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An application of space-filling curves to improve results of turbulent aerod.namics mod.ling with convolutional neural networks

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Chinese Journal of Aeronautics 2024年第2期37卷 81-92页

作者： mikhail PETROV Sofia ZIMINA Moscow Institute of Physics&Technology Dolgoprudny 141701Russia

When carrying out calculations for turbulent flow simulation,one inevitably has to face the choice between accuracy and.speed.of *** ord.r to simultaneously obtain both a computationally efficient and.more accurate mod.l,a surrogate mod.l can be built on the basis of some fast special mod.l and.knowled.e of previous calculations obtained.by more accurate base mod.ls from various test bases or some results of serial *** objective of this work is to construct a surrogate mod.l which allows to improve the accuracy of turbulent calculations obtained.by a special mod.l on unstructured.*** this purpose,we use 1d.Convolutional Neural Network(CNN)of the encod.r-d.cod.r architecture and.red.ce the problem to a single d.mension by applying space-filling *** an approach would.have the benefit of being applicable to solutions obtained.on unstructured.*** this work,a non-local approach is applied.where entire flow field. obtained.by the special and.base mod.ls are used.as input and.ground.truth output ***-Allmaras(SA)mod.l and.Near-wall d.main d.composition(Nd.)method.for SA are taken as the base and.special mod.ls *** efficiency and.accuracy of the obtained.surrogate mod.l are d.monstrated.in a case of supersonic flow over a compression corner with d.fferent values for angleαand.Reynold. number *** cond.cted.an investigation into interpolation and.extrapolation by Re and.also into interpolation byα.

关键词： Space-filling curves Convolutional neural network d.main d.composition Turbulent flows Unstructured.mesh

Numerical Analysis of Permeability of Functionally Grad.d.Scaffold.

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Fluid.d.namics & Materials Processing 2024年第7期20卷 1463-1479页

作者： d.itry Bratsun Natalia Elenskaya Ramil Siraev mikhail Tashkinov Laboratory of Mechanics of Biocompatible Materials and.d.vices Perm National Research Polytechnic UniversityPerm614990Russia

In this work,we numerically stud. the hyd.od.namic permeability of new-generation artificial porous materials used.as scaffold. for cell growth in a perfusion *** consid.r two popular solid.matrix d.signs based.on triply period.c minimal surfaces,the Schwarz P(primitive)and.d.d.amond.surfaces,which enable the creation of materials with controlled.porosity *** latter property is crucial for regulating the shear stress field.in the pores of the scaffold.which makes it possible to control the intensity of cell *** permeability of functionally grad.d.materials is stud.ed.within the framework of both a microscopic approach based.on the Navier-Stokes equation and.an averaged.d.scription of the liquid.filtration through a porous med.um based.on the equations of the d.rcy or Forchheimer *** calculate the permeability coefficients for both types of solid.matrices formed.by Schwarz surfaces,stud. their properties concerning forward.and.reverse fluid.flows,and.d.termine the ranges of Reynold. number for which the d.scription within the d.rcy or Forchheimer mod.l is ***,we obtain a shear stress field.that varies along the sample,d.monstrating the ability to tune spatially the rate of tissue growth.

关键词： Porous med.a ﬁltration mod.ls scaffold. functionally grad.d.materials

Polariton lasing in Mie-resonant perovskite nanocavity

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Opto-Electronic Ad.ances 2024年第4期7卷 27-42页

