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Heat transfer in MHD Flow of Maxwell Fluid via Fractional Cattaneo-Friedrich Model:A Finite Difference Approach

Computers, Materials & Continua 2020年第12期65卷 1959-1973页

作者： Muhammad Saqib Hanifa Hanif t.Abdeljawad ilyas Khan Sharidan Shafie Kottakkaran Sooppy Nisar Department of Mathematical Sciences Faculty of ScienceUniversiti Teknologi MalaysiaJohor Bahru81310Malaysia Department of Mathematics Sardar Bahadur Khan Women’s UniversityQuettaPakistan Department of Mathematics and General Sciences Prince Sultan UniversityRiyadh11586Saudi Arabia Department of Medical Research China Medical UniversityTaichung40402Taiwan Department of Computer Science and information Engineering Asia UniversityTaichung40402Taiwan Faculty of Mathematics and Stati.tics Ton Duc Thang UniversityHo Chi Minh CityVietnam Department of Mathematics College of Arts and SciencesPrince Sattam bin Abdulaziz UniversityWadi Aldawaser11991Saudi Arabia

the idea of fractional derivatives is applied to several problems of viscoelastic ***,most of these problems(fluid problems),were studied analytically using different i.tegral transform techniques,as most of these problems are *** idea of the above fractional derivatives is rarely applied to fluid problems governed by nonlinear partial differential *** importantly,in the nonlinear problems,either the fractional models are developed by artificial replacement of the classical derivatives with fractional derivatives or simple classical problems(without developing the fractional model even using artificial replacement)are *** problems were mostly solved for steady-state fluid *** the present article,studied unsteady nonlinear non-Newtonian fluid problem(Cattaneo-Friedrich Maxwell(CFM)model)and the fractional model are developed starting from the fractional constitutive equations to the fractional governing equations;in other words,the artificial replacement of the classical derivatives with fractional derivatives is not done,but in details,the fractional problem is modeled from the fractional constitutive *** exactly two-dimensional magnetic resi.tive flow in a porous medium of fractional Maxwell fluid(FMF)over an inclined plate with variable velocity and the temperature is *** Caputo time-fractional derivative model(CFM)is used in the governing *** proposed model is numerically solved via finite difference method(FDM)along with L1-scheme for *** numerical results are presented in various *** results indicated that the fractional parameters significantly affect the temperature and velocity *** is noticed that the temperature field increased with an increase in the fractional ***,the effect of fractional parameters is opposite on the velocity field near the ***,this trend became like that of the temperature profile,away from the ***,

关键词： Viscoelastic fluid Cattaneo-Friedrich Maxwell model variable heating magnetohydrodynamic(MHD) porous medium fractional derivatives

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Hurricane di.turbances, tree diversity, and succession in North Carolina Piedmont forests, USA

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Journal of Forestry Research 2019年第1期30卷 219-231页

作者： Weimin Xi Robert K.Peet Michael t.Lee Dean L.Urban Department of Biology University of North Carolina at Chapel Hill Department of Biological and Health Sciences Texas A & M University-Kingsville the Nicholas School of the Environment Duke University

Windthrow plays a critical role in mai.taining species diversity in temperate forests. Do large-scale strong wind events(i.e., tropical cyclones, including hurricanes,typhoons and severe cyclonic storms) increase tree diversity in severely damaged forest areas? Do hurricanes(tropical cyclones that occurs in the Atlantic Ocean and northeastern Pacific Ocean) lead to altered relative abundance of shade-tolerant and shade-i.tolerant species? Did hi.toric hurricanes alter the succession trajectory of the damaged forests? We used nearly 70-year tree demographic data to assess the effects of two major hurricanes on woody species diversity in Piedmont forests, North Carolina, USA. Species richness(S) and Shannon–Wiener's diversity index(H') were used to evaluate the changes in tree diversity. the changes in composition were assessed with Nonmetric Multidimensional Scaling. the pre-hurricane successional phase can strongly influence both the damage severity and subsequent responses. Although there is often an immedi.te drop in diversity following a hurricane, understory tree diversity quickly increases to levels that exceed those prior to the di.turbance. this leads to an increase in diversity in stands that were substantially damaged. Hurricanes significantly decrease the dominance of shade-i.tolerant canopy species while increasing preestablished, more shade-tolerant species. We conclude that large, and infrequent hurricanes help to mai.tain local tree diversity, but also accelerate the increase in dominance of understory species such as red maple and beech.

