943 resultados para SR– (R–, RC–, EF–) Proximities


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The reactions of [MCl2(cod)](M = Pd or Pt, cod = cycloocta-1,5-diene) with RN[P(OPh)2]2[R = Me (L1) or Ph (L2)] afford the chelate complexes [MCl2L1] and [MCl2L2]. The dinuclear palladium(O) complex, [Pd2L13] has been synthesized by starting from [Pd2(dba)3](dba = dibenzylideneacetone). Redox condensation of [Pd2(dba)3] and [PdCl2(PhCN)2] in the presence of the diphosphazane ligands gives the dinuclear palladium(I) complexes [Pd2Cl2L12] and [Pd2Cl2L22]. The structures of the complexes have been deduced from 1H and 31P NMR spectroscopic data. Single-crystal X-ray diffraction studies confirm the structures of [Pd2L13] and [Pd2Cl2L22].

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The phase relations in the systems Cu–O–R2O3(R = Tm, Lu) have been determined at 1273 K by X-ray diffraction, optical microscopy and electron probe microanalysis of samples equilibrated in evacuated quartz ampules and in pure oxygen. Only ternary compounds of the type Cu2R2O5 were found to be stable. The standard Gibbs energies of formation of the compounds have been measured using solid-state galvanic cells of the type, Pt|Cu2O + Cu2R2O5+ R2O3‖(Y2O3)ZrO2‖CuO + Cu2O‖Pt in the temperature range 950–1325 K. The standard Gibbs energy changes associated with the formation of Cu2R2O5 compounds from their binary component oxides are: 2CuO(s)+ Tm2O3(s)→Cu2Tm2O5(s), ΔG°=(10400 – 14.0 T/K)± 100 J mol–1, 2CuO(s)+ Lu2O3(s)→Cu2Lu2O5(s), ΔG°=(10210 – 14.4 T/K)± 100 J mol–1 Since the formation is endothermic, the compounds become thermodynamically unstable with respect to component oxides at low temperatures, Cu2Tm2O5 below 743 K and Cu2Lu2O5 below 709 K. When the chemical potential of oxygen over the Cu2R2O5 compounds is lowered, they decompose according to the reaction, 2Cu2R2O5(s)→2R2O3(s)+ 2Cu2O(s)+ O2(g) The equilibrium oxygen potential corresponding to this reaction is obtained from the emf. Oxygen potential diagrams for the Cu–O–R2O3 systems at 1273 K are presented.

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An air-stable and water-soluble diastereomeric half-sandwich ruthenium(I1) complex, [Ru(s-MeCsH4Pr'-p)(H*O)-(L*)] (C104) (l), has been isolated and structurally characterized [HL* = (27)-(a methylbenzyl)salicylaldimine,2-HOC6H4CH-NCHMePhI. Complex 1, Czd-I3oNO&lRu, crystallizes in the noncentric triclinic space group P1 with a = 9.885(1) A, b = 10.185(1) A, c = 14.187(2) A, a = 110.32(1)', 6 = 102.17(1)', y = 102.41(1)O, V=1243( 1) A3, and 2 = 2. The X-ray structure shows the presence of two diastereomers in a 1:l ratio having RR,,,SCand SR,,,&c onfigurations. The Ru-OHz bond distances are considerably long, and the values for RR, - a~n d SRu-1isomers are 2.1 19(5) and 2.203(5) A, respectively. The aqua complex (1) exists as a single diastereomer in solution,and it forms stable adducts with P-, N-, and halide-donor ligands. The stereochemical changes associated with adduct-forming reactions follow an inversion order: PPhs >> P(OMe)3 > pyridine bases >> halides (I, Br, Cl) >H20.

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Researchers and developers in academia and industry would benefit from a facility that enables them to easily locate, licence and use the kind of empirical data they need for testing and refining their hypotheses and to deposit and disseminate their data e.g. to support replication and validation of reported scientific experiments. To answer these needs initially in Finland, there is an ongoing project at University of Helsinki and its collaborators to create a user-friendly web service for researchers and developers in Finland and other countries. In our talk, we describe ongoing work to create a palette of extensive but easily available Finnish language resources and technologies for the research community, including lexical resources, wordnets, morphologically tagged corpora, dependency syntactic treebanks and parsebanks, open-source finite state toolkits and libraries and language models to support text analysis and processing at customer site. Also first publicly available results are presented.

