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NANO-MULtILAYERS WItH HIGH PERPENDICULAR ANISOtROPY FOR MAGNEtIC RECORDING

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Acta Metallurgica Sinica(English Letters) 2003年第4期16卷 261-265页

作者： t.Yang b.H.Li DepartmentofMaterialsPhysics UniversityofScienceandTechnologyBeijingBeijing100083China InformationStorageMaterialsLaboratory ToyotaTechnologicalInstituteNagoya468-8511JapanManuscriptreceived25November2002

(FePt/Ag)n nano-multilayers were deposited on MgO (100) single crystal with laser ablation and then subjected to annealing. FePt L1o grains with (001) texture and thus a large perpendicular magnetic anisotropy constant Ku of the order of 106 J/m3 were formed. A thick Ag layer is found to be favorable for decreasing the dispersion of the easy axis for magnetization. the measurement of time decay of magnetization gave rise to a small activation volume of the order of 10-25m3, showing the promising of being the recording medium for future high density perpendicular recording.

关键词： recording media perpendicular magnetic anisotropy activation volume

I-Quiz:An Intelligent Assessment tool for Non-Verbal behaviour Detection

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Computer Systems Science & Engineering 2022年第3期40卷 1007-1021页

作者： b.t.Shobana G.A.Sathish Kumar Department of Information technology Sri Venkateswara College of EngineeringSriperumbudur602117India Department of Electronics and Communication Engineering Sri Venkateswara College of EngineeringSriperumbudur602117India

Electronic learning(e-learning)has become one of the widely used modes of pedagogy in higher education today due to the convenience and flexibility offered in comparison to traditional learning *** in Information and Communication technology have eased learner connectivity online and enabled access to an extensive range of learning materials on the World Wide *** covid-19 pandemic,online learning has become the most essential and inevitable medium of learning in primary,secondary and higher *** recent times,Massive Open Online Courses(MOOCs)have transformed the current education strategy by offering a technology-rich and flexible form of online learning.A key component to assess the learner’s progress and effectiveness of online teaching is the Multiple Choice Question(MCQ)assessment in most of the MOOC *** exists on the reliability and validity of the assessment component as it raises a qualm whether the real knowledge acquisition level reflects upon the assessment *** is due to the possibility of random and smart guesses,learners can attempt,as MCQ assessments are more vulnerable than essay type *** paper presents the architecture,development,evaluation of the I-Quiz system,an intelligent assessment tool,which captures and analyses both the implicit and explicit non-verbal behaviour of learner and provides insights about the learner’s real knowledge acquisition *** I-Quiz system uses an innovative way to analyse the learner non-verbal behaviour and trains the agent using machine learning *** intelligent agent in the system evaluates and predicts the real knowledge acquisition level of learners.A total of 500 undergraduate engineering students were asked to attend an on-Screen MCQ assessment test using the I-Quiz system comprising 20 multiple choice questions related to advanced C *** non-verbal behaviour of the learner is recorded using a front-facing camera during t

关键词： E-Learning adaptive and intelligent e-learning systems intelligent tutoring systems emotion recognition non-verbal behaviour knowledge acquisition level

Numerical analysis for peristaltic transport of Carreau-Yasuda fluid with variable thermal conductivity and convective conditions

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Journal of Central South University 2015年第11期22卷 4467-4475页

作者： F.M.Abbasi t.Hayat b.Ahmad Department of Mathematics Comsats Institute of Information Technology Department of Mathematics Quaid-I-Azam University 45320 Nonlinear Analysis and Applied Mathematics (NAAM) Research Group Faculty of Science King Abdulaziz University

Peristalsis of Carreau-Yasuda fluid is investigated. Analysis is carried out in the presence of velocity slip and convective boundary conditions. thermal conductivity of the fluid is taken to be temperature dependent. Lubrication analysis is used in the formulation of the problem. Resulting nonlinear system of equations is solved numerically. Impact of embedded parameters on the quantities of interest is examined through graphs and tables. Comparison of the behavior of the Carreau-Yasuda, Carreau and Newtonian fluid models is presented. Results show that the heat transfer rate at the wall for the Carreau fluid model is large when compared with the Newtonian or the Carreau-Yasuda fluid model. Also the heat transfer rate at the wall decreases with increase in the velocity slip and variable thermal conductivity parameters. Further, an increase in the biot number reduces the fluid temperature by a considerable amount.

