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Chinese Physics B 2016年第5期25卷 321-325页

作者：武辰飞陈允峰陆海黄晓明任芳芳陈敦军张荣郑有炓 Jiangsu Provincial Key Laboratory of Advanced Photonic and Electronic Materials and School of Electronic Science and EngineeringNanjing UniversityNanjing 210093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China Peter Grunberg Research Center Nanjing University of Posts and TelecommunicationsNanjing 210003China

In this work, a method based on scanning Kelvin probe microscopy is proposed to separately extract source/drain（S/D） series resistance in operating amorphous indium–gallium–zinc–oxide（a-IGZO） thin-film transistors. The asymmetry behavior of S/D contact resistance is deduced and the underlying physics is discussed. The present results suggest that the asymmetry of S/D contact resistance is caused by the difference in bias conditions of the Schottky-like junction at the contact interface induced by the parasitic reaction between contact metal and a-IGZO. The overall contact resistance should be determined by both the bulk channel resistance of the contact region and the interface properties of the metalsemiconductor junction.

关键词： amorphous indium–gallium–zinc–oxide thin-film transistors contact resistance surface potential

Prediction of contact resistance of electrical contact wear using different machine learning algorithms

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Friction 2024年第6期12卷 1250-1271页

作者： Zhen-bing CAI Chun-lin LI Lei YOU Xu-dong CHEN Li-ping HE Zhong-qing CAO Zhi-nan ZHANG Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

H62 brass material is one of the important materials in the process of electrical energy transmission and signal transmission,and has excellent performance in all *** the wear behavior of electrical contact pairs is particularly complex when they are in service,we evaluated the effects of load,sliding velocity,displacement amplitude,current intensity,and surface roughness on the changes in contact *** learning(ML)algorithms were used to predict the electrical contact performance of different factors after wear to determine the correlation between different factors and contact *** forest(RF),support vector regression(SVR)and BP neural network(BPNN)algorithms were used to establish RF,SVR and BPNN models,respectively,and the experimental data were trained and *** was proved that BP neural network model could better predict the stable mean resistance of H62 brass alloy after *** analysis shows that the load and current have great influence on the predicted electrical contact *** wear behavior of electrical contacts is influenced by factors such as load,sliding speed,displacement amplitude,current intensity,and surface roughness during *** learning algorithms can predict the electrical contact performance after wear caused by these *** results indicate that an increase in load,current,and surface roughness leads to a decrease in stable mean resistance,while an increase in displacement amplitude and frequency results in an increase in stable mean resistance,leading to a decline in electrical contact *** reduce testing time and costs and quickly obtain the electrical contact performance of H62 brass alloy after wear caused by different factors,three algorithms(random forest(RF),support vector regression(SVR),and BP neural network(BPNN))were used to train and test experimental results,resulting in a machine learning model suitable for predicting the stable mean

关键词： electrical contact wear contact resistance machine learning(ML) neural network

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE M.T.MUNIR G.J.WENG K.Y.RHEE Biomaterials and Tissue Engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and Technology American University of the Middle EastEgaila 54200Kuwait Department of Mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of Mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

Analysis of sliding electric contact characteristics in augmented railgun based on the combination of contact resistance and sliding friction coefficient

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Defence Technology（防务技术） 2020年第4期16卷 747-752页

作者： Chun-yan Zhu Bao-ming Li National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyChina

The contact resistance between the armature and rails is an important indicator of the contact characteristics in electromagnetic *** the contact resistance depends not only on the contact state but also on the contact stress and temperature,there are some limitations in analyzing the contact characteristics using only the contact *** this paper,the contact characteristics of the augmented railgun are analyzed by the combination of contact resistance and sliding friction ***,the theoretical calculation model of the contact resistance and friction coefficient of the augmented electromagnetic railgun is *** the contact resistance and friction coefficient are calculated by the measured values of the muzzle voltage,rail current and armature ***,the contact characteristics are analyzed according to the features of the waveforms of the contact resistance and the friction coefficient,and the analysis conclusions are verified by experimental rail *** results showed that:the aluminum melt film gradually formed on the contact surface reduces the contact resistance and the friction coefficient;the wear and erosion of the armature cause deterioration of the contact state;after the transition,the reliability of the sliding contact between the armature and rails decreases,resulting in an increase in contact resistance.

关键词： Augmented railgun contact resistance Friction coefficient contact characteristics

Effect of multilayer CrN/CrAlN coating on the corrosion and contact resistance behavior of 316L SS bipolar plate for high temperature proton exchange membrane fuel cell

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Journal of Materials Science & Technology 2022年第2期97卷 134-146页

作者： S.Pugal Mani P.Agilan M.Kalaiarasan K.Ravichandran N.Rajendran Y.Meng Department of Analytical Chemistry University of MadrasChennai-25India Department of Chemistry Anna UniversityChennai-25India State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

