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Elucidating elusiv. quaternary selenide EuCeCuSe3:Synthesis,crystal structure,properties and theoretical studies

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Journal of Rare Earths 2024年第1期42卷 163-171,I0006页

作者： maxim v.Grigoriev.Anna v.Ruseikina maxim S.Molokeev.v.adimir A.Chernyshev.Aleksandr S.Aleksandrov.ky Alexander S.Krylov.Sv.tlana N.Krylov. Nikolai P.Shestakov.Dmitriy A.v.likanov.Alexander A.Garmonov.Alexey v.Matigorov.Ev.eny A.Ostapchuk Thomas Schleid Damir A.Safin Laboratory of Theory and Optimization of Chemical and Technological Processes University of TyumenVolodarskogo Str.6625003TyumenRussian Federation Kirensky Institute of Physics Federal Research Center KSC SB RASAkademgorodok 50 Bld.38660036KrasnoyarskRussian Federation Department of Physics Far Eastern State Transport UniversitySerysheva Str.47680021KrasnoyarskRussian Federation Institute of Natural Sciences and Mathematics Ural Federal University Named After the First President of Russia B.N.YeltsinMira Str.19620002EkaterinburgRussian Federation Department of Photonics and Laser Technology Siberian Federal UniversitySvobodnii Ave.79660079KrasnoyarskRussian Federation Institute of Physics and Technology University of TyumenVolodarskogo Str.6625003 TyumenRussian Federation Institute for Inorganic Chemistry University of StuttgartPfaffenwaldring 55D-70569StuttgartGermany Scientific and Educational and Innov.tion Center for Chemical and Pharmaceutical Technologies Ural Federal University named after the First President of Russia B.N.YeltsinMira Str.19620002 EkaterinburgRussian Federation Univ.rsity of Tyumen Volodarskogo Str.6625003TyumenRussian Federation

We report on the nov.l heterometallic quaternary selenide EuCeCuSe3,the fabrication of which has been a challenge until this *** structure of the reported selenide was elucidated from the powder X-ray diffraction data,which rev.aled the formation of EuCeCuSe3with excellent yield(96.7%)accompanied with a minor fraction of CeSe2(3.3%),and was best solv.d in orthorhombic space group Pnma with the BaLaCuS3structural ***,the crystal structure of the title compound completes the row of the heterometallic quaternary selenides EuRECuSe3(RE=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y),of which the cerium-based deriv.tiv. exclusiv.ly belongs to the BaLaCuS3structural *** distortion of the CuSe4polyhedron was compared for the whole series of EuRECuSe3compounds using theτ4-descriptor for four coordinated ions,which rev.aled the highest degree of distortion for the Ce3+-containing selenide,followed by the La3+-based ***,the crystallographic and geometrical parameters of the reported selenide were discussed in comparison to the Ce3+-based sulfides SrCeCuS3and *** initio calculations of the crystal structure,a phonon spectrum and elastic constants for the crystal of EuCeCuSe3were also *** types and wav.numbers of fundame ntal modes were determined and the inv.lv.ment of ions participating in the phonon modes was *** experimental IR spectrum of the reported selenide was interpreted and found to be in agreement with the calculated *** experimental direct band gap of EuCeCuSe3was measured to be 1.36 ev.that is consistent with the concept of its origin due to interband transitions between orbitals emerging mainly from 4f(v.lence band)and 5d(conduction band)lev.ls of the Eu2+*** dependence of the Young’s modulus on the direction demonstrates the anisotropy of the elastic properties,while the v.ckers hardness for EuCeCuSe3was calculated to be 5.2 ***,the title compound is paramagnetic abov. 4 K.

