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A NUMERICAL METHOD FOR THE SIMULATION OF FREE SURFACE FLOWS OF vISCOPLASTIC FLUID IN 3D

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Journal of Computational Mathematics 2011年第6期29卷 605-622页

作者： Kirill D. Nikitin Maxim A. Olshanskii Kirill M. Terekhov yuri v. vassilevski Institute of Numerical Mathematics Russian Academy of Sciences Moscow Russia Department of Mechanics and Mathematics Moscow State University Moscow Russia

In this paper we study a numerical method for the simulation of free surface flows of viscoplastic （Herschel-Bulkley） fluids. The approach is based on the level set method for capturing the free surface evolution and on locally refined and dynamically adapted octree cartesian staggered grids for the discretization of fluid and level set equations. A regu- larized model is applied to handle the non-differentiability of the constitutive relations. We consider an extension of the stable approximation of the Newtonian flow equations on staggered grid to approximate the viscoplastic model and level-set equations if the free boundary evolves and the mesh is dynamically refined or coarsened. The numerical method is first validated for a Newtonian case. In this case, the convergence of numerical solutions is observed towards experimental data when the mesh is refined. Further we compute several 3D viscoplastic Herschel-Bulkley fluid flows over incline planes for the dam-break problem. The qualitative comparison of numerical solutions is done versus experimental investigations. Another numerical example is given by computing the freely oscillating viscoplastic droplet, where the motion of fluid is driven by the surface tension forces. Altogether the considered techniques and algorithms （the level-set method, compact discretizations on dynamically adapted octree cartesian grids, regularization, and the surface tension forces approximation） result in efficient approach to modeling viscoplastic free-surface flows in possibly complex 3D geometries.

关键词： Free surface flows viscoplastic fluid Adaptive mesh refinement Oetree meshes.

Development of Zeff diagnostic system on the Globus-M（M2） tokamak and the first experimental results

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Plasma Science and Technology 2019年第10期21卷 33-39页

作者： E A TUKHMENEvA S Yu TOLSTYAKOv G S KURSKIEv v K GUSEv v B MINAEv Yu v petrov N v SAKHAROv A Yu TELNOvA N N BAKHAREv P B SHEGOLEv E O KISELEv Ioffe Institute

Studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the ASTRA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.

关键词： tokamak effective ion charge magnetic confinement

Hot spots of DNA double-strand breaks and genomic contacts of human rDNA units are involved in epigenetic regulation

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Journal of Molecular Cell Biology 2015年第4期7卷 366-382页

作者： Nickolai A.Tchurikov Daria M.Fedoseeva Dmitri v.Sosin Anastasia v.Snezhkina Nataliya v.Melnikova Anna v.Kudryavtseva yuri v.Kravatsky Olga v.Kretova Department of Epigenetic Mechanisms of Gene Expression Regulation Engelhardt Institute of Molecular BiologyMoscow 119334Russia Group of Postgenomic Studies Engelhardt Institute of Molecular BiologyMoscow 119334Russia Laboratory of DNA-Protein Interactions Engelhardt Institute of Molecular BiologyMoscow 119334Russia

DNA double-strand breaks(DSBs)are involved in many cellular mechanisms,including replication,transcription,and genome *** recent observation that hot spots of DSBs in human chromosomes delimit DNA domains that possess coordinately expressed genes suggests a strong relationship between the organization of transcription patterns and hot spots of *** this study,we performed mapping of hot spots of DSBs in a human 43-kb ribosomal DNA(rDNA)repeated *** observed that rDNA units corresponded to the most fragile sites in human chromosomes and that these units possessed at least nine specific regions containing clusters of extremely frequently occurring DSBs,which were located exclusively in non-coding intergenic spacer(IGS)*** hot spots of DSBs corresponded to only a specific subset of DNase-hypersensitive sites,and coincided with CTCF,PARP1,and HNRNPA2B1 binding sites,and H3K4me3 *** rDNA-4C data indicate that the regions of IGS containing the hot spots of DSBs often form contacts with specific regions in different chromosomes,including the pericentromeric regions,as well as regions that are characterized by H3K27ac and H3K4me3 marks,CTCF binding sites,ChIA-PET and RIP signals,and high levels of *** data suggest a strong link between chromosome breakage and several different mechanisms of epigenetic regulation of gene expression.

