Materials Literature
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Spatial-period (320-nm) square-wave gratings fabricated on amorphous SiO2 substrates were used to produce uniform alignment of the director in nematic and smectic liquid-crystal layers. This demonstrates that molecular alignment can be achieved using surface structures fabricated by a planar process. A novel method of…
Recombination mechanisms for electrons and holes in chalcogenide glasses and amorphous silicon are discussed. In chalcogenides the model of charged defects is assumed to hold. Recombination can occur either radiatively by an electron-hole pair at a defect, or nonradiatively by self-trapping of a free exciton or by tun…
A molecular-dynamcis study of silver diffusion in superionic conductor $\ensuremath{\alpha}$-AgI is performed. Interionic potentials are constructed using Pauling's ideas of ionic radii. The diffusion constant for silver and its temperature dependence are in good agreement with experiment. Good agreement is also obtai…
A first direct observation of the '50K' structural transition in beta -phase palladium hydride has been made using neutron scattering. This observation, of a superlattice reflection at ( 1 / 2 10), allows us to conclude that the transition is essentially an order-disorder transition involving a local rearrangement of…
The role of boundary scattering of phonons in reducing the lattice thermal conductivity is investigated in silicon, germanium and silicon-germanium alloy. The theoretical model gives a satisfactory explanation to the reduction in thermal conductivity observed in thin undoped films of silicon compared to bulk material.…
Abstract The permeation characteristics of cellulose acetate membranes in separation of polymers from their aqueous solutions were investigated by changing the preparation conditions of the membranes, that are the solvent evaporation period and the casting solution composition consisting of a mixture of cellulose acet…
The EPR of ${\mathrm{Gd}}^{3+}$ impurities in the interconfiguration-fluctuation (ICF) host Ce${\mathrm{Pd}}_{3}$ is reported. The observed linewidth is consistent with an intrinsic relaxation rate proportional to $T$, where the proportionality constant is 3 times smaller than in the isostructural non-ICF host Y${\mat…
We have measured the carbon $K$ edge in graphite using inelastic-electron-scattering spectroscopy. The extended x-ray absorption fine structure is in good agreement with theory for the first-neighbor atoms at a distance of 1.42 \AA{}. The momentum dependence of the edge structure is in qualitative agreement with a sim…
Abstract Type I (a) diamonds contain high concentrations of nitrogen, almost all of which is in an aggregated form. The two main aggregates are recognized by characteristic absorption features in the infrared region of the spectrum. These are called A and B features; usually a peak designated B' is also present. When…
Meßzelle aus Ringelektrode und darin zentrierter Stabelektrode. Elektrodenmaterial: Molybdän, Schmelzaggregat: Tammannofen. Untersucht wurden acht Schlacken zwischen 1240 und 1690°C. Messen der Admittanz in Abhängigkeit von der Stromfrequenz. Aus dem frequenzunabhängigen Bereich wurde die spezifische elektrische Leitf…
The effect of binder levels and needle and harb variables on selected physical properties and correlation between three subjective hand properties of compactness, stiffness, and roughness and the physical properties were investigated. The binder levels significantly influenced the mean values of initial modulus, ruptu…
The design of the imaging and deflection components in an electron probe is directly related to the resolution required in the target plane. The resolution has an especially strong effect on the design when the probe is to be scanned over a large area. The theoretical models of such systems commonly calculate the prop…
The equilibrium phase diagram for the system Li 2 O‐BeO‐SiO 2 contains only one ternary compound, Li 2 BeSi0 4 . Liquidus relations for compositions containing 33 mol% SiO 2 were determined; 10 liquidus invariant points were located and 7 subsolidus compatibility triangles. The most refractory compositions lie on the…
The electron-optical properties of a stigmatic crossed-field energy analyzer (double-focusing Wien filter) have been obtained from exact trajectory calculations. The results are given in the form of focusing and dispersing coefficients to the second order. These coefficients enable the device designer or potential use…
In this paper, we focus on the hypodermal component of the integument and its functional contribution to properties of skin mobility. A specially designed mechanical apparatus was used to measure hypodermal extensibility in vivo of 6-mm "island" punches at selected anatomical sites in anesthetized pigs. Representative…
A general problem of the dynamic Jahn-Teller effect for an electronic doublet ( E ) state in tetragonal symmetry has been studied. Numerical calculations of energy levels and Ham's reduction factors have been done for the cases in which the frequency for the two modes (β 1 and β 2 ) and the coupling to them are assume…
Surface compositions of single-crystal specimens of InSb have been investigated by XPS. A correlation between the degree of surface oxidation and the type of chemical etchant used has been found. This interpretation is based on chemical-shift data and argon-ion bombardment experiments, together with XPS results obtain…
Fabric luster is usually described visually (e.g. dull, bright, glittery, etc). Instrumental reflectance measurements have been applied to gauge luster, but these techniques only give overall reflectance values and do not adequately describe the luster. Image texture analysis, on the other hand, has been successfully…
Abstract Seit 1949 hat die industrielle Herstellung von Titan ausgehend von den USA in Europa, Japan und den UdSSR zunehmende Bedeutung gewonnen. Heute zählt der Werkstoff mit einer Erzeugung an Schmelzblöcken von rd. 30 000 jato in der westlichen Welt zu den Konstruktionswerkstoffen, die in weiten Bereichen der Techn…
As a liquid wire migrates through a solid in a thermal gradient, the cross-sectional shape of the liquid is deformed from the symmetric equilibrium shape. A force model of the thermomigration process is derived to calculate both the nonequilibrium shape and the effect of wire size on the migration velocity for thermal…