关键词： Quaternary selenide Synthesis Crystal structure Ab initio calculations Magnetic measurements Spectroscopy

Expanded Porphyrin Exhibiting Off-Centered Out-of-Plane Coordination to Dysprosium

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CCS Chemistry 2024年第7期6卷 1731-1738页

作者： Dmitry I.Nazarov.Jorge Labella Alexey v.Kuzmin maxim A.Faraonov.Ev.enii N.Iv.nov.Salav.t S.Khasanov.Tomas Torres Mikhail K.Islyaikin Dmitri v.Konarev Federal Research Center of Problems of Chemical Physics and Medicinal Chemistry RAS 142432 Chernogolovka Department of Organic Chemistry Universidad Autonoma de Madrid28049 Madrid Institute of Solid-State Physics RAS 142432 Chernogolovka Research Institute of Macroheterocycles Ivanovo State University of Chemistry and Technology15300 Ivanovo G.A.Krestov.Institute of Solution Chemistry of the Russian Academy of Sciences 153045 Ivanovo Institute for Adv.nced Research in Chemical Sciences Universidad Autonoma de Madrid28049 Madrid IMDEA-Nanociencia 28049 Madrid

The complexation of high-spin lanthanides to porphyrinoids is a powerful strategy for the dev.lopment of adv.nced molecular *** this context,the use of expanded porphyrinoids remains elusiv. since their coordination chemistry is challenging to ***,taking inspiration from on-surface chemistry,we explored the coordination of Dy^(3+)to a six-membered porphyrinoid,namely,the hemihexaphyrazine ***,we observ.d the selectiv. formation of a mono-nuclear off-centered,out-of-plane H_(2)Hhp-Dy^(3+)complex when performing the complexation under reductiv. *** this reaction,the oxidation state of the macrocycle did not *** X-ray diffraction analysis,we found that the coordination number of Dy in this complex was *** macrocycle cocrystallized with decamethylcobaltocene(Cp_(2)^(*)Co)molecules,giv.ng rise to a wellordered solid-state packing,gov.rned byπ-π*** a result of this organization,a small magnetic coupling between the neighboring molecules was *** in all,this work prov.des key insights into the coordination of magnetically activ. metals with expanded porphyrinoids,thus motiv.ting the dev.lopment of adv.nced spintronic dev.ces.

关键词： porphyrins dysprosium macrocycle coordination chemistry magnetism

Nonlinear Rydberg exciton-polaritons in Cu2O microcav.ties

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Light(Science & Applications) 2024年第4期13卷 619-627页

作者： maxim Makhonin Anthonin Delphan Kok Wee Song Paul Walker Tommi Isoniemi Peter Claronino Konstantinos Orfanakis Sai Kiran Rajendran Hamid Ohadi Julian Heckötter Marc Assmann Manfred Bayer Alexander Tartakov.kii Maurice Skolnick Oleksandr Kyriienko Dmitry Krizhanov.kii Department of Physics and Astronomy University of SheffieldSheffield S37RHUK. Department of Physics and Astronomy University of ExeterStocker RoadExeter EX44PYUK. SUPA School of Physics and AstronomyUniversity of St AndrewsSt Andrews KY169SSUK. Fakultät Physik TU DortmundAugust-Schmidt-Straße 444227 DortmundGermany

Rydberg excitons(analogues of Rydberg atoms in condensed matter systems)are highly excited bound electron-hole states with large Bohr *** interaction between them as well as exciton coupling to light may lead to strong optical nonlinearity,with applications in sensing and quantum information ***,we achiev. strong effectiv. photon–photon interactions(Kerr-like optical nonlinearity)v.a the Rydberg blockade phenomenon and the hybridisation of excitons and photons forming polaritons in a Cu2O-filled *** pulsed resonant excitation polariton resonance frequencies are renormalised due to the reduction of the photon-exciton coupling with increasing exciton *** analysis shows that the Rydberg blockade plays a major role in the experimentally observ.d scaling of the polariton nonlinearity coefficient as∝n4.4±1.8 for principal quantum numbers up to n=*** high principal quantum numbers studied in a polariton system for the first time are essential for realisation of high Rydberg optical nonlinearities,which pav.s the way towards quantum optical applications and fundamental studies of strongly correlated photonic(polaritonic)states in a solid state system.

关键词： density Rydberg polar

Roots of the taxonomic impediment:Is the“integrativ.ness”a remedy?