关键词： double-strand breaks fragile sites rDNA IGS PARP1 HNRNPA2B1 4C

Tunable chemical complexity to control atomic diffusion in alloys

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npj Computational Materials 2020年第1期6卷 1360-1367页

作者： yuri Osetsky Alexander v.Barashev Laurent K.Béland Zhongwen Yao Keyvan Ferasat Yanwen Zhang Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Department of Nuclear Engineering and Radiological Sciences University of MichiganAnn ArborMI 48109USA Department of Mechanical and Materials Engineering Queen’s UniversityKingstonON K7L 3N6Canada Department of Materials Science and Engineering University of TennesseeKnoxvilleTN 37996USA

In this paper we report a new fundamental understanding of chemically-biased diffusion in Ni–Fe random alloys that is tuned/controlled by the intrinsic quantifiable chemical *** of radiation-tolerant alloys has been a long-standing *** we show how intrinsic chemical complexity can be utilized to guide the atomic diffusion and suppress radiation *** influence of chemical complexity is shown by the example of interstitial atom(IA)diffusion that is the most important defect in radiation *** useμs-scale molecular dynamics to reveal sluggish diffusion and percolation of IAs in concentrated Ni–Fe *** develop a mean field diffusion model to take into account the effect of migrating defect energy properties on diffusion percolation,which is verified by a new kinetic Monte Carlo approach addressing detailed *** demonstrate that the local variations in the ground state energy of IA configurations in alloys,reflecting the chemical difference between alloying components,drives the percolation effects for atomic ***,chemically-biased and sluggish diffusion are phenomena that are directly related to the chemical complexity intrinsically to multicomponent alloys.

关键词： alloys alloying diffusion

How the adoption of industry 4.0 technologies is related to participation in global and domestic value chains: Evidence from Russia

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International Journal of Innovation Studies 2024年第2期8卷 93-108页

作者： Anna A.Fedyunina Nikolay A.Gorodnyi yuri v.Simachev Centre for Industrial Policy Studies National Research University Higher School of EconomicMoscow11Pokrovsky BoulevardZip Code:101000Russia

This study explores the relationships among Industry 4.0 technologies, their application areas,and the involvement of Russian manufacturing firms in global and domestic value chains. Weapply logit and multinomial logit regressions using an original survey dataset of approximately1700 Russian manufacturing firms. We make a novel contribution to the literature by uncoveringan asymmetry in adopting Industry 4.0 technologies among Russian industrial firms in domesticvalue chains (DvCs) and global value chains (GvCs). This asymmetry has the potential to impedeGvC localization and DvC internationalization. Based on our results, software automation solu-tions are the only ones demonstrating statistical significance for firms participating simulta-neously in GvCs, DvCs, and both GvCs and DvCs. Companies in DvCs demonstrate a broaderutilization of Industry 4.0 technologies across various application areas. We also identify evidenceof reshoring in DvCs, indicating that Industry 4.0 adoption encourages firms to establish enduringrelationships with domestic suppliers. Highlighting that differences in technology adoption areinfluenced by external factors, including adherence to international standards and regulatoryprinciples, we propose policy implications for developing countries. Recommendations encom-pass reducing entry barriers to DvCs, improving procurement transparency, and promotingcompetition in the digital solutions market to empower firms for seamless GvC integration.

关键词： Industry 4.0 Global value chains Domestic value chains Forward linkages Backward linkages

S. v. Kovalevskaya system, its generalization and discretization

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Frontiers of Mathematics in China 2013年第5期8卷 1047-1065页

作者： Matteo PETRERA yuri B. SURIS Institut fiir Mathematik MA 7-2 Technische Universitat Berlin Str. des 17. Juni 13610623 Berlin Germany

We consider an integrable three-dimensional system of ordinary differential equations introduced by S. v. Kovalevskaya in a letter to G. Mittag- Leffler. We prove its isomorphism with the three-dimensional Euler top, and propose two integrable discretizations for it. Then we present an integrable generalization of the Kovalevskaya system, and study the problem of integrable discretization for this generalized system.

