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Arc erosion behavior of a nanocomposite W-Cu electrical contact material

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Rare Metals 2006年第1期25卷 37-42页

作者： CHEN Wenge KANG Zhanying SHEN Hongfang DING Bingjun School of Materials Science and engineering Xi＇an University of Technology Xi＇an 710048 China department of Materials Physics Xi＇an Jiaotong University Xi＇an 710049 China

The erosion behavior of a nanocomposite W-Cu material under arc breakdown was investigated. The arc erosion rates of the material were determined, and the eroded surfaces and arc erosion mechanisms were studied by scanning eleclion microscopy. It is concluded that the nanocomposite W-Cu electrical contact material shows a characteristic of spreading arcs. The arc breakdown of a commercially used W-Cu alloy was limited in a few areas, and its average arc erosion rate is twice as large as that of the former. Furthermore, it is also proved that the arc extinction ability and arc stability of the nanocomposite W-Cu material are excellent, and melting is the major failure modality in the make-and-break operation of arcs.

关键词： arc erosion W-Cu alloy contact materials nanocomposite

An analytical solution for the elastic fields near spheroidal nano-inclusions

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Acta Mechanica Sinica 2009年第6期25卷 821-830页

作者： Z. Y. Ou G. F. Wang T. J. Wang department of engineering Mechanics,MOE Key Laboratory for Strength and Vibration,xi’an jiaotong university,{4., china department of engineering Mechanics MOE Key Laboratory for Strength and Vibration Xi’an Jiaotong University Xi’an 710049 China

When the size of an inclusion shrinks to nanometers, interface energy plays an important role in the deformation around it. In the present paper, we consider the effect of interface energy on the elastic fields near a spheroidal nanoinclusion embedded in an elastic medium on the basis of surface elasticity theory. Using Boussinesq-Sadowsky potential function method, we obtain the deformation field near the inclusion subjected to a uniformly uniaxial loading at infinity. The results show that the elastic fields near the nano-inclusion depend strongly on the interface properties, the size and shape of inclusion. These new characteristics may be helpful to understand various relevant mechanical performances of nanosized inhomogeneities.

关键词： Interface energy .Elastic fields .Inhomogeneity - Nanometer

3D-Printed Monolith Metallic Ni-Mo Electrodes for Ultrahigh Current Hydrogen Evolution

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Energy & environmental Materials 2024年第5期7卷 228-237页

作者： Yanran Xun Hongmei Jin Yuemeng Li Shixiang Zhou Kaixi Zhang xi Xu Win Jonhson Shuai Chang Teck Leong Tan Jun Ding department of Materials Science and engineering National University of Singapore Institute of High Performance Computing (IHPC) Agency for Science Technology and Research (ASTAR) Key Laboratory of Flexible Electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical University State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

In this work, we reported a series of monolithic 3D-printed Ni–Mo alloy electrodes for highly efficient water splitting at high current density(1500 mA cm-2) with excellent stability, which provides a solution to scale up Ni–Mo catalysts for HER to industry use. All possible Ni–Mo metal/alloy phases were achieved by tuning the atomic composition and heat treatment procedure, and they were investigated through both experiment and simulation, and the optimal NiMo phase shows the best performance.

关键词： 3D-printed electrode Ni–Mo catalyst phase tuning ultra-high current density HER

Effect of inorganic arsenic in paddy soil on the migration and transformation of selenium species in rice plants

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Journal of environmental Sciences 2024年第9期143卷 35-46页

作者： Ganga Raj Pokhrel Kaiteng Wang Kaiyang Ying Yongchen Wu Ze Wang xi Zhu Can Qu Hong Li Fengfu Fu Guidi Yang Fujian Provincial Key Laboratory of Agroecological Processing and Safety Monitoring Key Laboratory for Medicinal Plant Chemistry and Chemical BiologyCollege of JunCao Science and EcologyFujian Agriculture and Forestry UniversityFuzhou 350002China department of Chemistry Birendra Multiple CampusTribhuvan UniversityChitwan 00977-44200BharatpurNepal Key Laboratory for Analytical Science of Food Safety and Biology of Ministry of Education Fujian Provincial Key Lab of Analysis and Detection for Food SafetyCollege of ChemistryFuzhou UniversityFuzhou 350116China

Selenium(Se)in paddy rice is one of the significant sources of human Se ***,the effect of arsenic(As)pollution in soil on the translocation of Se species in rice plants is *** this research,a pot experiment was designed to examine the effect of the addition of 50 mg As/kg soil as arsenite or arsenate on the migration of Se species from soil to indica Minghui 63 and *** results showed that the antagonism between inorganic As and Se was closely related to the rice cultivar and Se oxidation state in *** to the standalone selenate treatment,arsenite significantly(p4.-100.0%,4..0%-100.0%,4..0%-100%,5.4.-96.3%,11.3%-100.0% and 26.2%-39.7% respectively,except for selenocystine in the kernels of indica Minghui 63 and selenomethionine in the leaves of indica Minghui 63 and the stems of indica *** also decreased(p4.9%-100.0%,30.2%-100.0%,11.3%-100.0% and 5.6%-39.6%respectively,except for selenate in the stems of indica Minghui ***,relative to the standalone selenite treatment,arsenite and arsenate decreased(p4..5%-100.0%.Our results suggested that arsenite and arsenate had better antagonism toward Se species in selenate-added soil than that in selenite-added soil;moreover,arsenite had a higher inhibiting effect on the accumulation of Se species than arsenate.