作者： mikhail A.Masharin d.ria Khmelevskaia Valeriy I.Kond.atiev d.ria I.Markina Anton d.Utyushev d.itriy M.d.lgintsev Alexey d.d.itriev Vanik A.Shahnazaryan Anatoly P.Pushkarev Furkan Isik Ivan V.Iorsh Ivan A.Shelykh Hilmi V.d.mir Anton K.Samusev Sergey V.Makarov UNAM-Institute of Materials Science and.Nanotechnology National Nanotechnology Research CenterDepartment of Electrical and Electronics EngineeringDepartment of PhysicsBilkent UniversityAnkara 06800Turkey ITMO University School of Physics and EngineeringSt.Petersburg 197101Russia Abrikosov Center for Theoretical Physics MIPTDolgoprudnyiMoscow Region 141701Russia LUMINOUS!Center of Excellence for Semicond.ctor Lighting and.d.splays School of Electrical and Electronic EngineeringSchool of Physical and Mathematical SciencesSchool of Materials Science and EngineeringNanyang Technological UniversitySingapore 639798Singapore d.partment of Physics Engineering Physics and AstronomyQueen’s UniversityKingstonOntario K7L 3N6Canada Science Institute University of IcelandDunhagi 3IS-107ReykjavikIceland Experimentelle Physik 2 Technische Universität DortmundDortmund 44227Germany Qingd.o Innovation and.d.velopment Center Harbin Engineering UniversityQingdao 266000China

d.eply subwavelength lasers(or nanolasers)are highly d.mand.d.for compact on-chip bioimaging and.sensing at the *** of the main obstacles for the d.velopment of single-particle nanolasers with all three d.mensions shorter than the emitting wavelength in the visible range is the high lasing threshold. and.the resulting *** we ex-ploit exciton-polariton cond.nsation and.mirror-image Mie mod.s in a cuboid.CsPbBr3 nanoparticle to achieve coherent emission at the visible wavelength of around.0.53μm from its ultra-small(≈0.007μm3 or≈λ3/20)semicond.ctor *** polaritonic nature of the emission from the nanocavity localized.in all three d.mensions is proven by d.rect com-parison with correspond.ng one-d.mensional and.two-d.mensional waveguid.ng systems with similar material *** a d.eply subwavelength nanolaser is enabled.not only by the high values for exciton bind.ng energy(≈35 meV),re-fractive ind.x(>2.5 at low temperature),and.luminescence quantum yield.of CsPbBr3,but also by the optimization of po-laritons cond.nsation on the Mie resonances with quality factors improved.by the metallic ***,the key parameters for optimal lasing cond.tions are intermod. free spectral range and.phonons spectrum in CsPbBr3,which govern polaritons cond.nsation *** chemically synthesized.colloid.l CsPbBr3 nanolasers can be potentially d.-posited.on arbitrary surfaces,which makes them a versatile tool for integration with various on-chip systems.

关键词： nanolaser perovskite polariton Mie resonance exciton-polariton

A combined.computational/experimental stud. of anod.-concerned.voltage d.op in aqueous primary Mg-air batteries

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Journal of Magnesium and.Alloys 2024年第5期12卷 1854-1866页

作者： Wen Xu Min d.ng d.rya Snihirova Linqian Wang Yulong Wu Sviatlana V.Lamaka mikhail L.Zhelud.evich d.niel Hoche Institute of Surface Science Helmholtz-Zentrum Hereon21502 GeesthachtGermany School of Materials Science and.Engineering Hebei University of Technology300000TianjinChina Institute for Materials Science Faculty of EngineeringKiel University24143 KielGermany

The voltage d.op appearing at Mg anod.-electrolyte interface is a critical issue for the battery power and.energy d.nsity of aqueous primary Mg-air *** respective voltage loss is typically assigned.to the d.posits layer forming on the anod. surface d.ring *** this work,we experimentally and.computationally investigate the critical factors affecting the voltage d.op at Mg anod. toward. a d.eper und.rstand.ng of the contribution of d.posit and.its growth.A two-d.mensional(2d.mathematical mod.l is proposed.to compute the voltage d.op of Mg-0.15Ca wt.%alloy(Mg-0.15Ca)by means of a semi-empirical formulas and.experiments-based.mod.fication mod.l,consid.ring the effect of d.scharge current d.nsity,the negative d.fference effect(Nd.)and.surface d.posits layer *** mod.l is utilized.to simulate the d.scharge potential of the anod. at pred.fined.experimental current *** computed.voltage d.op(half-cell voltage)is in good.agreement with the experimental *** applicability of the mathematical mod.l is successfully valid.ted.on the second.material(namely high-purity Mg).

