Materials Literature
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We have studied optical properties of Si-backbone polymers constructed by the organosilicon units having two or three Si-Si bonds in order to understand the mechanism of visible luminescence in silicon-based materials. The backbones of branch, ladder, and network polymers are constructed by the organosilicon units wit…
An efficient method developed for the calculation of quasiparticle corrections to density-functional-theory--local-density-approximation (DFT-LDA) band structures of diamond and zinc-blende materials is generalized for crystals with other cubic, hexagonal, tetragonal, and orthorhombic Bravais lattices. Local-field eff…
We present a quantitative analysis of the absorption and field-induced absorption (electroabsorption) spectra of dilute blends of the conjugated polymer poly[2-methoxy,5-(2'-ethyl-hexoxy)-p-phenylene vinylene] (MEH-PPV) oriented in ultrahigh-molecular-weight polyethylene (PE). Because of the orientation, the enhanced…
Ab initio and density functional calculations suggest that the carbenic tautomer 1 of an N-confused porphyrin is electronically similar to stable, nucleophilic, aromatic Arduengo-type carbenes such as 2, as reflected by ionization potentials and single–triplet energy gaps. In addition, this gives a partial explanation…
The nucleation and growth kinetics of epitaxial Ba2YCu3O7−x thin films prepared on (001) SrTiO3 by postdeposition annealing of a chemically derived intermediate layer were investigated in specimens quenched from the growth anneal. The films were produced by spin-on deposition of a metal-organic precursor solution at r…
Raman scattering investigations were performed over a large temperature range from 10 to 700 K on pure and Ti-doped PbHfO 3 single crystals. The modifications of the Raman spectra were precisely observed in the vicinity of two structural phase transitions occurring in the crystal: an antiferroelectric (A 1 ) to antife…
The Monte Carlo method has been used to simulate the interaction of incident electrons of 1--10 keV with Si, Cu, Ag, and Au solids. In the simulation, the trajectories of secondary electrons inside the solids have also been included. The distributions of secondary-electron-emission sites on the surfaces of Si, Cu, Ag,…
A 0.6 kb cDNA fragment encoding the human NAD(+)-specific isocitrate dehydrogenase alpha-subunit (H-IDH alpha) was amplified by PCR using oligonucleotide primers synthesized on the basis of pig tryptic peptide sequences [Huang and Colman (1990) Biochemistry 29, 8266-8273]. With the amplified cDNA as a probe, cDNA clon…
For thin films on a substrate, strains due to thermal expansion mismatch can produce very large stresses. While capillary forces create a grain boundary (GB) thermal groove, compressive and tensile stresses can form, respectively, a ridge or a canal at the grain boundary and can strongly influence the GB mobility. Fol…
Oxidized titanium surfaces resulting from various processes have been structurally characterized by means of scanning force microscopy, x-ray photoemission spectroscopy (XPS), x-ray diffraction, and electron energy-loss spectroscopy (EELS) with losses in the 0–100 eV range. It has been found that the surface morpholog…
Stress relaxation at room temperature in polycrystalline aluminium layers, deposited onto silicon wafers, was explained by processes in which changes in the dislocation structure play a dominant role. Applying x-ray diffraction, information was obtained simultaneously about the macrostress (from line position) and the…
Abstract In this paper, results are presented from a series of scale inhibitor core flood experiments using oil reconditioned reservoir cores from four North Sea fields. Phosphonate, poly phosphino carboxylic acid, poly acrylic acid and sulphonated acrylic acid scale inhibitors were used in order to evaluate their per…
Cr 3+ and Fe 3+ ions are used as paramagnetic probes of the local order in diamagnetic transition metal fluoride glasses (TMFG). EPR observations are made at S, X, K and Q band frequencies at different temperatures. It follows from the frequency dependence of the spectra that Cr 3+ and Fe 3+ ions are characterized by…
Induced optical absorption in three SiO2-core/SiO2:F-clad fibers (two high-OH, one low-OH) and one SiO2:Ge-core fiber was investigated in situ in the range 415–1100 nm during repeated 60Co γ-ray exposures to doses ≳1 MGy(Si). Injected visible light (∼5 μW) was maintained during the first and second irradiations at ∼27…
Growth and structural evolution of a MgO thin film fabricated on Si substrate by using sol-gel method were investigated. Textured MgO films displaying (111) MgO∥(100)Si and (111)MgO∥(111)Si orientations were obtained. Crystallization of (111) oriented MgO film was observed to occur above 500 °C regardless of the subst…
Rocking curves of reflection high-energy electron diffraction (RHEED) have been measured from the Si(111)-(\ensuremath{\surd}3 \ifmmode\times\else\texttimes\fi{} \ensuremath{\surd}3 )R30\ifmmode^\circ\else\textdegree\fi{}-Al, -Ga, and -In surfaces at [21\ifmmode\bar\else\textasciimacron\fi{} 1\ifmmode\bar\else\textasc…
Using a first-principles technique, we calculate the structural, electronic, and vibrational properties of the (100), (111), and (110) surfaces of diamond. Stable (2\ifmmode\times\else\texttimes\fi{}1) and Pandey chain reconstruction were found for the bare (100) and (111) surfaces, respectively. The surface zigzag ch…
The thermoelectric properties of systems in the form of superlattices have been studied. First, the electrical and thermal conductivities, the thermopowers, and the figures of merit of superlattice structures are given in terms of the bulk parameters of the two constituent materials for conduction both parallel and pe…
Submicroporous CdS films were fabricated by a two-step replication process, in which porous anodic alumina was used as a template. The films were grown on a porous gold support of the same structure, resulting in a free-standing CdS/Au membrane. The diameter of the holes of the regular porous structure is in the order…
A statistically based characterization of the topography of a multidimensional potential surface classifies not only local minima and saddles but entire basins containing many minima, and divides separating basins and monotonic sequences of local minima within each basin. The data fold readily into the formalisms of c…