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On the nonlocal stabilization by starting control of the normal equation generated from the Helmholtz system

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Science China Mathematics 2018年第11期61卷 2017-2032页

作者： andrey Fursikov Lyubov Osipova Department of Mechanics & Mathematics Moscow State University Mathematical Fluid Dynamics Laboratory Voronezh State University

We consider the problem of stabilization near zero of semilinear normal parabolic equations connected with the 3D Helmholtz system with periodic boundary conditions and arbitrary initial *** problem was previously studied in Fursikov and Shatina(2018).As it was recently revealed,the control function suggested in that work contains a term impeding transferring the stabilization construction on the 3D Helmholtz *** main concern of this paper is to prove that this term is not necessary for the stabilization result,and therefore the control function can be changed by a proper way.

关键词： equations of normal type nonlocal stabilization starting control estimates of stabilized solutions

Meta-optics and bound states in the continuum

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Science Bulletin 2019年第12期64卷 836-842页

作者： Kirill Koshelev andrey Bogdanov Yuri Kivshar Nonlinear Physics Centre Australian National UniversityCanberra ACT 2601Australia ITMO University St. Petersburg 197101Russia

We discuss the recent advances in meta-optics and nanophotonics associated with the physics of bound states in the continuum(BICs). Such resonant states appear due to a strong coupling between leaky modes in optical guiding structures being supported by subwavelength high-index dielectric Mieresonant nanoantennas or all-dielectric metasurfaces. First, we review briefly very recent developments in the BIC physics in application to isolated subwavelength particles. We pay a special attention to novel opportunities for nonlinear nanophotonics due to the large field enhancement inside the particle volume creating the resonant states with high-quality(high-Q) factors, the so-called quasi-BIC, that can be supported by the subwavelength particles. Second, we discuss novel applications of the BIC physics to alldielectric optical metasurfaces with broken-symmetry meta-atoms when tuning to the BIC conditions allows to enhance substantially the Q factor of the flat-optics dielectric structures. We also present the original results on nonlinear high-Q metasurfaces and predict that the frequency conversion efficiency can be boosted dramatically by smart engineering of the asymmetry parameter of dielectric metasurfaces in the vicinity of the quasi-BIC regime.

关键词： Bound states in the continuum Meta-optics Second-harmonic generation Nanoresonator Metasurfaces

Prediction of coating uniformity in batch fluidized-bed coating process

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Particuology 2022年第2期20卷 41-46页

作者： andrey A.Lipin Alexandr G.Lipin Department of Processes and Apparatuses of Chemical Technology Ivanovo State University of Chemistry and TechnologyIvanovoRussia

Coating of particulate materials in fluidized beds is a widely used technique to eliminate particle agglomeration,provide slow release of an active substance,or protect active *** thin polymer shells are applied on a particle surface,it is important to determine the process parameters that provide coating *** this study,the degree of coverage,defined as the fraction of the coated surface of the particles,is proposed as a quantitative criterion of coating uniformity.A new model for the batch fluidized-bed coating process is *** model allows prediction of the function of particle distribution according to the degree of coverage at a given process time and thereby enables assessment of coating *** algorithm for the numerical solution of model equations for a batch fluidized-bed coater is *** influences of the main process parameters on the coating uniformity were shown.

关键词： Coating uniformity Degree of coverage Encapsulation Fluidized-bed coating Mathematical modeling

Ligand density control boosts the efficiency of all-inorganic CsPbBr3 perovskite nanocrystal based light emitting diodes

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Science Bulletin 2017年第5期62卷 314-315页

作者： andrey L. Rogach Department of Physics and Materials Science Centre for Functional Photonics (CFP) City University of Hong Kong Hong Kong China

Lead halide perovskites attracted a lot of attention in the last several years,with a focus gradually shifting from the record power conversion efficiencies reported for photovoltaic devices based on thin perovskite f... 详细信息

关键词： LEDs Ligand density control boosts the efficiency of all-inorganic Cs Pb Br3 perovskite nanocrystal based light emitting diodes Cs Pb Br

Charged pion condensation in anti-parallel electromagnetic fields and nonzero isospin density

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Chinese Physics C 2020年第3期44卷 101-110页

作者： Jingyi Chao Mei Huang andrey Radzhabov Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Matrosov Institute for System Dynamics and Control Theory SB RAS Lermontov str. 134664033IrkutskRussia

The formation of charged pion condensate in anti-parallel electromagnetic fields and in the presence of the isospin chemical potential is studied in the two-flavor Nambu-Jona-Lasinio *** method of Schwinger proper time is extended to explore the quantities in the off-diagonal flavor space,*** charged *** this framework,π^± are treated as bound states of quarks and not as point-like charged *** isospin chemical potential plays the role of a trigger for charged pion *** obtain the associated effective potential as a function of the strength of the electromagnetic fields and find that it contains a sextic term which possibly induces a weak first order phase *** dependence of pion condensation on model parameters is investigated.

