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The analysis of composite laminated beams using a 2D interpolating meshless technique

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Acta mechanica Sinica 2018年第1期34卷 99-116页

作者： S.H.m.Sadek J.belinha m.P.L.Parente R.m.Natal Jorge J.m.A.César de Sá A.J.m.Ferreira Department of mechanical Engineering Faculty of EngineeringUniversity of Porto Institute of mechanical Engineering and Industrial management University of Porto

Laminated composite materials are widely implemented in several engineering constructions. For its relative light weight, these materials are suitable for aerospace, military, marine, and automotive structural applications. To obtain safe and economical structures, the modelling analysis accuracy is highly relevant. Since meshless methods in the recent years achieved a remarkable progress in computational mechanics, the present work uses one of the most flexible and stable interpolation meshless technique available in the literature—the Radial Point Interpolation method(RPIm).Here, a 2 D approach is considered to numerically analyse composite laminated beams. both the meshless formulation and the equilibrium equations ruling the studied physical phenomenon are presented with detail. Several benchmark beam examples are studied and the results are compared with exact solutions available in the literature and the results obtained from a commercial finite element software. The results show the efficiency and accuracy of the proposed numeric technique.

关键词： Radial point interpolators RPIm Laminated beam meshless method

A Quantitative Comparison of Physical Accuracy and Numerical Stability of Lattice boltzmann Color Gradient and Pseudopotential multicomponent models for microfluidic Applications

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Communications in Computational Physics 2022年第7期32卷 450-489页

作者： Karun P.N.Datadien Gianluca Di Staso Herman m.A.Wijshoff Federico Toschi Department of Applied Physics Eindhoven University of Technology5612 AZ EindhovenNetherlands FLOW matters Consultancy b.V. 5612AEEindhovenThe Netherlands Department of mechanical Engineering Eindhoven University of Technology5612 AZ EindhovenNetherlands Canon Production Printing Netherlands b.V. 5914 HHVenloThe Netherlands Department of mathematics and Computer Science Eindhoven University of Technology5612 AZ EindhovenNetherlands Istituto per le Applicazioni del Calcolo Consiglio Nazionale delle Ricerche00185 RomeItaly

The performances of the Color-Gradient(CG)and the Shan-Chen(SC)multicomponent Lattice boltzmann models are quantitatively compared side-by-side on multiple physical flow problems where breakup,coalescence and contraction of fluid ligaments are *** flow problems are relevant to microfluidic applications,jetting of microdroplets as seen in inkjet printing,as well as emulsion dynamics.A significantly wider range of parameters is shown to be accessible for CG in terms of density-ratio,viscosity-ratio and surface tension *** stability for a high density ratio O(1000)is required for simulating the drop formation process during inkjet printing which we show here to be achievable using the CG model but not using the SC *** results show that the CG model is a suitable choice for challenging simulations of droplet formation,due to a combination of both numerical stability and physical *** also present a novel approach to incorporate repulsion forces between interfaces for CG,with possible applications to the study of stabilized ***,we show that the CG model can produce similar results to a known multirange potentials extension of the SC model for modelling a disjoining pressure,opening up its use for the study of dense stabilized emulsions.

关键词： Lattice boltzmann method multiphase flow multicomponent flow inkjet printing turbulent emulsion

Periodic interstellar scintillation variations of PSRs J0613-0200 and J0636+5128 associated with the Local bubble shell

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中国科学:物理学、力学、天文学英文版 2023年第11期66卷 221-232页

作者： Yulan Liu Robert A.main Joris P.W.Verbiest Ziwei Wu Krishnakumar m.Ambalappat Jiguang Lu David J.Champion Ismael Cognard Lucas Guillemot Kuo Liu James W.mc Kee Nataliya Porayko Golam.m.Shaifullah Gilles Theureau National Astronomical Observatories Chinese Academy of SciencesBeijing100101China Fakultät für Physik Universität BielefeldBielefeld33501Germany max-Planck-Institut für Radioastronomie Bonn53121Germany Florida Space Institute University of Central FloridaOrlandoFL32826USA Station de radioastronomie de Nançay Observatoire de ParisNançay18330France Laboratoire de Physique et Chimie de l’Environnement et de l’Espace Universitéd’OrléansOrléans45071France E.A.milne Centre for Astrophysics University of HullHullHU67RXUK Centre of Excellence for Data Science Artificial Intelligence and ModellingUniversity of HullHullHU67RXUK Dipartimento di Fisica“G.Occhialini” Universitàdi Milano-BicoccaMilano20126Italy INAF-Osservatorio Astronomico di Cagliari Selargius(CA)09047Italy INFN Sezione di Milano-BicoccaMilano20126Italy

