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SPLITTING EXTRAPOLATIONS FOR SOLVING BOUNDARY INTEGRAL EQUATIONS OF LINEAR ELASTICITY DIRICHLET PROBLEMS ON POLYGONS BY MECHANICAL QUADRATURE METHODS

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Journal of Computational Mathematics 2006年第1期24卷 9-18页

作者： jin huang Tao Lu University of electronic & science technology of China Chengdu 610055 Mathematical College Sichuan University Chengdu 610065 China

Taking hm as the mesh width of a curved edge Гm （m = 1, ..., d ） of polygons and using quadrature rules for weakly singular integrals, this paper presents mechanical quadrature methods for solving BIES of the first kind of plane elasticity Dirichlet problems on curved polygons, which possess high accuracy O（h0^3） and low computing complexities. Since multivariate asymptotic expansions of approximate errors with power hi^3 （i = 1, 2, ..., d） are shown, by means of the splitting extrapolations high precision approximations and a posteriori estimate are obtained.

关键词： Splitting extrapolation Linear elasticity Dirichlet problem Boundary integral equation of the first kind Mechanical quadrature method

Examination of Extraordinary Transmission of Waves Propagation through Gaps of Vertical Thin Barriers in Channels by A Hypersingular Boundary Element Method

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China Ocean Engineering 2019年第5期33卷 509-521页

作者： TENG Bin huang jin State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology

The extraordinary transmission (ET) phenomenon is examined for waves propagating through gaps of vertical thin barriers in channels with a hypersingular boundary element method model on the linear potential theory, and an estimate formula based on small gap approximation for predicting the number of ET frequencies is proposed. Numerical computations are carried out to examine the influences of barrier number, barrier interval, gap size, gap position and barrier arrangement on extraordinary transmission and wave height in the channel. It shows that all of those factors evidently affect the extraordinary transmission frequencies. The contours of wave amplitude show that very high waves can be excited in the basins between barriers at the extraordinary transmission frequencies. Proper arrangement of barriers in a channel can avoid the occurrence of ET phenomenon and reduce wave height in the channel.

关键词： extraordinary transmission reflection and transmission coefficients wave height in channels hypersingular BEM

Effect of Ti Additions on Mechanical and Thermodynamic Properties of W-Ti Alloys:A First-principles Study

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期 246-257页

作者：张建 NIE Wei huang jin ZHU Ke LIU Ruxia 张睿智 LUO Guoqiang SHEN Qiang State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of Technology Institute for Carbon Neutrality University of Science and Technology Beijing

The mechanical and thermodynamic properties of W-Ti alloys (including W15Ti1,W14Ti2,W12Ti4and W8Ti8alloys) were investigated by the first-principles approach based on density functional *** results indicate that W-Ti alloys except W8Ti8are thermodynamically *** modulus and hardness of W-Ti alloys are smaller than those of pure tungsten and gradually decrease with increasing Ti ***,their B/G ratios and Poisson's ratios exceed those of pure tungsten,suggesting that the introduction of Ti decreases the mechanical strength while enhancing the ductility of W-Ti *** thermal expansion coefficients for W-Ti alloys all surpass those of pure tungsten,indicating that the introduction of titanium exacerbates the thermal expansion behavior of W-Ti ***,elevated pressure has the capacity to suppress the thermal expansion tendencies in titanium-doped tungsten *** study offers theoretical insights for the design of nuclear materials by exploring the mechanical and thermodynamic properties of W-Ti alloys.

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Bending of Timoshenko beam with effect of crack gap based on equivalent spring model

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Applied Mathematics and Mechanics(English Edition) 2016年第4期37卷 513-528页

作者： Xiao YANG jin huang Yu OUYANG Department of Civil Engineering Shanghai University

Considering the effect of crack gap, the bending deformation of the Timoshenko beam with switching cracks is studied. To represent a crack with gap as a nonlinear unidirectional rotational spring, the equivalent flexural rigidity of the cracked beam is derived with the generalized Dirac delta function. A closed-form general solution is obtained for bending of a Timoshenko beam with an arbitrary number of switching cracks. Three examples of bending of the Timoshenko beam are presented. The influence of the beam＇s slenderness ratio, the crack＇s depth, and the external load on the crack state and bending performances of the cracked beam is analyzed. It is revealed that a cusp exists on the deflection curve, and a jump on the rotation angle curve occurs at a crack location. The relation between the beam＇s deflection and load is bilinear, each part corresponding to an open or closed state of crack, respectively. When the crack is open, flexibility of the cracked beam decreases with the increase of the beam＇s slenderness ratio and the decrease of the crack depth. The results are useful in identifying non-destructive cracks on a beam.

关键词： Timoshenko beam switching crack crack gap generalized function parameter study

Effects of soybean meal replacement with fermented alfalfa meal on the growth performance,serum antioxidant functions,digestive enzyme activities,and cecal microflora of geese

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Journal of Integrative Agriculture 2016年第9期15卷 2077-2086页

作者： YIN Hai-cheng huang jin College of Biological Engineering Henan University of Technology

