Materials Literature
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Expressions are derived for the sixteen wave front aberration coefficients of a single grating. These give the wave aberrations to the fourth order for a plane symmetric grating system. The contributions from each mirror and grating can be added to give the aberrations in the final image. Problems encountered with int…
We report the polarized Raman spectra of vitreous $^{30}\mathrm{Si}$${\mathrm{O}}_{2}$ and compare the principal frequencies with those of vitreous $^{28}\mathrm{Si}$${\mathrm{O}}_{2}$. This yields the $^{28}\mathrm{Si}$\ensuremath{\rightarrow}$^{30}\mathrm{Si}$ isotopic shifts for nearly all vibrational modes of the…
The temperature dependence of the refractive indices of high-purity fused silica and crystal quartz was measured in the 450-1600 nm wavelength range and at temperatures from room temperature to 400 degrees C. The average thermal coefficients of the refractive indices of those materials show opposite sign. The waveleng…
The core level electrons in iron and its three oxides FeO, Fe 3 O 4 and alpha -Fe 2 O 3 have been studied by means of X-ray photoelectron spectroscopy. The main features of the spectra have been identified and electron binding energies have been measured. The Fe 2p peaks of the oxide spectra are broadened (FWHM approx…
The molecular field theory of nematics is rephrased in density functional language. The free energy in the nematic state is expressed as a functional expansion around the isotropic state in powers of the nematic order parameters P l and the fractional density change eta at the isotropic-nematic transition. The crucial…
The authors present a band calculation for antiferromagnetic MnTe. MnTe is found to be a semiconductor with an indirect energy gap of 0.35 eV. The density of states and reflectivity spectra are presented and compared with experiment. As a result of comparison they conclude that optical properties of MnTe can be descri…
The interactions of tetrakis(4-N-methylpyridyl)-porphine (H2TMpyP-4) and its copper(II), nickel(II), zinc(II), cobalt(III), iron(III), and manganese(III) derivatives with several nucleic acids have been investigated. Spectrophotometric titrations of H2TMpyP-4 and Cu(II)TMpyP-4 with the synthetic polymer poly(dG-dC) co…
A strong case is made to show that the $F$-type color centers in oxide crystals are qualitatively different from the color centers of alkali halides. A semiquantitative discussion is followed by the results of an $X\ensuremath{\alpha}$ self-consistent-field calculation for the $\ensuremath{\alpha}$-${\mathrm{Al}}_{2}$…
Both elastic and inelastic electron scattering have been used to characterize and investigate the electronic properties of As${\mathrm{F}}_{5}$-doped polyparaphenylene. Evidence is presented for the existence of a polaron state slightly above the top of the valence band at low doping levels. An increase in the doping…
The local translational structure of a two-dimensional colloidal liquid is observed by use of cross correlation of the intensity fluctuations of light scattered by the liquid through two different wave vectors. The utility of multidetector scattering in probing multipoint correlations in disordered phases is thereby d…
Abstract Three-dimensional diffraction patterns of monochromatic electromagnetic waves contain moving line singularities where the magnitude of the transverse field is zero, and its direction is therefore indeterminate. They are called disclinations, by analogy with the corresponding linear features in liquid crystals…
Abstract TANTALOY 61 METAL is a tantalum-tungsten alloy of high density. It was developed for use as a spring material or for other elastic parts which must operate under chlorinating or severe acid conditions. Its combination of mechanical and anti-corrosion properties has led to extensive use for chlorinator valve s…
The paper comprises a theoretical and experimental investigation into the impulse breakdown voltage-time characteristics of a spherical- particle-contaminated coaxial-cylinder gap in compressed SF6and SF6-N2mixture. The experimental work was carried out on a 25/70-mm diameter coaxial-cylinder gap with a 3.2-mm spheric…
The description of current-induced failures in thin film metallizations used in microelectronic devices should not be limited to electron wind arguments. Several failure mechanisms such as grain boundary grooving, thermotransport and electrotransport, may contribute to matter transport under conditions normally encoun…
Alternative sandwich-panel decorative films were investigated as replace ments for the polyvinyl fluoride currently used in aircraft interiors. Candidate films were studied for flammability, smoke emission, selected toxic gas emis sion, flame spread, and suitability as a printing surface for the decorative acrylic ink…
Abstract The use of binary systems as accelerators in the vulcanization of rubber has received considerable attention, since many of them in suitable combinations, have been shown to provide efficient vulcanization systems. Dogadkin and co-workers and Skinner and Watson reported mutual activation with a number of popu…
Abstract Es wurde der Einfluß der Temperatur auf die Hydratation des Monocalciumaluminats, CaO · Al 2 O 3 , mittels der Differentialcalorimetrie, der Bestimmung der zeitlichen Änderung der aus 1 H‐NMR‐Messungen zu ermittelnden Spin‐Gitter‐Relaxationszeit T 1 der Protonen sowie durch röntgenographische Charakterisierun…
The potentiostatic scratch method has been systematically applied to rank the pitting corrosion (PC) resistance of commercial and laboratory austenitic, superaustenitic, and extra low interstitial ferritic stainless steels in chloride solutions simulating the aggressivity of the human body and seawater. This technique…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRole of higher triplet states in the anthracene-sensitized photoisomerization of stilbene and 2,4-hexadieneJack Saltiel, David E. Townsend, and Alan SykesCite this: J. Am. Chem. Soc. 1983, 105, 9, 2530–2538Publication Date (Print):May 1, 1983Publication History Published onl…
The sorption rate of swelling penetrants in glassy polymers has been considered as controlled both by the swelling kinetics and the penetrant diffusion through the swollen layer. The stress exerted on the glassy core at the moving boundary is the driving force for the swelling, and results from an osmotic stress and a…