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Charge disproportionation and site-selective local magnetic moments in the post-perovskite-type Fe_(2)O_(3) under ultra-high pressures

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npj Computational Materials 2019年第1期5卷 345-351页

作者： ivan Leonov Gregory Kh.Rozenberg Igor A.Abrikosov M.N.Miheev Institute of Metal Physics Russian Academy of Sciences620137 YekaterinburgRussia Materials Modeling and Development Laboratory National University of Science and Technology‘MISIS’119049 MoscowRussia School of Physics and Astronomy Tel Aviv University69978 Tel AvivIsrael Department of Physics Chemistry and Biology(IFM)Linköping UniversitySE-58183 LinköpingSweden

The archetypal 3d Mott insulator hematite,Fe_(2)O_(3),is one of the basic oxide components playing an important role in mineralogy of Earth’s lower *** high pressure-temperature behavior,such as the electronic properties,equation of state,and phase stability is of fundamental importance for understanding the properties and evolution of the Earth’s ***,we study the electronic structure,magnetic state,and lattice stability of Fe_(2)O_(3)at ultra-high pressures using the density functional plus dynamical mean-field theory(DFT+DMFT)*** the vicinity of a Mott transition,Fe_(2)O_(3) is found to exhibit a series of complex electronic,magnetic,and structural *** particular,it makes a phase transition to a metal with a post-perovskite crystal structure and site-selective local moments upon compression above 75 *** show that the site-selective phase transition is accompanied by a charge disproportionation of Fe ions,with Fe^(3±δ)and δ~0.05–0.09,implying a complex interplay between electronic correlations and the *** results suggest that site-selective local moments in Fe_(2)O_(3) persist up to ultra-high pressures of~200–250 GPa,i.e.,sufficiently above the core-mantle *** latter can have important consequences for understanding of the velocity and density anomalies in the Earth’s lower mantle.

关键词： magnetic local high

One-Generated Nilpotent Bicommutative Algebras

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Algebra Colloquium 2022年第3期29卷 453-474页

作者： ivan Kaygorodov Pilar Páez-Guillán Vasily Voronin Centro de Matemática e Aplicacōes Universidade da Beira InteriorCovilhãPortugal Institute of Mathematics and Mathematical ModelingAlmatyKazakhstan University of Santiago de Compostela Santiago de CompostelaSpain University of ViennaViennaAustria Novosibirsk State University NovosibirskRussia

We give a classification of 5-and 6-dimensional complex one-generated nilpotent bicommutative algebras.

关键词： bicommutative algebras nilpotent algebras algebraic classification central extension

Single-photon avalanche diode imagers in biophotonics:review and outlook

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Light(Science & Applications) 2019年第1期8卷 409-436页

作者： Claudio Bruschini Harald Homulle ivan Michel Antolovic Samuel Burri Edoardo Charbon AQUA EPFLNeuchatelSwitzerland AQUA TU DelftDelftThe Netherlands

Single-photon avalanche diode(SPAD)arrays are solid-state detectors that offer imaging capabilities at the level of individual photons,with unparalleled photon counting and time-resolved *** fascinating technology has progressed at a very fast pace in the past 15 years,since its inception in standard CMOS technology in 2003.A host of architectures have been investigated,ranging from simpler implementations,based solely on off-chip data processing,to progressively“smarter”sensors including on-chip,or even pixel level,time-stamping and processing *** the technology has matured,a range of biophotonics applications have been explored,including(endoscopic)FLIM,(multibeam multiphoton)FLIM-FRET,SPIM-FCS,super-resolution microscopy,time-resolved Raman spectroscopy,NIROT and *** will review some representative sensors and their corresponding applications,including the most relevant challenges faced by chip designers and ***,we will provide an outlook on the future of this fascinating technology.