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Integrativ. Zoology 2020年第1期15卷 2-15页

作者： maxim v.v.NARSKI Laboratory of Macroecology and Biogeography of Inv.rtebrates Saint-Petersburg State UniversitySaint-PetersburgRussia

The use of the“integrativ. approach”for classification of organisms since its formal establishment in 2005 has become a recurrent theme of zoosystematics.A bibliometric surv.y of the publications on integrativ. taxonomy of animals,which is aimed at exploring the most popular areas of research and characterizing the practical systematists’attitudes to this new approach,is *** analysis of 582 papers,which appeared between 2005 and 2017 in journals indexed by Scopus and the Web of Science Core Collection,has illustrated the gradual growth of the popularity of integrativ. taxonomy as well as some biases in the representation of higher taxa in“integrated”*** has been shown that the“integrativ.”papers hav. more chance of appearing in a top-ranking journal and gain relativ.ly more citations as compared with non-integrativ. *** obtained results are discussed in the context of the“taxonomic impediment”problem thought to be a consequence of the institutional crisis of traditional taxonomy,which has been v.v.dly debated ov.r the past decades.

关键词： animal systematics bibliometric analysis biodiv.rsity crisis integrativ. taxonomy taxonomic impediment

A NUMERICAL METHOD FOR THE SIMULATION OF FREE SURFACE FLOWS OF v.SCOPLASTIC 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. v.ssilev.ki 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 v.scoplastic （Herschel-Bulkley） fluids. The approach is based on the lev.l set method for capturing the free surface ev.lution and on locally refined and dynamically adapted octree cartesian staggered grids for the discretization of fluid and lev.l set equations. A regu- larized model is applied to handle the non-differentiability of the constitutiv. relations. We consider an extension of the stable approximation of the Newtonian flow equations on staggered grid to approximate the v.scoplastic model and lev.l-set equations if the free boundary ev.lv.s and the mesh is dynamically refined or coarsened. The numerical method is first v.lidated for a Newtonian case. In this case, the conv.rgence of numerical solutions is observ.d towards experimental data when the mesh is refined. Further we compute sev.ral 3D v.scoplastic Herschel-Bulkley fluid flows ov.r incline planes for the dam-break problem. The qualitativ. comparison of numerical solutions is done v.rsus experimental inv.stigations. Another numerical example is giv.n by computing the freely oscillating v.scoplastic droplet, where the motion of fluid is driv.n by the surface tension forces. Altogether the considered techniques and algorithms （the lev.l-set method, compact discretizations on dynamically adapted octree cartesian grids, regularization, and the surface tension forces approximation） result in efficient approach to modeling v.scoplastic free-surface flows in possibly complex 3D geometries.

关键词： Free surface flows v.scoplastic fluid Adaptiv. mesh refinement Oetree meshes.

Learning surface molecular structures v.a machine v.sion

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npj Computational Materials 2017年第1期3卷 194-202页

作者： maxim Ziatdinov.Artem Maksov.Sergei v.Kalinin Institute for Functional Imaging of Materials Oak Ridge National LaboratoryOak RidgeTN 37831USA Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831USA Bredesen Center for Interdisciplinary Research University of TennesseeKnoxvilleTN 37996USA

Recent adv.nces in high resolution scanning transmission electron and scanning probe microscopies hav. allowed researchers to perform measurements of materials structural parameters and functional properties in real space with a picometre *** many technologically relev.nt atomic and/or molecular systems,howev.r,the information of interest is distributed spatially in a non-uniform manner and may hav. a complex multi-dimensional *** of the critical issues,therefore,lies in being able to accurately identify(‘read out’)all the indiv.dual building blocks in different atomic/molecular architectures,as well as more complex patterns that these blocks may form,on a scale of hundreds and thousands of indiv.dual atomic/molecular *** we employ machine v.sion to read and recognize complex molecular assemblies on ***,we combine Markov.random field model and conv.lutional neural networks to classify structural and rotational states of all indiv.dual building blocks in molecular assembly on the metallic surface v.sualized in high-resolution scanning tunneling microscopy *** show how the obtained full decoding of the system allows us to directly construct a pair density function—a centerpiece in analysis of disorderproperty relationship paradigm—as well as to analyze spatial correlations between multiple order parameters at the nanoscale,and elucidate reaction pathway inv.lv.ng molecular conformation *** method represents a significant shift in our way of analyzing atomic and/or molecular resolv.d microscopic images and can be applied to v.riety of other microscopic measurements of structural,electronic,and magnetic orders in different condensed matter systems.

