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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 *** is critical to understanding the influence mechanism of selective surface hydrogenation on the tribological behaviors of textured a-C film under oil-lubricated *** particular,the interactions of hydrogen atoms and lubricants are confusing,which is enslaved to the in situ characterization *** reactive molecular dynamics(RMD)simulations were conducted to analyze the friction response of textured a-C films with selective hydrogenation surfaces under oil-lubricated *** 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 *** repulsion between hydrogen atoms and lubricant molecules prompts the formation of a dense lubricant film on the surface of the mating ***,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)

Optimization study of station track utilization in high-speed railroad based on constraints of control in random origin and process

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Railway Sciences 2024年第3期3卷 332-343页

作者： Yajing Zheng dekun zhang School of Civil Engineering and Transportation South China University of TechnologyGuangzhouChina

Purpose-The purpose of this paper is to eliminate the fluctuations in train arrival and departure times caused by skewed distributions in interval operation *** fluctuations arise from random origin and process factors during interval operations and can accumulate over multiple *** aim is to enhance the robustness of high-speed rail station arrival and departure track utilization ***/methodologylapproach-To achieve this objective,the paper simulates actual train operations,incorporating the fluctuations in interval operation times into the utilization of arrival and departure tracks at the *** Monte Carlo simulation method is adopted to solve this *** approach transforms a nonlinear model,which includes constraints from probability distribution functions and is difficult to solve directly,into a linear programming model that is easier to *** method then linearly weights two objectives to optimize the ***-Through the application of Monte Carlo simulation,the study successfully converts the complex nonlinear model with probability distribution function constraints into a manageable linear programming *** continuously adjusting the weighting coefficients of the linear objectives,the method is able to optimize the Pareto ***,this approach does not require extensive scene data to obtain a satisfactory Pareto solution ***/value-The paper contributes to the field by introducing a novel method for optimizing high-speed rail station arrival and departure track utilization in the presence of fluctuations in interval operation *** use of Monte Carlo simulation to transform the problem into a tractable linear programming model represents a significant ***,the method's ability to produce satisfactory Pareto solutions without relying on extensive data sets adds to its practical value and applicability in real-world scenarios.

关键词： Control in random origin Control in random process High-speed railroad station Arrival and departure track utilization Optimization Paper type Research paper

Textured Perovskite/Silicon Tandem Solar Cells Achieving Over 30% Efficiency Promoted by 4-Fluorobenzylamine Hydroiodide

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Nano-Micro Letters 2024年第9期16卷 557-570页

作者： Jingjing Liu Biao Shi Qiaojing Xu Yucheng Li Yuxiang Li Pengfei Liu Zetong SunLi Xuejiao Wang Cong Sun Wei Han Diannan Li Sanlong Wang dekun zhang Guangwu Li Xiaona Du Ying Zhao Xiaodan zhang Renewable Energy Conversion and Storage Center Solar Energy Conversion CenterInstitute of Photoelectronic Thin Film Devices and TechnologyNankai UniversityTianjin 300350People’s Republic of China Key Laboratory of Photoelectronic Thin Film Devices and Technology of Tianjin Tianjin 300350People’s Republic of China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192People’s Republic of China Engineering Research Center of Thin Film Photoelectronic Technology of Ministry of Education Tianjin 300350People’s Republic of China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin 300072People’s Republic of China Center of Single‑Molecule Sciences Institute of Modern OpticsTianjin Key Laboratory of Micro‑Scale Optical Information Science and TechnologyCollege of Electronic Information and Optical EngineeringNankai University38 Tongyan RoadJinnan DistrictTianjin 300350People’s Republic of China Shenzhen Research Institute of Nankai University 16Th FloorYantian Science and Technology BuildingHaishan StreetYantian DistrictShenzhen 518083People’s Republic of China

