Materials Literature

文献浏览

按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。

清除
第 116345 / 123798 页 · 当前展示 2,326,881–2,326,900 / 2,475,959 条匹配结果 · 摘要仅作预览

Understanding the Role of Stereoelectronic Effects in Determining Collagen Stability. 1. A Quantum Mechanical Study of Proline, Hydroxyproline, and Fluoroproline Dipeptide Analogues in Aqueous Solution

Roberto Improta、Caterina Benzi、Vincenzo Barone2001-11-17Journal of the American Chemical Society

The importance of local (intraresidue) effects in determining the stability of the collagen triple helix has been investigated with special reference to the role played by hydroxyproline. To this end the dipeptide analogues of L-proline (ProDA), 4(R)-hydroxy-L-proline (HypDA), and 4(R)-fluoro-L-proline (FlpDA) have be…

Chemical Synthesis and AnalysisProtein Hydrolysis and Bioactive PeptidesCollagen: Extraction and Characterization

Tracking: a method for structural characterization of grains in powders or polycrystals

E.M. Lauridsen、S. Schmidt、Robert M. Suter 等 4 位作者2001-11-17Journal of Applied Crystallography

A method is presented for fast and non-destructive characterization of the individual grains inside bulk materials (powders or polycrystals). The positions, volumes and orientations of hundreds of grains are determined simultaneously. An extension of the rotation method is employed: a monochromatic beam of high-energy…

Advanced X-ray Imaging TechniquesX-ray Spectroscopy and Fluorescence AnalysisX-ray Diffraction in Crystallography

Thermal Degradation of Poly(3-hydroxyalkanoates): Preparation of Well-Defined Oligomers

Sophie Nguyen、Ga‐Er Yu、R. H. Marchessault2001-11-17Biomacromolecules

The thermal degradation of the biodegradable bacterial polyesters poly(3-hydroxybutyrate), PHB, poly(3-hydroxyvalerate), PHV, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate), 0-21 mol % of hydroxyvalerate, was studied. At moderately low temperatures (170-200 degrees C), the main product is a well-defined oligomer, es…

biodegradable polymer synthesis and propertiesMicroplastics and Plastic PollutionCarbon dioxide utilization in catalysis

Accurate kinetic energy evaluation in electronic structure calculations with localised functions on real space grids

Chris-Kriton Skylaris、Arash A. Mostofi、Peter D. Haynes 等 5 位作者2001-11-17arXiv

We present a method for calculating the kinetic energy of localised functions represented on a regular real space grid. This method uses fast Fourier transforms applied to restricted regions commensurate with the simulation cell and is applicable to grids of any symmetry. In the limit of large systems it scales linear…

Materials Science

Statistical equilibrium measures in micromagnetics

Markos A. Katsoulakis、Petr Plechac2001-11-17arXiv

We derive an equilibrium statistical theory for the macroscopic description of a ferromagnetic material at positive finite temperatures. Our formulation describes the most-probable equilibrium macrostates that yield a coherent deterministic large-scale picture varying at the size of the domain, as well as it captures…

Materials Sciencecond-mat.stat-mech

Three-dimensional maps of grain boundaries and the stress state of individual grains in polycrystals and powders

Henning Friis Poulsen、S. F. Nielsen、E.M. Lauridsen 等 9 位作者2001-11-17OpenAlex

A fast and non-destructive method for generating three-dimensional maps of the grain boundaries in undeformed polycrystals is presented. The method relies on tracking of micro-focused high-energy X-rays. It is verified by comparing an electron microscopy map of the orientations on the 2.5 × 2.5 mm surface of an alumin…

Microstructure and mechanical propertiesElectron and X-Ray Spectroscopy TechniquesScientific Research and Discoveries

The structural, magnetic and electrical properties of the hole-doped cobaltites La0.7(Ca1-xBax)0.3CoO3(x= 0.0, 0.5 and 1.0)

R. Ganguly、M. Hervieu、N. Nguyen 等 6 位作者2001-11-16Journal of Physics Condensed Matter

We have studied the structural, magnetic and electrical properties of hole-doped cobaltites with compositions, La 0.7 (Ca 1- x Ba x ) 0.3 CoO 3 ( x = 0.0, 0.5 and 1.0). Due to the large difference in size between the Ca and Ba ions (size mismatch), these compounds show interesting changes in the magnetic and transport…

Magnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter PhysicsThermal Expansion and Ionic Conductivity

Synthesis, Structural Characterization, and Photophysics of Dinuclear Gold(II) Complexes [{Au(dppn)Br}2](PF6)2and [{Au(dppn)I}2](PF6)2with an Unsupported AuII−AuIIBond

Vivian Wing‐Wah Yam、Chi-Kwan Li、Chui‐Ling Chan 等 4 位作者2001-11-16Inorganic Chemistry

A series of novel dinuclear gold(II) complexes having an unsupported Au(II)-Au(II) bond with well-defined oxidation state at the gold center were synthesized. Red shifts in both the low-energy absorption and emission bands were observed upon increasing the donor ability of the coordinated halogen atoms.

