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Dynamic magnetic hysteresis in a liquid suspension of acicular maghemite particles

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Particuology 2009年第6期7卷 451-458页

作者： Bronislav E.Kashevsky sergey B.Kashevsky Igor V.Prokhorov A.V.Luikov Heat and Mass Transfer Institute Belarus Academy of SciencesP.Brovka str.15Minsk 220072Belarus

This paper presents theoretical and experimental studies on the magnetodynamics and energy absorption in a dilute suspension of small ferromagnetic particles with magnetic hysteresis and mechanical mobility in an AC magnetic field. Experiments with 0.1% suspensions of acicular particles of gamma ferric oxide in solid and liquid matrices, subjected to a 430 Hz magnetic field with an intensity of up to 1200 Oe, revealed important role of particle mobility. The main qualitative and quantitative features of the phenomenon are in agreement with a model of joint magneto-mechanical dynamics of particles with a chain-of-spheres mode of incoherent magnetic reversal.

关键词： High-coercive magnetic particles Magnetic suspensions Dynamic magnetic hysteresis

Assessing suspended sediment fluxes with acoustic Doppler current profilers:case study from large rivers in Russia

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Big Earth Data 2022年第4期6卷 504-526页

作者： sergey Chalov Vsevolod Moreido Victor Ivanov Aleksandra Chalova Faculty of Geography Lomonosov Moscow State UniversityMoscowRussia Institute of Physics Kazan Federal UniversityKazanRussia Flood Hydrology Lab Water Problems Institute of Russian Academy of SciencesMoscowRussia

Surrogate measures are becoming increasingly used to measure suspended sediment flux,but only few particular computer techniques of data processing are recently *** study demonstrates capabilities of acoustic Doppler current profilers(ADCPs)to infer information regarding suspended-sand concentrations in river systems and calculate suspended sediment flux via big data analytics which includes process of analyzing and data mining of measurements based on ADCP signal backscatter intensity *** present here specific codes done by R language using RStudio software with open-source tidyverse and plotly packages aimed to generate tables containing data of suspended load for cells,verticals and whole cross-section based on backscattering values from 600 kH Teledyne RDInstruments RioGrande WorkHorse ADCP unit,as well perform estimates of morphometric,suspended sediment concentration(SSC)and velocity characteristics of the *** developed tools enabled to process large data array consisting of over 56,526,480 geo-referenced values of river depth,streamflow velocity,and backscatter intensity for each river cross-section measured at six case study sites in Russia.

关键词： Big data ADCP backscatter intensity sediment transport

Domain wall-localized phonons in BiFeO_(3):spectrum and selection rules

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npj Computational Materials 2020年第1期6卷 1255-1260页

作者： Peng Chen Louis Ponet Keji Lai Roberto Cingolani sergey Artyukhin Quantum Materials Theory Istituto Italiano di Tecnologia16163 GenovaItaly Scuola Normale Superiore di Pisa 56126 PisaItaly Department of Physics University of Texas at AustinAustinTX 78712USA

Ferroelectric domain walls(DWs)are nanoscale topological defects that can be easily tailored to create nanoscale *** excitations,recently discovered to be responsible for GHz DW conductivity,hold promise for faster signal transmission and processing compared to the existing *** we find that DW phonons have unprecedented dispersion going from GHz all the way to THz frequencies,and resulting in a surprisingly broad GHz signature in DW *** activation of nominally forbidden DW sliding modes in BiFeO_(3) is traced back to DW tilting and resulting asymmetry in wall-localized *** obtained phonon spectra and selection rules are used to simulate scanning impedance microscopy,emerging as a powerful probe in *** results will guide the experimental discovery of the predicted phonon branches and design of DWbased nanodevices operating in the technologically important frequency range.

