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Recent advances in room temperature phosphorescence of crystalline boron containing organic compounds

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Aggregate 2022年第4期3卷 15-22页

作者： Hannah e.Hackney dmitrii F.Perepichka Department of Chemistry McGill UniversityMontrealQCCanada

In organic compounds,room temperature phosphorescence(RTP)is a rare,yet highly desirable,property that is important for a wide variety of applications,including tissue imaging,anticounterfeiting technologies,photodynamic therapy,and organic light-emitting *** most organic RTP molecules rely on heavy atoms or carbonyl functional groups to accelerate singlet-to-triplet intersystem crossing,in the past few years there have been several reports of RTP induced by boroncontaining functional *** minireview covers the recent literature on RTP of crystalline boroorganic compounds and analyzes the connections between molecular structure,intermolecular interactions,and the resulting phosphorescence.

关键词： luminescence organic crystals organoboron chemistry room temperature phosphorescence

Quantum fluids in nanoporous media——effects of the confinement and fractal geometry

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Chinese Science Bulletin 2011年第34期56卷 3617-3622页

作者： TAYURSKII dmitrii LYSOGORSKIY Yury Department of Physics Kazan Federal University

The complex behavior of such quantum fluids like liquid 4He and liquid 3He in nanoporous media is determined by spatial quantization because of geometrical confinement as well as by significant contribution from the surface atoms. In the present report we will review the procedure, results and discuss the issues for fractionalized nonextensive hydrodynamical approach to describe the properties of quantum fluids inside nanopores and propose consideration of strong correlated quantum liquid by means of fractionalized Schro¨dinger equation.

关键词：量子流体多孔介质分形几何薛定谔方程复杂行为报告审查力学方法量子液体

electron–plasmon and electron–magnon scattering in ferromagnets from first principles by combining GW and GT self-energies

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npj Computational Materials 2021年第1期7卷 1619-1632页

作者： dmitrii Nabok Stefan Blügel Christoph Friedrich Peter Grünberg Institut and Institut for Advanced Simulation Forschungszentrum JülichJülich 52425Germany

This work combines two powerful self-energy techniques:the well-known GW method and a self-energy recently developed by us that describes renormalization effects caused by the scattering of electrons with magnons and Stoner *** GT selfenergy,which is fully k-dependent and contains infinitely many spin-flip ladder diagrams,was shown to have a profound impact on the electronic band structure of Fe,Co,and *** the present work,we refine the method by combining GT with the GW *** resulting GWT spectral functions exhibit strong lifetime effects and emergent dispersion *** are in an overall better agreement with experimental spectra than those obtained with GW or GT alone,even showing partial improvements over local-spin-density approximation dynamical mean-field *** performed analysis provides a basis for applying the GWT technique to a wider class of magnetic materials.

关键词： materials theory infinitely

Design of bidirectional frictional behaviour for tactile contact using ellipsoidal asperity micro-textures

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Friction 2022年第5期10卷 762-771页

作者： dmitrii SeRGACHeV David MATTHeWS emile VAN DeR HeIDe Laboratory for Surface Technology and Tribology Faculty of Engineering TechnologyUniversity of TwenteOverissel 7522 LIWEnschedethe Netherlands Faculty of engineering and Architecture Ghent UniversitEast Flanders 9000GhenBelgium

Tactile perception and friction can be modified by producing a deterministic surface *** of surface feature arrangement and texture symmetry can produce an anisotropic frictional *** is generally achieved through skin hysteresis by promoting its *** work investigates whether a bidirectional friction can be created with microscale ellipsoidal asperity textures,thus relying on the adhesive component of *** this purpose,four textured samples with various asperity dimensions were moulded with a silicone rubber having an elastic modulus comparable to that of the *** of friction measurements were conducted in-vivo in two sliding directions with a range of normal loads up to 4 *** element method(FeM)was used to study elastic deformation effects,explain the observed friction difference,and predict surface material *** performed perpendicular to the asperity major radii showed consistently higher friction coefficients than that during parallel *** the larger asperity dimensions,a change of the sliding direction increased friction up to a factor of *** numerical analysis showed that this effect is mostly related to elastic asperity *** friction differences can be further controlled by asperity dimensions,spacing,and material properties.

关键词： surface texture sliding direction skin friction elastomer

Numerical study of viscosity and heat flux role in heavy species dynamics in Hall thruster discharge

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Plasma Science and Technology 2023年第1期25卷 165-180页

作者： Andrey SHASHKOV Alexander LOVTSOV Dmitri TOMILIN dmitrii KRAVCHeNKO JSC'Keldysh Research Center' 8 Onezhskaya st.Moscow 125438Russia

A two-and three-dimensional velocity space axisymmetric hybrid-PIC model of Hall thruster discharge called Hybrid2D has been *** particle-in-cell(PIC) method was used for neutrals and ions(heavy species),and fluid dynamics on a magnetic field-aligned(MFA) mesh was used for electrons.A time-saving method for heavy species moment interpolation on a MFA mesh was *** method comprises using regular rectangle and irregular triangle meshes,connected to each other on a pre-processing *** electron fluid model takes into account neither inertia terms nor viscous terms and includes an electron temperature equation with a heat flux *** developed model was used to calculate all heavy species moments up to the third one in a stationary *** analysis of the viscosity and the heat flux impact on the force and energy balance has shown that for the calculated geometry of the Hall thruster,the viscosity and the heat flux terms have the same magnitude as the other terms and could not be ***,it was shown that the heat flux is not proportional to the temperature gradient and,consequently,the highest moments should be calculated to close the neutral fluid equation *** the same time,ions can only be modeled as a cold non-viscous fluid when the sole aim of modeling is the calculation of the operating parameters or distribution of the local parameters along the centerline of the discharge *** is because the magnitude of the viscosity and the temperature gradient terms are negligible at the ***,when a simulation’s focus is either on the radial divergence of the plume or on magnetic pole erosion,three components of the ion temperature should be taken into *** non-diagonal terms of ion pressure tensor have a lower impact than the diagonal *** to the study,a zero heat flux condition could be used to close the ion equation system in calculated geometry.

