selective hydrogenation of textured surface under lubricant conditions

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Friction 2024年第1期12卷 174-184页

作者： Naizhou DU Xubing WEI Xiaowei LI Zan CHEN Shiqi LU Jiaqing DING Cunao FENG Kai CHEN Jianghao QIAO Dekun ZHANG Kwang-Ryeol LEE Tiancai zhang School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221116China Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology&EngineeringChinese Academy of SciencesNingbo 315201China Computational Science Center Korea Institute of Science and TechnologySeoul 136-791Republic of Korea Technology Development Department Shipbuilding Technology Research InstituteShanghai 200032China

The passivation of hydrogen atoms and the conformation of textured surfaces under oil-lubricated conditions are effective strategies to obtain amorphous carbon(a-C)films with extremely low friction.It is critical to understanding the influence mechanism of selective surface hydrogenation on the tribological behaviors of textured a-C film under oil-lubricated conditions.In particular,the interactions of hydrogen atoms and lubricants are confusing,which is enslaved to the in situ characterization technique.The reactive molecular dynamics(RMD)simulations were conducted to analyze the friction response of textured a-C films with selective hydrogenation surfaces under oil-lubricated conditions.The results indicate that the existence of hydrogen atoms on specific bump sites significantly decreases the friction coefficient(μ)of textured a-C film,which is highly dependent on the surface hydrogen content.The repulsion between hydrogen atoms and lubricant molecules prompts the formation of a dense lubricant film on the surface of the mating material.Interestingly,with the enhancement of the surface hydrogen content,the passivation of the friction interface and the repulsion between hydrogen atoms and lubricants play dominant roles in reducing the friction coefficient instead of hydrodynamic lubrication.

关键词： textured amorphous carbon(a-C) selective hydrogenation oil lubrication friction mechanism reactive molecular dynamics(RMD)

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Synthesis and Characterization of PVA-HA-Silk Composite Hydrogel by Orthogonal Experiment

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Journal of Bionic Engineering 2012年第2期9卷 234-242页

作者： Dekun ZHANG Kai Chen Lin Wu Dagang Wang Shirong Ge School of Materials Science and Engineering China University of Mining and Technology Xuzhou 221116 P. R. China School of Mechanical and Electrical Engineering China University of Mining and Technology Xuzhou 221116 P. R. China

PVA-HA-Silk composite hydrogel was synthesized with polyvinyl alcohol （PVA）, nano-hydroxyapatite （HA） and natural silk by using the method of repeated freezing and thawing. A series of tests were performed to study water content, stress relaxation behavior, elastic modulus, and creep characteristics of PVA-HA-Silk composite hydrogel. Orthogonal experimental design method was used to analyze the influence degree of PVA, HA and silk （three kinds of raw materials） on mechanical properties and water content of the PVA-HA-Silk composite hydrogel to select the best material ratio according to their overall performance. The results demonstrate that the mass percentage of PVA has the greatest impact on the water content, followed by HA and silk. Compression stress-strain variation of PVA-HA-Silk composite hydrogel presents a nonlinear relationship, which proves that it is a typical viscoelastic material. Comparing the mechanical properties of 16 formulas, the formula of PVA-HA-silk composite hydrogel with mass percentage of PVA 15%, HA 2.0% and silk 1.0% is the best.

关键词： polyvinyl alcohol hydroxyapatite composite hydrogel orthogonal experiment

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