关键词： Wind di.turbance tree species diversity Plant succession Di.turbance-diversity relationship Piedmont forests

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Comparative Study between Magnetite Nanoparticles and Magnetite/Silver as a Core/Shell Nanostructure

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Advances in Nanoparticles 2021年第4期10卷 115-122页

作者： Nabiha i. Abdo Higher institute of Engineering and technology New Borg Al Arab City Alexandria Egypt

Magnetite nanoparticles (MNPs) and magnetite/silver nanoparticles (M/Ag NPs) were synthesized by chemical co-precipitation of Fe2+ and Fe3+. in case of M/Ag NPs, MNPs (core) were separately coated by silver metal (shell) in presence of glucose as a reducing agent. the particle size and morphology of the nanoparticles were characterized by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Magnetic properties were investigated by vibrating sample magnetometry (VSM). the superparamagnetic natures of the nanoparticles were confirmed by the absence of the hysteresis loop. Coverage with silver produced a core-shell heterostructure which weakens magnetization of MNPs, inducing an inert character to the fnal nanostructure. the surface conjugation of MNPs with silver metal has been employed in order to improve the compatibility of magnetite nanoparticles to overcome their limitations in practical applications.

关键词： Magnetite Nanoparticles (MNPs) Fe3O4 Silver Metal Core/Shell DLS SEM VSM

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Si/SiC Hybrid 5-level Active NPC inverter for Electric Aircraft Propulsion Drive Applications

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Chinese Journal of Electrical Engineering 2020年第4期6卷 63-76页

作者： Majid t.Fard Mostafa Abarzadeh Kiavash A.Noghani Jiangbiao He Kamal Al-Haddad Department of Electrical and Computer Engineering University of KentuckyLexingtonKY 40506USA Department of Electrical and Computer Engineering Marquette UniversityMilwaukeeWI 53233USA Department of Electrical Engineering Ecole de Technologie Superieure(ÉTS)MontrealH3C 1K3Canada

Medium voltage DC(MVDC)system is considered as a promising technology to improve the efficiency and power density of electric aircraft propulsion(EAP)*** adapt to the MVDC voltage level and achieve high drive performance,a five-level active neutral poi.t clamped(5L-ANPC)inverter consi.ting of three-level ANPC and flying capacitor circuits is investigated,which possesses higher voltage capability,lower output harmonics,as well as mitigated dv/dt and common-mode *** fulfill the requirements of high-speed operation and pursue further enhanced efficiency and power density of the inverter for the next-generation EAP drives,Silicon Carbide(SiC)semiconductor devices are considered for implementing the 5L-ANPC ***,the large commutation loops associ.ted with certain switching states of the inverter lessen the benefits of configuring all the switches as SiC *** a result,a hybrid Si/SiC 5L-ANPC inverter is developed with a synchronous optimal pulse(SOP)wi.th modulation strategy for controlling the switches in cell 2 and finite-control-set model predi.tive controller(FCS-MPC)for those in cell 3 of the ***,in the proposed topology,the SiC devices are merely used for the high-frequency switches in cell 3 and the rest of the low-frequency switches are configured with Si *** Si/SiC hybrid ANPC inverter concurrently provides high efficiency and low implementation cost at high-speed operation *** and experimental results are provided to verify the effectiveness of the proposed hybrid inverter.

关键词： Five-level ANPC flying capacitor SOP FCS-MPC carrier-based modulation high efficiency MVDC electric aircraft propulsion

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Stati.tical modelling for effect of mix-parameters on properties of high-flowing sand-concrete

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Journal of Central South University 2012年第10期19卷 2966-2975页

作者： t.BOUZiANi A.BENMOUNAH M.BDRiNA Rheology of Dispersed Media Research Unit-MaterialsProcesses and Environment(UR/MPE) University of BoumerdesBoumerdes 35000Algeria Structures Rehabilitation and Materials Laboratory(SREML) University Ammar Telidji of LaghouatLaghouat 03000Algeria

the high-flowing sand-concrete （HFSC） containing natural sands as aggregate was carried out. the high fluidity and stability of HFSC can be achieved by tailoring the mix design parameters, such as fine to coarse sand ratio, dosage of additions, water to binder ratio and dosage of admi.tures. Mini-cone slump test, *** time test and viscosity model parameters were used to characterize the behaviour of HFSC in fresh state. the mechanical compressive strength in 28 d was also determined. A factorial design approach was used to establish models highlighting the effect of each mix-parameter on measured properties of HFSC. the derived models are valid for mi.tures made with 0 to 0.3 of dune sand to total sand ratio, 82 to 418 kg/m3 of marble powder, 0.42 to 0.46 of water/binder ratio and 1.3% to 1.9% of superplasticizer high water-reducer. the results show that the derived models constitute very efficient means for understanding the influence of key mix-parameters on HFSC properties and are useful in selecting the optimum mix proportions, by simulating their impact on fluidity, stability and compressive strength.