关键词： Hall thruster hybrid-PIC model moments of distribution function magnetic-field-aligned mesh

Morphology of crater and caldera lakes in the Far eastern region of Russia and the features of their development

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Journal of Mountain Science 2024年第4期21卷 1246-1258页

作者： dmitrii N.KOZLOV ekaterina V.LeBeDeVA Institute of Marine Geology and Geophysics Far Eastern Branch of the Russian Academy of SciencesYuzhno-Sakhalinsk 693022Russia Institute of Geography Russian Academy of SciencesMoscow 119017Russia

Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data *** authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric *** has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal *** lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric *** was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their *** volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous *** the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were *** observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 *** analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their *** results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying

关键词： Volcanic lakes echolocation survey Volcanism Gashydrotherms Kamchatka Kuril Islands

Machine learning-based method to adjust electron anomalous conductivity profile to experimentally measured operating parameters of Hall thruster

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Plasma Science and Technology 2022年第6期24卷 148-156页

作者： Andrey SHASHKOV Mikhail TYUSHeV Alexander LOVTSOV Dmitry TOMILIN dmitrii KRAVCHeNKO JSC'Keldysh Research Center' 8 Onezhskaya St.Moscow 125438Russia

The problem of determining the electron anomalous conductivity profile in a Hall thruster,when its operating parameters are known from the experiment,is *** solve the problem,we propose varying the parametrically set anomalous conductivity profile until the calculated operating parameters match the experimentally measured ones in the best *** axial 1D3V hybrid model was used to calculate the operating parameters with parametrically set *** of the conductivity profile was performed using Bayesian optimization with a Gaussian process(machine learning method),which can resolve all local minima,even for noisy *** calculated solution corresponding to the measured operating parameters of a Hall thruster in the best way proved to be unique for the studied operating modes of *** local plasma parameters were calculated and compared to the measured ones for four different operating *** results show the qualitative *** agreement between calculated and measured local parameters can be improved with a more accurate model of plasma-wall interaction.

关键词： Hall thruster anomalous conductivity machine learning Bayesian optimization Gaussian process electric propulsion

Algorithm for solving problems related to the natural vibrations of electro-viscoelastic structures with shunt circuits using ANSYS data

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International Journal of Smart and Nano Materials 2019年第2期10卷 156-176页

作者： Nataliia Iurlova Natalia Sevodina dmitrii Oshmarin Maksim Iurlov Institute of Continuous Media Mechanics of the Ural Branch of RAS PermRussian Federation

An algorithm for numerical realisation of a mathematical statement of the natural vibrations problem for electro-viscoelastic bodies with passive external electric circuits(*** circuits)with an arbitrary configuration using the finite element method is proposed in the present *** proposed algorithm allows considering the viscoelastic properties of materials using the model of linear hereditary viscoelasticity with complex dynamic moduli and is used to solve 3D solid structure problems that are compatible for ANSYS package element *** technique implies the usage of the global assembled matrices of stiffness and mass,formed in the ANSYS *** basis of the algorithm is a novel approach that allows performing decomposition of the global assembled stiffness matrix formed in the ANSYS software package into constituents that are needed for calculation of the natural vibration frequencies of the objects under *** matrix components are used in the program that was written in FORTRAN(Formula Translation)*** problem could be efficiently applied for analysis of the dynamic processes in smart systems based on piezoelectric materials and could also form a basis for the development of numerical finite element algorithms for optimization of the dissipative characteristics of electromechanical systems with shunted piezoelectric elements.

关键词： Numerical simulation finite element method electroviscoelasticity piezoelement external electric circuit natural vibrations

Algorithm for the layout of a piezoelectric element in an elastic medium providing the maximal piezoelectric effect within a specified frequency range

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International Journal of Smart and Nano Materials 2019年第4期10卷 268-284页

作者： dmitrii Oshmarin Nataliia Iurlova Natalia Sevodina Maksim Iurlov Department of complex problems of deformable solids mechanics Institute of Continuous Media Mechanics of the Ural Branch of RASPermRussian Federation

An algorithm for the layout of a piezoelectric that provides the most efficient performance within a specified range of vibration frequencies is proposed in this *** algorithm is based on the consideration of a special parameter within the area of a piezoelectric element’s possible *** parameter characterizes the superposition of electromechanical coupling coefficients’for all the natural vibration frequencies included in a specified frequency *** condition for defining the best option for location of the piezoelectric element in the case of several equivalent positions is *** efficiency of the proposed algorithm is shown *** electromechanical coupling coefficients were calculated numerically based on solution to the problem of natural vibrations for electroelastic bodies using a finite element *** calculations were performed to define the best location for a single piezoelectric element at the surface of a thin-walled shell having a half-cylindrical *** results are presented for natural vibration frequencies within the frequency range from 0 up to 1100 *** numerical results were obtained by solving the problem of natural vibrations with a finite element method using the ANSYS software package.

关键词： Piezoelectric element’s layout natural vibrations continuous frequency range electromechanical coupling coefficient