gem-Polyols — a unique class of compound
The formation and conversions of gem-polyols have been examined together with their chemical and physical properties. The bibliography includes 123 references.
Materials Literature
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Oxide desorption from InP under stabilizing pressures of P2 or As4
The oxide desorption processes of InP have been investigated under molecular-beam epitaxy conditions, determining thickness and composition of the surface layer by x-ray photoelectron spectroscopy and surface reconstructions by reflection high-energy electron diffraction (RHEED). Under P2 stabilization the oxide desor…
Atomic structure of a grain boundary in a metallic alloy: Combined electron microscope and theoretical study
A synergistic high-resolution electron microscopy (HREM) and theoretical analysis of the structure of a grain boundary in copper containing bismuth is presented. The calculation of the structure of the boundary were carried out using N-body empirical potentials constructed using results of ab initio full-potential lin…
Pinning andI-Vcharacteristics of a two-dimensional defective flux-line lattice
Using a variational argument, we show that a two-dimensional (2D) crystal becomes defective in the presence of a random potential. The threshold pinning force and flow properties of a plastically deformed crystal are studied using a perturbation theory valid for weak pinning potential and strong driving force. In the…
The chemistry of processes which create dielectric layers with functional group substituents on semiconductors by impurity thermo-oxidation
Processes are examined which involve the growth of film layers with dielectric properties on the surfaces of semiconductors during thermo-oxidation in the presence of impurity compounds specially introduced into the system. It is shown in relation to the thermo-oxidation of silicon and gallium arsenide that impurities…
Energy level of the nitrogen dangling bond in amorphous silicon nitride
The composition dependence and room-temperature metastability of the paramagnetic nitrogen dangling-bond center is amorphous silicon nitride suggest that its energy level lies close to the N pπ states, in agreement with theoretical calculations.
Calculation of shape-truncation functions for Voronoi polyhedra
The authors develop a new efficient method for calculating the shape-truncation functions of arbitrary Voronoi polyhedra by combining analytical and numerical techniques. Applications are presented for cells of cubic symmetry as well as for hexagonal close-packed (HCP) atomic polyhedra with different values of the c/a…
Ferroelectric bismuth titanate/superconductor (Y-Ba-Cu-O) thin-film heterostructures on silicon
The growth by pulsed-laser deposition of c-axis-oriented bismuth titanate (BTO)/YBa2Cu3O7(YBCO) superconductor heterostructures on [001]-oriented Si with epitaxial yttria-stabilized ZrO2 as a buffer layer is reported. X-ray-diffraction studies of the heterostructures show that all the layers grow in the c-axis orienta…
Features of the complexation of trivalent rare earths
Reasons why chelates of rare earths (RE) do not obey the tetrad 'doublet' effect are discussed. The examination is based on the concept of an ionic metal–ligand bond in RE complexes. The mutual influence of ligands in lower, higher, polynuclear and mixed complexes formed by ligands of low, medium and high denticity is…
Biogeochemistry of brachiopod intracrystalline molecules
Abstract Brachiopods contain both proteins and lipids within the biocrystals of their shell. One intracrystalline chromoprotein causes red shell coloration, whereas the other molecules may be involved with biomineralization, may strengthen the biocrystal, or may simply have been inadvertently engulfed by calcite durin…
Boundary-induced phase transitions in driven diffusive systems
Steady states of driven lattice gases with open boundaries are investigated. Particles are fed into the system at one edge, travel under the action of an external field, and leave the system at the opposite edge. Two types of phase transitions involving nonanalytic changes in the density profiles and the particle numb…
Thermochemical Reactivity of Metal Carbonates
The thermochemical reactivity of alkaline earth metal and transition-metal carbonates is discussed. Emphasis is given to the dependence of degradation mechanisms and the concomitant formation of solid and volatile products on temperature range, gas atmosphere, and type of energy impact. The experimental findings compr…
Pharmaceutical Dissolution Testing
Introduction, Historical Highlights, and the Need for Dissolution Testing Theories of Dissolution Dissolution Testing Devices Automation in Dissolution Testing, by William A. Hanson and Albertha M. Paul Factors That Influence Dissolution Testing Interpretation of Dissolution Rate Data Techniques and of In Vivo Dissolu…
Generalized Fibonacci lattices: dynamical maps, energy spectra and wavefunctions
Electronic properties of the generalized Fibonacci lattices are studied using the dynamical system technique, for which the off-diagonal tight-binding model is employed. The matrix and trace maps are obtained and investigated in a unified way. It is found that the energy spectra are Cantor-like and the wavefunctions a…
Phase-matching retracing behavior: New features in LiB3O5
Retraces of phase-matching (PM) angles and noncritical phase-matching temperatures for both type I and type II second harmonic generation in LiB3O5(LBO) are first demonstrated. By fitting to the measured PM angles at room temperature, new Sellmeier’s equations of LBO are obtained. Further analyzing the spectral and an…
Influence of substrate topography on the nucleation of diamond thin films
We have investigated the effect of substrate topography on nucleation behavior by producing a variety of substrate features on molybdenum and silicon substrates. The initial stages of nucleation on these substrates were studied by exposing them to similar conditions in a hot filament chemical vapor deposition reactor.…
M2,3absorption spectroscopy of 3d transition-metal compounds
The author calculates M 2,3 (3p) absorption spectra of the first-row transition-metal ions using a localized description for the 3d n to 3p 5 3d n+1 excitation that includes 3p and 3d spin-orbit interaction and octahedral crystal-field symmetry. Each electronic or spin configuration has a distinctly different spectrum…
First-principles study of phase stability in Cu-Zn substitutional alloys
A parameter-free approach to phase stability in Cu-Zn substitutional alloys is shown to describe order-disorder phenomena and structural transformations with remarkable accuracy. The method is based on a multiple-scattering description of the electronic structure properties of the random alloy. Configurational order i…
In situ deposition of epitaxial PbZrxTi(1−x)O3 thin films by pulsed laser deposition
Epitaxial thin films of PbZrxTi(1−x)O3 (PZT) with 0≤x≤0.6 have been deposited in situ by pulsed laser deposition from stoichiometric targets onto 〈100〉 oriented single crystals of MgO and SrTiO3. Film composition was extremely sensitive to the substrate temperature and the oxygen deposition pressure. In a high (200–30…
Thermal conductivity of a polyethylene filled with disoriented short‐cut carbon fibers
Abstract Thermal conductivity of polyethylene composites, filled with randomly dispersed and disoriented (oriented at random) carbon fibers with various aspect ratios, were investigated. Orientation of fibers was quantitatively evaluated by Hermans' parameter. In specimens of isotropic composites, i.e., filled with ra…