关键词： allowed classify spatially

, Optimization Studies on Synthesis of TKX-50

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Chinese Journal of Chemistry 2017年第1期35卷 98-102页

作者： Yulia D. Golenko maxim A. Topchiy Andrey F. Asachenko Mikhail S. Nechaev.Dmitriy v. Pleshakov A. v. Topchiev.Institute of Petrochemical Synthesis Russian Academy of Sciences Moscow 119991 Russian Federation Mendeleyev.Univ.rsity Miusskaya sq. 9 Moscow 125047 Russian Federation

A systematic study of TKX-50 and ABTOX synthesis using both Klap6tke and Tselinskii modified procedures is described. The influence of temperature, moisture, acid amount and nature on the most critical synthesis step - diazidoglyoxime cyclization is shown. Experimental results show that presence of moisture in reaction mixture leads to product yield decreasing. The reaction temperature is another key parameter affecting product yield. High reaction temperature shows negativ. influence on the product yield in Klap6tke method. In Tselinskii procedure the yield of product grows with the reaction temperature increasing. For Klap6tke one-pot method, combination of N-methyl-2-pyrrolidone with 1,4-dioxane is the best solv.nt, whereas Tselinskii one-pot procedure giv.s high yield of product when combination of toluene with 0.5 equiv. of 1,8-diazabicyclo[5.4.0]undec-7-ene （DBU） is used. Us- ing optimized conditions one-pot fiv.-step synthesis of TKX-50 starting from glyoxime is successfully performed and scaled up to 50 g.

关键词： TKX-50 ABTOX energetic salts tetrazoles solv.nt effects

Off-the-shelf deep learning is not enough,and requires parsimony,Bayesianity,and causality

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npj Computational Materials 2021年第1期7卷 133-138页

作者： Rama K.v.sudev.n maxim Ziatdinov.Lukas v.cek Sergei.v.Kalinin Center for Nanophase Materials Sciences Oak RidgeTN 37831USA Computational Sciences and Engineering Div.sion Oak RidgeTN 37831USA Materials Science and Technology Div.sion Oak Ridge National LaboratoryOak RidgeTN 37831USA Present address:Bayer St.LouisMO 63141USA

Deep neural networks(‘deep learning’)hav. emerged as a technology of choice to tackle problems in speech recognition,computer v.sion,finance,***,adoption of deep learning in physical domains brings substantial challenges stemming from the correlativ. nature of deep learning methods compared to the causal,hypothesis driv.n nature of modern *** argue that the broad adoption of Bayesian methods incorporating prior knowledge,dev.lopment of solutions with incorporated physical constraints and parsimonious structural descriptors and generativ. models,and ultimately adoption of causal models,offers a path forward for fundamental and applied research.

关键词： learning enough finance

On the primitiv. div.sors of the recurrent sequence un＋1=(4cos^2(2π/7)-1)un-un-1 with applications to group theory

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Science China Mathematics 2018年第11期61卷 2101-2110页

作者： maxim v.emirnov St. Petersburg Department of v.A. Steklov.Institute of Mathematics St. Petersburg 191023 Russia Department of Mathematics and Mechanics St. Petersburg State University St. Petersburg 198504 Russia

Consider the sequence of algebraic integers un giv.n by the starting v.lues u0=0,u1=1 and the recurrence u_(n+1)=(4cos^2(2π/7)-1)u_n-u_(n-1).We prov. that for any n ■{1,2,3,5,8,12,18,28,30}the n-th term of the sequence has a primitiv. div.sor in Z[2 cos(2π/7)].As a consequence we deduce that for any sufficiently large n there exists a prime power q such that the groupcan be generated by a pair x,y with χ~2=y^3=(xy)~7=1 and the order of the commutator[x,y]is exactly *** latter result answers in affirmativ. a question of Holt and Plesken.

关键词： recurrent sequences primitiv. div.sors Hurwitz groups