关键词： image photon simpler

Fluoride solid electrolytes containing rare earth elements

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Journal of Rare Earths 2008年第2期26卷 225-232页

作者： Viera Trnovcová Pavel P. Fedorov ivan Furár1 Department of Physics Faculty of Materials Science and Technology Slovak University of Technology SK-91724 Trnava Slovakia Institute of General Physics Russian Academy of Sciences Moscow Russia

Relations between the structure, ionic conductivity and dielectric properties of fluoride systems of different structures containing rare earth elements were presented. Superionic conductivities, by fluoride ions, of fluorite-structured （MF2-REF3, M=Ba, Pb, RE=La-Lu, Sc, Y）, orthorhombic （REF3, RE=Tb-Er, Y）, tysonite-structured （REF3-MF2, RE=La-Nd, M=Sr）, monoclinic （BaRE2Fs, RE=Ho-Yb, Y） fluoride single crystals and eutectic composites （LiF-REF3, RE=La-Gd, Y） were compared. Anisotropy of electrical properties of crystals with a lower symmetry was explained by modeling optimum ionic paths. For explanation of concentration dependences of fast ionic conductivity, models of aggregation of defects into clusters were proposed. In fluorite-structured crystals, the highest ionic conductivity was found for PbF2：7 mol% ScF3 （at 500 K, σ500=0.13 S/cm）. In tysonite-structured crystals, the highest ionic conductivity was found for LaF3：3 mol% SrF2 （σ500=2.4×10^-2 S/cm）. Different types of coordination polyhedrons and their different linking in orthorhombic and tysonite structure explained large differences between conductivities in both structures. Eutectic systems, prepared as directionally solidified composites, enabled to study some orthorhombic fluoride phases （GdF3, SmF3）, which cannot be prepared as single crystals. An influence of the orthorhombic-tysonite phase transition on the ionic conductivity was shown.

关键词： rare earth containing fluorides superionic conductivity defects conduction mechanisms clustering single crystals composites

Visualization of Large Amount of Spectra in Virtual Observatory Environment

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International Journal of Automation and computing 2014年第6期11卷 613-620页

作者： Petr aloun David Andrei Petr koda ivan Zelinka Department of Computer Science Faculty of Electrical Engineering and Computer Science VB-Technical University of Ostrava17.listopadu 15 708 33 Ostrava-Poruba Czech Republic Astronomical Institute of the Academy of Sciences Fricova 298 251 65 Ondrejov Czech Republic

This paper presents overview of new features so far prepared for new version of spectral analysis tool SPLAT-VO that allows to retrieve a large amount of spectra(and other data) based on its characteristics by detailed querying a virtual observatory s resources. The overview is focused on enhancements of user experience, work with simple application messaging protocol(SAMP) and other interoperability that improves work with global list of spectra, plot window and analysis menu.

关键词： SPLAT-VO virtual observatory spectra simple application message protocol (SAMP) flexible image transport system (FITS)

The role of isotropic and anisotropic Hubbard corrections for the magnetic ordering and absolute band alignment of hematite α-Fe2O3(0001)surfaces

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Progress in Natural Science:Materials International 2019年第3期29卷 349-355页

作者： Sateesh Bandaru ivan Scivetti Chi-Yung Yam Gilberto Teobaldi School of Chemical and Bioprocess Engineering University College Dublin Beijing Computational Science Research Center Stephenson Institute for Renewable Energy Department of ChemistryThe University of Liverpool Scientific Computing Department Science and Technology Facilities CouncilDaresbury Laboratory

An isotropic (+U) and anisotropic [+(U-J)] corrected Density Functional Theory study for bulk hematite (α-Fe2O3) was carried out,and several competing terminations of its (0001) surface modeled via slabs of increasing thickness from twelve to thirty-six *** spite of small quantitative differences,the use of either U or (U-J)corrections showed not to qualitatively affect the results of the simulations both for bulkα-Fe2O3and the lowestenergyα-Fe2O3(0001) surface studied,regardless of the thickness of the slab *** energy favored antiferromagnetic ordering of bulkα-Fe2O3was preserved in the relaxed slabs,with the largest surface-induced effects limited to the outermost three Fe-layers in the *** O-and Fe-terminations were found to be energetically favored and ***,fully O-or Fe-terminated surfaces were calculated to be energetically disfavored and ***,the role of Fe-or O-termination for the semiconducting or metallic nature as well as absolute band alignment ofα-Fe2O3(0001) surfaces was analyzed and discussed with respect to the challenges in enhancing the activity ofα-Fe2O3samples as photo-electrode for water splitting.

