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Olefin Polymerization Behavior of Titanium(IV) Complexes with Fluorinated and non-fluorinated Aliphatic Phenoxyimine Ligands

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Chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： Vladislav A.Tuskaev Kasim F.Magomedov Svetlana Ch.Gagieva Dmitry A.Kurmaev Yulia V.nelyubina evgenii K.Golubev Maria D.evseeva Viktor G.Vasil'ev Galina G.nikiforova Mikhail I.Buzin Vyacheslav S.Bogdanov Boris M.Bulychev Department of Chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.n.nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer Materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 Dalton(Da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million Da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： FI catalysts Titanium(IV) (Co)polymerization Al/Mg co-catalyst Ultra-high molecular weight polyethylene

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Tuning structural,electrical,dielectric and magnetic properties of Mg-Cu-Co ferrites via dysprosium(Dy^(3+))doping

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Journal of Rare Earths 2024年第1期42卷 137-146,I0005页

作者： Maria Akhtar M.S.Hasan nasir Amin n.A.Morley Muhammad Imran Arshad Department of Physics Government College UniversityFaisalabad38000Pakistan Department of Physics The University of Lahore53700Pakistan Department of Materials Science and Engineering The University of SheffieldS13JDUK Department of Physics&Astronomy University College LondonUK

In current research work,Dy3+substituted Mg0.5Cu0.25Co0.25Fe2-xDyxO4(0.0≤x≤0.04 with the step interval of 0.01)soft ferrites were synthesized by the sol-gel auto combustion *** prepared samples were characterized by the techniques using X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),Fourier transform infrared(FTIR)spectroscopy,curre nt-voltage(Ⅰ-Ⅴ)measurement,LCR meter,vibrating sample magnetometer(VSM)and *** data reveal that the average crystallite size is 49.71 nm and the lattice constant is 0.83703 nm for sample x=*** non-uniform grain growth was demonstrated by micrographs and impurity-free elemental composition was observed from EDX *** DC resistivity has an increasing and decreasing trend in ferromagnetic and paramagnetic regions with an increase in ***,the high resistivity is observed with the order of 1010Ω·cm,and the activation energy is 0.944 ev for samples x=*** dielectric parameters including dielectric constant,dielectric losses,and impedance gradually decrease with the increase in frequency from 8 Hz to 8 *** minimum dielectric loss at high frequency is found for sample x=*** coercivity(Hc)and saturation magnetization(Ms)are found in the ranges of 520.82-544.02 Oe and 20.5841-21.1473 emu/g,*** observations confirm that dysprosium(x=0.03)doped MCC-soft ferrites may be applicable in transformer cores,microwave absorbance,and telecommunication devices.

关键词： Soft ferrites DC resistivity Dielectric loss Impedance Coercivity Rare earths

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On a Question of the Theory of Partially Composition Formations（Dedicated to Professor K.P. Shum on the occasion of his 70th birthday）

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Algebra Colloquium 2014年第3期21卷 437-447页

作者： A.A. Tsarev n.n. Vorob'ev Department of Mathematics P.M. Masherov Vitebsk State University Vitebsk 210038 Belarus Department of Mathematics F. Skorina Gomel State University Gomel' 246019 Belarus

Let n 〉 0 and w be a non-empty set of primes. It is proved that the lattice of all τ-closed n-multiply ω-composition formations is inductive. It gives a positive answer to a question of Skiba asked in 2001 at the G... 详细信息

关键词： finite group formation of groups ω-composition satellite of formation,τ -closed n-multiply ω-composition formation inductive lattice of formations

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Factorizations of Fitting classes

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Frontiers of Mathematics in China 2012年第5期7卷 943-954页

作者： nanying YAnG Wenbin GUO n.T. VOROB'ev School of Mathematics University of Science and Technology of China Hefei 230026 China Department of Mathematics Vitebsk State University Vitebsk 210038 Belarus

In this paper, we prove that there exists a infinite set of non-trivial local Fitting classes every element in which is decomposable as a non-trivial product of Fitting classes such that every factor in the product is neither local nor a formation. In particular, this gives a positive answer to Problem 11.25 a） in The Kourovka notebook.

关键词： Fitting class normal Fitting class semilocal Fitting class Lockett class

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On Finite non-Solvable Groups Whose Gruenberg-Kegel Graphs are Isomorphic to the Paw

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Communications in Mathematics and Statistics 2022年第4期10卷 653-667页

作者： A.S.Kondrat’ev n.A.Minigulov n.n.Krasovskii Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences 16 S.Kovalevskaya StrYekaterinburg 620108Russia

The Gruenberg-Kegel graph(or the prime graph)Γ(G)of a finite group G is a graph,in which the vertex set is the set of all prime divisors of the order of G and two different vertices p and q are adjacent if and only if there exists an element of order pq in *** paw is a graph on four vertices whose degrees are 1,2,2,*** consider the problem of describing finite groups whose Gruenberg-Kegel graphs are isomorphic as abstract graphs to the *** example,the Gruenberg-Kegel graph of the alternating group A_(10)of degree 10 is isomorphic as abstract graph to the *** this paper,we describe finite non-solvable groups G whose Gruenberg-Kegel graphs are isomorphic as abstract graphs to the paw in the case when G has no elements of order 6 or the vertex of degree 1 ofΓ(G)divides the order of the solvable radical of G.

