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International Journal of Mining science and Technology 2017年第2期27卷 379-386页

作者： B.K.sahoo s.De B.C.Meikap Department of Chemical Engineering Indian Institute of Technology Research and Development Centre for Iron and steel Steel Authority of India Limited Chemical Engineering School of Engineering Howard College University of Kwazulu-Natal

Detailed experimental investigations were carried out for microwave pre-treatment of high ash Indian coal at high power level(900 W) in microwave oven. The microwave exposure times were fixed at60 s and 120 s. A rheology characteristic for microwave pre-treatment of coal-water slurry(CWs) was performed in an online Bohlin viscometer. The non-Newtonian character of the slurry follows the rheological model of Ostwald de Waele. The values of n and k vary from 0.31 to 0.64 and 0.19 to 0.81 Pa·sn,respectively. This paper presents an artificial neural network(ANN) model to predict the effects of operational parameters on apparent viscosity of CWs. A 4-2-1 topology with Levenberg-Marquardt training algorithm(trainlm) was selected as the controlled ANN. Mean squared error(MsE) of 0.002 and coefficient of multiple determinations(R^2) of 0.99 were obtained for the outperforming model. The promising values of correlation coefficient further confirm the robustness and satisfactory performance of the proposed ANN model.

关键词： Microwave pre-treatment Coal-water slurry Apparent viscosity Artificial neural network Back propagation algorithm

Maintaining nano-lamellar microstructure in friction stir welding (FsW) of accumulative roll bonded (ARB) Cu-Nb nano-lamellar composites (NLC)

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Journal of Materials science & Technology 2018年第1期34卷 92-101页

作者： Judy schneider Josef Cobb John s.Carpenter Nathan A.Mara Department of Mechanical & Aerospace Engineering University of Alabama in Huntsville Department of Mechanical Engineering Mississippi State University Materials science and Technologies Division Los Alamos National Laboratory Center for Integrated Nanotechnologies and the Institute for Materials ScienceLos Alamos National Laboratory

Accumulative roll bonded （ARB） Copper Niobium （Cu-Nb） nano-lamellar composite （NLC） panels were friction stir welded （FsWed） to evaluate the ability to join panels while retaining the nano-lamellar structure. During a single pass of the friction stir welding （FsW） process, the nano-lamellar structure of the parent material （PM） was retained but was observed to fragment into equiaxed grains during the second pass. FsW has been modeled as a severe deformation process in which the material is subjected to an instantaneous high shear strain rate followed by extreme shear strains. The loss of the nano-lamellar layers was attributed to the increased strain and longer time at temperature resulting from the second pass of the FsW process. Kinematic modeling was used to predict the global average shear strain and shear strain rates experienced by the ARB material during the FsW process. The results of this study indicate that through careful selection of FsW parameters, the nano-lamellar structure and its associated higher strength can be maintained using FsW to join ARB NLC panels.

关键词： Nano-lamellar materials Accumulative roll bonded Cu-Nb FsW solid state joining

Low temperature thermoluminescence behaviour of Y_2O_3 nanoparticles

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Journal of Rare Earths 2019年第1期37卷 19-23,M0002页

作者： s.Delice M.Isik N.M.Gasanly Department of Physics Hitit University Department of Electrical and Electronics Engineering Atilim University Department of Physics Middle East Technical University Virtual International scientific Research Centre Baku State University

Y_2O_3 nanoparticles were investigated using low temperature thermoluminescence (TL) experiments. TL glow curve recorded at constant heating rate of 0.4 K/s exhibits seven peaks around 19, 62, 91,115,162,196 and 215 K. Activation energies and characteristics of traps responsible for observed curves were revealed under the light of results of initial rise analyses and T_(max)-T_(stop) experimental methods. Analyses of TL curves obtained at different stopping temperatures resulted in presence of one quasi-continuously distributed trap with activation energies increasing from 18 to 24 meV and six single trapping centers at49, 117, 315, 409, 651 and 740 meV. Activation energies of all revealed centers were reported in the present paper. structural characterization of Y_2O_3 nanoparticles was accomplished using X-ray diffraction and scanning electron microscopy measurements.

关键词： Y2O3 Luminescence Thermoluminescence Defects Rare earths

POLYMERIC NANOPARTICLEs FROM sUPERCRITICAL CO_2 MICROEMULsION POLYMERIZATION

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Chinese Journal of Polymer science 2006年第1期24卷 95-101页

作者： Wei-jun Ye Jason s. Keiper Joseph M. Desimone NsF science and Technology Center for Environmentally Responsible solvents and Processes Department of Chemistry University of North Carolina at Chapel Hill CB# 3290 Venable Hall Chapel Hill NC 27599-3290 USA Department of Chemical Engineering North Carolina State University P. O. Box 7905 Raleigh NC 27695-7905 USA

Herein, we reported the microemulsion polymerization in supercritical carbon dioxide. With the aid of an anionic phosphate fluorosurfactant （bis-[2-（F-hexyl）ethyl]phosphate sodium）, water-soluble/CO2-insoluble acryloxyethyltrimethyl ammonium chloride monomer and N,N＇-methylene-bisacrylamide cross-linker were solubilized into CO2 continuous phase via the formation of water-in-CO2 （w/c） microemulsion water pools. Initiated by a CO2-soluble initiator, 2,2＇-azo-bisisobutyronitrile （AIBN）, cross-linked poly（acryloxyethyltrimethyl ammonium chloride） particles were produced and stabilized in these w/c internal water pools. Nano-sized particles with sizes less than 20 nm in diameter and narrow particle size distributions were obtained.

关键词： supercritical carbon dioxide Nanoparticles Microemulsion polymerization.