Monolithic textured perovskite/silicon tandem solar cells(TSCs)are expected to achieve maximum light capture at the lowest cost,potentially exhibiting the best power conversion ***,it is challenging to fabricate high-quality perovskite films and preferred crystal orientation on commercially textured silicon substrates with micrometersize ***,we introduced a bulky organic molecule(4-fluorobenzylamine hydroiodide(F-PMAI))as a perovskite *** is found that F-PMAI can retard the crystallization process of perovskite film through hydrogen bond interaction between F^(−)and FA^(+)and reduce(111)facet surface energy due to enhanced adsorption energy of F-PMAI on the(111)***,the bulky molecular is extruded to the bottom and top of perovskite film after crystal growth,which can passivate interface defects through strong interaction between F-PMA+and undercoordinated Pb^(2+)/I^(−).As a result,the additive facilitates the formation of large perovskite grains and(111)preferred orientation with a reduced trap-state density,thereby promoting charge carrier transportation,and enhancing device performance and *** perovskite/silicon TSCs achieved a champion efficiency of 30.05%based on a silicon thin film tunneling *** addition,the devices exhibit excellent longterm thermal and light stability without *** work provides an effective strategy for achieving efficient and stable TSCs.

关键词： Perovskite crystallization (111)preferred orientation Defect passivation Perovskite/silicon tandem solar cells

滑液组分对“软-软”配副关节材料摩擦学行为的影响

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清华大学学报（自然科学版） 2024年第3期64卷 454-470页

作者：岑佳佳张德坤陈琴张欣悦冯存傲冯海燕陈凯中国矿业大学材料与物理学院徐州221116 中国矿业大学化工学院徐州221116

人体内关节滑液中各成分浓度的变化对人工关节滑动配副的摩擦学行为具有重要影响。该文基于人工关节置换后关节滑液的各组分浓度,以聚醚醚酮(polyether-ether-ketone,PEEK)和高交联聚乙烯(highly crosslinked polyethylene,XLPE)组成的... 详细信息

人体内关节滑液中各成分浓度的变化对人工关节滑动配副的摩擦学行为具有重要影响。该文基于人工关节置换后关节滑液的各组分浓度,以聚醚醚酮(polyether-ether-ketone,PEEK)和高交联聚乙烯(highly crosslinked polyethylene,XLPE)组成的“软-软”关节配副为研究对象,体外配制不同浓度的白蛋白(albumin,Alb)、γ-球蛋白(γ-globulin,γ-Glo)、透明质酸(hyaluronic acid,HA)和脂质体(phospholipids,PLs)等人体关节滑液主要成分的复合滑液,研究了不同成分复合滑液润滑条件下PEEK-XLPE关节配副的摩擦磨损行为,探明了滑液组分和浓度对“软-软”关节配副摩擦磨损的影响机制,揭示了“软-软”关节配副在不同成分复合滑液润滑作用下的磨损机理。结果表明:复合滑液中的4种主要成分均对“软-软”配副人工关节材料的摩擦磨损性能有较大影响,其中γ-Glo浓度对摩擦系数(coefficient of friction,COF)影响较大,当γ-Glo浓度由5.83mg/mL增加至8.75mg/mL时,摩擦系数增加了29.4%;总蛋白质浓度对磨损率影响较大,由15mg/mL Alb+3.75mg/mL γ-Glo增加至35mg/mL Alb+8.75mg/mL γ-Glo时,磨损率增加了166.0%。当复合滑液中γ-Glo或总蛋白质浓度过高时,蛋白质在摩擦表面发生不良黏附,使“软-软”配副关节材料的磨损加剧。此外,蛋白质混合液中同时加入HA和PLs,能促进Alb吸附而抑制γ-Glo吸附。

关键词：复合滑液蛋白质透明质酸脂质体摩擦磨损

RIS辅助的无蜂窝大规模MIMO关键技术研究

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移动通信 2024年第4期48卷 18-26,40页

作者：张德坤白宝明西安电子科技大学空天地一体化综合业务网全国重点实验室陕西西安710071 中兴通讯股份有限公司西安研发中心陕西西安710111

针对密集蜂窝组网干扰受限难题,无蜂窝大规模MIMO利用大规模宏分集,构建以用户为中心的新架构,大规模灵活协作显著提升每个用户性能。同时,无蜂窝辅以智能超表面技术,以低成本和低功耗极大提升网络容量。聚焦研究了RIS辅助的无蜂窝大规... 详细信息

