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Journal of Energy chemistry 2019年第10期28卷 35-42页

作者： Abdul Rehman Valentine c. Eze M.f.M.Gunam Resul Adam Harvey School of Engineering Merz CourtNewcastle UniversityNewcastle Upon Tyne NE1 7RUUK Department of chemical and Polymer Engineering University of Engineering and Technology LahoreFaisalabad CampusPakistan

formation of styrene carbonate (Sc) by the cycloaddition of cO2 to styrene oxide (SO) catalysed by pyrrolidinopyridinium iodide (PPI) in combination with zinc halides (Zncl2, ZnBr2 and ZnI2) was investigated. complete conversion of the SO to Sc was achieved in 3 h with 100% selectivity using 1/0.5 molar (PPI/ZnI2) catalyst ratio under mild reaction conditions i.e., 100℃ and 10 bar cO2 pressure. The synergistic effect of ZnI2 and PPI resulted in more than 7-fold increase in reaction rate than using PPI alone. The cycloaddition reaction demonstrated the first-order dependence with respect to the epoxide, cO2 and catalyst concentrations. Moreover, the kinetic and thermodynamic activation parameters of Sc formation were determined using the Arrhenius and Eyring equations. The positive values of △H(42.8 kJ mol^-1) and △G(102.3 kJ mol^-1) revealed endergonic and chemically controlled nature of the reaction, whereas the large negative values of △S(-159.4 J mol^-1 K^-1) indicate a highly ordered activated complex at the transition state. The activation energy for Sc formation catalyzed by PPI alone was found to be 73.2 kJ mol^-1 over a temperature range of 100-140℃, which was reduced to 46.1 kJ mol^-1 when using PPI in combination with ZnI2 as a binary catalyst. Based on the kinetic study, a synergistic acid-based reaction mechanism was proposed.

关键词： cycloaddition cO2 utilization cyclic carbonates Homogeneous catalysis Activation energy

filling the Disaster Data Gap:Lessons from cataloging Singapore’s Past Disasters

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International Journal of Disaster Risk Science 2021年第2期12卷 188-204页

作者： Yolanda c.Lin feroz Khan Susanna f.Jenkins David Lallemant Department of Geography and Environmental Studies University of New MexicoAlbuquerqueNM87131USA Asian School of the Environment Nanyang Technological UniversitySingapore639798Singapore Earth Observatory of Singapore Singapore639798Singapore Disaster Resilience Leadership Academy Tulane UniversityNew OrleansLA70112USA

International disaster databases and catalogs provide a baseline for researchers,governments,communities,and organizations to understand the risk of a particular place,analyze broader trends in disaster risk,and justify investments in *** because Singapore is routinely identified as one of the safest countries in the world,Singapore’s past disasters have not been studied extensively with few events captured in major global databases such as *** this article,we fill the disaster data gap for postwar Singapore(1950–2020)using specified metrics through an archival search,review of literature,and analysis of secondary *** present four key lessons from cataloging these ***,we expand Singapore’s disaster catalog to 39 events in this time period and quantify the extent of this data ***,we identify the mitigating actions that have followed past events that contribute to Singapore’s present-day ***,we discuss how these past events uncover continuities among vulnerability bearers in ***,we identify limitations of a disaster catalog when considering future *** expanding the disaster catalog,this case study of Singapore supports the need for comprehensive understanding of past disasters in order to examine current and future disaster resilience.

关键词： catalog Database Data gap Disasters Resilience Singapore

Analytical　Study　on　Impingement　Heat　Transfer　with　Single－Phase　free－Surface　circular　Liquid　Jets

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Journal of Thermal Science 1996年第4期5卷 271-277页

作者： c.f.Ma T.Masuoka 等 BeijingPolytechnicUniversity Beijing100022China KyushuInstituteofTechnology Kitakyushu804Japan

An analytical research was conducted to study heat transfer from horizontal surfaces to normally impinging circular jets under arbitrary-heat-flux conditions. The laminar thermal and hydraulic boundary layers were divided into five regions of flow. General expressions of heat transfer coefficients were obtained in all the four regions of stagnation and wall jet zones before the hydraulic jump.

关键词： jet impingement connective heat transfer boundary layer theory.

Local convective Heat Transfer from Small Heaters to Impinging Submerged Axisymmetric Jets of Seven coolants with Prandtl Number Ranging from 0.7 to 348

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Journal of Thermal Science 1997年第4期6卷 286-297页

作者： H.Sun c.f.Ma 等 DepartmentofThermalScience＆Engineering BeijingPolytechnicUniversityBeijing100022China DepartmentofT

Using seven working fluids, a systematic experimental study was performed to investigate the local convective heat transfer from vertical heaters to impinging circular submerged jets in the range of Reynolds number between 1.17 ×102 and 3.69 × 104 with the emphasis placed on the examination of Prandtl number dependence. Heat transfer coefficiellts at the stagnation point were collected and correlated with the plate held within and beyond the potential core. Radial distribution of the local heat transfer coefficient was measured with five test liquids. Based on the measured profiles of the local heat transfer, a correlation was developed to cover the entire range of the radial distance. Besides the presellt data, the correlations developed in this work were also compared with a large quantity of available data of circular air jets. General agreement was observed between the air data and the correlat ions.