关键词： Rice(Oryza sativa L.) Inorganic arsenic Selenium species Translocation Antagonistic effect

STUDY FOR NATURAL GAS HYDRATE CONVERSED FROM ICE

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化工学报 2003年第Z1期54卷 23-28页

作者： WANG Shengjie, SHEN Jiandong, HAO Miaoli and LIU Furong (School of environmental and Chemical engineering, xi’an jiaotong university, xi’an 710049, Shaanxi,{4.) School of environmental and Chemical engineering Xi'an Jiaotong University Xi'an 710049 Shaanxi China

Natural gas hydrates are crystalline clathrate compounds composed of water and gases of small molecular diameters that can be used for storage and transport of natural gas as a novel method. In the paper a series of experiments of aspects and kinetics for hydrate formed from natural gas and ice were carried out on the industrial small scale production apparatus. The experimental results show that formation conditions of hydrate conversed from ice are independent of induction time, and bigger degrees of supersaturation and supercooling improved the driving force and advanced the hydrate *** is also favorable for ice particle conversion to hydrate. In addition, it was found there have an optimal reaction time during hydrate formation.

关键词： natural gas hydrate, formation, ice, supersuturation, supercooling, superpressure

Aging assessment of large generator insulation based on PD measurements

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Progress in Natural Science:Materials International 2005年第11期15卷 1035-1043页

作者： YUE Bo, CHEN xiaolin, CHENG Yonghong and xiE Hengkun (State Key Laboratory of Electrical Insulation and Power Equipment, xi'an jiaotong university, xi'an 710049, china Graduate School at Shenzhen, Tsinghua university, Shenzhen 518055, china department of Electrical engineering, Tsinghua university, Beijing 100084. china) State Key Laboratory of Electrical Insulation and Power Equipment Xi''an Jiaotong University Xi''an 710049 China. Graduate School Shenzhen Tsinghua University Shenzhen 518055 China. department of Electrical engineering Tsinghua University Beijing 100084 China

The statistical parameters of phase resolved partial discharge (PD) distribution and ultra-wideband (UWB) characteristics of PD pulse are proposed for aging assessment of large generator insulation. Multi-stress aging tests of the model generator stator bar specimens were performed and PD measurements were conducted using both digital PD detector with frequency ranging from 4. kHz to 4.0 kHz and UWB PD detector with bandwidth from 10 MHz to 3 GHz at different aging stages. The test results show that the skewness and UWB frequency characteristics of PD can be taken as the characterization parameters for aging assessment of generator insulation. Furthermore, the measurement results of real generator stator bars show that these methods based on statistical parameters and UWB characteristics of PD are prospective for aging assessment and residual lifetime estimation of large generator stator insulation.

关键词： partial discharge stator insulation multi-stress accelerated aging statistical parameters ultra-wideband aging assessment.

ANALYTICAL AND NUMERICAL SOLUTIONS FOR THE FLOW IN MICROTUBE WITH THREE-DIMENSIONAL CORRUGATED SURFACE,PART 1:STEADY FLOW

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Journal of Hydrodynamics 2010年第5期22卷 647-656页

作者： WANG Hao-li YANG Meng WANG Yuan College of Metrological Technology and engineering China Jiliang University Hangzhou 310018China department of Fluid engineering School of Energy and Power Engineering Xi＇an Jiaotong University Xi＇an710049 China

The influences of three-dimensional corrugated wall on the fully-developed steady no-slip flows in microtube are studied by analytical and numerical methods in this article. Detailed analytical solutions for the space-averaged equations and the numerical method for the solutions of the disturbance equations are given. An iterative arithm of coupled equations with respect to space-averaged velocities and disturbance velocities is suggested. The study shows that a three-dimensional subsidiary stress layer exists in the near-wall region. The relative roughness, wavenumber and Reynolds number are three important parameters influencing the subsidiary stresses and the space-averaged pressure drop. The space-averaged pressure drop subject to an invariable flow rate mainly depends on the position of datum surface. When the datum surface is taken at the balance position of wall function, the value of pressure drop is determined by the dynamic characteristics of the flow.

关键词： microtube three-dimensional corrugated surface space-averaged method subsidiary stress

NUMERICAL STUDY OF SEMI-CONFINED SLOT JET IMPINGEMENT

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Journal of Hydrodynamics 1999年第3期11卷 14-18页

作者： Xu Jing lei, Xu Zhong, Huang Shu juan department of Fluid engineering, Energy and Power School,xi′an jiaotong university, xi′an {4., P.R.china (Received June 1, 1998)

The standard k ε turbulence model in conjunction with the logarithmic law of the wall has been applied to the prediction of a fully developed turbulent slot impinging jet within a semi confined space. A single geometry with a Reynolds number of 10,000 and a nozzle to plate spacing of eight slot widths has been considered with inlet boundary conditions based on the previous calculated result of a fully developed turbulent 2 D flow. The numerical results of mean velocity agree with the experimental data. But the fluctuating velocity is somewhat poorly predicted. The difference between the numerical study and the experimental data is attributed directly to the turbulence model, and the application of the wall function.

关键词： slot impinging jet turbulence kε model wall function

HARMLESS DELAYS FOR UNIFORM PERSISTENCE

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Systems Science and Mathematical Sciences 2000年第2期13卷 126-135页

作者： JIN Zhen MA Zhien (department of Mathematics, xi’an jiaotong university, xi’an 710049, china) 西安交通大学数学系陕西西安 710049 西安交通大学数学系陕西西安

This paper studies a three-dimensional competition system with discrete de- lays. We prove that the time delays are harmless for uniform persistence of the solutions of the system by constructing suitable persistence ... 详细信息

关键词： Uniform persistence strong persistence delay equilibrium.