Organometallic Complex Synthesis and CatalysisMetal complexes synthesis and propertiesMagnetism in coordination complexes

Conducting‐Polymer Electrochemical Switching as an Easy Means for Control of the Molecular Properties of Grafted Transition Metal Complexes

Claire Mangeney、Jean Lacroix、Kathleen I. Chane‐Ching 等 8 位作者2001-11-16Chemistry - A European Journal

Copper(II) 3',4'-bis(N,N'-oxamato)terthiophene has been synthesized and electropolymerized. The copper(II)-complex centers are not affected by the polymerization process, which involves coupling between Calpha carbon atoms of the terthiophene units and leads to a new conjugated polymer consisting of polythiophene chai…

Organic Electronics and PhotovoltaicsConducting polymers and applicationsElectrochemical Analysis and Applications

Metal Imidazolato Complexes: Synthesis, Characterization, and X-ray Powder Diffraction Studies of Group 10 Coordination Polymers

Norberto Masciocchi、G. Attilio Ardizzoia、G. LaMonica 等 6 位作者2001-11-16Inorganic Chemistry

Binary metal imidazolates of the group 10 metals have been prepared and typically found amorphous. However, the intermediacy of a number of (poly)crystalline species during their formation has been evidenced; their selective preparation and characterization, by chemical, spectroscopic, and thermal methods and their st…

Crystallography and molecular interactionsThermal and Kinetic AnalysisX-ray Diffraction in Crystallography

SERS study of some novel metal complexes derived from D‐glucosamine

Yong Ye、Jiming Hu、Yun’e Zeng2001-11-16Journal of Raman Spectroscopy

Abstract Copper(II), nickel(II), cobalt(III) and iron(III) complexes of D ‐glucosamine, and their complexes with α‐glycine were synthesized. The eight novel metal complexes were characterized by means of IR, electronic absorption and 1 H NMR spectroscopy. The surface‐enhanced Raman scattering (SERS) spectra of these c…

Gold and Silver Nanoparticles Synthesis and ApplicationsProtein Interaction Studies and Fluorescence AnalysisNanocluster Synthesis and Applications

Unusual charge disproportionation and associated magnetic behaviour in nanocrystalline LaMn0.5Co0.5O3

V. L. Joseph Joly、Yogesh B. Khollam、P. A. Joy 等 5 位作者2001-11-16Journal of Physics Condensed Matter

Evidence for an unusual double charge disproportionation, Mn 4+ + Co 2+ → Mn 3+ + Co 3+ → Mn 4+ + Co 2+ , is observed in nanocrystalline LaMn 0.5 Co 0.5 O 3 synthesized by a low-temperature method and annealed in the temperature range 200–1300 °C. The Curie temperature of nanocrystalline LaMn 0.5 Co 0.5 O 3 is increas…

Magnetic and transport properties of perovskites and related materialsRare-earth and actinide compoundsAdvanced Condensed Matter Physics

Pressure-induced orthorhombic to rhombohedral phase transition in LaGaO3

Brendan J Kennedy、Thomas Vogt、C. David Martin 等 5 位作者2001-11-16Journal of Physics Condensed Matter

The influence of pressure on the crystal structure of LaGaO 3 has been studied using synchrotron x-ray diffraction. At atmospheric pressure LaGaO 3 has an orthorhombic structure in Pnma and undergoes a first-order phase transition to a rhombohedral structure near 2.5 GPa. The transition is reversible and the orthorhom…

High-pressure geophysics and materialsMagnetic and transport properties of perovskites and related materialsElectronic and Structural Properties of Oxides

Electronic structures of Ba1-xCaxTiO3studied by x-ray absorption spectroscopy and theoretical calculation

K. Asokan、J. C. Jan、J. W. Chiou 等 12 位作者2001-11-16Journal of Physics Condensed Matter

We report O and Ca K-edges x-ray absorption near edge structure (XANES) spectra of Ba 1- x Ca x TiO 3 ( x = 0.01 and 0.08), BaTiO 3 and CaTiO 3 and the electronic structure of Ba 0.875 Ca 0.125 TiO 3 obtained by first-principles calculation. The characteristic features in the O K-edge XANES spectra of these ferroelect…

