Bernd Schnabel1999-02-01Optical Engineering
One method for influencing the polarization of light is the use of wire-grid polarizers. For the visible region, this type of element can be realized as a metal-stripe grating with periods less than the wavelength. We fabricate metal-stripe gratings with periods down to 190 nm in thin chromium layers of 35-nm thicknes…
Photonic and Optical DevicesPhotonic Crystals and ApplicationsOptical Coatings and Gratings
A. Gavezzotti1999-02-01Chemistry - A European Journal
Molecular-crystal precursor states: Molecular dynamics in the nanosecond timescale shows how acetic acid molecules aggregate (see figure for one example) out of a solution in a nonpolar solvent. Is this demixing into a microemulsion the first stage of crystal nucleation?
Crystallization and Solubility Studies
Stefano Battaglia1999-02-01Clays and Clay Minerals
Abstract A new method is proposed for applying the chlorite geothermometer using X-ray diffraction (XRD) data. A linear correlation has been found between the (001) basal spacing of chlorite and its “crystallization” temperature. The basal spacing values were corrected for an increase of Al(IV) with Fe enrichment (Fe/…
Geological and Geochemical AnalysisClay minerals and soil interactionsX-ray Diffraction in Crystallography
J. E. Riccieri、A. Vázquez、Laura Hécker de Carvalho1999-02-01Polymer Composites
Abstract In this work the interfacial properties of polyester/vegetable fiber composites were analyzed by flexural testing. The compressive/tensile (σ) and shear (τ) stresses were determined for each composite in function of the span‐to‐depth ratio (λ). The general behavior of the composites was similar to that of com…
Mechanical Behavior of CompositesNatural Fiber Reinforced CompositesTextile materials and evaluations
H. Shariatmadari、A. R. Mermut、Mônica B. Benke1999-02-01Clays and Clay Minerals
Abstract Palygorskite and sepiolite show a high sorption capacity for organic molecules. Adsorption of 2 organic cations, methylene blue (MB) and crystal violet (CV), by palygorskite and sepiolite were examined. The maximum sorption of MB and CV far exceeded the cation exchange capacity (CEC) of these minerals. This s…
Soil and Unsaturated FlowClay minerals and soil interactionsIron oxide chemistry and applications
A. Juan、Roald Hoffmann1999-02-01Surface Science
The bonding of H to Fe is analyzed using qualitative band structure calculations in the framework of extended Hückel tight-binding theory and the ASED-MO cluster method. The changes in the electronic structure of bcc Fe upon the introduction of H at a vacancy are addressed, and a comparison drawn with H adsorption at…
Advanced Chemical Physics StudiesFusion materials and technologiesHydrogen Storage and Materials
Hartmut Graf、Hartmut Löwen1999-02-01Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
The phase behavior of an aqueous suspension of rodlike tobacco mosaic viruses is investigated theoretically as a function of the virus density and the concentration of added salt. The total free energy involves ``volume terms'' from the microscopic counter- and co-ions and an effective pair interaction between the col…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesSurfactants and Colloidal Systems
Marcus Remmers、Beate Müller、Kai Martin 等 5 位作者1999-02-01Macromolecules
A series of soluble low molecular weight poly( p -phenylene)s (PPP) has been synthesized by an excess polycondensation with the Suzuki coupling method. The reaction mixture therefore only contains oligomers of an odd number of phenylene units which are terminated by bromine atoms. The mixture has been preparatively se…
Conducting polymers and applicationsLuminescence and Fluorescent MaterialsOrganoboron and organosilicon chemistry
Susanne Kloeker、Brian E. Wadzinski1999-02-01Journal of Biological Chemistry
The catalytic subunit of protein serine/threonine phosphatase 4 (PP4C) has greater than 65% amino acid identity to the catalytic subunit of protein phosphatase 2A (PP2AC). Despite this high homology, PP4 does not appear to associate with known PP2A regulatory subunits. As a first step toward characterization of PP4 ho…
Protein Kinase Regulation and GTPase SignalingEnzyme Structure and FunctionAlkaline Phosphatase Research Studies
Yu. F. Popov、A. M. Kadomtseva、Д. В. Белов 等 5 位作者1999-02-01Journal of Experimental and Theoretical Physics Letters
The appearance of a toroidal moment is observed in the magnetoelectric Cr 2 O 3 in a strong magnetic field above the spin-flop transition field. This conclusion is based on the experimentally established fact that the off-diagonal components of the magnetoelectric susceptibility tensor of Cr 2 O 3 contains an antisymm…
Multiferroics and related materialsAdvanced Condensed Matter PhysicsHeusler alloys: electronic and magnetic properties
R. Bertacco、F. Ciccacci1999-02-01Physical review. B, Condensed matter