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Maurice Merleau-Ponty (1908-1961) has been known as the philosopher of painting. His interest in the theory of perception intertwined with the questions concerning the artist s perception, the experience of an artwork and the possible interpretations of the artwork. For him, aesthetics was not a sub-field of philosophy, and art was not simply a subject matter for the aesthetic experience, but a form of thinking. This study proposes an opening for a dialogue between Merleau-Pontian phenomenology and contemporary art. The thesis examines his phenomenology through certain works of contemporary art and presents readings of these artworks through his phenomenology. The thesis both shows the potentiality of a method, but also engages in the critical task of finding the possible limitations of his approach. The first part lays out the methodological and conceptual points of departure of Merleau-Ponty s phenomenological approach to perception as well as the features that determined his discussion on encountering art. Merleau-Ponty referred to the experience of perceiving art using the notion of seeing with (voir selon). He stressed a correlative reciprocity described in Eye and Mind (1961) as the switching of the roles of the visible and the painter. The choice of artworks is motivated by certain restrictions in the phenomenological readings of visual arts. The examined works include paintings by Tiina Mielonen, a photographic work by Christian Mayer, a film by Douglas Gordon and Philippe Parreno, and an installation by Monika Sosnowska. These works resonate with, and challenge, his phenomenological approach. The chapters with case studies take up different themes that are central to Merleau-Ponty s phenomenology: space, movement, time, and touch. All of the themes are interlinked with the examined artworks. There are also topics that reappear in the thesis, such as the notion of écart and the question of encountering the other. As Merleau-Ponty argued, the sphere of art has a particular capability to address our being in the world. The thesis presents an interpretation that emphasises the notion of écart, which refers to an experience of divergence or dispossession. The sudden dissociation, surprise or rupture that is needed in order for a meeting between the spectator and the artwork, or between two persons, to be possible. Further, the thesis suggests that through artworks it is possible to take into consideration the écart, the divergence, that defines our subjectivity.

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1. The metabolic disposition of R-(+)-pulegone (1) was examined in rats following four daily oral doses (250 mg/kg). 2. Six metabolites, namely pulegol (II), 2-hydroxy-2-(1-hydroxy-1-methylethyl)-5-methylcyclohexanone (III), 3,6-dimethyl-7a-hydroxy-5,6,7,7a-tetrahydro-2(4H)-benzofuranone (IV), menthofuran (V), 5-methyl-2-(1-methyl-1-carboxyethylidene)cyclohexanone (VI), and 5-methyl-5-hydroxy-2-(1-hydroxy-1-carboxyethyl)cyclohexanone (VII) have previously been isolated from rat urine, and identified (Moorthy et al. (1989a). Eight new metabolites have now been isolated from rat urine, namely, 5-hydroxy-pulegone (VIII), piperitone (IX), piperitenone (X), 7-hydroxy-piperitone (XI), 8-hydroxy piperitone (XII), p-cresol (XIII), geranic acid (XIV) and neronic acid (XV). These were identified by n.m.r., i.r. and mass spectrometry. 3. Based on these results, metabolic pathways for the biotransformation of R-(+)-pulegone in rat have been proposed.

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We have examined the stability of the ferromagnetic (FM) state in CaRuO3 and SrRuO3 as a function of the GdFeO3 distortion. Model calculations predict the dependence of the FM transition temperature (T-c) on the rotation angle theta to vary as cos(2)(2 theta) for e(g)-electron systems. However, here, we find an initial increase and then the expected decrease. Furthermore, a much faster decrease is found than predicted for e(g)-electron systems. Considering the specific case of CaRuO3, a larger deviation of the Ru-O-Ru angle from 180 degrees in CaRuO3 as compared to SrRuO3 should result in a more reduced bandwidth, thereby making the former more correlated. The absence of long-range magnetic order in the more correlated CaRuO3 is traced to the strong collapse of various exchange interaction strengths that arises primarily from the volume reduction and increased distortion of the RuO6 octahedra network that accompanies the presence of a smaller ion at the A site.

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Non-polar a-plane GaN films were grown on an r-plane sapphire substrate by plasma assisted molecular beam epitaxy (PAMBE). The effect of growth temperature on structural, morphological and optical properties has been studied. The growth of non-polar a-plane (1 1 - 2 0) orientation of the GaN epilayers were confirmed by high resolution X-ray diffraction (HRXRD) study. The X-ray rocking curve (XRC) full width at half maximum of the (1 1 - 2 0) reflection shows in-plane anisotropic behavior and found to decrease with increase in growth temperature. The atomic force micrograph (AFM) shows island-like growth for the film grown at a lower temperature. Surface roughness has been decreased with increase in growth temperature. Room temperature photoluminescence shows near band edge emission at 3.434-3.442 eV. The film grown at 800 degrees C shows emission at 2.2 eV, which is attributed to yellow luminescence along with near band edge emission. (C) 2010 Elsevier B.V. All rights reserved.