Annual variations of interstellar scintillation can be modelled to constrain parameters of the ionized interstellar *** a pulsar is in a binary system,then investigating the orbital parameters is possible through analysis of the orbital variation of *** observations carried out from 2011 to 2020 by the European Pulsar Timing Array radio telescopes,PSRs J0613-0200and J0636+5128 show strong annual variations in their scintillation velocity,while the former additionally exhibits an orbital *** theory and markov-chain-monte-Carlo methods are used to interpret these periodic *** assume a thin and anisotropic scattering screen model,and discuss the mildly and extremely anisotropic scattering *** J0613-0200is best described by mildly anisotropic scattering,while PSR J0636+5128 exhibits extremely anisotropic *** measure the distance,velocity,and degree of anisotropy of the scattering screen for our two pulsars,finding that scattering screen distances from Earth for PSRs J0613-0200 and J0636+5128 are 316_(-20)^(+28)pc and 262_(-38)^(+96)pc,*** positions of these scattering screens are coincident with the shell of the Local bubble towards both *** associations add to the growing evidence of the Local bubble shell as a dominant region of scattering along many sightlines.

关键词： pulsar interstellar scintillation ionized interstellar medium

Viscous Cosmology and Thermodynamics of Apparent Horizon

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Chinese Physics Letters 2008年第12期25卷 4199-4202页

作者： m. Akbar Centre for Advanced mathematics and Physics National University of Sciences and Technology Peshawar Road Rawalpindi Pakistan

It is shown that the differential form of Friedmann equations of Friedman-Robertson-Walker （FRW） universe can be recast as a similar form of the first law ThdSh = dE＋ WdV of thermodynamics at the apparent horizon of FRW universe filled with the viscous fluid. It is also shown that by employing the general expression of temperature Th=｜k｜/2π=1/2π~rA（1-2~rA/2H^rA）associated with the apparent horizon of an FRW universe and assumed that the temperature Tm of the energy inside the apparent horizon is proportional to the horizon temperature Tm.bTh, we are able to show that the generalized second law of thermodynamics holds in the Einstein gravity provided Th-Tm/~rA≤（ρ＋~P）.

关键词： field emission molybdenum dioxide enhancement factor

methanol oxidation in acidic and alkaline electrolytes using PtRuIn/C electrocatalysts prepared by borohydride reduction process

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燃料化学学报 2018年第12期46卷 1462-1471页

作者： Santos m.C.L. Nandenha J. Ayoub J.m.S. Assumpao m.H.m.T. Neto A.O. Instituto de Pesquisas Energéticas e Nucleares IPEN/CNEN-SPAv.Prof.Lineu Prestes2242 Cidade UniversitáriaCEP 05508-000Sao PauloSPBrazil Universidade Federal de Sao Carlos UFSCar Campus Lagoa do Sino Rodovia Lauri Simoes de Barros Km 12 CEP 18290-000-Buri-Sao Paulo SP Brazil

PtRuIn/C electrocatalysts( 20% metal loading by weight) were prepared by sodium.borohydride reduction process using H_2PtCl6·6H_2O,RuCl_3·xH_2O and InCl_3·xH_2O as metal sources,borohydride as reducing agent and Carbon Vulcan XC72 as support. The synthetized PtRuIn/C electrocatalysts were characterized by X-ray diffraction( XRD),energy dispersive analysis( EDX),transmission electron microscopy( TEm),cyclic voltammetry( CV),chronoamperommetry( CA) and polarization curves in alkaline and acidic electrolytes( single cell experiments). The XRD patterns showPtpeaks are attributed to the face-centered cubic( fcc) structure,and a shift of Pt( fcc) peaks indicates that Ru or In is incorporated into Ptlattice. TEmmicrographs showmetal nanoparticles with an average nanoparticle size between 2.7 and 3.5 nm. methanol oxidation in acidic and alkaline electrolytes was investigated at room temperature,by CV and CA. PtRu/C( 50 ∶ 50) shows the highest activity among all electrocatalysts in study considering methanol oxidation for acidic and alkaline electrolyte. Polarization curves at 80 ℃ showPtRuIn/C( 50 ∶ 25 ∶ 25)with superior performance for methanol oxidation,when compared to Pt/C,PtIn/C and PtRu/C for both electrolytes. The best performance obtained by PtRuIn/C( 50 ∶ 25 ∶ 25) in real conditions could be associated with the increased kinetics reaction and/or with the occurrence simultaneously of the bifunctional mechanism and electronic effect resulting from the presence of Ptalloy.

