Waldemar Adam、Paul L. Alsters、Ronny Neumann 等 6 位作者2003-01-28The Journal of Organic Chemistry
Sandwich-type polyoxometalates (POMs), namely [WZnM2(ZnW9O34)2]q- [M = Mn(II), Ru(III), Fe(III), Pd(II), Pt(II), Zn(II); q = 10-12], are shown to catalyze selectively the epoxidation of chiral allylic alcohols with 30% hydrogen peroxide under mild conditions (ca. 20 degrees C) in an aqueous/organic biphasic system. Th…
Polyoxometalates: Synthesis and ApplicationsChemical Synthesis and ReactionsVanadium and Halogenation Chemistry
Norikazu Nishiyama、Shunsuke Tanaka、Yasuyuki Egashira 等 5 位作者2003-01-28Chemistry of Materials
Nano-phase transition of an organic−inorganic nanocomposite under vapor infiltration of tetraethoxysilane (TEOS) or tetramethoxysilane (TMOS) was found in mesoporous thin film preparation. The rearrangement into a hexagonal periodic structure implies high mobility of the surfactant−silicate composites in solid phase.…
Polyoxometalates: Synthesis and ApplicationsMesoporous Materials and CatalysisAerogels and thermal insulation
Wendelin J. Stark、Lutz Mädler、Marek Maciejewski 等 5 位作者2003-01-28Chemical Communications
Spraying cerium and zirconium precursors dissolved in carboxylic acids into a methane-oxygen flame resulted in well-structured nanocrystals of ceria-zirconia mixed oxides with high temperature stability and surface area.
Catalytic Processes in Materials ScienceThermal and Kinetic AnalysisCatalysis and Oxidation Reactions
Yanning Song、Peter Y. Zavalij、Masatsugu Suzuki 等 4 位作者2003-01-28ChemInform
Abstract For Abstract see ChemInform Abstract in Full Text.
Polyoxometalates: Synthesis and ApplicationsMagnetism in coordination complexesOrganometallic Compounds Synthesis and Characterization
C. Gros、P. Lemmens、M. Vojta 等 11 位作者2003-01-28arXiv
We present a comprehensive study of the coupled tetrahedra-compound Cu2Te2O5Br2 by theory and experiments in external magnetic fields. We report the observation of a longitudinal magnon in Raman scattering in the ordered state close to quantum criticality. We show that the excited tetrahedral-singlet sets the energy s…
Strongly Correlated ElectronsMaterials Science
J. Quintanilla、K. Capelle、L. N. Oliveira2003-01-28arXiv
In recent photodoping experiments Decca et al. [PRL 85, 3708 (2000)] have observed an unusually long-ranged proximity effect between the superconducting and insulating phases of YBCO. Here we critically examine the claim in that reference that such long range is anomalous. We show that, once the novel nature of the ex…
SuperconductivityMaterials Science
M. Nazih、A. de Visser、L. Zhang 等 5 位作者2003-01-28arXiv
We report thermal expansion measurements carried out on a single-crystal of the giant magnetocaloric effect material Gd5(Si0.43Ge0.57)4. At the magneto-structural phase transition at T_0 ~ 240 K, large steps in the relative length change DELTAL/L along the principle crystallographic axes are observed. The single-step…
Materials Science
Alexander Unzicker、Karl Fabian2003-01-28arXiv
A circular twist disclination is a nontrivial example of a defect in an elastic continuum that causes large deformations. The minimal potential energy and the corresponding displacement field is calculated by solving the Euler-Lagrange-equations. The nonlinear incompressibility constraint is rigorously taken into acco…
gr-qcphysics.comp-phMaterials ScienceSoft Condensed Matter
M. H. Ghatee、A. Maleki、H. Ghaed-Sharaf2003-01-28arXiv
The recent empirical correlation for the surface tension is further investigated for universality. C5-C8 liquid hydrocarbons, for which accurate surface tension data over the complete liquid range are available, are used. Functional reduced surface entropy is derived, which is in the general form of Trouton's rule. It…
cond-mat.stat-mechMaterials Science
Sergei V. Kalinin、Dawn A. Bonnell2003-01-28arXiv
Electric Scanning Probe Microscopies are used to characterize the surface behavior of ferroelectric materials. The effects of local charge density on the chemistry and physics of ferroelectric surfaces are investigated. The kinetics and thermodynamics parameters of adsorption are assessed by variable temperature Scann…
Materials Science
A. Tracz、J.K. Jeszka、Mark D. Watson 等 6 位作者2003-01-28Journal of the American Chemical Society
Uniaxially aligned, thin films of a discotic columnar thermotropic liquid crystalline material can be prepared by a simple solution zone-casting method, without the need for modified surfaces or traditional alignment techniques. Atomic force microscopy together with X-ray diffraction reveals single-crystalline-like or…
Nonlinear Optical Materials ResearchLiquid Crystal Research AdvancementsForce Microscopy Techniques and Applications