Fermented forages are important feedstuffs. Bacillus subtilis inoculants are often used to improve the value of forage legume fermentation. The present work was conducted to study the effects of replacing soybean meal with solid-state fermented alfalfa meal（FAM） with B. subtilis ACCC 01746 on growth performance, serum antioxidant and digestive enzyme activities, and cecal microflora in goose. 300 healthy geese with similar body weights were randomly assigned to six treatment groups with five replicates of 10 geese（five males and five females） each. Geese were fed ad libitum for 35 days. Results showed that the geese fed with 4 and 8% FAM exhibited no significant effects on their final body weights（FBW） and average day gain（ADG）（P〉0.05）, whereas 12% or higher FAM caused poor growth of the geese compared with control diet（linear（L）： P〈0.05）. The average daily feed intake（ADFI）（quadratic（Q）： P〈0.05） and feed conversion ratio（FCR）（L： P〈0.05） with 8% or higher supplementation level were higher than those of the control group. The activities of antioxidant enzyme in serum increased, and the level of malondialdehyde（MDA） significantly decreased with increasing dietary FAM level（L： P〈0.05）. However, no significant differences were observed at 8% or lower supplementation level for glutathione peroxidase（GSH-Px） and superoxide dismutase（SOD）（P〉0.05） and at 4% for catalase（CAT） supplementation level compared with the control group. All diets containing FAM increased digestive enzyme activities in geese. However, geese fed diets with 12% FAM supplementation showed the highest trypsin activities in pancreas（Q： P〈0.05）. Supplementation with 12% or higher FAM significantly increased amylase activities in pancreas（L： P〈0.05） and duodenum（L： P〈0.05） compared with the control group. Significant differences were not observed in total anaerobic bacteria between geese fed with FAM and control diets on day 35（P〉0.05）. The numbers of Bifidobacterium and Lactobacillus in the cecum of geese

关键词： fermented alfalfa meal geese growth performance serum antioxidant enzyme digestive enzyme cecal microflora

Phase diagram characterized by transmission in a triangular quantum dot

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Chinese Physics B 2018年第11期27卷 575-580页

作者： jin huang and Wei-Zhong Wang Department of Physics Wuhan University Wuhan 430072 China

We propose a theoretical model to detect the quantum phase transition in a triangular quantum dot molecule with frustration. The boundaries of the phase diagram are accurately determined by the transmission. For small frustration t, as the interdot Coulomb repulsion V increases, the system undergoes a Kosterlitz–Thouless（KT） transition from the Kondo resonance state with a transmission peak at zero energy to the Coulomb blocked state with zero transmission, which is followed by a first transition to the V-induced resonance（VIR） state with unitary transmission. For large frustration t, as V increases, the orbital spin singlet without transmission transits to the VIR state through a KT transition.

关键词： quantum dots quantum phase transition Kondo effect transmission

Analysis of a new 5-phase bearingless induction motor

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第8期8卷 1311-1319页

作者： huang jin KANG Min YANG Jia-qiang School of Electrical Engineering Zhejiang University Hangzhou 310027 China

This paper addresses the bearingless motor with a single set of multiphase windings. The interaction between M and M±1 pole-pair magnetic fields produces radial force. Based on this principle,a bearingless machine is obtained. Conventional bearingless machine has dual windings,levitation windings and torque windings,which produce the two magnetic fields. In the proposed bearingless motor,the two needed magnetic fields are produced by feeding two groups of currents to a single set of multiphase windings. Taking a 5-phase induction motor as example,the inductance matrices,considering air gap eccentricity,are calculated with the modified winding function method. The radial force analytical model is deduced by virtual displacement,and its results are validated by FEA. The mathematical model of the new bearingless machine is set up,and the simulation results verified the feasibility of this novel bearingless motor.

关键词： Air-gap-flux-oriented control Bearingless motor Multiphase Radial force Single set of windings Modified winding function method

Diagnosis of stator faults in induction motor based on zero sequence voltage after switch-off

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 165-172页

作者： Jia-qiang YANG jin huang Tong LIU School of Electrical Engineering Zhejiang University Hangzhou 310027 China

To improve the accuracy of the stator winding fault diagnosis in induction motor,a new diagnostic method based on the Hilbert-huang transform(HHT)was *** ratio of fundamental zero sequence voltage to positive sequence voltage after switch-off was selected as the stator fault characteristic,which could effectively avoid the influence of the supply unbalance and the load fluctuation,and directly represent the asymmetry in the *** the empirical mode decomposition(EMD)based on HHT,the zero sequence voltage after switch-off was decomposed and the fundamental component was ***,the fault characteristic can be *** results on a 4-kW induction motor demonstrate the feasibility and effectiveness of this method.

关键词： Induction motor Stator fault diagnosis Hilbert-huang transform (HHT) Zero sequence voltage Empirical modedecomposition (EMD)

Morphology-dependent interfacial interactions of Fe2O3 with Ag nanoparticles for determining the catalytic reduction of p-nitrophenol

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Journal of Environmental Sciences 2020年第6期32卷 1-10页

作者： Ningning Wang Shuai Zeng Hong Yuan jin huang Key Laboratory of Pesticide and Chemical Biology of Ministry of Education College of ChemistryCentral China Normal UniversityWuhan 430079China Chongqing Key Laboratory of Soft-Matter Material Chemistry and Function Manufacturing School of Chemistry and Chemical EngineeringSouthwest UniversityChongqing 400715China

In this work,we fabricated three kinds of Ag/Fe2O3 model catalysts with different morphologies to study the interfacial interactions between Ag and Fe2O3,and how they affected the catalytic activity in hydrogenation of p-nitrophenol was *** hydrothermal method was used to synthesize the metal oxide supported silver catalyst,with various morphologies including nanoplates(NPs),nanospheres(NSs),and nanocubes(NCs).The crystal structure,morphology and surface elements of the composite were investigated by various measurements,such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS).The catalytic activity was also evaluated by the reduction of p-nitrophenol to *** was found that the activities of the above catalysts varied with the morphology of the *** them,Ag/Fe2O3 NPs promoted the highest performance,Ag/Fe2O3 NSs were slightly inferior,and Ag/Fe2O3 NCs were the *** last,we ascribed the remarkable activity of Ag/Fe2O3 NPs to the strong metal-support interactions between Ag and Fe2O3.

关键词： Ag/Fe2O3 Interfacial interaction Catalytic activity p-Nitrophenol Morphology dependence