Materials Literature
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We study a novel surface superlattice structure formed by a honeycomb gate pattern on GaAs/AlGaAs heterostructures with a high-mobility two-dimensional electron gas. The hexagonal gate arrays, fabricated by electron beam lithography, had pitches as small as 150 nm, corresponding to hexagons with 87 nm between adjacent…
Films of a single polyimide having a rodlike molecular skeleton of uniform thickness were prepared on silicon and quartz substrates under several different heating rates during the thermal curing cycle. The molecular orientation in the cured polyimide film was evaluated by polarizing infrared and visible light investi…
A numerical method for obtaining the vibrating sample magnetometer (VSM) sensitivity functions due to a uniformly magnetized sample in the shape of ellipsoid, cuboid or cylinder, and then calculating the induced voltage in a VSM detection coil systems is presented. The induced voltage, which depends on the equilibrium…
Sodium sulphate is produced mainly from land ores by conventional crystallization methods of evaporation and dehydration; these sources are fast being exhausted and new processes should be found which do not use the conventional sources. Seawater bittern produced as by-product from solar halite plants contains about 6…
An experiment on Raman scattering in porous silicon containing a regular system of quantum wires reveals a shift of the phonon frequencies of the silicon lattice toward higher energies. The effect is interpreted as a manifestation of a compressed state of the material in the quantum wires. It is shown that the observe…
We present efficient blue electroluminescence devices based on pure soluble poly(paraphenylene) polymers and poly(phenylene) oligomers. Highly efficient green and red emission light is produced with a new color conversion technique by pumping fluorescent dye layers with blue organic light-emitting diodes. The high int…
Heat capacity measurements have been made in the temperature range 1-310 K for a phasonless perfect quasicrystal Al65Cu20Ru15, an Al65Cu20Ru15 quasicrystal with phason disorder, and a crystal approximant Al70Cu20Ru10. The electronic heat capacity of the perfect quasicrystal was found to be essentially zero. The existe…
Abstract Low temperature spectroelectrochemistry was performed to generate highly reduced σ‐alkyl iron porphyrins, which were unstable at room temperature and oxygen sensitive. Suitable conditions for obtaining a stable compound were provided by keeping the thin‐layer cell under strictly anaerobic conditions. To calib…
Article Redetermination of the crystal structure of tris(acetylacetonato)iron(III) (ferric acetylacetonate), C30H42Fe2O12 was published on November 1, 1996 in the journal Zeitschrift für Kristallographie - Crystalline Materials (volume 211, issue 11).
Extending the usable bandwidth of shape memory alloy actuators for vibration control is investigated, both analytically and experimentally. The differential actuator, which uses SMA wires in agonist-antagonist pairs, is a potential solution. Simulation shows that only modest power requirements are necessary to achieve…
The interfacial activity of 2-hydroxy-5-l-butylbenzophenone (E)-oxime (HBBO), two model a-acyloin oximes: 9-hydroxy-8-hexadecanone oxime (HHO) and 13-hydroxy-12-tetracosanone oxime (HTO), and a model modifier such as p-tertbutylphenol (BPh) is investigated at toluene/ water interface, at 21°C. Interfacial tension isot…
Abstract The Raman spectrum of icosahedral α‐boron presents a very sharp peak at 525cm −1 that was consistently rejected from the lattice modes but is still unexplained. New Raman scattering experiments under pressure are compared with ab‐initio lattice dynamics calculations. The very good agreement of the mode freque…
Abstract At ambient pressure the phase transition in hydrogen-bonded ferroelectric crystals of the (KDP stands for KH2PO4) is a combined effect of atomic displacements and of proton disordering in hydrogen bonds. It is shown, that the occurrence of tricritical point in these materials result from the competition betwe…
We have studied the temperature evolution of the optical absorption and Raman scattering spectra of a trans-cis blend of “soluble” polyacetylene in a polyvinylbutyral/butanol mixture. On decreasing temperature a reversible restructuring of the electronic and lattice systems of trans -(CH) x occurs: the electronic ener…
Cellulose, as the most abundant natural biopolymers in the world, has attracted much attention in recent years, as concerns have been raised on environmental issues associated with the use of petroleum related products. Nano crystalline cellulose (NCC) is a special type of cellulose that is derived from renewable and…
Abstract Durch Kristallisation aus MSeO 3 ‐ und M(HSeO 3 ) 2 ‐Lösungen wurden die Selenite MSeO 3 · H 2 O (M = Mn, Co, Ni, Zn, Cd) erhalten und röntgenographisch sowie IR‐spektroskopisch charakterisiert. Von ZnSeO 3 · H 2 O wurde die Kristallstruktur bestimmt. Die IR‐Spektren deuten auf Isotypie der Hydrate und H 2 O‐…
A DNA clone which complemented an arg-14 mutation of Neurospora crassa was isolated by sib selection from a cosmid library (pMOcosX). Southern and restriction-fragment-length polymorphism (RFLP) analysis confirmed that the cloned DNA contained the arg-14 gene. The arg-14 gene was identified as the structural gene for…
We present a combined molecular dynamics and Monte Carlo simulation method that treats the vibrational and magnetic degrees of freedom on an equal footing in calculating the equilibrium properties of magnetovolume-coupled local moment systems. We apply this method to a simple model system, a single-species ferromagnet…
Optimizing a charged particle optical system utilizing a high brightness source requires the inclusion of the effect of Coulomb interactions in the evaluations. A new computer program package, named ANALIC, has been developed to perform the combined calculation of lens aberrations, space charge aberrations, and statis…
The parabolic wave equation method is used to describe the complex wave field inside the body of a thick zone plate used to focus X ray radiation. Two analytical approaches are applied: (1) Diffraction of a plane wave incident onto a separate interface between opaque and open zones is considered. We construct an appro…