检索结果-南通市图书馆

A surface engineering strategy for the stabilization of zinc metal anodes with montmorillonite layers toward long-life rechargeable aqueous zinc ion batteries

引用

Journal of Energy Chemistry 2025年第1期100卷 94-105页

作者： Wenbo Wang Ruifeng Xu Xu Zhang Peiyu Wang Bao Yang Bingjun Yang Juan Yang Kailimai Su Pengjun Ma Yanan Deng Xianfeng Fan Wanjun Chen Key Laboratory for Electronic Materials College of Electrical Engineering Northwest Minzu University Resource Chemistry and Energy Materials Research Center State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences University of Chinese Academy of Sciences institute for Materials and Processes School of Engineering University of Edinburgh

Rechargeable aqueous zinc-ion batteries （AZIBs） exhibit appreciable potential in the domain of electrochemical energy ***,there are serious challenges for AZIBs,for instance zinc dendrite growth,hydrogen evolution reaction （HER）,and corrosion side ***,we propose a surface engineering modification strategy for coating the montmorillonite （MMT） layer onto the surface of the Zn anode to tackle these issues,thereby achieving high cycling stability for rechargeable *** results reveal that the MMT layer on the surface of the Zn anode is able to provide ordered zincophilic channels for zinc ions migration,facilitating the reaction kinetics of zinc *** functional theory（DFT） calculations and water contact angle （CA） tests prove that MMT@Zn anode exhibits superior adsorption capacity for Zn2+and better hydrophobicity than the bare Zn anode,thereby achieving excellent cycling ***,the MMT@Zn||MMT@Zn symmetric cell holds the stable cycling over 5600 h at 0.5 mA cm-2and 0.125 m A h cm-2,even exceeding 1800 h long cycling under harsh conditions of 5 m A cm-2and 1.25 m A h *** MMT@Zn||V2O5full cell reaches over 3000 cycles at 2 A g-1with excellent rate ***,this surface engineering modification strategy for enhancing the electrochemical performance of AZIBs represents a promising application.

关键词： Hydrogen evolution reaction

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A new type SVM——projected SVM

引用

Science China(Physics,Mechanics & Astronomy) 2004年第z1期47卷 21-28页

作者： ZHU Yongsheng ZHANG Youyun theory of lubrication and bearing institute Xi'an Jiaotong University Xi'an 710049 China Theory of Lubrication and Bearing Institute Xi'an Jiaotong University Xi'an 710049 China

Support vector machine (SVM), developed by Vapnik et al., is a new and promising technique for classification and regression and has been proved to be competitive with the best available learning machines in many applications. However, the classification speed of SVM is substantially slower than that of other techniques with similar generalization ability. A new type SVM named projected SVM (PSVM), which is a combination of feature vector selection (FVS) method and linear SVM (LSVM), is proposed in present paper. In PSVM, the FVS method is first used to select a relevant subset (feature vectors, FVs) from the training data, and then both the training data and the test data are projected into the subspace constructed by FVs, and finally linear SVM(LSVM) is applied to classify the projected data. The time required by PSVM to calculate the class of new samples is proportional to the count of FVs. In most cases, the count of FVs is smaller than that of support vectors (SVs), and therefore PSVM is faster than SVM in running. Compared with other speeding-up techniques of SVM, PSVM is proved to possess not only speeding-up ability but also de-noising ability for high-noised data, and is found to be of potential use in mechanical fault pattern recognition.

关键词： support vector machine, feature vector selection, machine learning, projected SVM, speedup of SVM.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A MIXED lubrication MODEL MODIFIED BY SURFACES' FRACTAL CHARACTERISTICS

引用

Journal of Pharmaceutical Analysis 2003年第1期15卷 6-9页

作者：孟凡明张有云 theory of lubrication and bearing Institution

Fractal characteristics are introduced into solving lubrication problems. Based on the analysis of the relationship between roughness and engineering surfaces' fractal characteristics and by introducing fractal parameters into the mixed lubrication equation, the relationship between flow factors and fractal dimensions is analyzed. The results show that the pressure flow factors' values increase, while the shear flow factor decreases, with the increasing length to width ratio of a representative asperity γ at the same fractal dimension. It can be also found that these factors experience more irregular and significant variations and show the higher resolution and the local optimal and the worst fractal dimensions, by a fractal dimension D , compared with the oil film thickness to roughness ratio h/R q . As an example of application of the model to solve the lubrication of the piston skirt in an engine, the frictional force and the load capacity of the oil film in a cylinder were analyzed. The results reveal that the oil film frictional force and the load capacity fluctuate with increasing fractal dimension, showing big values at the small D and smaller ones and slightly variable in the range of bigger one, at the same crank angle.

