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12-Tungstophosphoric acid/zirconia—a highly active stable solid acid—comparison with a tungstated zirconia catalystElectronic supplementary information (ESI) available: W and P analysis in the reaction mixtures. Fig. S1: 31P MAS NMR. Fig. S2: FT-IR pyridine adsorption spectra. Fig. S3: conversion and acidity vs. TPA loading. See http://www.rsc.org/suppdata/cc/b2/b200722c/

Biju M. Devassy、S.B. Halligudi、S.G. Hegde 等 5 位作者2002-04-16Chemical Communications

A highly active and stable zirconia supported 12-tungstophosphoric acid catalyst is found to be 2-3 times more active in benzylation and acylation reactions than a tungstated zirconia catalyst.

Metal-Organic Frameworks: Synthesis and ApplicationsChemical Synthesis and ReactionsPolyoxometalates: Synthesis and Applications

Highly reactive heterogeneous Heck and hydrogenation catalysts constructed through ‘bottom-up’ nanoparticle self-assemblyElectronic supplementary information (ESI) available: experimental methods. See http://www.rsc.org/suppdata/cc/b2/b200334a/

Trent H. Galow、Ulf Drechsler、Jarrod A. Hanson 等 4 位作者2002-04-16Chemical Communications

Polymer-mediated self-assembly of functionalized Pd and SiO2 nanoparticles provides highly active hydrogenation and Heck coupling catalysts.

Nanomaterials for catalytic reactionsCatalytic Cross-Coupling ReactionsCovalent Organic Framework Applications

Elasticity of the Oriented Mesomorphic Form of Syndiotactic Polypropylene

Liberata Guadagno、Concetta D’Aniello、Carlo Naddeo 等 5 位作者2002-04-16Macromolecules

Syndiotactic polypropylene (sPP) was melt-quenched in an ice−water bath and directly drawn at 0 °C up to a draw ratio of 6. The oriented sample was kept in the cold bath for 10 days under tension, and then analyzed at room temperature either fixed or after releasing tension. The fully extended fiber showed by X-ray di…

Polymer crystallization and propertiesNatural Fiber Reinforced CompositesPolymer Nanocomposites and Properties

Effect of Selective Perfluoroalkylation on the Segregation Strength of Polystyrene−1,2-Polybutadiene Block Copolymers

Yu Ren、Timothy P. Lodge、Marc A. Hillmyer2002-04-16Macromolecules

A series of partially fluorinated (C 6 F 13 H-modified) polystyrene- b -1,2-polybutadiene (PS- b -1,2-PB) copolymers were prepared by the reaction of a model PS- b -1,2-PB copolymer with n -C 6 F 13 I followed by substitution of hydrogen for the iodine by hydrogenolysis. The morphologies and domain spacings of the ord…

Polymer crystallization and propertiesBlock Copolymer Self-AssemblyRheology and Fluid Dynamics Studies

ChemInform Abstract: Convergent Dendrons and Dendrimers: From Synthesis to Applications

Scott M. Grayson、Jean M. J. Fréchet2002-04-16ChemInform

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” opt…

Chemical Synthesis and AnalysisDendrimers and Hyperbranched PolymersLuminescence and Fluorescent Materials

Investigation of the Deformation and Recovery Behavior of Nylon-6/Rubber Thermoplastic Vulcanizates on the Molecular Level by Infrared-Strain Recovery Measurements

J. Oderkerk、G. Groeninckx、Maria Soliman2002-04-16Macromolecules

Thermoplastic vulcanizates (TPVs) prepared by dynamic vulcanization are blends in which cross-linked rubber particles are finely dispersed in a thermoplastic matrix. These blend materials, which are in our case based on nylon-6 and EPDM rubber, show excellent strain recovery behavior, even though the matrix consists o…

Polymer Nanocomposites and Propertiesbiodegradable polymer synthesis and propertiesPolymer crystallization and properties

Variable Range Hopping in Two-Dimensional Systems of Interacting Electrons

Dmitry Tsigankov、A. L. Efros2002-04-16Physical Review Letters

Computer modeling of the variable-range-hopping (VRH) conductivity in two-dimensional systems has been done by a kinetic Monte Carlo method, which includes some new elements. Study of the temperature dependence of the conductivity, testing of the different scaling relations, and study of the size effect show the detai…

Luminescence Properties of Advanced MaterialsTransition Metal Oxide NanomaterialsGlass properties and applications

Investigation of the role of ansocalcin in the biomineralization in goose eggshell matrix

Rajamani Lakshminarayanan、R. Manjunatha Kini、Suresh Valiyaveettil2002-04-16Proceedings of the National Academy of Sciences

The role of proteins in biomineralization and the mechanism of eggshell formation are not well understood. We have isolated and purified the major protein, ansocalcin from goose eggshell matrix. The amino acid sequence study indicates that ansocalcin is homologous to the chicken eggshell protein, ovocleidin 17, and C-…

Polymer Surface Interaction StudiesCalcium Carbonate Crystallization and InhibitionIron oxide chemistry and applications

First-order metal-insulator transition and spin-polarized tunneling inFe3O4nanocrystals

Pankaj Poddar、Tcipi Fried、Gil Markovich2002-04-16Physical review. B, Condensed matter

Tunneling junctions of stacked monolayers of uniform, organically functionalized ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}$ nanocrystals of 5.5 nm average diameter were prepared. Current-voltage characteristics of the junctions were studied as function of temperature and magnetic field. An abrupt increase in the resistance w…

Iron oxide chemistry and applicationsMagnetic Properties and Synthesis of FerritesMagnetic properties of thin films

Supramolecular chemistry and self-assembly

Fredric M. Menger2002-04-16Proceedings of the National Academy of Sciences

Supramolecular systems--their successes, problems, and potential--are discussed with allusion to specific examples.

