Search results for "Model theory"
showing 10 items of 681 documents
Heterometallic 3d−4f Polyoxometalate Derived from the Weakley-Type Dimeric Structure
2009
Polyanion [{Ce(H(2)O)(2)}(2)Mn(2)(B-alpha-GeW(9)O(34))(2)](8-) (1) constitutes the first example of a heterometallic 3d-4f cluster related to the Weakley-type dimeric structure, and it contains an unprecedented Ce(III)(2)Mn(III)(2)O(20) rhomblike moiety displaying dominant Ce(III)-Mn(III) ferromagnetic interactions.
Organotin(IV)n+ complexes formed with biologically active ligands: equilibrium and structural studies, and some biological aspects
2002
Abstract The organotin(IV) cations form complexes with ligands containing {O}, {N}, {S}, or {phosphorus(O)} donor atoms with various composition and stability. The emergence of new experimental techniques (EXAFS, multinuclear 1 H-, 13 C-, 119 Sn-NMR, 119 Sn Mossbauer, etc., spectroscopic techniques) provided useful information about the structure and stabilities of the complexes formed. We reviewed the literature on these type of complexes taking into account the biological aspects of the complexes discussed.
NbxRu6-xTe8, New Chevrel-Type Clusters Containing Niobium and Ruthenium,
1996
Phases of composition Nb(x)()Ru(6)(-)(x)()Te(8) were prepared by reacting stoichiometric mixtures of the elements at high temperature in evacuated silica ampules. The structure of Nb(3.33)Ru(2.67)Te(8) was refined from X-ray powder data using the Rietveld method. Nb(3.33)Ru(2.67)Te(8) crystallizes isotypic with Mo(6)Q(8) (Q = S, Se, Te) in the rhombohedral space group Rthremacr; with the hexagonal lattice parameters a = 10.34106(5) Å, c = 11.47953(7) Å, and Z = 3. Its structure consists of M(6)Te(8) mixed-metal clusters (M = Nb, Ru) which are connected by intercluster M-Te bonds to form a three-dimensional network. Metal-metal bonding in these phases is analyzed in terms of Pauling bond ord…
A heterobimetallic [MnII5CuII5] nanowheel modulated by a flexible bis-oxamate type ligand
2015
The synthesis, crystal structure and preliminary magnetic characterization of a new heterobimetallic [MnII5CuII5] wheel containing a flexible bis-oxamate type ligand are described. This decanuclear compound exhibits a relatively strong intra-wheel antiferromagnetic interaction leading to a ground spin state S = 10.
Spin Crossover in a Series of Non-Hofmann-Type Fe(II) Coordination Polymers Based on [Hg(SeCN)3]− or [Hg(SeCN)4]2– Building Blocks
2021
Self-assembly of [Hg(SeCN)4]2- tetrahedral building blocks, iron(II) ions, and a series of bis-monodentate pyridyl-type bridging ligands has afforded the new heterobimetallic HgII-FeII coordination polymers {Fe[Hg(SeCN)3]2(4,4'-bipy)2}n (1), {Fe[Hg(SeCN)4](tvp)}n (2), {Fe[Hg(SeCN)3]2(4,4'-azpy)2}n (3), {Fe[Hg(SeCN)4](4,4'-azpy)(MeOH)}n (4), {Fe[Hg(SeCN)4](3,3'-bipy)}n (5) and {Fe[Hg(SeCN)4](3,3'-azpy)}n (6) (4,4-bipy = 4,4'-bipyridine, tvp = trans-1,2-bis(4-pyridyl)ethylene, 4,4'-azpy = 4,4'-azobispyridine, 3,3-bipy = 3,3'-bipyridine, 3,3'-azpy = 3,3'-azobispyridine). Single-crystal X-ray analyses show that compounds 1 and 3 display a two-dimensional robust sheet structure made up of infini…
Structure and Properties of One-Dimensional Heterobimetallic Polymers Containing Dicyanoaurate and Dirhodium(II) Fragments
2012
The synthesis and characterization of compound [Rh(2)(O(2)CEt)(4)(H(2)O)(2)] (1) and one-dimensional heterobimetallic polymers K(n){Rh(2)(O(2)CEt)(4)[Au(CN)(2)]}(n) (2) and K(n){Rh(2)(O(2)CMe)(4)[Au(CN)(2)]}(n)·4nH(2)O (3), constructed from dirhodiumtetracarboxylato units, [Rh(2)(O(2)CR)(4)](+), and dicyanoaurate, [Au(CN)(2)](-), fragments are described. In both compounds 2 and 3 the resulting polymeric chains are nonlinear and have in common similar structural parameters, although the solid state supramolecular arrangement is very different. These structural differences explain the fact that complex 2 displays aurophilic interactions while this type of interactions are absent in complex 3.…
Distinctive and comparative places: Alternative narratives of distinction within international student mobility
2017
Moving beyond the ‘world-class’ institutional model of international student mobility, this paper examines alternative narratives of distinction relating to place of study. Drawing on semi-structured interviews with international students at universities in the UK, Austria and Latvia, we illustrate how students inside and outside mainstream reputable higher education institutions narrate and reconfigure markers of distinction to validate their international mobility and location of study, in part to compete with peers at other (more prestigious) institutions. We demonstrate the importance of lifestyle and experiential places within a global differentiated higher education landscape and argu…
Quantitative uniqueness estimates for pp-Laplace type equations in the plane
2016
Abstract In this article our main concern is to prove the quantitative unique estimates for the p -Laplace equation, 1 p ∞ , with a locally Lipschitz drift in the plane. To be more precise, let u ∈ W l o c 1 , p ( R 2 ) be a nontrivial weak solution to div ( | ∇ u | p − 2 ∇ u ) + W ⋅ ( | ∇ u | p − 2 ∇ u ) = 0 in R 2 , where W is a locally Lipschitz real vector satisfying ‖ W ‖ L q ( R 2 ) ≤ M for q ≥ max { p , 2 } . Assume that u satisfies certain a priori assumption at 0. For q > max { p , 2 } or q = p > 2 , if ‖ u ‖ L ∞ ( R 2 ) ≤ C 0 , then u satisfies the following asymptotic estimates at R ≫ 1 inf | z 0 | = R sup | z − z 0 | 1 | u ( z ) | ≥ e − C R 1 − 2 q log R , where C > 0 depends …
Back to the Amitsur-Levitzki theorem: a super version for the orthosymplectic Lie superalgebra osp(1, 2n)
2003
We prove an Amitsur-Levitzki type theorem for the Lie superalgebras osp(1,2n) inspired by Kostant's cohomological interpretation of the classical theorem. We show that the Lie superalgebras gl(p,q) cannot satisfy an Amitsur-Levitzki type super identity if p, q are non zero and conjecture that neither can any other classical simple Lie superalgebra with the exception of osp(1,2n).
Ellipsis in Finnish Sign Language
2013
This paper deals with syntactic ellipsis in clauses in Finnish Sign Language (FinSL). The point of departure for the paper is the observation, confirmed by several studies, that clauses in FinSL are often syntactically incomplete. Building on this, the paper first describes how all core-internal clausal material may be elided in FinSL: core arguments in clauses with a verbal nucleus, core-internal NPs in clauses with a nominal nucleus, and even nuclei themselves. The paper then discusses several grammatical contexts which especially favor ellipsis in FinSL. These are question–answer pairs, two-clause coordinated structures, topic–comment structures, blend structures, and structures containi…