关键词： fractal characteristics mixed lubrication flow factor roughness piston skirt

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Stripe theory based numerical method for solving asymmetrical hysteresis of friction force in linear rolling guideways

引用

Science China(Technological Sciences) 2016年第9期59卷 1320-1327页

作者： ZHAO Yang XI YinHu MAO JunHong WONG Patrick Pat Lam theory of lubrication and bearing institute Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi'an Jiaotong University Department of Mechanical and Biomedical Engineering City University of Hong Kong

Linear rolling guideways(LRGs) play an important role in precision engineering. In the pre-rolling region, the hysteretic friction force exerts great impacts on the positioning accuracy. Numerical and experimental studies of the hysteresis of friction force are presented in this paper. A model, which is based on the stripe theory and the simplified theory of rolling contact, is built to describe the transient hysteresis of the friction force. Then, the model is modified by taking the anelasticity effect into consideration. Experimentally, a linear motor direct-drive setup is utilized to measure the transient asymmetrical hysteresis of the friction force in the pre-rolling region of an LRG. The influences of the pre-rolling displacement and the dwelling time on the asymmetrical hysteresis of the friction force are studied. The numerical and experimental results are well correlated, which shows good accuracy of the model. The transient asymmetrical hysteresis of friction force in the pre-rolling region of LRGs can thus be determined using the model.

关键词： pre-rolling friction anelasticity hysteresis linear rolling guideway

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An experimental method for measuring friction behaviors of linear rolling guides

引用

Chinese Science Bulletin 2014年第29期59卷 3912-3918页

作者： Yinhu Xi Yuan Zhou Wei Zhang Junhong Mao theory of lubrication and bearing institute Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing SystemSchool of Mechanical EngineeringXi’an Jiaotong University

Friction behaviors of linear rolling guides(LRGs)are determined by many factors and are crucial for precision *** is difficult to create an expression to describe the friction behaviors exactly and completely.A new experimental method for measuring the friction behaviors of one LRG individually was developed,and linear motor direct drive technology is utilized in the experiment *** position signal is acquired by a grating,and the friction of the LRG is deduced by the product of the mass of the moving part and its *** the experiment,the LRG can move with the friction only,and the friction transition from normal rolling to prerolling stage was *** asperities’deformations were utilized to explain *** loops and internal loops were *** results indicate the non-local memory of the LRG,and the historical trajectory have an important impact on the friction behaviors of LRGs in the pre-rolling stage.

关键词：直线滚动导轨摩擦行为测量验方精确定位驱动技术直线电机位置信号

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Molecular dynamics simulation of the deposition process of hydrogenated diamond-like carbon (DLC) films

引用

Chinese Science Bulletin 2008年第7期53卷 1094-1099页

作者： ZHANG Yujun DONG GuangNeng MAO JunHong XIE YouBai theory of lubrication and bearing institute Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi'an Jiaotong University Xi'an 710049 China

The deposition process of hydrogenated diamond-like carbon (DLC) film greatly affects its frictional properties. In this study, CH3 radicals are selected as source species to deposit hydrogenated DLC films for molecular dynamics simulation. The growth and structural properties of hydrogenated DLC films are investigated and elucidated in detail. By comparison and statistical analysis, the authors find that the ratio of carbon to hydrogen in the films generally shows a monotonously increasing trend with the increase of impact energy. Carbon atoms are more reactive during deposition and more liable to bond with substrate atoms than hydrogen atoms. In addition, there exists a peak value of the number of hydrogen atoms deposited in hydrogenated DLC films. The trends of the variation are opposite on the two sides of this peak point, and it becomes stable when impact energy is greater than 80 eV. The average relative density also indicates a rising trend along with the increment of impact energy, while it does not reach the saturation value until impact energy comes to 50 eV. The hydrogen content in source species is a key factor to determine the hydrogen content in hydrogenated DLC films. When the hydrogen content in source species is high, the hydrogen content in hydrogenated DLC films is accordingly high.

关键词：分子动力学沉积程序氢化作用 DLC 薄膜

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Dry Friction Characteristics of Ti-6Al-4V Alloy under High Sliding Velocity

引用

Journal of Wuhan University of Technology(Materials Science) 2007年第4期22卷 582-585页

作者：邱明 School of Mechatronic Engineering Henan University of Science and Technology theory of lubrication and bearing institute Xi'an Jiaotong UniversityXi'an 710049China

Tribological behaviours of Ti-6Al-4V alloy pins sliding against GCr15 steel discs over a range of contact pressures （0.33-1.33 MPa） and sliding velocities （30-70 m/s） were investigated using a pin-on-disc tribometer under unlubricated conditions. The wear mechanisms and the wear transition were analyzed based on examinations of worn surfaces using SEM, EDS and XRD. When the velocity increases, the friction coefficient and the wear rate of the Ti-6Al-4V alloy show typical transition features, namely, the critical values of sliding velocities for 0.33 and 0.67 MPa are 60 and 40 m/s, respectively. The experimental results reveal that the tribological behaviours of Ti-6Al-4V alloys are controlled by the thermal-mechanical effects, which connects with the friction heat and hard particles of the pairs. A tribolayer containing mainly Ti oxides and V oxides is formed on the worn surface of Ti-6Al-4V alloy.