关键词： peristaltic transport Carreau-Yasuda fluid variabl

COORDINAtING A tWO-ECHELON SUPPLY CHAIN tHROUGH DIFFERENt CONtRACtS UNDER PRICE AND PROMOtIONAL EFFORt-DEPENDENt DEMAND

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Journal of Systems Science and Systems Engineering 2013年第3期22卷 295-318页

作者： b.C.GIRI S.bARDHAN t.MAItI Department of Mathematics Jadavpur UniversityIndia

Retail price and promotional effort are two important parameters on which demand of a commodity largely depends. this paper develops and analyzes a two-echelon supply chain where market demand depends on both retail price and sales effort. the centralized model is studied as the benchmark case, and the wholesale price-only contract is studied as the base case in which each entity tries to maximize its individual profit. Different contract mechanisms are implemented to outperform the base case in terms of both total chain＇s as well as individual profits. Comparisons among the coordinating contracts are provided so that any entity may choose the better one from available contracts after the contract parameters are negotiated. the model is extensively examined through a numerical example.

关键词： Price and effort-dependent demand wholesale price-only contract wholesale price discount revenue sharing profit sharing two-part tariff

Effect of bagasse ash reinforcement on the wear behaviour of Al-Cu-Mg/bagasse ash particulate composites

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Acta Metallurgica Sinica(English Letters) 2010年第2期23卷 81-89页

作者： V.S. Aigbodion S.b. Hassan G.b. Nyior t. Ause Department of Metallurgical and Materials Engineering Ahmadu Bello University

the effect of bagasse ash （bAp） particle reinforcement on the wear behavior of Al-Cu- Mg alloy has been studied. bagasse ash particles were varied from 0 wt pct-10 wt pct with interval of 2 wt pct. Unlubricated pin-on disc tests were conducted to examine the wear behaviour of the aluminium alloy/bagasse ash particulate composites. the tests were conducted at varying loads, from 5 to 20 N and sliding speeds of 1.26 m/s, 2.51 m/s, 3.77 m/s and 5.02 m/s for a constant sliding distance of 5000 m. the results showed that the wear rates of the A1-Cu-Mg/bAp composites are lower than that of the matrix alloy and further decrease with increasing bagasse ash content. Wear rate increases as the sliding speed and applied load increase. the microstructure of the worn surface revealed that a large amount of plastic deformation appeared on the surface of the unreinforced alloy. While bagasse ash reinforced Al-Cu-Mg alloy showed worn out surface that is not smooth, and grooves, scratches and parallel lines were observed. A combination of adhesion and delamination wear was in operation. these results show that improve wear properties is achievable for the aluminium alloy by the addition of bagasse ash particles as reinforcement material.

关键词： Al-Cu-Mg alloy bagasse ash Composites Load Sliding speed and Wear

Phase Formation and Magnetic Properties of Nanocomposite Nd-Fe-b Adjusted by Small Amount of Dy and Co

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Journal of Rare Earths 2004年第z2期22卷 89-94页

作者： t S Jang t W Lim H S Aum D H Lee M b Kim Division of Materials and Chemical Engineering Sun Moon UniversityKorea Division of Materials and Chemical EngineeringSun Moon UniversityKorea Division of Mechanical EngineeringSun Moon University 100 Kalsan LiTangjung MyonAsan CityChoongnam 336-708Korea Division of Materials and Chemical EngineeringSun Moon UniversityKorea Division of Materials and Chemical EngineeringSun Moon UniversityKorea