DILECTRIC AND THERMAL PROPERTIEs OF PEO DOPED WITH CADIMIUM CHLORIDE sALT

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Chinese Journal of Polymer science 2012年第2期30卷 143-151页

作者： Jibril Al-Hawarin Ayman s.Ayesh Rami A.Abdel-Rahem Chemistry Department College of ScienceAl Hussein Bin Talal UniversityMaanJordan Physics Department College of ScienceKing Faisal UniversityAl-AhssaKingdom of Saudi Arabia Chemistry Department College of ScienceKing Faisal UniversityAl-AhssaKingdom of Saudi Arabia

The main aim of this research is to investigate the effect of salt concentration on the dielectric properties （AC （CrAC）, permittivity （d）, dielectric loss （d＇）, and dielectric relaxation process） and melting behavior of polyethylene oxide （PEO）/CdC12 complexes. The dielectric study was carried out over a frequency range 10-335 kHz and a temperature range 25--45~C. The AC conductivity, permittivity and dielectric loss of the PEO/CdC12 complexes increase with increasing salt concentration and temperature. Also, it was found that the addition of CdC12 salt to PEO host reduced the melting temperature of PEO host. Dielectric results reveal that the relaxation process of these complexes is due to viscoelastic relaxation or non-Debye relaxation at room temperature. Additionally, it was found that relaxation behavior remained viscoelastic at different temperatures and salt concentrations.

关键词： Polyethylene oxide CdC12 salt Dielectric properties Dielectric relaxation Relaxation process Thermalproperties.

Numerical Analysis on the Effect of n-si on Cu(In, Ga)se2 Based Thin-Films for High-Performance solar Cells by 1D-sCAPs

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Gain enhancement in two-stream free electron laser with a planar wiggler and an axial guide magnetic field

Open Journal of Applied sciences（应用科学） 2024年第5期 1315页

作者： Rasika N.Mohottige Micheal Farndale Gary s.Coombs shahnoza saburhhojayeva

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Chinese Physics B 2012年第9期21卷 247-250页

作者： s.saviz Z.Rezaei Farzin M.Aghamir Plasma Physics Research Center Science and Research BranchIslamic Azad University Department of Physics University of Tehran

The theory for a two-stream free electron laser （FEL） consisting of a relativistic electron beam transported alongthe axis of a planar wiggler in the presence of an axial guiding magnetic field is proposed and investigated. The electron trajectories and the small signal gain are derived. The characteristic of the linear gain and the normalized maximum gain are studied numerically. The result shows that the normalized maximum gain is considerably enhanced in comparison with that of the single stream. The effect of the difference between the energies of the two beams in this configuration of FEL is also considered, and we find that the gain is affected by the energy differences between groups 1 and 2.

关键词： wo-stream free-electron laser

Effects of site preparation methods on soil physical properties and outplanting success of coniferous seedlings in boreal forests

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Heat transfer in a porous saturated wavy channel with asymmetric convective boundary conditions

林业研究（英文版） 2024年第2期 74页

作者： Aleksey s.Ilintsev Elena N.Nakvasina Alexander P.Bogdanov

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Journal of Central south University 2015年第1期22卷 392-401页

作者： Q.Hussain s.Asghar T.Hayat A.Alsaedi Department of Mathematics COMSATS Institute of Information Technology Department of Mathematics Faculty of Science King Abdulaziz University Department of Mathematics Quaid-I-Azam University 45320

The viscous flow in a wavy channel with convective boundary conditions is investigated. The channel is filled with a porous viscous fluid. Two cases of equal and different external convection coefficients on the walls are taken into account. Effect of viscous dissipation is also considered. The governing equations are derived employing long wavelength and low Reynolds number approximations. Exact closed form solutions are obtained for the simplified equations. Important physical features for peristaltic flow caused by the wavy wave are pumping, trapping and heat transfer rate at the channel walls. These are discussed one by one in depth and detail through graphical illustrations. special attention has been given to the effects of convective boundary conditions. The results show that for Bi1≠Bi2, there exists a critical value of Brinkman number Brc at which the temperatures of both the walls become equal. And, for Bi1>Bi2 and Br>Brc, the temperature of the cold wall exceeds the temperature of hot wall.

关键词： peristalsis heat transfer porous medium convective boundary conditions

Nanophase Decomposition of a Zn-Al Based Alloy Zn_(68)Al_(10)Cu_(22)

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Journal of Materials science & Technology 2004年第6期20卷 687-690页

作者： Y.H.Zhu W.B.Lee s.To Advanced Materials Research Center Department of Industrial and systems Engineering The Hong Kong Polytechnic University Hong Kong ChinaAdvanced Materials Research Center Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hong Kong ChinaAdvanced Materials Research Center Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hong Kong China

The nanostructural evolution and phase transformation of the films of a Zn-Al based alloy (Zn68Al10Cu22 in wt pct) have been studied by using X-ray diffraction and scanning electron microscopy. Nanostructural thin films of the Zn-AI based alloy were produced by using an electron beam deposition technique. It was found that a nanocrystalline phase η'n had a strong preferred crystal orientation at (0002) crystal planes in the as-deposited films. During ageing at 220℃, the decomposition of nanophase η'n started with clustering to form Z-zones, and transitionai phase, which was accompanied by an eutectoid decomposition of the η'n phase: η'n β'eut T'. Decomposition, such as clustering and the formation of the Z-zones, and the transitionai phase etc. were observed in the nanophase β'eut. The formation and the decomposition of the transitionai phase of micrometers in size were involved in the decomposition of the main nanophase η'n. The mechanism of the Z-zones formation and the stability of nanophases were discussed.

关键词： Ageing Nanostructure Nanophase stability Zn-Al based alloy film