关键词： forced convection jets Prandtl number

Luminous Activity Study of a Long Atmospheric Pressure DBD Afterglow

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Plasma Science and Technology 2007年第6期9卷 678-681页

作者： E.PANOUSIS f.cLEMENT N.SPYROU J.f.LOISEAU c.MONGE B.HELD Laboratory of Gas Electronics and Plasmas-Pau University 64000 PanFrance Electrotechnic Materials LaboratoryUniversity of Patras26500 Patras-RioGreece Laboratory of Gas Electronics and Plasmas-Pau University 64000 PanFrance Electrotechnic Materials Laboratory University of Patras26500 Patras-RioGreece

The experimental work reported here is devoted to the study of the luminous activity of a long dielectric barrier discharge （DBD） afterglow at atmospheric pressure. The discharge plasma is generated in a commercially available （AcXys Technologies） reactor, using a N2 flow of a few tens SL/min, whereas the luminous afterglow when channelled into a quartz tube extends at a distance of 50 cm, finishing in a luminous arrow at the tube＇s exit. The luminous activity of the afterglow is studied by means of photomultiplier scans and optical emission spectroscopy, revealing an interesting transient phase. An attempt is made to correlate this effect with the active species＇ creation and destruction mechanisms.

关键词： DBD flowing afterglow optical emission spectroscopy

A Discrete flux Scheme for Aerodynamic and Hydrodynamic flows

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communications in computational Physics 2011年第5期9卷 1257-1283页

作者： S.c.fu R.M.c.So W.W.f.Leung Mechanical Engineering Department Hong Kong Polytechnic UniversityHung HomKowloonHong Kong School of Mechanical Engineering Purdue UniversityWest LafayetteIN 47907-2088USA Research Institute of Innovative Products&Technologies Hong Kong Polytechnic UniversityHung HomKowloonHong Kong

The objective of this paper is to seek an alternative to the numerical simulation of the Navier-Stokes equations by a method similar to solving the BGK-type modeled lattice Boltzmann *** proposed method is valid for both gas and liquid flows.A discrete flux scheme(DfS)is used to derive the governing equations for two distribution functions;one for mass and another for thermal *** equations are derived by considering an infinitesimally small control volume with a velocity lattice representation for the distribution *** zero-order moment equation of the mass distribution function is used to recover the continuity equation,while the first-order moment equation recovers the linear momentum *** recovered equations are correct to the first order of the Knudsen number(Kn);thus,satisfying the continuum ***,the zero-order moment equation of the thermal energy distribution function is used to recover the thermal energy *** aerodynamic flows,it is shown that the finite difference solution of the DfS is equivalent to solving the lattice Boltzmann equation(LBE)with a BGK-type model and a specified equation of *** formulated,the DfS can be used to simulate a variety of aerodynamic and hydrodynamic *** of classical aeroacoustics,compressible flow with shocks,incompressible isothermal and non-isothermal couette flows,stratified flow in a cavity,and double diffusive flow inside a rectangle are used to demonstrate the validity and extent of the *** good to excellent agreement with known analytical and/or numerical solutions is obtained;thus lending evidence to the DfS approach as an alternative to solving the Navier-Stokes equations for fluid flow simulations.

关键词： Aerodynamics hydrodynamics lattice Boltzmann equation

A Lattice Boltzmann and Immersed Boundary Scheme for Model Blood flow in constricted Pipes:Part 1-Steady flow

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communications in computational Physics 2013年第6期14卷 126-152页

作者： S.c.fu W.W.f.Leung R.M.c.So Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHung HomHong Kong

Hemodynamics is a complex problem with several distinct characteristics;fluid is non-Newtonian,flow is pulsatile in nature,flow is three-dimensional due to cholesterol/plague built up,and blood vessel wall is *** order to simulate this type of flows accurately,any proposed numerical scheme has to be able to replicate these characteristics correctly,efficiently,as well as individually and *** the equations of the finite difference lattice Boltzmann method(fDLBM)are hyperbolic,and can be solved using cartesian grids locally,explicitly and efficiently on parallel computers,a program of study to develop a viable fDLBM numerical scheme that can mimic these characteristics individually in any model blood flow problem was *** present objective is to first develop a steady fDLBM with an immersed boundary(IB)method to model blood flow in stenoic artery over a range of Reynolds *** resulting equations in the fDLBM/IB numerical scheme can still be solved using cartesian grids;thus,changing complex artery geometry can be treated without resorting to grid *** fDLBM/IB numerical scheme is validated against known data and is then used to study Newtonian and non-Newtonian fluid flow through constricted *** investigation aims to gain insight into the constricted flow behavior and the non-Newtonian fluid effect on this behavior.

