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theoretical study of differential cross sections for the ionization of helium by fast proton impact

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Chinese Physics b 2024年第11期33卷 255-264页

作者： M Mondal b Mandal t Mistry D Jana M Purkait Department of Physics Ramakrishna Mission Residential CollegeNarendrapurKolkata-700103India

We present the angular distribution of the ejected electron for single ionization of He by fast proton impact.A fourbody formalism of the three-Coulomb wave is applied to calculate the triple differential cross sections at several impact energies in the scattering,perpendicular and azimuthal ***,the three-body formalism of three-Coulomb,two-Coulomb and first born approximation models has also been used to study the many-body effect on electron emission and the validity of the *** the three-Coulomb wave model,the final state wave function incorporates distortion due to the three-body mutual Coulombic *** this formalism,we use an uncorrelated and correlated born initial state,which consists of a plane wave for the incoming projectile times a two-electron bound state wavefunction of the helium atom representing the 1s2(1S)***,in the case of the three-body formalism,the initial state wavefunction consists of a long-range Coulomb distortion for the incoming projectile and one active electron of the He atom described by the Roothaan–Hartree–Fock *** structure with a single or two peaks with unequal intensity is observed in the angular distributions of the triple differential cross sections for the different kinematic *** addition,the influence of static electron correlations is investigated using different bound state wavefunctions for the ground state of the He *** the four-body formalism,the present computations are very fast by reducing a nine-dimensional integral to a two-dimensional real *** the simplicity and speed of the proposed quadrature,the comparison shows that the obtained results are in reasonable agreement with the experiment and are compatible with those of other theories.

关键词： ionization cross sections collision atoms ions

Simulation of cooling channel rheocasting process of A356 aluminum alloy using three-phase volume averaging model

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中国有色金属学会会刊:英文版 2005年第2期15卷 389-394页

作者： t.Wang b.Pustal M.Abondano t.Grimmig A.bührig-Polaczek M.Wu A.Ludwig Foundry Institute Aachen University of TechnologyAachenD-52072Germany Department of Metallurgy University of LeobenLeobenA-8700Austria Research Center of Foundry Engineering Dalian University of TechnologyDalian 116024China

the cooling channel process is a rehocasting method by which the prematerial with globular microstructure can be produced to fit the thixocasting process.A three-phase model based on volume averaging approach is proposed to simulate the cooling channel process of A356 Aluminum *** three phases are liquid,solid and air respectively and treated as separated and interacting continua,sharing a single pressure *** mass,momentum,enthalpy transport equations for each phase are *** developed model can predict the evolution of liquid,solid and air fraction as well as the distribution of grain density and grain *** effect of pouring temperature on the grain density,grain size and solid fraction is analyzed in detail.

关键词： A356 alloy modeling cooling channel three-phase semi-solid

γ"variant-sensitive deformation behaviour of Inconel 718 superalloy

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journal of Materials Science & technology 2022年第31期126卷 169-181页

作者： R.Y.Zhang H.L.Qin Z.N.bi Y.t.tang J.Araújo de Oliveira t.L.Lee C.Panwisawas S.Y.Zhang J.Zhang J.Li H.b.Dong Centre of Excellence for Advanced Materials Dongguan 523808China School of Engineering University of LeicesterUniversity RoadLeicester LE17RHUnited Kingdom beijing Key Laboratory of Advanced High temperature Materials Central Iron and Steel Research InstituteBeijing 100081China Department of Materials University of OxfordParks RoadOxford OX13PHUnited Kingdom StressMap Engineering and Innovation DepartmentThe Open UniversityWalton HallMilton Keynes MK76AAUnited Kingdom ISIS Neutron Source Rutherford Appleton LaboratoryHarwell Science and Innovation CampusChiltonOxfordshire OX110QXUnited Kingdom School of Material Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Strengthening in Inconel 718 superalloy is derived from dislocation interaction withγ"precipitates,which exist in disk-shaped three possible orientation variants with theirthabit plane normal to each *** interactions between dislocations andγ"precipitates vary according to theγ"orienta-tion variants,which makes the deformation behaviour complicated and difficult to reveal *** this work,γ"variant distributions of Inconel 718 samples were tailored by ageing heat treatment under either tensile or compressive ***γ"variant-sensitive deformation behaviours were then studied by in situ tensile tests via neutron diffraction at room *** is demonstrated that yield-ing first takes place in grains oriented withparallel to the loading *** identical lattice strain response to applied stress of both theγmatrix and theγ"precipitates was observed during yield-ing,suggesting that dislocations shearing through theγ"precipitates is predominant at this ***-ations in yield strength for samples with differentγ"variant distributions were observed,which can be attributed to different strengthening that arises from interactions between dislocation and differentγ"variants.

关键词： Ni-base superalloys Precipitation strengthening Neutron diffraction Lattice strains Plastic deformation

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

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

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