Supramolecular Chemistry and ComplexesSupramolecular Self-Assembly in MaterialsAdvanced Polymer Synthesis and Characterization

Optical properties of structurally relaxedSi/SiO2superlattices: The role of bonding at interfaces

Pierre Carrier、Laurent J. Lewis、M. W. C. Dharma‐wardana2002-04-16Physical review. B, Condensed matter

We have constructed microscopic, structurally relaxed atomistic models of $\mathrm{Si}/{\mathrm{SiO}}_{2}$ superlattices. The structural distortion and oxidation-state characteristics of the interface Si atoms are examined in detail. The role played by the interface Si suboxides in raising the band gap and producing d…

Silicon Nanostructures and PhotoluminescenceSemiconductor materials and interfacesSemiconductor materials and devices

Diffuse Neutron Scattering Study of Relaxor Ferroelectric (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO3(PZN-xPT)

D. La-Orauttapong、J. Toulouse、Z. -G. Ye 等 6 位作者2002-04-16arXiv

Diffuse neutron scattering is a valuable tool to obtain information about the size and orientation of the polar nanoregions that are a characteristic feature of relaxor ferroelectrics. In this paper, we present new diffuse scattering results obtained on Pb(Zn1/3Nb2/3)O3 (PZN for short) and (1-x)Pb(Zn1/3Nb2/3)O3-xPbTiO…

Materials Science

Atomistic Description of Shallow Levels in Semiconductors

A. S. Martins、J. G. Menchero、R. B. Capaz 等 4 位作者2002-04-16arXiv

The wave function and binding energy for shallow donors in GaAs are calculated within the tight binding (TB) approach, for supercells containing up to two million atoms. The resulting solutions, coupled with a scaling law, allow extrapolation to the bulk limit. A sharp shallow-deep transition is obtained as the impuri…

Materials Science

Spatial and temporal probes in inhomogeneous systems: Theory and experiment

D. Mihailovic2002-04-16arXiv

The experimental and theoretical challenges posed by the study of dynamically inhomogeneous systems are outlined in the context of cuprates and other oxides. Considering the pitfalls in the single-component approach to the analysis of inhomogeneous systems, the effect of either temporal or spatial averaging by differe…

Materials ScienceSuperconductivity

Direct syntheses of ordered SBA-15 mesoporous materials containing arenesulfonic acid groups

Juan A. Melero、Galen D. Stucky、R. Van Grieken 等 4 位作者2002-04-16OpenAlex

SBA-15 mesoporous silica has been functionalized with arenesulfonic acid groups by means of a one-step simple synthesis approach involving co-condensation of tetraethoxysilane (TEOS) and 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane (CSPTMS) in the presence of a poly(alkylene oxide) block copolymer (Pluronic 123) un…

Mesoporous Materials and CatalysisPolyoxometalates: Synthesis and ApplicationsCovalent Organic Framework Applications

Dendrimers and supramolecular chemistry

Jean M. J. Fréchet2002-04-16OpenAlex

Since their introduction in 1985 by Tomalia et al. (1) and Newkome et al. (2), dendrimers have attracted much attention because of their fascinating structure and unique properties (3, 4). Dendrimers are globular, size monodisperse macromolecules in which all bonds emerge radially from a central focal point or core wi…

Advanced Polymer Synthesis and CharacterizationRNA Interference and Gene DeliveryDendrimers and Hyperbranched Polymers

Is the first hydration shell of lysozyme of higher density than bulk water?

Franci Merzel、Jeremy C. Smith2002-04-16OpenAlex

Characterization of the physical properties of protein surface hydration water is critical for understanding protein structure and folding. Here, using molecular dynamics simulation, we provide an explanation of recent x-ray and neutron solution scattering data that indicate that the density of water on the surface of…

Protein Structure and DynamicsEnzyme Structure and FunctionSpectroscopy and Quantum Chemical Studies

Growth and form of gold nanorods prepared by seed-mediated, surfactant-directed synthesis

Christopher J. Johnson、Erik Dujardin、Sean A. Davis 等 5 位作者2002-04-16OpenAlex

Gold nanorods were prepared via a seed-mediated sequential growth process involving the use of citrate-stabilised seed crystals and their subsequent growth in a series of reaction solutions containing [AuCl4]−, ascorbic acid and the cationic surfactant cetyltrimethylammonuim bromide (CTAB). Electron diffraction analys…

Nanocluster Synthesis and ApplicationsGold and Silver Nanoparticles Synthesis and ApplicationsQuantum Dots Synthesis And Properties

Resonance effect in ELNES from perovskite-type manganites BiMnO3 and LaMnO3

Yûichi Murakami2002-04-15QJM

Fine structures in electron energy-loss spectra, observed 30-40 eV beyond the threshold of oxygen K-edges in perovskite-type manganites BiMnO3 and LaMnO3, are discussed. LaMnO3 with orthorhombic symmetry (space group Pbnm) shows a clear peak in this region. However, BiMnO3 with a heavily distorted perovskite-type stru…

Transition Metal Oxide NanomaterialsCatalytic Processes in Materials ScienceElectronic and Structural Properties of Oxides