关键词： finite difference method lattice Boltzmann method immersed boundary method blood flow constricted pipe

EffEcT Of HEAT TREATMENTS ON THE MIcROSTRUcTURE AND TRANSfORMATION cHARAcTERISTIcS Of TiNiPd SHAPE MEMORY ALLOY THIN fILMS

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Acta Metallurgica Sinica(English Letters) 2005年第6期18卷 707-713页

作者： c.c. Zhang c.S. Yang G.f. Ding S. Q. Qian J.S. Wu National Key Laboratory of Nano/Micro fabrication Technology Key Laboratory for Thin Film and Microfabrication of Ministry of Education Institute of Micro and Nano Science and Technology Shanghai Jiaotong University Shanghai 200030 China School of Material Science and Engineering Shanghai Jiaotong University Shanghai 200030 China

Microstructure and phase transformation behaviors of the film annealed at different temperatures were studied by X-ray diffractometry （XRD）, transmission electron microscopy and differential scanning calorimeter （DSc）. Also tensile tests were examined. for increasing annealed temperature, multiple phase transformations, transformations via a B19-phase or direct martensite/austenite transformtion are observed. The TiNiPd thin film annealed at 750℃ had relatively uniform martensite/austenite transformtion and shape memory effect. Martensite/austenite transformtion was also found in strain-temperature curves. Subsequent annealing at 450℃ had minor effect on transformation temperatures of Ti-Ni-Pd thin films but resulted in more uniform transformation and improved shape memory effect.

关键词： Ti-Ni-Pd thin films microstructure martensitic phase transformation,shape memory effect

Structure and Magnetic Properties of Magnetostrictive feGa film on Single-crystal(100) GaAs and(001) Si Substrate fabricated by Pulsed Laser Deposition

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Acta Metallurgica Sinica(English Letters) 2018年第6期31卷 623-628页

作者： Y.Zhang M.Turghun c.J.Huang T.Wang f.f.Wang W.Z.Shi Key Laboratory of Optoelectronic Material and Device Shanghai Normal University Mathematics and Science college Shanghai Normal University

feGa thin film has been deposited on（100）-oriented GaAs and（001）-oriented Si substrates with different film thicknesses and laser energy densities at room temperature by pulsed laser deposition *** structure and static magnetic of feGa film have great changes depending on the substrate and energy density of pulsed laser.X-ray diffraction reveals the presence of first-order order–disorder structure ofgrain phase and disordered bcc A2 structure on GaAs *** coercivity and remanence of feGa film on GaAs substrate ratio show a regular dependence on the thickness and energy ***,film on Si substrate did not exhibit structure change,which can be attributed to a large lattice mismatch between feGa and Si.

关键词： Magnetostrictive film Soft magnetic film Texture Galfenol

Environmental and biological factors affecting the abundance of Prosopis flexuosa saplings in the central-west Monte of Argentina

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forest Ecosystems 2022年第1期9卷 103-110页

作者： cappa f.M. campos V.E. Barri f.R. Ramos L. campos c.M. INTERBIODES(Interacciones Biologicas del Desierto) Facultad Ciencias ExactasFísicas y Naturales(Universidad Nacional de San Juan)San JuanArgentina cIGEOBIO-cONIcET(centro de Investigaciones de la Geosfera y Biosfera Consejo Nacional de Investigaciones Científicas y Tecnicas)San JuanArgentina Instituto de Diversidad y Ecología Animal CONICET–UNCCordobaArgentina IADIZA Instituto Argentino de Investigaciones de las Zonas AridasUniversidad Nacional de CuyoGobierno de MendozaCONICETMendozaArgentina

Background:Trees and forests in drylands help mitigate the challenges through provision of economic products and vital environmental services such as habitat for biodiversity,prevention of erosion and desertification,regulation of water,microclimate,and soil *** condition and changes in dry forests can be assessed by using ecological indicators able to quantify spatial and temporal changes in *** of the ways to determine the condition of the forest is to study the dominant tree species and its *** study aimed to assess whether the abundance of Prosopis flexuosa saplings is affected by environmental and biological ***:To evaluate the first variables we used data from remote sensing such as satellite images and Aster Global Digital Model(GDEM).The second set of variables was about exotic and native ungulates and we used feces of these animals and camera traps to take *** found that sapling abundance related positively to sandy substrates and negatively to Wetness *** the other hand,in relation to biological variables,the abundance of saplings was positively affected by density of adult trees and by number of seeds dispersed by equines,but space use by Lama guanicoe had a negative relationship with *** research shows that *** saplings are benefited from sandy substrates and the conditions around adult *** addition to this,we found that exotic ungulates in low densities have neutral(***)or positive(***)effects on sapling ***:Based on these findings,we conclude that regeneration of the population of *** in our study area has no major *** addition,we corroborated that the presence of exotic and domestic ungulates in low densities does not have deleterious consequences for saplings of the dominant tree,***.

关键词： Bos primigenius taurus Dry forests Equines Exotic and domestic ungulates Lama guanicoe Prosopis flexuosa Remote sensing Saplings Seed dispersal