In order to improve and stabilize the magnetic properties of nanocomposite Nd2Fe14b/α-Fe magnetic alloys by a compositional adjustment, small amount of Dy and/or Co was added to Nd9Fe84b7 alloys. DtA analysis on the amorphous of the alloys took place as the soft magnetic phases were crystallized, and then the hard magnetic Nd2Fe14b was precipitated from them. While α-Fe and a metastable 1:7 (tbCu7-type) phase were formed simultaneously in Dy and Co-free alloys, they were crystallized separately at different temperatures after Dy or Co was added. this phase separation occurred more clearly in the Dy-treated alloys and the other soft magnetic phase Fe3b was also stabilized by Dy and/or Co. the 1: 7 phase that was stabilized by Dy and/or Co was not eliminated at 700 ℃, decreasing magnetic properties of the alloys. It was eventually disappeared above 725 ℃, but Fe3b was not eliminated even at 750 ℃ when Dy was added more than 0.5 at% or Co was added more than 2.0 at%. Amount of Nd2Fe14b in the alloys tended to increase as Dy addition increased,whereas Co addition did not lead to any appreciable change in the ratio of α-Fe and Nd2Fe14b. Moreover, Dy addition apparently increased coercivity of an alloy while Co addition had a beneficial effect on remanence. the grains in the Dytreated alloys were usually finer than those in the Co-treated alloys. the grain size of both α-Fe and Nd2Fe14b in the alloys exhibiting mr ≥ 0.72 was in the range of 20 ～ 40 nm or even larger 50 nm, which is larger than the theoretical optimum size ( ～ 10 nm). typical magnetic properties obtained from a Nd7.5Dy1.5Fe82.5Co1.5b7 alloy annealed for 12 min at 725 ℃were iHc=4.85 kOe, br= 11.32 kG, (bH)max = 15.73 MGOe, and mr=0.73.

关键词： nanocomposite Nd-Fe-b magnetic properties remanence coercivity

An Investigation of Ionic Flows in a Sphere-Plate Electrode Gap

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Plasma Science and technology 2013年第10期15卷 1012-1019页

作者： H.Z.ALISOY S.ALAGOZ G.t.ALISOY b.b.ALAGOZ Department of Electrical-Electronics Inonu University Department of Physics Inonu University Department of Mathematics Inonu University

this paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain （FDtD） based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics.

关键词： ion flow FDtD simulation space charge motion

Suzuki Reaction of Aryl bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

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催化学报 2011年第11期32卷 1667-1676页

作者： Nghia t. bUI trung b. DANG Ha V. LE Nam t. S. PHAN Department of Chemical Engineering HCMC University of Technology VNU-HCM 268 Ly Thuong Kiet Distriet 10 Ho Chi Minh City Viet Nam

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. the catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. the immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. the recovery of catalyst was simply by magnetic decantation in the presence of a magnet. the immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.

关键词： superparamagnetic nanoparticle Suzuki reaction palladium aryl bromide

Dynamics of the plane and solitary waves in a Noguchi network:Effects of the nonlinear quadratic dispersion

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Chinese Physics b 2020年第3期29卷 105-111页

作者： S A t Fonkoua M S Ngounou G R Deffo F b Pelap S b Yamgoue A Fomethe Unite de Recherche de Matiere Condensee d’Electronique et de traitement du Signal(UR-MACEtS) Faculte des SciencesUniversite de DschangBP 67 DschangCameroun Unite de Recherche de Mecanique et de Modelisation des Systemes Physiques(UR-2MSP) Faculte des SciencesUniversite de DschangBP 69 DschangCameroun Department of Physics Higher Teacher Training College BambiliUniversity of BamendaP.O.Box 39 BamendaCameroon

We consider a modified Noguchi network and study the impact of the nonlinear quadratic dispersion on the dynamics of modulated waves. In the semi-discrete limit, we show that the dynamics of these waves are governed by a nonlinear cubic Schrodinger equation. From the graphical analysis of the coefficients of this equation, it appears that the nonlinear quadratic dispersion counterbalances the effects of the linear dispersion in the frequency domain. Moreover, we establish that this nonlinear quadratic dispersion provokes the disappearance of some regions of modulational instability in the dispersion curve compared to the results earlier obtained by Pelap et al.(Phys. Rev. E 91 022925(2015)). We also find that the nonlinear quadratic dispersion limit considerably affects the nature, stability, and characteristics of the waves which propagate through the system. Furthermore, the results of the numerical simulations performed on the exact equations describing the network are found to be in good agreement with the analytical predictions.

关键词： Noguchi network nonlinear quadratic dispersion modulational instability soliton