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We study the hydrodynamic properties of strongly coupled SU(N) Yang-Mills theory of the D1-brane at finite temperature and at a non-zero density of R-charge in the framework of gauge/gravity duality. The gravity dual description involves a charged black hole solution of an Einstein-Maxwell-dilaton system in 3 dimensions which is obtained by a consistent truncation of the spinning D1-brane in 10 dimensions. We evaluate thermal and electrical conductivity as well as the bulk viscosity as a function of the chemical potential conjugate to the R-charges of the D1-brane. We show that the ratio of bulk viscosity to entropy density is independent of the chemical potential and is equal to 1/4 pi. The thermal conductivity and bulk viscosity obey a relationship similar to the Wiedemann-Franz law. We show that at the boundary of thermodynamic stability, the charge diffusion mode becomes unstable and the transport coefficients exhibit critical behaviour. Our method for evaluating the transport coefficients relies on expressing the second order differential equations in terms of a first order equation which dictates the radial evolution of the transport coefficient. The radial evolution equations can be solved exactly for the transport coefficients of our interest. We observe that transport coefficients of the D1-brane theory are related to that of the M2-brane by an overall proportionality constant which sets the dimensions.

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For Barren's degree of consolidation, U-r, versus the time factor, T-r, relationship for soils undergoing consolidation with radial drainage for the equal vertical strain condition, a simple method has been developed to determine the value of the coefficient of consolidation with radial drainage c(r). Theoretical log(10)(d(e)(2)/t) versus U-r curves where d(e) is the diameter of influence and r is the real time for the different known value of c(r) have been generated. A method has been developed wherein both the theoretical and experimental behaviors of soils undergoing consolidation with radial drainage can be simultaneously compared and studied on the same plot. The experimental log(10)(d(e)(2)/t) versus U-r curves have been compared with the theoretical curves. Effects of initial compression, secondary compression, and duration of load increment are studied. Simple procedures are presented for calculating the values of c(r) using the experimental log(10)(d(e)(2)/t) versus U-r curves. A comparative study of the coefficient of consolidation and the coefficient of permeability between the cases of vertical and radial drainage has been done.

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Enantioselective synthesis of both the enantiomeric forms of the hydrindane derivatives mentioned in the title, potential chiral precursors in terpenoid synthesis, starling from R-carvone employing two different cyclopentannulation methodologies is described.

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C17H17N3O2, M(r) = 295.34, orthorhombic, P2(1)2(1)2(1), a = 7.659 (1), b = 12.741 (1), c = 15.095 (1) angstrom, V = 1473.19 (2) angstrom 3, Z = 4, D(m) = 1.33, D(x) = 1.32 Mg m-3, lambda(Cu K-alpha) = 1.5418 angstrom, mu = 0.68 mm-1, F(000) = 624, T = 295 K, R = 0.031 for 1549 unique observed reflections with I > 2.5-sigma(I). The seven-membered heterocyclic ring adopts a boat conformation flattened at the nitroso end of the ring. The substituent phenyl rings occupy pseudo-axial positions and the nitroso group is coplanar with the C(2), N(1), C(7) plane of the central ring. The crystal structure is stabilized by intermolecular N-H...O and weak C-H...O hydrogen bonds.

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The intensity ratio between L2-M45M45 and L3-M45M45 spectral features for both Fe and Co indicates significant tranfer of intensity from L2- to L3-M45M45 region due to Coster-Kronig L2-M45M45 transition. The L2-L3M45 transition can be suppressed by turning the photon energy between the L2 and L3 thresholds; however, the L3-M45M45 spectral shapes for Fe and Co do not change very significantly even at these photom energies unlike the cases of Ni, Cu and Zn, thus establishing that the M45-hole decays predominantly before the L3-hole Auger decay in the early transition elements in contrast to the late ones.

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Reactions of [Rh(COD)Cl](2) with the ligand RN(PX(2))(2) (1: R=C6H5; X=OC6H5) give mono- or disubstituted complexes of the type [Rh-2(COD)Cl-2{eta(2)-C6H5N(P(OC6H5)(2))(2)}-] or [RhCl{eta(2)-C6H5N(P(OC6H5)(2))(2)}](2), depending on the reaction conditions. Reaction of 1 with [Rh(CO)(2)Cl](2) gives the symmetric binuclear complex, [Rh(CO)Cl{mu-C6H5N(P(OC6H5)(2))(2)}], whereas the same reaction with 2 (R=CH3; X=OC6H5) leads to the formation of an asymmetric complex of the type [Rh(CO)(mu-CO)Cl{mu-CH3N(P(OC6H5)(2))(2)}] containing both terminal and bridging CO groups. Interestingly the reaction of 3 (R=C6H5, X = OC6H4Br-p) with either [Rh(COD)Cl](2) or [Rh(CO)(2)Cl](2) leads only to the formation of the chlorine bridged binuclear complex, [RhCl{eta(2)-C6H5N(P(OC6H4Br-p)(2))(2)}](2). The structural elucidation of the complexes was carried out by elemental analyses, IR and P-31 NMR spectroscopic data.