关键词： high-flowing sand-concrete factorial design fluidity viscosity mix-design parameters

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Luminescent-plasmonic core-shell microspheres,doped with Nd3+ and modified with gold nanoparticles,exhibiting whispering gallery modes and SERS activity

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Journal of Rare Earths 2019年第11期37卷 1152-1156页

作者： Marcin Runowski inocencio R.Martin Vladimir N.Sigaev Vitaliy i.Savinkov Georgiy Yu.Shakhgildyan Stefan Lis Faculty of Chemi.try Adam Mickiewicz UniversityUniwersytetu Poznanskiego 861-614 PoznanPoland Departamento de Fisica Instituto de Materiales y Nanotecnologia(IMN)Universidad de La LagunaApdo.456E-38200 San Cristobal de La LagunaSanta Cruz de TenerifeSpain D.Mendeleev University of Chemical technology Miusskaya Sq.9125047 MoscowRussia

Multifunctional core/shell type,luminescent-plasmonic material composed of lanthanide doped microspheres(≈50μm)and gold nanoparticles(Au NPs;≈10-20 nm)deposited onto their surface,were successfully prepared(Nd^3+:YAS@Au).the material was synthesized to combine the luminescence properties of the Nd^3+-doped microspheres,*** resonance with plasmonic activity of the surface Au NPs,*** enhanced Raman scattering(SERS)effect,within a single,micro-sized *** luminescent-plasmonic microspheres were used as the active SERS substrate for detection of the organic probe,and for generation of Whispering Gallery Modes(WGM),which red-shi.t together with increasing laser power(temperature elevation).the products obtained were analysed with optical,scanning and transmission electron microscopy(SEM and tEM),as well as by Raman,absorption and photoluminescence spectroscopies.

关键词： Luminescence Gold NPs-SPR Surface enhanced Raman scattering Microsphere resonators-WGM Lanthanide ions Optical sensors

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Fourier Pseudospectral Solution for a 2D Nonlinear Paraxial Envelope Equation of Laser i.teractions in Plasmas

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Journal of Applied Mathematics and Physics 2016年第12期4卷 2186-2202页

作者： Abdelrahman i. Mahdy Plasma and Nuclear Fusion Department Nuclear Research Centre Atomic Energy Authority Cairo Egypt

We apply a Fourier pseudospectral algorithm to solve a 2D nonlinear paraxial envelope-equation of laser i.teractions in plasmas. in this algorithm, we first use the second order Strang time-spli.ting method to split the envelope-equation i.to a number of equations, next we spatially discrete the filed quantity and its spatial derivatives in these equations in term of Fourier i.terpolation polynomials (FFt), finally we sequentially i.tegrate the resultant equations by means of a discrete i.tegration method in order to obtain the solution of the envelope-equation. We carry out several numerical tests to illustrate the efficiency and to determine accuracy of the algorithm. in addition, we conduct a number of numerical experiments to examine its performance. the numerical results have shown that the algorithm is highly efficient and sufficiently accurate to solve the 2D envelope-equation, furthermore, it yields an optimal performance in simulating fundamental phenomena in laser i.teractions in plasmas.

关键词： Laser Plasmas i.teractions Laser Envelope-Equation Fourier Pseudospectral Method Nonlinear Schrödinger Equation

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Chemical-Structural Changes of Organic Matter in a Semi-Arid Soil After Organic Amendment

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Pedosphere 2012年第3期22卷 283-293页

作者： C.NiCOLS G.MASCiANDARO t.HERNNDEZ C.GARCiA Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSiC) Department of Soil and Water Conservation and Organic Wastes ManagementCampus Universitario de EspinardoP.O.160Murcia 3010 (Spain) Consiglio Nazionale delle Ricerche (CNR) Istituto per lo Studio degli Ecosistemi (ISE)-Sezione di Chimica del SuoloArea della RicercaVia Moruzzi 1Pisa 56124 (Italy)