关键词： Ti alloy dry sliding friction behavior contact temperature wear mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Wet and Dry Tribological Behaviors of Circular Islandic Protrusion Patterns on M2 Steel Discs under Spinning Condition

引用

Journal of Wuhan University of Technology(Materials Science) 2008年第5期23卷 720-726页

作者：马庆贤董光能 Department of Manufacturing Engineering and Engineering Management City University of Hong Kong Key Laboratory of Rotor-bearing and Modern Design of Education Ministry Theory of Lubrication and Bearing Institute Xi'an Jiaotong University

Under spinning conditions, lubricant on islandic spot patterned M2 steel disc experiences centrifugal and tangential force components. Depending upon the relative position of the spots and the flow of lubricant, accumulation of lubricant in front of patterned islandic spots creates thrusting to mating part and subsequently reduces contact between the mating couple. Whilst wear debris is likely to be spun off the plateau of the spots to their neighbouring valleys so as to reduce wear. Hence, it gives favorable tribological characteristics. Aiming at verifying such mechanisms, studies were performed on M2 steel disc specimens slid with ASSAB 17 tool steel pin. The M2 steel disc specimens were respectively （i） machined with non-patterned （NP）, （ii） etched to produce in-lined （INE） islandic patterns, and （iii） etched to produce staggered （STE） islandic spot patterns. Results indicated that the INE patterned discs gave most favorable wear characteristics, the NP of the worse characteristics whilst the STE ranged in the middle. However, the actual contact mechanism leads to the descending sequence of favorable friction behaviors nominally as： NP, INE and STE.

关键词： dry and wet lubrication friction and wear circular islandic spot patterns M2 steel disc ASSABI7 steel pin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Research on Effect of Oil Film Inertia on Piston Skirt by Iteration Method

引用

Chinese Journal of Aeronautics 2004年第1期17卷 1-6页

作者：孟凡明张优云 theory of lubrication and bearing institute Xi'an Jiaotong University

The influence of oil film inertia on piston skirt lubrication in a high speedengine is investigated by an iteration method that alternately solves the Navier-Stocks equationsand the Reynolds equa-tion by finite element method and difference method. The Reynolds lubricationequation including oil film inertia is developed, in which the inertia coefficient is introduced toinvestigate the effect of oil film inertia. The iteration procedure and finite formulation ofsolving the new Reynolds lubrication equation are given to analyze the effect of oil film on pistonskirt in this kind of engine. The calculation results show that the oil film inertia has someeffects on the friction force, pressure force and load capacity of oil film and its effect isobvious for the last. The Reynolds lubrication equation proposed can be also used to analyze thelubrication performance of the piston skirt in low or medium speed engine and some other lubricationproblems generally excluding oil film inertia with the inertia coefficient being set at zero.

关键词： high speed engine piston skirt inertia inertia coefficient reynoldslubrication equation iteration method finite element difference method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Abrasive Wear Mechanisms of Sand Particles Intruding into ATM Roller-scraper Tribosystem

引用

Chinese Journal of Mechanical Engineering 2011年第5期24卷 905-910页

作者： WU Tonghai DIAO Dongfeng FANG Liang theory of lubrication and bearing institute Xi＇an Jiaotong University Xi＇an 710049 China Post-doctoral Research Center of Material Science and Engineering Xi＇an Jiaotong University Xi＇an 710049 China

The roller-scraper tribosystem of automatic teller machine（ATM） plays an important role in reliable cash ***,the abrasive wear of the polymer tribosystem becomes a prominent problem when operating in sandy *** wear behavior of the tribosystem in a simulated sandy environment has been experimentally studied *** the abrasive wear mechanism of roller-scraper tribosystems is still unknown to new *** wear rates of polymer rollers were examined comprehensively and several jumping variations were found in the full data *** wear stages were classified by the magnitude of wear rates,and different dominant wear mechanisms corresponding with different particle diameter were found by examining the worn *** a presumption was proposed that wear mechanisms in different stages were correlated with sand particles of different *** a verification experiment,three typical wear mechanisms including cutting,ploughing,and wedging were found corresponding with different wear stages by scanning electron microscope（SEM） examination.A theoretical analysis was carried out with a simplified sphere particle intrusion model and the transfer conditions for different wear mechanisms were studied referring to the slip-field *** a main result,three typical wear models versus friction coefficient of particle/roller,and particle radius were mapped with variant hardness of the polymer roller and ratio of contact shear stress to bulk shear *** result illuminated the abrasive wear mechanism during particle ***,the critical transition conditions gave the basis for improving the wear performance of roller-scraper tribosystems in a sandy environment.

关键词： tribosystem abrasive wear mechanism

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：