针对密集蜂窝组网干扰受限难题,无蜂窝大规模MIMO利用大规模宏分集,构建以用户为中心的新架构,大规模灵活协作显著提升每个用户性能。同时,无蜂窝辅以智能超表面技术,以低成本和低功耗极大提升网络容量。聚焦研究了RIS辅助的无蜂窝大规模MIMO天线校准和导频分配两个关键问题。针对大规模RAU校准难题,首先在最低校准信噪比和校准相干时间约束下,提出动态分簇的可自愈校准拓扑构建方法,然后为降低校准时域开销,设计了RAU簇内和簇间校准时序,研究了可扩展的天线校准算法,能实现任意多RAU联合相位校准。针对导频分配问题,首先提出基于空间高相关性的用户动态簇的构建新方法,然后提出用户簇内基于信道相关性最低和用户簇间最小复用概率的导频分配方法。仿真结果表明,提出的校准算法具有较小的校准误差和较好的扩展性。同时,提出的导频分配算法性能可逼近最大化容量导频分配算法,且复杂度大幅降低。

关键词：无蜂窝大规模MIMO 分簇拓扑构建互易性校准用户动态簇导频分配

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 ***,in the application of superhydrophobic materials,fabricating stable and practical superhydrophobic surfaces through facile and low-cost approaches still faces considerable ***,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 ***,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 ***,the superhydrophobic coating still exhibited superhydrophobicity after calcination at 350°C for 1 h,indicating its outstanding thermal *** antistatic and anticorrosion properties were obtained on the prepared coating surface,which allows the coating to be applied under harsh *** 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

Research on the friction and wear mechanism of Poly(vinyl alcohol)/hydroxylapatite composite hydrogel

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Science China(Technological Sciences) 2009年第8期52卷 2474-2480页

作者： zhang dekun SHEN YanQiu GE ShiRong School of Materials Science and Engineering China University of Mining and TechnologyXuzhou 221116China Biotribology Center State Key Laboratory of TribologyTsinghua UniversityBeijing 100083China Long Pan College Jin Ling Institute of TechnologyNanjing 211169China

Poly(vinyl alcohol)/Hydroxylapatite(PVA/HA) composite hydrogel was prepared with poly(vinyl alcohol) and hydroxylapatite as raw materials, using the method of repeated freezing and *** morphologies of PVA/HA composite hydrogel were observed by means of high-accuracy 3D profiler and scanning electron microscope(SEM).The compressive elastic modulus and the stress relaxation characteristics of PVA/HA composite hydrogel were measured using the flat-head cylinder *** friction and wear tests between PVA/HA composite hydrogel and bovine knee articular cartilage were performed on the *** worn morphologies of PVA/HA composite hydrogel were observed with environmental scanning electron microscope(ESEM).The results showed that PVA/HA composite hydrogel has the cross-link network microstructure which is similar to that of the natural bovine knee articular *** the increase of freezing-thawing cycles and the HA content, the degree of cross-link and the crystallization of PVA/HA composite hydrogel both increase, the elastic modulus increases evidently, the rate of stress relaxation is improved and the value of balance stress *** friction coefficient decreases with the increase of the freezing-thawing cycles and the HA *** more the freezing-thawing cycles are, the earlier the friction coefficient reaches the stable balance *** friction deformation depth between PVA/HA composite hydrogel and bovine knee articular cartilage is inversely proportional to freezing-thawing cycles and the HA *** main wear mechanisms of PVA/HA composite hydrogel are plastic flowing and adhesive *** wear severity degree decreases with the increase of freezing-thawing cycles and the HA content.

关键词： poly(vinyl alcohol) hydroxylapatite composite hydrogel microstructure tribological properties

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’*** 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 *** 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 *** size distribution of XLPE wear debris in PEEK-XLPE is relatively dispersed,which in CoCrMo-XLPE is relatively *** debris is mainly flake and block debris,and the wear mechanism of XLPE was abrasive *** 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 *** PEEK wear debris is mainly in flakes and blocks,and the CoCrMo wear debris is mainly in the shape of rods and *** 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

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 *** friction coefficient and wear coefficient of wires were *** corrosion behavior(Tafel polarization curves,Nyquist diagram,and equivalent circuit diagram)was characterized by electrochemical *** morphology was observed by scanning electron *** volume loss and corrosion‒wear interaction were quantitatively demonstrated by high-precision weighing *** results show that the electrochemical corrosion ability of the steel wires increases with the increase of the contact load or relative *** increased contact load or relative displacement increases the volume loss of corrosion‒wear and pure wear,but decreases the wear *** 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 *** wear mechanisms of parallel steel wires are slightly different under different relative *** the main wear mechanisms are similar to that under different contact *** 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