Materials Literature
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Two-, three-, and even four-bond coupling constants are reported for the first time across the N →Si coordination bond in neutral, hexacoordinate silicon chelates. Two-bond coupling constants depend critically on bond angles, and three-bond couplings follow a Karplus-type correlation with dihedral angles obtained from…
Temporal relaxation of the electric field-induced polarization in single crystalline PbMg1/3Nb2/3O3 has been measured at temperatures 180 ≤ T ≤ 230 K and times up to 104 s via polarization-optically induced linear birefringence, Δn 1/2. The data are excellently described within the framework of Chamberlin's dynamicall…
Succinic anhydride groups have been introduced on the surface of and in bulk poly(ethylene) film by a mild photochemical process. These groups on the poly(ethylene) film undergo facile transformation to various functional groups such as acids, esters, or amides by reaction with water, amine compounds, or PEG, etc. The…
Employing modified sol−gel techniques, trialkoxysilanes bearing either epoxy or 1-propenyl ether functional groups can be condensed under well controlled conditions to yield a series of soluble multifunctional siloxane oligomers. The key to the success of this synthetic approach was the use of weakly acidic ion-exchan…
Abstract Opportunities exist to exploit the unique properties of carbon dioxide to process polymers for advanced applications. The diffusion of deuterated water in poly(methyl methacrylate) films swollen by carbon dioxide at 35°C over the pressure range 0 to 90 bar (corresponding density range: 0.0 to 0.66 g/cm 3 ) wa…
The genes coding for aspartate transcarbamylase (ATCase) in the deep-sea hyperthermophilic archaeon Pyrococcus abyssi were cloned by complementation of a pyrB Escherichia coli mutant. The sequence revealed the existence of a pyrBI operon, coding for a catalytic chain and a regulatory chain, as in Enterobacteriaceae. C…
The locations of the stacking faults in β-form single crystals of syndiotactic polystyrene, which were grown isothermally from a dilute solution at temperatures ranging from 150 to 210 °C, were identified in high-resolution and dark-field (DF) images taken by transmission electron microscopy. The shift or kink of the…
We describe a local linear grating model that permits estimation of the diffraction efficiency of high-numerical-aperture two-dimensional circular lenses with one-dimensional rigorous coupled-wave analysis. The model is self-consistent and is consistent with the scalar theory that results for low-numerical-aperture le…
Abstract Over‐oxidation of poly(pyrrole) films has been shown to result in permselective films favoring cation transport and excluding anions. The exclusion principal depends on both the size of the analyte and electrostatic interactions between the analyte and the polymer film. The size of the polymer dopant anion an…
Persistent spectral hole burning in the $f\ensuremath{\rightarrow}f$ transition and changes in the $f\ensuremath{\rightarrow}d$ transition spectra upon laser irradiation were investigated in ${\mathrm{Sm}}^{2+}$-doped ${\mathrm{Al}}_{2}{\mathrm{O}}_{3}{\ensuremath{-}\mathrm{S}\mathrm{i}\mathrm{O}}_{2}$ glasses prepare…
The effect of Nd content in Al films on hillock formation was investigated for applications of interconnections for thin film transistor liquid crystal displays. It was found that the hillock density of Al–Nd alloy films was strongly dependent on the Nd content, and the hillocks were completely suppressed in Al–2.0–6.…
Static and dynamic low-angle light-scattering experiments carried out on semidilute and moderately concentrated solutions of polystyrene in toluene provide evidence for the existence of heterogeneities in the entanglement network with correlation lengths of several hundred nanometers. The slow mode showing up in the c…
Recent results on the composition, structural characterization and mechanical properties of amorphous hydrogenated carbon-nitrogen films (a-C(N):H) deposited by plasma enhanced chemical vapor deposition (PECVD) have been discussed. The use of different nitrogen-containing gases, ammonia, methylamine or nitrogen itself…
In this study two solubility-parameter models have been compared using as dependent variables the logarithm of the mole fraction solubility, lnX2e, and ln(alpha)/U (originally used in the extended Hansen method), where alpha is the activity coefficient and U is a function of the molar volume of the solute and the volu…
Luminescence studies have been performed on phosphorous-doped diamond films deposited by hot-filament chemical vapor deposition. A broad luminescence band, centered around 1.9 eV is revealed, in the cathodo luminescence spectra of homoepitaxial and polycrystalline films, whereas the blue band-A luminescence, which is…
The low-temperature specific heat ${C}_{p}$ of vitreous B${}_{2}$O${}_{3}$ has been measured between 1.5 K and 25 K, for several B${}_{2}$O${}_{3}$ glasses with different thermal histories and water contents. A noticeable variation of the specific heat from glass to glass is found in the temperature range around the b…
The monopersulfate oxidation of 4-isopropylbenzoic acid performed in H(2)(18)O and catalyzed by a water-soluble metalloporphyrin indicated that half of the oxygen atoms incorporated in 4-(1-hydroxy-1-methylethyl)benzoic acid, the primary hydroxylation product, came from water. A redox tautomerism of the active high-va…
Pt/(Ba, Sr)TiO 3 /Pt capacitors were fabricated on TiN/Ti/ Poly –Si/SiO 2 /Si substrate by sputtering technique and effects of post-annealing conditions on the current vs. voltage ( I–V ) characteristics of the capacitors were investigated. It was found that leakage currents of Pt/BST/Pt capacitors were greatly depend…
The effects of concentration and modification of fibre surface in oil palm fibre-reinforced rubber composites have been studied. Modification of the fibre surface increased the physical properties of the rubber composites. Increasing concentration of oil palm fibre in the rubber matrix resulted in reduction of tensile…
Six different behavioral models for ferroelectric capacitors are surveyed with an emphasis on their usefulness in the transient circuit simulation of integrated nonvolatile memories. These models can be broadly classified into two categories, namely, those that rely on the hysteresis loop and those that rely on the sw…