关键词： borohydride reduction process PtRuIn/C electrocatalysts methanol oxidation acidic and alkaline electrolytes polarization curves

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铝合金及铝基复合材料的固体焊接

轻金属 1993年第7期 48-51页

作者： m.b.D.Ellis 武红林英国特威公司(TWT)材料部

前言铝及铝合金可采用多种熔焊法焊接,例如钨极氩弧焊(TIG)、熔化极氩弧焊(mIG)、激光焊、电子束焊和各种电阻焊(点焊、缝焊、对焊等)。大家知道,因为铝易于氧化和吸收氮和氢,对焊件性能有害,所以高温熔焊时必须使用隋性气体保护熔池,... 详细信息

前言铝及铝合金可采用多种熔焊法焊接,例如钨极氩弧焊(TIG)、熔化极氩弧焊(mIG)、激光焊、电子束焊和各种电阻焊(点焊、缝焊、对焊等)。大家知道,因为铝易于氧化和吸收氮和氢,对焊件性能有害,所以高温熔焊时必须使用隋性气体保护熔池,以免空气的侵害。由于热裂等原因,有些铝合金不能采用熔化焊。

关键词：铝合金铝基复合材料固体焊接

Dynamics of Fermionic Geometric Discord beyond Single-mode Approximations

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Chinese Physics Letters 2013年第6期30卷 34-37页

作者： m.Ramzan Department of Physics Quaid-i-Azam UniversityIslamabad 45320Pakistan

Geometric quantum discord of fermionic systems in the relativistic regime,that is,beyond the single-mode approximation,is *** is shown that geometric quantum discord for the fermionic systems in non-inertial frames converges at an infinite acceleration limit,which means that the fermionic systems become independent of the choice of Unruh modes(qR)beyond single-mode *** discord may vanish or be retained depending upon the level of mixedness of the fermionic *** dynamics of geometric discord are investigated under amplitude damping,depolarizing,phase damping and flipping *** vanishing behavior of discord is seen for a higher level of decoherence in the infinite acceleration *** depolarizing channel dominantly affects the fermionic geometric discord as compared to the amplitude and phase damping *** implies that the depolarizing channel has most destructive influence on the discord of the fermionic ***,the flipping channels have a symmetrical effect on the ***,the discord heavily depends on the mixedness parameter of the quantum state of the fermionic systems in accelerated frames beyond single-mode approximation.

关键词： quantum infinite frames

以金属氧化物为原料改进燃烧法合成γ-LiAlO_2（英文）

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Transactions of Nonferrous metals Society of China 2018年第9期28卷 1793-1800页

作者： Daniel CRUZ H.b.ORTIZ-OLIVEROS L.m.PéREZ-DíAZ R.m.FLORES-ESPINOSA G.ROSANO-ORTEGA Facultad de Ingeniería Química Benemérita Universidad Autónoma de Puebla14 Sur y San ClaudioCiudad UniversitariaC.P.72570Cd.PueblaMéxico Instituto Nacional de Investigaciones Nucleares Dirección de Investigación TecnológicaApartado Postal 18-102711801 MéxicoDFMéxico Universidad Popular Autónoma del Estado de Puebla 21 Sur no.1103Colonia SantiagoC.P.72410PueblaMéxico

提出一种合成γ-LiAlO_2的替代解决方案—改进燃烧法直接合成γ-LiAlO_2,并将其用于相对简单的反应体系中,原料为非氧化性化合物如Al_2O_3和LiOH,燃料为尿素。采用1:1、1.5:1和2:1的非化学计量Li/Al摩尔比,在900和1000°C下反应5 min,制... 详细信息

提出一种合成γ-LiAlO_2的替代解决方案—改进燃烧法直接合成γ-LiAlO_2,并将其用于相对简单的反应体系中,原料为非氧化性化合物如Al_2O_3和LiOH,燃料为尿素。采用1:1、1.5:1和2:1的非化学计量Li/Al摩尔比,在900和1000°C下反应5 min,制备LiAlO_2,并对其组织和结构进行表征。考察Li/Al摩尔比对材料形貌和高γ射线辐照下材料稳定性的影响。结果表明,所得粉体的晶体结构为?-LiAlO_2和?-LiAlO_2,其取决于Li/Al摩尔比。因此,用该方法可以成功合成微砖状、多面体状和层状?-LiAlO_2,而无需任何后续处理。γ辐照结果表明,所得到的?-LiAlO_2不分解,只形成少量的Li_2CO_3;由此可以确定,辐照会导致固结,不利于氚的有效提取;结果证明,用燃烧法生产高纯度?-LiAlO_2不需要硝酸盐前驱体。

关键词：尿素氧化物燃烧铝酸锂陶瓷

Observation of Hydration-Drying Effect on Clotrimazole-Carbopol System

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Chinese Physics Letters 2008年第7期25卷 2674-2676页

作者： m. Todica Faculty of Physics Babes-Bolyai University 400084 Cluj-Napoca Romania

The possibility to use the polyacrylic acid （carbopol） as polymeric matrix for the clotrimazole is analysed. The hydration-drying effect on the polymeric matrix is observed by Raman spectroscopy. Similar observations are obtained on the clotrimazole included in the polymeric matrix. No modifications of the properties of the clotrimazole and of the polymeric matrix are observed under the repeated action of water.

关键词： HYDROGELS