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Development of Mathematical Model of Slag Flow Field and Temperature Field in ESr System

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Journal of Iron and Steel research International 2000年第2期7卷 27-31页

作者： YANG Yin-dong SOMMErVILLE I D JOHNSTON r F McLEAN A University of Toronto LaTrobe University

The heat transfer phenomena and driving forces of slag bath flow in ESr process were analyzed, and the mathematical models in ESr system were reviewed and evaluated. The electromagnetic force is the main driving force for the flow formation in the ESr slag pool, and the temperature difference in the pool creates a convective flow in the system. The shape of the electrode tip has an effect on electromagnetic field distribution in slag pool, thus affects the flow pattern. Finally an improved mathematical model of slag pool flow was proposed.

关键词： ESr electromagnetic force buoyancy force flow field temperature field mathematical model

Efficient Exciton Transfer from In0.35Ga0.65As Template into InAs Quantum Dots Grown on GaAs （311）B Substrates

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Chinese Physics Letters 2006年第5期23卷 1310-1313页

作者：王防震陈张海龚谦 r. Notzel 柏利慧沈学础 Surface Physics Laboratory Department of Physics Fudan University Shanghai 200433 Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 COBrA Inter-University research Institute Eindhoven University of Technology 5600 MB Eindhoven Netherlands

Atomic force microscopy （AFM） and power-dependent micro-photoluminescence （μ-PL） spectroscopy are used to study the structure and exciton energy states in InAs quantum dots （QDs） grown on an In0.35Ga0.65As template on GaAs （311）B. The In0.35Ga0.65As template, consisting of a two-dimensionally modulated layer of closely packed connected cells, has a remarkable effect on the optical properties of the IhAs QDs. By comparing the emission spectra of the samples without and with InAs QDs and the work carried out by Gong et al. [J. Cryst. Growth 251 （2003） 150; Appl. Phys. Lett. 81 （2002） 3254] we conclude that the existence of the In0.35Ga0.65As template enhances the photo-absorption and therefore the exeiton emission from the QDs due to efficient exciton transfer from the template into the QDs. Furthermore, the PL emission from the QDs dearly reveals four discrete energy levels, S, P, D, and F with increasing excitation power.

关键词： MOLECULAr-BEAM EPITAXY NUCLEATION CONTrOL SELF-OrGANIZATION AMPLIFIErS

Calculation of Surface Energy of Metals and Alloys by theElectron Density Functional Method

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Journal of Materials Science & Technology 1998年第4期14卷 320-322页

作者： Kuznetsov, V.M. Kadyrov, r.I. rudenskii, G.E. Institute of Strength Physics and Material Science Russian Academy of Sciences Siberian Branch Academicheskii av. 2/1 634048 Tomsk Russian Federation

The surface energy of (100), (110), (111) surfaces in Ni, Al and ordered alloys NiAl and Ni//3Al has been calculated within the framework of methodology based upon the electron density functional method. The results of calculations are in good agreement with the known for pure metals experimental data and in case of Ni//3Al alloy. There is also a good agreement with the results obtained by calculation using the embedded atom method. The investigation has been carried out in this work to show that the surface energy sigma of alloys can not be interpreted as an averaged concentration sigma of pure metals. For NiAl, the obtained results reveal considerable distinctions in anisotropy of sigma in comparison to the anisotropy of surface energy in pure metals. (Edited author abstract) 8 refs.

关键词： Aluminum

An electron moir■ method for a common SEM

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Acta Mechanica Sinica 2006年第6期22卷 595-602页

作者： Y. M. Xing S. Kishimoto Y. r. Zhao Department of Applied Mechanics Inner Mongolia University of Technology Hohhot 010051 China National Institute for Materials Sciences Tsukuba Ibaraki 305-0047 Japan

In the electron moiré method, a high-frequency grating is used to measure microscopic deformation, which promises significant potential applications for the method in the microscopic analysis of materials. However, a special beam scanning control device is required to produce a grating and generate a moiré fringe pattern for the scanning electron microscope （SEM）. Because only a few SEMs used in the material science studies are equipped with this device, the use of the electron moiré method is limited. In this study, an electron moiré method for a common SEM without the beam control device is presented. A grating based on a multi-scanning concept is fabricated in any observing mode. A real-time moiré pattern can also be generated in the SEM or an optical filtering system. Without the beam control device being a prerequisite, the electron moiré method can be more widely used. The experimental results from three different types of SEMs show that high quality gratings with uniform lines and less pitch error can be fabricated by this method, and moiré patterns can also be correctly generated.