Stainless steels have received wide attention as a substitute material for bipolar plates in high temperature proton exchange membrane fuel cell(HT-PEMFC).In the present work,the CrN,CrAlN and multilayer CrN/CrAlN coatings were deposited on 316 L SS to increase the corrosion resistance and decrease the interfacial contact *** deposited coatings exhibited face centered cubic phase structure and it was verified from the X-ray diffraction pattern.X-ray photo electron spectroscopy results showed the formation of both CrN and CrAlN layers on 316 L ***/CrAlN coating is more helpful in water management due to low surface roughness and high contact angle in the HT-PEMFC *** corrosion resistance behavior of all the samples were studied in 85%H_(3)PO_(4)solution at 140℃purged with H_(2)(HT-PEMFC anode)and O_(2)(HT-PEMFC cathode)*** results showed that all the coatings considerably improved the performance of 316 L SS and superior corrosion resistance was observed for CrN/CrAlN multilayer coating,whose protective efficiency was 98.12%and 96.14%in the two simulated HT-PEMFC *** results of electrochemical impedance spectroscopic studies demonstrated higher impedance for CrN/CrAlN *** morphological studies performed after corrosion studies revealed that protection ability of CrN/CrAlN coating still remained acceptable.A very low interfacial contact resistance value of 6 mΩ cm^(2) at 140 N/cm;was observed for CrN/CrAlN ***,after corrosion studies,the interfacial contact resistance value of CrN/CrAlN coated 316 L was much lower than that of CrN and CrAlN coatings due to the increased oxidation *** maximum power density of about 0.93 W/cm^(2) at 2 A/cm^(2) and output voltage of 0.96 V was observed for CrN/CrAlN coating.

关键词： Bipolar plate 316L SS Corrosion contact resistance contact angle Surface roughness

Monolayer MoS_(2)-based transistors with low contact resistance by inserting ultrathin Al_(2)O_(3)interfacial layer

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Science China(Technological Sciences) 2023年第6期66卷 1831-1840页

作者： CHEN Gang LIN Xin LIU Yuan WANG Fang HU Kai SHAN Xin WU ZeYu ZHANG YuPeng NIE WeiCan ZHONG JiXiang REN TianLing ZHANG KaiLiang Tianjin Key Laboratory of Film Electronic&Communication Devices School of Integrated Circuit Science and EngineeringTianjin University of TechnologyTianjin 300384China School of Materials Science and Engineering Tianjin University of TechnologyTianjin 300384China Tianjin Key Laboratory of Composite and Functional Materials Key Laboratory of Advanced Ceramics and Machining Technology(Ministry of Education)School of Materials Science and EngineeringTianjin UniversityTianjin 300072China School of Integrated Circuits Beijing National Research Center for Information Science and Technology(BNRist)Tsinghua UniversityBeijing 100084China

Transition metal dichalcogenides(TMDCs)are promising high performance electronic materials due to their interesting semiconductor ***,it is acknowledged that the effective electrical contact between TMDCs-layered materials and metals remains one of the major *** this work,the homogeneous monolayer MoS_(2)films with high crystalline quality were prepared by chemical vapor deposition method on SiO2/Si *** back-gate field-effect transistors(FETs)were fabricated by inserting an ultrathin Al_(2)O_(3)interlayer between the metal electrodes and MoS_(2)*** the addition of an ultrathin 0.8 nm Al_(2)O_(3)interlayer,the contact resistance decreased dramatically from 59.9 to 1.3 kΩμm and the Schottky barrier height(SBH)dropped from 102 to 27 meV compared with devices without the Al_(2)O_(3)*** the same time,the switching ratio increased from~106to~108,and both the on-current and field-effect mobility were greatly *** find that the ultrathin Al_(2)O_(3)interlayer can not only reduce the SBH to alleviate the Fermi level pinning phenomenon at the interface,but also protect the channel materials from the influence of air and moisture as a covering *** addition,the lattice and band structures of Al_(2)O_(3)/MoS_(2)film were calculated and analyzed by first-principles *** is found that the total density of states of the Al_(2)O_(3)/MoS_(2)film exhibits interfacial polarized metals property,which proves the higher carrier transport *** with Al_(2)O_(3)interlayers have excellent stability and repeatability,which can provide effective references for future low power and high performance electronic devices.

关键词： MoS_(2) Schottky barrier height contact resistance Al_(2)O_(3)interlayer first-principles calculation

Realization of low contact resistance close to theoretical limit in graphene transistors

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Nano Research 2015年第5期8卷 1669-1679页

作者： Hua Zhong Zhiyong Zhang Bingyan Chen Haitao Xu Dangming Yu Le Huang Lianmao Peng Key Laboratory for the Physics and Chemistry of Nanodevices and Department of Electronics Peking University Beijing 100871 China

Realizing low contact resistance between graphene and metal electrodes remains a well-known challenge for building high-performance graphene devices. In this work, we attempt to reduce the contact resistance in graphene transistors and further explore the resistance limit between graphene and metal contacts. The Pd/graphene contact resistance at room temperature is reduced below the 100 Ω·μm level both on mechanically exfoliated and chemical-vapor-deposition graphene by adopting high-purity palladium and high-quality graphene and controlling the fabrication process to not contaminate the interface. After excluding the parasitic series resistances from the measurement system and electrodes, the retrieved contact resistance is shown to be systematically and statistically less than 100 Ω·μm, with a minimum value of 69 Ω·μm, which is very close to the theoretical limit. Furthermore, the contact resistance shows no clear dependence on temperature in the range of 77-300 K; this is attributed to the saturation of carrier injection efficiency between graphene and Pd owing to the high quality of the graphene samples used, which have a sufficiently long carrier mean-free-path.