关键词： Finite group non-solvable group Gruenberg-Kegel graph The paw

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First-principles calculations to investigate structural,electronic,magnetic,optical and thermodynamic properties of RE_(2)Rh_(3)Ge(RE=Pr,Sm)

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Journal of Rare Earths 2024年第7期42卷 1385-1393,I0007页

作者： A.Ezaier R.Masrour M.Hamedoun J.Kharbach A.Rezzouk A.Hourmatallah n.Benzakour K.Bouslykhane Laboratory of Solid Physics Faculty of Sciences Dhar El MehrazSidi Mohamed Ben Abdellah UniversityBP 1796FezMorocco Equipe de Physique du Solide LaboratoiresLIPIEcole Normale SupérieureBensoudaFèsMorocco

In this paper,we analyzed the physical characteristics of the ternary alloys RE_(2)Rh_(3)Ge(RE=Pr and Sm)using the first principles calculation based on functional density theory integrated in the Wien2k *** calculated formation energies of Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge are−5.3827 and−5.2782 ev/atom,respectively,showing that these alloys may exist *** results of the band structure and density of states indicate that all of the compounds tested are magnetic metals,and their magnetism is mostly related to the contribution of Pr and Sm *** total magnetic moments of Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge are 4.07245 and 11.16161μB/f.u,*** parameters such as heat capacity at constant pressure,entropy,Debye temperature,lattice volume,compressibility coefficients,and Grüneisen parameter alloys were calculated using the Gibbs algorithm and studied in depth over a large temperature range of 0-900 *** Debye temperature increases with increasing pressure and decreases with decreasing ***,the Debye temperatures calculated at p=0 GPa and T=300 K are equal to be 342 and 322 K for Pr_(2)Rh_(3)Ge and Sm_(2)Rh_(3)Ge,*** optical characteristics such as the real and imaginary portions of the dielectric function,the absorption coefficient,the energy-loss function,and the refractive index were investigated and discussed in more depth.

关键词： Magnetic metals Functional density theory Density of states Magnetic moment Optical and thermodynamic properties Rare earths

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On the Cover-Avoid Property of Injectors for Hartley Classes

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Algebra Colloquium 2015年第2期22卷 211-214页

作者： Yufeng Liu Xiaolan Yi n.T. Vorob'ev School of Mathematics and Informational ScienceShandong Institute of Business and Technology Yantai Shandong 264005 China Department of Mathematics Zhejiang Sci-Tech University Hangzhou Zhejiang 310018 China Department of Mathematics Masherov Vitebsk State University Vitebsk 210038 Belarus

In this paper, we study the cover-avoid property of -injectors on chief factors of a group G for a Fitting class in some universe with partial solubility.

关键词： Fitting class Hartley class -injector cover-avoid property chief factor

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On Injectors of a Hartley Set of a Finite Group

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Algebra Colloquium 2018年第4期25卷 671-680页

作者： nanying Yang n.T.Vorob'ev T.B.Vasilevich School of Science Jiangnan UniversityWuxiJiangsu 214122China Department of Mathematics Masherov Vitebsk State University

Let G be a finite group andНbe a Hartley set of *** this paper,we prove the existence and conjugacy ofН-injectors of G and describe the characterization of injectors via *** applications,some known results are direc... 详细信息

关键词： Hartley set injector h-radical H-function

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Bismuth-based halide double perovskite Cs_(2)KBiCl_(6): Disorder and luminescence

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Chinese Chemical Letters 2024年第5期35卷 504-508页

作者： Pan Liu Yanming Sun Alberto J.Fernández-Carrión Bowen Zhang Hui Fu Lunhua He Xing Ming Congling Yin Xiaojun Kuang MOE Key Laboratory of new Processing Technology for nonferrous Metal and Materials Guangxi Key Laboratory of Optic and Electronic Materials and DevicesCollege of Materials Science and EngineeringGuilin University of TechnologyGuilin 541004China Analytical Instrumentation Center College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Spallation neutron Source Science Center Dongguan 523803China Chinese Academic of Science Institute of PhysicsBeijing National Laboratory for Condensed Matter PhysicsBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China College of Science Guilin University of TechnologyGuilin 541004China College of Chemistry and Bioengineering Guilin University of TechnologyGuilin 541004China

A new bismuth-based halide double perovskite Cs_(2)KBiCl_(6) was isolated successfully through solid-state reactions and investigated using X-ray and neutron *** than an ordered structure,the crystal structure consists of shifted Cs,K,Bi,and Cl sites from the ideal positions with fractional occupancy in compensation,leading to variable local coordination of Cs^(+)ions,as revealed by^(133)Cs solid-state nuclear magnetic resonance ***_(2)KBiCl_(6) displays volume hysteresis at 5-298 K range upon heating and *** Cs_(2)KBiCl_(6) has a direct bandgap of 3.35(2)ev and red-shift luminescence of around 600 nm upon Mn doping compared with the na *** stabilization of disordered structure in Cs_(2)KBiCl_(6) is related to two factors including the large-sized K^(+)cation which prefers to coordinate with more than six Cl^(-),and the Bi^(3+)with 6s^(2) lone pair which has a preference for a local asymmetric *** findings could have general application and help to understand the structure and property of halide perovskites.

关键词： Halide perovskite Double perovskite Luminescence Disordered structure Direct bandgap

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Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

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Journal of Semiconductors 2024年第9期45卷 28-35页

作者： Leonarde n.Rodrigues Wesley F.Inoch Marcos L.F.Gomes Odilon D.D.Couto Jr. Bráulio S.Archanjo Sukarno O.Ferreira Physics Department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de Física Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil national Institute of Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 ev)is associated to defects and bound exciton states, while the main emission at 1.61 ev has a weak 2D character and the higher energy one at 1.71 ev has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

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