关键词： Hematite α-Fe2O3 Surfaces Photo-electrodes Density functional theory Electronic properties Magnetic properties

Products of Commutator Ideals of Some Lie-admissible Algebras

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1875-1892页

作者： ivan KAYGORODOV Farukh MASHUROV Tran Giang NAM Ze Rui ZHANG CMA-UBI Universidade da Beira InteriorCovilhaPortugal Shenzhen International Center for Mathematics(SICM) Southern University of Science and TechnologyShenzhen 518055P.R.China Institute of Mathematics VAST18 Hoang Quoc VietCau GiayHanoiVietnam School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this article,we mainly study the products of commutator ideals of Lie-admissible algebras such as Novikov algebras,bicommutative algebras,and assosymmetric *** precisely,we first study the properties of the lower central chains for Novikov algebras and bicommutative *** we show that for every Lie nilpotent Novikov algebra or Lie nilpotent bicommutative algebra A,the ideal of A generated by the set{ab−ba|a,b∈A}is ***,we study properties of the lower central chains for assosymmetric algebras,study the products of commutator ideals of assosymmetric algebras and show that the products of commutator ideals have a similar property as that for associative algebras.

关键词： Novikov algebra bicommutative algebra assosymmetric algebra Lie nilpotent algebra

Interatomic Interaction Models for Magnetic Materials:Recent Advances

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Chinese Physics Letters 2024年第6期41卷 54-66页

作者： Tatiana S.Kostiuchenko Alexander V.Shapeev ivan S.Novikov Emanuel Institute of Biochemical Physics RAS 4 Kosygin StreetMoscow119334Russian Federation Independent investigator

Atomistic modeling is a widely employed theoretical method of computational materials *** has found particular utility in the study of magnetic ***,magnetic empirical interatomic potentials or spinpolarized density functional theory(DFT)served as the primary models for describing interatomic interactions in atomistic simulations of magnetic ***,in recent years,a new class of interatomic potentials known as magnetic machine-learning interatomic potentials(magnetic MLIPs)has *** MLIPs combine the computational efficiency,in terms of CPU time,of empirical potentials with the accuracy of DFT *** this review,our focus lies on providing a comprehensive summary of the interatomic interaction models developed specifically for investigating magnetic *** also delve into the various problem classes to which these models can be ***,we offer insights into the future prospects of interatomic interaction model development for the exploration of magnetic materials.

关键词： materials interaction empirical

Late Paleozoic alkaline magmatism in Western Transbaikalia,Russia:Implications for magma sources and tectonic settings

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Geoscience Frontiers 2020年第4期11卷 1289-1303页

作者： ivan Izbrodin Anna Doroshkevich Mikhail Rampilov Alexey Elbaev German Ripp Geological Institute Siberian Branch of the Russian Academy of SciencesRussia V.S.Sobolev Institute of Geology and Mineralogy Siberian Branch of the Russian Academy of SciencesRussia

This paper presents the results of geochronological(40Ar-39Ar,U-Pb SHRIMP Ⅱ),petrological and geochemical studies of the Late Paleozoic complexes of alkaline rocks(Zimovechinsky,Tuchinsky and Koma) located within the Vitim Plateau(the western part of the Mongol-Okhotsk Orogenic Belt).The rocks were formed at 310-280 *** is coeval with Late Paleozoic magmatism within the Central Asian Orogenic *** εNd(T) values show large variations from-2.1 to +3.3 as well as the initial Sr(I) isotopic ratios from 0.7042 to 0.7138,that demonstrate strong isotopic heterogeneity of the magmatic *** geochemical characteristics of the rocks show pronounced positive Pb and negative Ti,Zr-Hf anomalies that can be explained by involvement of the subducted component in primary *** rocks intruded in a setting of extension at the active continental margin of the Siberian Craton during subduction of Mongol-Okhotsk oceanic crust under the Siberian Craton.

关键词： Nepheline-bearing and nepheline-free syenites Geochronological and isotope data Late paleozoic magmatism Sources Central Asian orogenic belt