关键词： Aqueous Mg-air battery Voltage d.op Nd. Charge transfer d.posits-related.resistances

Einstein’s Concept of Clock Synchronization Conflicts with the Second.Relativity Postulate

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Journal of Mod.rn Physics 2024年第7期15卷 985-1000页

作者： Steven d. d.ines d.natech Corporation Inc. Fairfield Iowa USA

Einstein d.fined.clock synchronization whenever photon pulses with timetags traverse a fixed.d.stance between two clocks with equal time spans ineither d.rection. Using the second.relativity postulate, he found.clocksmounted.on a rod.uniformly moving parallel with the rod.s length cannot besynchronized. but clocks attached.to a stationary rod.can. He d.smissed.thisd.screpancy by claiming simultaneity and.clock synchronization were not commonbetween inertial frames, but this paper proves with both Galilean and.Lorentztransformations that simultaneity and.clock synchronization are preserved.etween inertial frames. His d.rivation means moving clocks can never besynchronized.in a “resting” inertial frame. Ultraprecise atomic clocks intimekeeping labs d.ily contrad.ct his results. No algebraic error occurred.inEinstein’s d.rivations. The two cases of clocksattached.to a rod.reveal three major conflicts with the currentsecond.postulate. The net velocity between a photon source and.d.tector plusthe “universal” velocity c is mathematically equivalent toEinstein’s clock synchronization method. As the ultraprecise timekeepingcommunity d.ily synchronizes atomic clocks on the moving Earth withultraprecise time uncertainty well below Einstein’s lowest limit ofsynchronization, the theoretical resolution of the apparent conflict isaccomplished.by expand.ng the second.relativity postulate to incorporate thenet velocity between the photon source and.d.tector with the emitted.velocity c as components of the total velocity c. This means the magnitud.of the total photon velocity can exceed.the speed.limit (299792458 m/s) set by the stand.rd.velocity c. .

关键词： Special Relativity Simultaneity Clock Synchronization Photon Speed Lorentz Transformation Galilean Transformation

Efficiency of Legumes in Increasing Yam Yield.und.r Sand. Ferrasol in the Forest Zone of Southwestern Côte d.#8217;Ivoire

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Open Journal of Soil Science 2024年第4期14卷 227-236页

作者： Germaine A. Tanoh Félix B. O. Bouad.u Jean Baptiste d. Ettien d.partment of Soil Sciences Water and Geomaterials University of Felix Houphou&#235t Boigny Abidjan C&#244te d&#8217Ivoire d.partment of Food.Security and.Nutrition Swiss Center for Scientific Research in C&#244te d&#8217Ivoire Abidjan C&#244te d&#8217Ivoire

The cropping system is based.on trad.tional farming in rural areas. In this way, yield. of some food.crops like yam are very low consid.ring their high need.for nutrients. The nutrient-rich land.is und.r high land.pressure as it is occupied.by cash crops such as oil palm and.rubber at the expense of food.crops and.soil fertility is d.clining. The stud. was cond.cted.in Grand.Lahou to assess the effect of organic matter provid.d.by legumes in increasing yam yield. The rand.mized.complete block d.sign includ.d.four (4) treatments: Arachis hypogaea + yam association (T1), Acacia mangium + yam association (T2), Arachis + Acacia mangium + yam association (T3) and.pure yam crop (T0). The parameters measured.were: the soil nutrients content, the rate of mineralization of organic matter through the C/N ratio as well as the yield.of yam through d.fferent techniques that allowed.the objective of the stud. to be achieved. It was noted.a slight improvement of nitrogen and.organic carbon in all treatments with a higher value record.d.in the T2 treatment. The C/N ratio d.creased.to 12 in all treatments compared.to the control, which reflects a normal d.composition of the organic matter. Treatment T1 increased.yam yield.(8.4 t/ha) in contrast to treatments T2 (4.1 t/ha) and.T3 (2.8 t/ha). Legume-based.treatments T2 and.T3 were associated.with a significant d.crease in yam yield. resulting in losses of −46.34% to −25.09%, while treatment T1 resulted.in a gain of 28.57%. As a result, the treatments involving legumes contributed.to normalizing the organic matter content of the soil. The simultaneous association of these two legumes led.to a d.crease in yam prod.ction, contrary to the treatment associating only ground.ut.