Timothy J. White、Dong ZhiLi2003-01-28OpenAlex
The crystal structures of the [A(1)(2)][A(2)(3)](BO(4))(3)X apatites and the related compounds [A(1)(2)][A(2)(3)](BO(5))(3)X and [A(1)(2)][A(2)(3)](BO(3))(3)X are collated and reviewed. The structural aristotype for this family is Mn(5)Si(3) (D8(8) type, P6(3)/mcm symmetry), whose cation array approximates that of all…
Chemical Synthesis and CharacterizationCrystal Structures and PropertiesX-ray Diffraction in Crystallography
Joel L. Stevens、Aaron Y. Huang、Haiqing Peng 等 6 位作者2003-01-28OpenAlex
Single-walled carbon nanotubes (SWNTs) with the N -alkylidene amino groups covalently attached to their side walls have been prepared starting from colloidal solutions of fluorinated SWNTs (fluoronanotubes) in terminal alkylidene diamines followed by heating at 70−170 °C. On the basis of data from thermal gravimetric…
Graphene research and applicationsCarbon Nanotubes in CompositesFiber-reinforced polymer composites
Kundan P Chaudhari、D. D. Kale2003-01-27Polymer International
Abstract Waste poly(ethylene terephthalate) [PET] and a polyolefinic elastomer (POE), Engage™ 8150, were melt blended in a co‐rotating twin screw extruder having initial distributive mixing followed by high shearing/stretching. Compositions having POE up to 10% with and without poly(ethylene‐ co ‐acrylic acid), as a c…
biodegradable polymer synthesis and propertiesPolymer crystallization and propertiesPolymer Nanocomposites and Properties
Hiroyuki Nishikawa、Asami Machida、T. Morimoto 等 9 位作者2003-01-27Chemical Communications
In addition to two organic superconductors (DODHT)2X [DODHT = (1,4-dioxane-2,3-diyldithio)dihydrotetrathiafulvalene; X = PF6 and AsF6] previously reported by us, the BF4 salt of DODHT containing one water molecule [(DODHT)2BF4 x H2O] has been found to undergo a superconducting transition at 3.2 K under a hydrostatic p…
Organic and Molecular Conductors ResearchMagnetism in coordination complexesTakotsubo Cardiomyopathy and Associated Phenomena
Małgorzata M. Jaworska、K. Kula、Philippe Chassary 等 4 位作者2003-01-27Polymer International
Abstract The sorption of platinum on glutaraldehyde cross‐linked chitosan was investigated at pH 2, using several chitosan samples prepared from different origins and characterized by different mol fractions of N ‐acetylation ( F A ). The influence of material conditioning was also tested: chitosan was dissolved and t…
Polymer Surface Interaction StudiesNanocomposite Films for Food PackagingAdsorption and biosorption for pollutant removal
Manolis J. Manos、Haralampos N. Miras、V. Tangoulis 等 6 位作者2003-01-27Angewandte Chemie International Edition
An unexplored family of polyoxometalates has evolved through the synthesis and structural characterization of vanadium(IV) sulfite heteropolyanions. The hexanuclear vanadium(IV) compound, which is ferromagnetic down to 2 K, exhibits a unique structural motif for such metal species, with a central cubic {M4O2(OH)2} fra…
Vanadium and Halogenation ChemistryPolyoxometalates: Synthesis and ApplicationsMetal-Organic Frameworks: Synthesis and Applications
Wayde N. Martens、Ray L. Frost、Peter A. Williams2003-01-27Journal of Raman Spectroscopy
Abstract The application of Raman microscopy to the study of closely related mineral phases of the adelite group has allowed their molecular characterization. The adelite group of minerals are orthorhombic arsenates and vanadates of general formula AB 2+ (XO 4 )(OH), where X may be As 5+ or V 5+ , cation A may be Ca o…
Clay minerals and soil interactionsGeological and Geochemical AnalysisCrystal Structures and Properties
Min Zhao、Charlotte L. Stern、Anthony G. M. Barrett 等 4 位作者2003-01-27Angewandte Chemie International Edition
Strong Heisenberg exchange between the core MnIII ion (S=2) and peripheral CuII ion (S=) creates S= and total-spin manifolds in a ClMnIII-complexed porphyrazine (tetraazaporphyrin) to which a CuII-complexed Schiff base is rigidly linked through nitrogen atoms attached to the macrocycle periphery (1). EPR spectroscopy…
Porphyrin and Phthalocyanine ChemistryMagnetism in coordination complexesPhotosynthetic Processes and Mechanisms
Zhengrong R. Tian、Jun Liu、James A. Voigt 等 5 位作者2003-01-27Angewandte Chemie International Edition
Crystals as building blocks: Self-assembled crystals are obtained through hierarchical and self-similar growth. Using microscopic, polyhedral, self-assembled crystals as building blocks, large crystals and open mesophase structures which preserve the shape and orientation of the basic structural units are spontaneousl…
Mesoporous Materials and CatalysisCalcium Carbonate Crystallization and InhibitionSupramolecular Self-Assembly in Materials