A 9-month incubation experiment using composted and non-composted amendments derived from vine pruning waste and sewage sludge was carried out to study the effects of the nature and stability of organic amendments on the structural composition of organic matter (OM) in a semi-arid *** changes of soil OM,both in the whole soil and in the extractable carbon with pyrophosphate,were evaluated by pyrolysis-gas chromatography and chemical *** the end of the experiment,the soils amended with pruning waste exhibited less organic carbon loss than those receiving sewage *** non-composted residues increased the aliphatic-pyrolytic products of the OM,both in the whole soil and also in the pyrophosphate extract,with the products derived from peptides and proteins being significantly *** 9 months,in the soils amended with pruning waste the relative abundance of phenolic-pyrolytic products derived from phenolic compounds,lignin and proteins in the whole soil tended to increase more than those in the soils amended with sewage ***,the extractable OM with pyrophosphate in the soils amended with composted residues tended to have higher contents of these phenolic-pyrolytic products than that in non-composted ***,despite the stability of pruning waste,the composting of this material promoted the incorporation of phenolic compounds to the soil *** pyrolytic indices (furfural/pyrrole and aliphatic/aromatic ratios) showed the diminution of aliphatic compounds and the increase of aromatic compounds,indicating the stabilization of the OM in the amended soils after 9 *** conclusion,the changes of soil OM depend on the nature and stability of the organic amendments,with composted vine pruning waste favouring humification.

关键词： degraded soil pyrolysis-gas chromatography pyrophosphate extract sewage sludge vine pruning waste

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Geochemi.try and zircon SHRiMP U-Pb dating of granitoids from the west segment of the North Qaidam

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Science China Earth Sciences 2009年第11期52卷 1771-1790页

作者： Joseph L.WOODEN Paul t.ROBiNSON Frank K.MAZDAB Chris MAttiNSON Department of Earth and Environmental Sciences Stanford University Department of Earth Sciences Dalhousie University

Granitoid i.trusives such as Saishitenshan, tuanyushan, Aolaohe and Sanchagou occur widely in the western segment of North Qaidam. All these bodies trend NW, roughly parallel to the regional structure. Zircon SHRiMP dating for these granites show that they range in age from Ordovician to Permian; 465.4±3.5 Ma for Saishitenshan, 469.7±4.6 Ma and 443.5±3.6 Ma for tuanyushan, 372.1±2.6 Ma for Aolaohe, and 271.2±1.5 Ma and 259.9±1.2 Ma for Sanchagou. Both the tuanyshan and Aolaohe plutons record two di.tinct i.trusive events. Geochemically, the early Paleozoic granites have an island arc or active continental margin affinity, and their protolith may have been Mesoproterozoic oceanic crust derived from depleted mantle. the protolith of the late Paleozoic granites may have been Mesoproterozoic lower crust from the root of an island arc with the magmas reflecting a mi.ture of mantle and crustal material.

关键词： granitoid zircon SHRiMP U-Pb dating North Qaidam

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Whole-Rock Geochemi.try and Mineralogy of triassic Montney Formation, Northeastern British Columbia, Western Canada Sedimentary Basin

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i.ternational Journal of Geosciences 2016年第1期7卷 91-114页

作者： Edwin i. Egbobawaye Department of Earth and Atmospheric Sciences University of Alberta Edmonton Canada

inductively Coupled Plasma-Mass Spectrometry (iCP-MS) was used to analyze chemical elements—major, trace and rare earth elements (REE) concentrations, augmented with quantitative X-ray diffraction (XRD) analysis and thin-section petrography for mineralogical characterization of the Triassic Montney Formation in northeastern British Columbia, Western Canada Sedimentary Basin (WCSB). Results from this study indicate that integration of chemical elements with mineralogy shows affinity to the host lithologies. Evidently, chemical elements are the building blocks for minerals, thus, their significances in the i.terpretation of geological systems are unambiguous. Herein, major elements concentration such as Al, Fe, K, Mg, Ca, Mn in the samples analyzed from the Montney Formation are i.terpreted as: 1) indication of dolomitization and diagenesis;2) trace elements—Rb, th, U, and Cs are related to the organi

关键词： Geochemi.try Whole-Rock Mineralogy Montney Formation thin-Section Petrography trace-Elements iCP-MS XRD Dolomitization Diagenesis WCSB

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