关键词： phonon walls faster

Solvent induced enhancement of nonlinear optical response of graphdiyne

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Chinese Chemical Letters 2021年第1期32卷 525-528页

作者： Yuze Dong sergey Semin Yaqing Feng Jialiang Xu Theo Rasing School of Chemical Engineering and Technology Tianjin UniversityTianjin 300350China Radboud University Institute for Molecules and Materials(IMM)Heyendaalseweg 1356525AJNijmegenthe Netherlands School of Materials Science and Engineering Nankai UniversityTianjin 300350China Collaborative Innovation Center of Chemical Science and Engineering(Tianjin) Tianjin UniversityTianjin 300072China

Flat and crystalline materials with exceptional nonlinear optical(NLO) properties are highly desirable for their potential applications in integrated NLO photonic ***(GD),a new twodimensional(2 D) carbon allotrope,has recently evoked burgeoning research attention by virtue of its tunable bandgap along with a high carrier mobility and extended π-conjugation compared with most conventional optical ***,we experimentally probe the third-order nonlinear optical response of GD dispersed in several common solvents(alcohols) using a femtosecond Z-scan *** measured nonlinear optical refractive index is in the order of ~10^(-8) cm^(2)/W,which is approximately one order of magnitude higher than that of most 2 D *** particular,we find that different NLO responses can be observed from GD when dispersed in different solvents,with the strongest NLO response when dispersed in *** is proposed that some intrinsic properties of the solvents,such as the polarity and viscosity,could influence the NLO response of GD *** experimental results confirm the assumptions on the NLO behavior in GD and demonstrate its great potential for future generations of Kerr-effect-based NLO materials and devices.

关键词： 2D materials Graphdiyne Nonlinear optics Kerr-effect Solvent effect

Modern problems of aircraft aerodynamics

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Advances in Aerodynamics 2019年第1期1卷 145-159页

作者： sergey L.Chernyshev sergey V.Lyapunov Andrey V.Wolkov Department of Aerodynamics Central Aerohydrodynamic Institute named after Prof.N.EZhukovsky(TsAGI)140180Zhukovsky str.1ZhukovskyRussia

The article represents the discussion of several separate directions of investigations,which are performed by TsAGI flight vehicles aerodynamics specialists at the *** are some major trends of classical layout of route aircraft and also peculiarities of some prospective flight *** there are some hypersonic vehicles aerodynamics questions examined along with problems of creation of civil supersonic transport *** is a description given for well-known and some newer methods of flow control for drag reduction.

关键词： Aircraft aerodynamics Hypersonic vehicles aerodynamics Civil supersonic transport aircraft Sonic boom

Undersea Buried Pipeline Reconstruction Based on the Level Set and Inverse Multiquadric Regularization Method

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Journal of Ocean University of China 2022年第1期21卷 101-112页

作者： SHANG Wenjing XUE Wei XU Yidong MAKAROV sergey B LI Yingsong College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China Key Laboratory of Advanced Marine Communication and Information Technology Ministry of Industry and Information TechnologyHarbin 150001China Yantai Research Institute and Graduate School of Harbin Engineering University Yantai 264006China Institute of Physics Nanotechnology and TelecommunicationsHigher School of Applied Physics and Space TechnologiesPeter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251Russia

The electric inversion technique reconstructs the subsurface medium distribution from acquired *** the basis of electric inversion,objects buried under the earth or seabed,such as pipelines and unexploded ordnance,are detected and located in a contactless ***,the process of accurately reconstructing the shape of the target object is challenging because electric inversion is a nonlinear and ill-posed *** this work,we present an inverse multiquadric(IMQ)regularization method based on the level set function for reconstructing buried *** the case of locating underwater objects,the unknown inversion area is split into two parts,the background and the pipeline with known *** geometry of the pipeline is represented based on the level set function for achieving a noiseless inversion *** obtain a binary image,the IMQ is used as the regularization term,which‘pushes’the level set function away from *** also provide an appropriate method to select the bandwidth and regularization parameters for the IMQ regularization term,resulting in reconstructed images with sharp *** simulation results and analysis show that the proposed method performs better than classical inversion methods.