Ferroelectric and Piezoelectric MaterialsMagnetic and transport properties of perovskites and related materialsElectronic and Structural Properties of Oxides

Coordinated B2 Bridges in Porphyrins-Unexpected Formation of a Diborane(4)- from a Diborylporphyrin

Andre Weiß、Hans Pritzkow、Penelope J. Brothers 等 4 位作者2001-11-16Angewandte Chemie International Edition

Fitting B2 bridges in porphyrins (see picture) can be achieved by reaction of dilithiated porphyrins with B2Cl4 as well as by reductive elimination from diborylporphyrins. Coordination takes place under rectangular distortion of the porphyrin framework.

Porphyrin and Phthalocyanine ChemistryOrganoboron and organosilicon chemistryPorphyrin Metabolism and Disorders

High oxide ion conductivity in Bi2MoO6 oxidation catalyst

Leng Tze Sim、C. K. Lee、Anthony R. West2001-11-16Journal of Materials Chemistry

Both the low (γ)- and high (γ′)-temperature polymorphs of Bi2MoO6 are oxide ion conductors. The γ′ conductivity at 300 °C is comparable to that of yttria-stabilized zirconia (YSZ) while its activation energy, 0.510(2) eV, is much less than that of YSZ, 0.79 eV, and is lower than that of the best low temperature oxide…

Advancements in Solid Oxide Fuel CellsZeolite Catalysis and SynthesisCatalysis and Oxidation Reactions

Probing the Magnetic Anisotropy of Lanthanide‐Containing Metallomesogens by Luminescence Spectroscopy

Koen Binnemans、Larisa Malykhina、Vladimir S. Mironov 等 9 位作者2001-11-16ChemPhysChem

The alignment of liquid crystals through magnetism demands a high value of the magnetic anisotropy. The magnitude of the anisotropy for a series of isostructural lanthanide-containing metallomesogens can be estimated on basis of the crystal-field splitting of the (7)F1 multiplet in the corresponding europium(III) comp…

Magnetism in coordination complexesCrystal Structures and PropertiesLanthanide and Transition Metal Complexes

Unique formation of two different W/Ag/S clusters from the same components via a low heating temperature solid state reaction and a solution reaction and their third-order NLO properties in solutionElectronic supplementary information (ESI) available: experimental: general comments, synthesis of complexes, third-order NLO measurements, time response spectra. See http://www.rsc.org/suppdata/cc/b1/b107251j/

Hong Yu、Qingfeng Xu、Zhenrong Sun 等 8 位作者2001-11-16Chemical Communications

Reaction of (NH4)2[WS4], [Ag(MeCN)4](PF6) and dppm (molar ratio = 1∶2∶4) in the solid state at 110 °C followed by extraction with CH2Cl2 yielded a hexanuclear neutral cluster [(WS4)2Ag4(dppm)3] 1, while the same materials when mixed directly in CH2Cl2 produced a tetranuclear cluster salt [WS4Ag3(dppm)4](PF6) 2; both c…

Metal complexes synthesis and propertiesMagnetism in coordination complexesOrganometallic Compounds Synthesis and Characterization

1,2-Bis(3-methyl-imidazolin-2-ylium iodobromoselenanide)ethane: Oxidative Addition of IBr at the Se Atom of a >C=Se Group

M. Carla Aragoni、Massimiliano Arca、Alexander J. Blake 等 10 位作者2001-11-16Angewandte Chemie International Edition

Almost linear I-Se-Br groups with d(Se-Br)>d(Se-I) occur in 1⋅2 IBr, the first "T-shaped" Se adduct with IBr, which was synthesized by the oxidative addition of IBr to 1,2-bis(3-methylimidazoline-2-selonyl)ethane (1) in MeCN. Density functional theory calculations indicate the intramolecular Br⋅⋅⋅H interactions as bei…

Magnetism in coordination complexesOrganic and Molecular Conductors ResearchN-Heterocyclic Carbenes in Organic and Inorganic Chemistry

Pore-Size Engineering of Silicon Imido Nitride for Catalytic Applications

David Farrusseng、Klaus Schlichte、Bernd Spliethoff 等 7 位作者2001-11-16Angewandte Chemie International Edition

High specific surface areas and adjustable pore sizes are outstanding characteristics of nanoporous silicon nitride based materials prepared by using oxygen-free molecular precursors in a novel template-assisted sol-gel approach. The nitrides represent a new class of shape-selective superbase catalysts (see, for examp…

Advanced ceramic materials synthesisSemiconductor materials and devicesMXene and MAX Phase Materials