关键词： Birational map integrable map algebraically integrable system

SnO_(2)-ZnO nanocomposite thin films:The influence of structure,composition and crystallinity on optical and electrophysical properties

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Journal of Advanced Dielectrics 2021年第5期11卷 25-32页

作者： E.M.Bayan v.v.petrov M.G.volkova v.Yu Storozhenko A.v.Chernyshev Faculty of Chemistry Southern Federal University Rostov-on-DonRussia Institute of Nanotechnologies Electronicsand Equipment Engineering Southern Federal UniversityTaganrogRussia Research Institute of Physical and Organic Chemistr Southern Federal University Rostov-on-DonRussia

SnO_(2)-ZnO thin films consisting of nanoscale crystallites were obtained on glass and silicon substrates by solid-phase low-temperature *** synthesized materials were studied by XRD and SEM methods,electrophysical and optical properties were evaluated,as well as the band gap was *** was shown that regardless of the phase composition all films were optically transparent in the visible range(310-1000 nm).The nanocrystallites’minimum size,the highest activation energy of the conductivity and the smallest band gap calculated for indirect transitions were shown for a thin film 50SnO_(2)-*** was assumed that the band gap decreasing might be attributed to the existence of surface electric fields with a strength higher than 4×10^(5)v/cm.

关键词： Zinc tin oxide crystal structure optical property thin films semiconductors nanocomposite

v2551 Cyg:a pulsating star with enigmatic peculiarities

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Research in Astronomy and Astrophysics 2017年第7期17卷 57-66页

作者： Diana P.Kjurkchieva velimir A.Popov Dragomir v.Marchev Kenneth T.Menzies Nikola I.petrov Department of Physics Shumen University IRIDA Observatory Rozhen NAO Tigh Speuran Observatory Institute of Astronomy and NAO Bulgarian Academy of Sciences

Intensive photometric and spectral observations of the variable star v2551 Cyg are *** light curve shape reveals that the target is a pulsating star, contrary to its previous classification as an eclipsing binary. The period and amplitude of the light curve, the amplitudes of color changes and the radial velocity curve of v2551 Cyg are similar to those of a high-amplitude δ Scuti variable. The target seems to pulsate with the fundamental mode. However, v2551 Cyg exhibits several important peculiarities：（i） the decreasing branch of its light curve is steeper than the increasing one;（ii） the radial velocity curve has a flat section in the phase range 0.7-1.2 and short increase of the negative radial velocity at phase 0.7;（iii） the rotational velocity is quite big for a HADS star;（iv） the Fourier coefficients of v2551 Cyg are quite different from those of HADS stars. The target classification is difficult due to these peculiarities.

关键词： stars variables delta Scuti - stars variables RR Lyrae - stars individual (v2551 Cyg)

Influence of the safety factor profile on the particle and heat transport in the Globus-M spherical tokamak

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Plasma Science and Technology 2019年第11期21卷 1-6页

作者： A YU TELNOvA G S KURSKIEv E O KISELEv N N BAKHAREv v K GUSEv N A KHROMOv S YU MEDvEDEv v B MIINAEv I v MIROSHNIKOv M I PATROv Yu v petrov N v SAKHAROv A D SLADKOMEDOvA P B SHCHEGOLEv v v SOLOKHA v A TOKAREv S YU TOLSTYAKOv E A TUKHMENEvA Ioffe Institute Saint-Petersburg 194021Russia Keldysh Institute Russian Academy of SciencesMoscow 125047Russia NRC'Kurchatov Institute’ Moscow 123098Russia

The advanced tokamak scenario is a promising operation scenario for ITER and fusion neutron *** this scenario the minimum value of the safety factor in the center of the plasma exceeds *** the compact spherical tokamak Globus-M,the formation of such conditions is possible with neutral beam injection at the current ramp-up *** to the slower diffusion of current inside the plasma,a zone is formed with reduced heat and particle transport across the magnetic field,which affects the temperature and density profiles of the *** leads to the peaked density profile formation and improvement of the energy confinement *** achieve a high fraction of the bootstrap current,it is necessary to increase the plasma *** the same time,the maximum allowable pressure is limited to the normalized beta limit.

关键词： advanced tokamak mode transport analysis internal transport barriers