关键词： Electron moiré Grating Multi-scanning Electron beam moiré

A study of fire propagation in coal seam with numerical simulation of heat transfer and chemical reaction rate in mining field

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International Journal of Mining Science and Technology 2019年第6期29卷 873-879页

作者： Moisés Oswaldo Bustamante rúa Alan José Daza Aragón Pablo Bustamante Baena National University of Colombia Cr 65 # 63 20 CIMEX Minerals Institute

Spontaneous combustion of coal is a problem that affects the mining operation and generates environ-mental,economic,social and geotechnical *** phenomenon has been divided into two pro-cesses:ignition and *** propagation develops in coal seams because of a set of factors such as direction and wind speed,fracturing and *** this work,heat transfer and chemical kinetics are studied from conservation equations of energy and species,respectively,using the software COMSOL Multiphysics to simulate the propagation of fires in coal *** possible scenarios were analyzed that usually occur in the walls of the coal seams,such as fire focus and fire complete *** was found that the propagation kinetics of the fire changes depending on the temperature,the fractur-ing of rock mass and the area of fire *** temperature values lower than 300℃,there is con-sumption around 250 cm^3/h,values around 700℃,the consumption is 1500 cm^3/h,and for fires of 1200℃ have values of 3000 cm^3/*** on the speed of propagation can vary from 4 to 17cm/day,considering on the level and fracturing of the final wall of the open pit.

关键词： Spontaneous combustion of coal Open pit mines Simulation Heat transfer Chemical reaction COMSOL

Dual phase titanium alloy hot forging process design： experiments and numerical modeling

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Advances in Manufacturing 2015年第4期3卷 269-281页

作者： A. Ducato G. Buffa L. Fratini r. Shivpuri Department of Chemical Management Computer and Mechanical Engineering University of Palermo Viale delle Scienze Palermo 90128 Italy Integrated Systems Engineering The Ohio State University 1971 Neil Ave Columbus OH 43210 USA

Titanium alloys materials when both good weight reduction are required are considered desirable mechanical properties and at the same time. This class of materials is widely used in those fields （aeronautics, aerospace） in which common steels and light-weight materials, e.g., aluminum alloys, are not able to satisfy all operative service conditions. During the last decade, forg- ing of titanium alloys has attracted greater attention from both industrial and scientific/academic researchers because of their potential in providing a near net shaped part with minimal need for machining. In this paper, a numerical model of the forging sequences for a Ti-6A1-4V titanium alloy aerospace component is presented. The model was tested and validated against experimental forgings. The model is then applied to predict loads final microstructure and defects of an aeronautical component. In addition to metal flow and die stresses, microstructural transformations （α and β phases） are considered for the determination of proper process parameters. It is found that transformation from α/β to β phase during forging and reverse transformations in post-forge cooling needs to be considered in the computational model for reasonable prediction of forging loads and product properties.

关键词： Finite element method (FEM) Ti-6Al-4V Hot forging Phase prediction

Global investigation of the ionospheric irregularities during the severe geomagnetic storm on September 7-8, 2017

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Geodesy and Geodynamics 2020年第3期11卷 211-221页

作者： ramazan Atıcı Selçuk Sagır Mus¸Alparslan University Faculty of EducationDepartment of Classroom TeachingMus¸Turkey Mus¸Alparslan University Faculty of Science and ArtDepartment of PhysicsMus¸Turkey