关键词： pion condensate electromagnetic fields weakly first order phase transition

Simulating cyclotron-Bloch dynamics of a charged particle in a 2D lattice by means of cold atoms in driven quasi-lD optical lattices

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Frontiers of physics 2012年第1期7卷 3-7页

作者： Kolovsky, andrey R. Kirensky Institute of Physics Siberian Branch of Russian Academy of Sciences Krasnoyarsk Russia Institute of Engineering Physics Siberian Federal University Krasnoyarsk Russia

Quantum dynamics of a charged particle in a two-dimensional （2D） lattice subject to magnetic and electric fields is a rather complicated interplay between cyclotron oscillations （the case of vanishing electric field） and Bloch oscillations （zero magnetic field）, details of which has not yet been com- pletely understood. In the present work we suggest to study this problem by using cold atoms in optical lattices. We introduce a one-dimensional （1D） model which can be easily realized in labora- tory experiments with quasi-lD optical lattices and show that this model captures many features of the cyclotron-Bloch dynamics of the quantum particle in 2D square lattices.

关键词： optical lattice Bloch dynamics cyclotron oscillations cold atoms

On Differential Equations of Integrable Billiard Tables

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Acta Mathematica Sinica,English Series 2024年第1期40卷 417-424页

作者： Vladimir DRAGOVIC andrey E.MIRONOV Department of Mathematical Sciences The University of Texas at DallasRichardson TXUSA Mathematical Institute SANU BelgradeSerbia Novosibirsk State University NovosibirskRussia Sobolev Institute of Mathematics of the Siberian Branch of the Russian Academy of Sciences NovosibirskRussia

We introduce a method to find differential equations for functions which define tables,such that associated billiard systems admit a local first *** illustrate this method in three situations:the case of(locally)integrable wire billiards,for finding surfaces in R^(3)with a first integral of degree one in velocities,and for finding a piece-wise smooth surface in R^(3)homeomorphic to a torus,being a table of a billiard admitting two additional first integrals.

关键词： Polynomial first integrals wire billiards piece-wise smooth surfaces

Modeling of Leachate Propagation in a Municipal Solid Waste Landfill Foundation

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1407-1424页

作者： Nadezhda Zubova andrey Ivantsov Institute of Continuous Media Mechanics of the Ural Branch Russian Academy of SciencePerm614013Russia

The study deals with the numerical modeling of leachate distribution in the porous medium located under a municipal solid waste disposal landfill(MSWLF).The considered three-layer system is based on geological data obtained from field *** simplicity,the problem is investigated by assuming a two-component ***,the heat produced by landfills due to biological and chemical processes and the thermal diffusion mechanism contributing to pollution transport are taken into *** numerical modeling of the propagation of leachate in the considered layered porous medium is implemented for parameters corresponding to natural soil and for the case where disruption of the porous medium structure is due to cracks formation or *** latter is accompanied by an increase in rock *** this case,the emergence of multi-vortex flow in the layer of high permeability is observed to substantially influence the bottom layers and cause intensification of the leachate *** effects should be taken into account when estimating the parameters and properties of materials required for the construction of solid waste disposal facilities.

关键词： Three-layer porous medium binary mixture diffusion thermal diffusion

Spreading of a Multicomponent Drop in Water: Solutions and Suspensions

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Fluid Dynamics & Materials Processing 2020年第4期16卷 723-735页

作者： andrey Y.Ilinykh Ishlinsky Institute for Problems in Mechanics of the Russian Academy of Sciences Moscow119526Russia

The distribution of material resulting from the impact of a freely falling drop with a target liquid has been studied by photo and video registration *** cases have been investigated by considering drops made of aqueous solutions(ink,salt,acid)and including fine solid particles(i.e.,suspensions).New features have been observed in terms of flow dynamics and thin components produced as a result of the impact(such as banded elements,ligaments,and vortices at the surface of the liquid).In particular,the characteristics of emerging netlike structures have been found to depend on the size of the suspension *** the case of acetic acid,a different patterning behavior has been obtained:sequences of concentric arcs are produced in that ***,linear scaling laws and the discrete nature of the distribution of the droplet material seem to be features common to all the cases considered.

关键词： Drop impact splashes ligaments material distribution