关键词： inverse problems level set function inverse multiquadric regularization method buried pipeline

Complementary and alternative medicine in European countries legislative framework

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Traditional Medicine Research 2020年第3期5卷 125-135页

作者： Jovana Milenkovic sergey Bolevich Gvozden Rosic Department of Dentistry Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia Department of Human Pathology I.M.Sechenov First Moscow State Medical University(Sechenov University)Moscow 119991Russia Department of Physiology Faculty of Medical SciencesUniversity of KragujevacKragujevac 34000Serbia

Complementary and alternative medicine(CAM)is a set of different diagnostic and therapeutic procedures,as well as the use of natural products for the treatment of patients,derived from previously known traditional methods and enriched with modern scientific *** present article reviews the available data regarding the use of CAM and the legislation behind it in European *** use of CAM is recorded in Europe as a whole and varies between 1070%of the population of individual European *** least 300,000 registered CAM providers have been identified in the European Union(EU),of which slightly more than half includes non-medical *** most practiced discipline is acupuncture,followed by *** regulation and legislation in Europe is not precisely defined and is constantly striving to find a common *** legal frameworks for CAM are not defined,each European country has its own regulations and *** order to define universal legislation for CAM,the EU created the CAMbrella project,a project of the EU designed to find a unique system that would include the treatment of CAM in *** to the data from CAMbrella,from 39 countries in the EU,17 have general CAM *** status of CAM in Europe is characterized by enormous heterogeneity in all aspects,including terminology,methods,prevalence and ultimately,legal status,regulations and legislation.

关键词： Complementary and alternative medicine European countries Methods of therapy Legal status Regulation Legislation

Measuring Internal Velocity of Debris Flows by Temporally Correlated Shear Forces

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Journal of Earth Science 2012年第3期23卷 373-380页

作者：韦方强杨红娟胡凯衡 sergey Chernomorets Key Laboratory of Mountain Hazards and Earth Surface Process Chinese Academy of Sciences Institute of Mountain Hazards and Environment Chinese Academy of Sciences Faculty of Geography Moscow State UniversityMoscowRussia

Debris flow is a kind of geological hazard occurring in mountain *** velocity is very important for debris flow dynamics research and designing debris flow control ***,most of past researches focused on surface velocity and mean velocity of debris flow,while few researches involve its internal velocity because there is no available method for measuring the internal velocity for its destructive *** this paper,a method of temporally correlated shear forces（TCSF） for meas-uring the internal velocity of debris flows is *** principle of this method is to calculate the internal velocity of a debris flow using the distance between two detecting sections and the time differ-ence between the two waveforms of shear forces measured at both *** measuring method has been tested in 14 lab-based flume experiments.

关键词： debris flow internal velocity velocity measuring shear force flume experiment

Particles-induced turbulence: A critical review of physical concepts,numerical modelings and experimental investigations

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Theoretical & Applied Mechanics Letters 2020年第4期10卷 241-248页

作者： Guodong Gai Abdellah Hadjadj sergey Kudriakov Olivier Thomine DEN-DM2S-STMF CEAUniversitéParis-SaclayFrance University of Normandy INSACORIA UMR-6614 CNRS76000 RouenFrance

The presence of solid particles or water droplets in continuous fluid flow can either induce turbulence attenuation or amplification. The modification of the state of the turbulence depends on the characteristics of the particles, such as volume fraction, mean diameter, mass density, or carrier phase flow properties. In this brief review, the main physical concepts related to the most important physical aspects of turbulence modulation are summarized. Different criteria used to distinguish the enhancement or the attenuation effects of the particles on the carrier phase flows are recalled. For the interest of large-scale industrial applications, several theoretical,experimental and empirical approaches are discussed, which provides an interesting framework for the study of the effect of particles on turbulence behavior modification.

关键词： Particle-induced turbulence Turbulence modulation Physical and numerical modeling