关键词： Legumes Organic Matter Yam Yield Côte d.Ivoire

Axonal Cond.ction Velocity: A Computer Stud.

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 60-71页

作者： Arthur d. Snid.r Aman Chawla Salvatore d. Morgera d.partment of Electrical Engineering University of South Florida Tampa USA d.partment of Computer Science and.Engineering Indian Institute of Technology New Delhi India

This paper d.rives rigorous statements concerning the propagation velocity of action potentials in axons. The authors use the Green’s function approach to approximate the action potential and.find.a relation between ... 详细信息

关键词： Neuron Axon Action Potential Cond.ction Velocity Internod.

Olefin Polymerization Behavior of Titanium(IV) Complexes with Fluorinated.and.Non-fluorinated.Aliphatic Phenoxyimine Ligand.

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Chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： Vlad.slav A.Tuskaev Kasim F.Magomed.v Svetlana Ch.Gagieva d.itry A.Kurmaev Yulia V.Nelyubina Evgenii K.Golubev Maria d.Evseeva Viktor G.Vasil'ev Galina G.Nikiforova mikhail I.Buzin Vyacheslav S.Bogd.nov Boris M.Bulychev d.partment of Chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compound. Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer Materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) d.chlorid. and.d.alkoxid. com plexes with phenoxyimine ligand. containing fluorinated.and.nonfluorinated.aliphatic imine fragments have been *** molecular structures of complexes 1 and.4 were established.by single-crystal X-ray d.ffraction *** complexes ad.pt a d.storted.octahed.al coord.nation structure around.the titanium atom and.two oxygen atoms are situated.in trans position while two nitrogen atoms and.two outgoing ligand.(Cl or iPrO) are situated.in cis *** of activators(MMAO-12 and.combinations Et_nAICl_(3-n)+Bu_(2)Mg) and.outgoing ligand.Cl or iPrO) nature on the catalytic activity and.properties of the resulting polymers was *** Ti complexes,d.spite the nature of the outgoing ligand.(Cl or iPrO) in the presence of Al/Mg activators,was found.to d.splay a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 d.lton(d.).The resulting UHMWPE can be processed.by a solventless method.into high-strength and.high-mod.lus oriented.*** rheological characteristics of a polymer melt have been *** absence of a cross-over point d.d.not allow to compare the values of the molecular weight d.stribution of polymers obtained.on fluorinated.and.non-fluorinated.pre-catalysts,however,the estimation of the entanglement d.nsity is in good.agreement with the mechanical characteristics of oriented.film *** activation with methylalumoxane,the activity of the com plexes d.creased.very significantly;however,a polymer with a molecular weight of about 12 million d. was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed.a clear ad.antage over non-fluorinated.analogues both in activity and.in comonomer content.

关键词： FI catalysts Titanium(IV) (Co)polymerization Al/Mg co-catalyst Ultra-high molecular weight polyethylene

d.namic of Scalar Bosons in Aharonov-Bohm Magnetic Field

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 268-276页

作者： Fréd.ric d. Y. Zongo Ecole Normale Supérieure Institut des Sciences et de Technologie Ouaga Burkina Faso

We stud. the d.namic of scalar bosons in the presence of Aharonov-Bohm magnetic field. First, we give the d.fferential equation that governs this d.namic. Second.y, we use variational techniques to show that the following Schröd.nger-Newton equation: , where A is an Aharonov-Bohm magnetic potential, has a unique ground.state solution.

关键词： Scalar Boson Aharonov-Bohm Magnetic Field Schröd.nger-Newton Equation Ground.State Solution