关键词： graphene field-effect transistors contact resistance metal-graphene interface transfer length method

Toward High Carrier Mobility and Low contact resistance:Laser Cleaning of PMMA Residues on Graphene Surfaces

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Nano-Micro Letters 2016年第4期8卷 336-346页

作者： Yuehui Jia Xin Gong Pei Peng Zidong Wang Zhongzheng Tian Liming Ren Yunyi Fu Han Zhang Materials Physics Laboratory State Key Laboratory for Mesoscopic PhysicsSchool of PhysicsPeking University Key Laboratory of Microelectronic Devices and Circuits(MOE) Institute of MicroelectronicsPeking University School of Electronic and Computer Engineering Peking University Shenzhen Graduate School

Poly(methyl methacrylate)(PMMA) is widely used for graphene transfer and device ***,it inevitably leaves a thin layer of polymer residues after acetone rinsing and leads to dramatic degradation of device *** to eliminate contamination and restore clean surfaces of graphene is still highly *** this paper,we present a reliable and position-controllable method to remove the polymer residues on graphene films by laser *** proper laser conditions,PMMA residues can be substantially reduced without introducing defects to the underlying ***,by applying this laser cleaning technique to the channel and contacts of graphene fieldeffect transistors(GFETs),higher carrier mobility as well as lower contact resistance can be *** work opens a way for probing intrinsic properties of contaminant-free graphene and fabricating high-performance GFETs with both clean channel and intimate graphene/metal contact.

关键词： Graphene PMMA residues Laser exposure Carrier mobility contact resistance

A correlation analysis method for analyzing tribological states using acoustic emission, frictional coefficient, and contact resistance signals

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Friction 2015年第1期3卷 36-46页

作者： Pengyi TIAN Yu TIAN Lei SHAN Yonggang MENG Xiangjun ZHANG State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

A multi-physical signal correlation analysis method is proposed to identify the different tribological properties of *** acoustic emission(AE),contact resistance,and frictional force behaviors during dry sliding between four metals,45#carbon steel,YG12 carbide,2A12 aluminum alloy,and H62 brass,have been *** positive and negative correlations between the root mean square of the amplified AE(AE RMS)signal and the frictional coefficient have been found in the *** addition,the AE RMS signal and the contact resistance changed with changing sliding speed and normal load in different *** different correlation behaviors have been attributed to diverse tribological states under different experimental conditions due to different material *** correlation analysis provides a new method of quantitatively identifying the tribological states and the AE sources during frictional *** observed anomalous correlations between the AE signal and frictional coefficient should be properly considered according to the different material properties during industrial friction condition monitoring using AE technology.

关键词： acoustic emission correlation analysis dry friction contact resistance

AC loss and contact resistance in highly flexible rebco cable for fusion applications

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Superconductivity 2022年第2期2卷 39-45页

作者： Zichuan Guo Jinggang Qin R.Lubkemann Keyang Wang Huan Jin Guanyu Xiao Jiangang Li Chao Zhou Arend Nijhuis University of Twente Faculty of Science&Technology7522 NB EnschedeThe Netherlands University of Science and Technology of China HefeiAnhui 230026People’s Republic of China Institute of Plasma Physics Chinese Academy of SciencesHefeiAnhui 230031People’s Republic of China Department of Mechanics and Engineering Science Lanzhou UniversityLanzhouGansu 730000People's Republic of China

High Temperature Superconductor(HTS)materials can operate at higher magnetic fields up to 20 T with high critical current and higher operating temperature,compared to low temperature superconductors(LTS).A Highly Flexible REBCO Cable(HFRC)is introduced at the Institute of Plasma Physics,Chinese Academy of Sciences(ASIPP);a cabling method that is suitable for REBCO HTS tape having anisotropic material properties in its thin REBCO *** type of HTS superconducting cable shows high potential for applications in nuclear *** alternating currents and magnetic fields in tokamak type of fusion magnets,cause AC power losses in such cables,which can provoke instability of the conductor by induced currents and increase the *** a first step in characterizing the electromagnetic(EM)performance of an HFRC cable,the AC loss and contact resistance of the HFRC prototype cable were measured at the University of *** measurements were done in liquid helium(4.2 K)with AC magnetic fields,applied perpendicular to the cable's long *** AC loss was measured simultaneously by a calibrated gas flow calorimeter utilizing the helium boil-off method,and by the magnetization method using pick-up *** the applied test conditions,no coupling loss could be distinguished as a part of the overall AC *** is suggested that this might be explained by the shielding of the conductor interior from the applied magnetic field by the outer tape layer due to the high critical current density of the REBCO tape,leading to a high penetration field.

关键词： High temperature superconductor REBCO tape HFRC AC loss contact resistance