Oxygen adsorption in an ordered $p(1\ifmmode\times\else\texttimes\fi{}1)$ fashion on the Fe(001) surface has been studied by empty states spectroscopies using a spin-polarized electron beam. The low-energy electron absorption and reflection display a much larger spin dependence in Fe(001)-$p(1\ifmmode\times\else\textt…
Magnetic properties of thin filmsAdvanced Electron Microscopy Techniques and ApplicationsElectron and X-Ray Spectroscopy Techniques
Weiping Ma、Paul W. Brown1999-02-01Journal of the American Ceramic Society
The reactivities of four hydratable aluminas were investigated. Rates of heat liberation during hydration from 15° to 55°C were determined by isothermal calorimetry. Rates of heat evolution show two peaks. An initial mixing peak is due to wetting and initial dissolution reactions. A second, main heat peak is associate…
Advanced ceramic materials synthesisZeolite Catalysis and SynthesisAerogels and thermal insulation
А. И. Колесников、Jichen Li、Stewart F. Parker 等 5 位作者1999-02-01Physical review. B, Condensed matter
Using inelastic neutron scattering, we have measured a range of amorphous forms of ice, including high-density and low-density amorphous ices, in the energy transfer region from 2 to 500 meV (16--4033 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$). The measured spectra show that the pressure-produced high-density amorpho…
Carbon Nanotubes in CompositesMaterial Dynamics and Propertiesnanoparticles nucleation surface interactions
Tata N. Rao、Donald A. Tryk、Kazuhito Hashimoto 等 4 位作者1999-02-01Journal of The Electrochemical Society
Photoelectrochemical characterization of semiconducting diamond was carried out in a weakly UV‐absorbing aqueous electrolyte using suprabandgap illumination in order to examine the influence of electrochemical oxidative surface treatment on the energetic positions of bandedges. Anodic treatment of diamond photoelectro…
Electron and X-Ray Spectroscopy TechniquesElectronic and Structural Properties of OxidesIntegrated Circuits and Semiconductor Failure Analysis
J. Kreisel、G. Lucazeau、H. Vincent1999-02-01Journal of Raman Spectroscopy
This paper reports the first single-crystal Raman spectra of substituted barium hexaferrites, BaFe12−2x MexCoxO19 (Me=Ir, Ti). The spectra were investigated in the 200–900 cm−1 range and are discussed in comparison with unsubstituted barium hexaferrite. Emphasis was placed on the different factors influencing the Rama…
Multiferroics and related materialsMagnetic Properties and Synthesis of FerritesAdvanced Condensed Matter Physics
Jeff W. M. Bulte、Marcel De Cuyper、Daryl Despres 等 4 位作者1999-02-01Journal of Magnetic Resonance Imaging
We evaluated the relaxation enhancement and biodistribution of short- vs. long-circulating magnetoliposomes as a new contrast agent for magnetic resonance (MR) imaging of bone marrow. Magnetoliposomes with (ML-PEG) and without (ML) incorporation of polyethylene glycol (PEG, Mw 2000) were prepared, measuring 40 nm in d…
Nanoparticle-Based Drug DeliveryErythrocyte Function and PathophysiologyCharacterization and Applications of Magnetic Nanoparticles
X.-G. Li、Xiaodong Fan、G. Ji 等 7 位作者1999-02-01Journal of Applied Physics
The thermodynamics and kinetics of the magnetic states of the semiconductor-like compound La0.7Sr0.3Mn0.7Co0.3O3 were studied by detailed magnetic measurements. The spontaneous magnetic state was found to be a cluster-glass phase which can cross over to a ferromagnetic state under an external magnetic field H. The def…
Magnetic and transport properties of perovskites and related materialsRare-earth and actinide compoundsAdvanced Condensed Matter Physics
A. Meldrum、S.J. Zinkle、L. A. Boatner 等 4 位作者1999-02-01Physical review. B, Condensed matter
The effects of displacive, heavy-ion irradiation on the properties of synthetic single-crystals of ${\mathrm{ZrSiO}}_{4}$ (zircon), ${\mathrm{HfSiO}}_{4}$ (hafnon), tetragonal ${\mathrm{ThSiO}}_{4}$ (thorite), and monoclinic ${\mathrm{ThSiO}}_{4}$ (huttonite) have been investigated. All four $\mathrm{AB}{\mathrm{O}}_{…
Geological and Geochemical AnalysisGlass properties and applicationsNuclear materials and radiation effects
A. A. Sattar、A. H. Wafik、K. M. El-Shokrofy 等 4 位作者1999-02-01physica status solidi (a)
Samples of Cu–Zn ferrites doped with different rare earth ions (La, Sm, Nd, Gd, and Dy) are investigated. X-ray diffraction patterns indicated the presence of a single spinel phase. The lattice parameter is found to be nearly independent of the doped rare earth ion type. The density is measured and the porosity is cal…
Magnetic Properties and Synthesis of FerritesElectromagnetic wave absorption materialsMagneto-Optical Properties and Applications
Sarah L. Woodruff、W. A. House、Maureen E. Callow 等 4 位作者1999-02-01Freshwater Biology
1. The objectives of the present work were: (a) to evaluate the effects of the development and the presence of a photosynthetically active algal biofilm on chemical fluxes and processes at the sediment–water interface; (b) to measure the effects of the biofilm on chemical concentration gradients in the bulk sediment;…
Marine and coastal ecosystemsMarine Biology and Ecology ResearchDiatoms and Algae Research