In this study,the global effects of the severe geomagnetic storm on the Earth’s ionosphere on September5 e9,2017 with Coronal Mass Ejections(CMEs)associated with X-9.3 flares on September 6,2017 were investigated by the rate of Total Electron Content(TEC)Index(rOTI).rOTI was used as a criterion of ionospheric irregularities that took place during the *** study was conducted with TEC values obtained from fifty stations connected to the International GNSS System(IGS)-GPS network for five different latitude *** a result,it was observed that the irregularities in the high latitude regions of the southern hemisphere were greater in number in comparison with those at the high latitude regions of the northern hemisphere during the *** was observed that these irregularities generally occurred during the main and recovery phases of the storm at all *** weak and moderate ionospheric irregularities that developed at high latitudes during the storm were more in the southern ***,moderate ionospheric irregularities in high latitudes of both hemispheres took place in eastern longitudes(18 oE-160 oE).However,ionospheric irregularities in the mid-latitude regions were observed in more stations at the northern hemisphere than at the southern ***,ionospheric irregularities during the storm developed at eastern longitudes in all sectors.

关键词： Earth's ionosphere Geomagnetic storm Ionospheric irregularities rOTI

Dynamics of Information Entropies of Atom-Field Entangled States Generated via the Jaynes-Cummings Model

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Communications in Theoretical Physics 2016年第3期65卷 266-272页

作者： r.Pakniat M.K.Tavassoly M.H.Zandi Faculty of Physics Shahid Bahonar University of Kerman Atomic and Molecular Group Faculty of PhysicsYazd University Photonic research Group Engineering Research CenterYazd University The Laboratory of Quantum Information Processing Yazd University

In this paper we have studied the dynamical evolution of Shannon information entropies in position and momentum spaces for two classes of（nonstationary） atom-field entangled states,which are obtained via the JaynesCummings model and its *** have focused on the interaction between two- and（1）-type three-level atoms with the single-mode quantized *** three-dimensional plots of entropy densities in position and momentum spaces are presented versus corresponding coordinates and time,*** is observed that for particular values of the parameters of the systems,the entropy squeezing in position space ***,we have shown that the well-known BBM（Beckner,Bialynicki-Birola and Mycielsky） inequality,which is a stronger statement of the Heisenberg uncertainty relation,is properly satisfied.

关键词： Shannon information entropy entropy squeezing BBM inequality Jaynes-Cummings model

Evaluating the Impact of Prediction Techniques: Software reliability Perspective

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Computers, Materials & Continua 2021年第5期67卷 1471-1488页

作者： Kavita Sahu Fahad A.Alzahrani r.K.Srivastava rajeev Kumar Department of Computer Science Dr.Shakuntala Misra National Rehabilitation UniversityLucknow226017India Department of Computer Engineering College of Computer and Information SystemsUmm Al-Qura UniversityMakkah21955Saudi Arabia Department of Computer Application Shri Ramswaroop Memorial UniversityBarabanki225003India Department of Information Technology Babasaheb Bhimrao Ambedkar UniversityLucknow226025India

Maintaining software reliability is the key idea for conducting quality *** can be done by having less complex *** developers and other experts have made signicant efforts in this context,the level of reliability is not the same as it should ***,further research into the most detailed mechanisms for evaluating and increasing software reliability is essential.A signicant aspect of growing the degree of reliable applications is the quantitative assessment of *** are multiple statistical as well as soft computing methods available in literature for predicting reliability of ***,none of these mechanisms are useful for all kinds of failure datasets and *** nding the most optimal model for reliability prediction is an important *** paper suggests a novel method to substantially pick the best model of reliability *** method is the combination of analytic hierarchy method(AHP),hesitant fuzzy(HF)sets and technique for order of preference by similarity to ideal solution(TOPSIS).In addition,using the different iterations of the process,procedural sensitivity was also performed to validate the *** ndings of the software reliability prediction models prioritization will help the developers to estimate reliability prediction based on the software type.

关键词： Software reliability reliability prediction prediction techniques hesitant-fuzzy-AHP hesitant-fuzzy-TOPSIS