Materials Literature
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The reliability of the continuous transformations of origin of the current density method, which makes the transverse paramagnetic current vanish (CTOCD-PZ), for the prediction of nearly gauge-origin independent molecular magnetic susceptibility and gauge-origin independent nuclear magnetic shielding, is proved on the…
For nematic liquid crystals, we study the local stability of a radial hedgehog against biaxial perturbations. Our analysis employs the Landau - de Gennes functional to describe the free energy stored in a ball, whose radius is a parameter of the model. We find that a radial hedgehog may be either unstable or metastabl…
一様気流中におかれた橋梁断面に作用する動的空気力は桁の状態量 (速度, 変位) で表すことが多い. そのために動的空気力係数は風速, 振動数の関数となり, 周波数領域の解析を強いられる欠点がある. 本研究では, 拡張変数を導入して定数系の微分方提式で空気力を表す有理関数近似法の橋梁断面への適用を検討している. (1) 最小二乗法と最小状態量法を適用し. 後者の方が拡張変数の数が少なくてすむこと, (2) 翼形断面の場合は, 拡張変数が1つ, 偏平箱桁では2つ, トラス断面では3つ程度導入すれば精度よく動的空気力を表現でき, フラッター限界風速も精度よく予測できることを明らかにしている.
We study various models of independent particles hopping between energy `traps' with a density of energy barriers , on a d-dimensional lattice or on a fully connected lattice. If decays exponentially, a true dynamical phase transition between a high-temperature `liquid' phase and a low-temperature `aging' phase occurs…
A random field Potts model is used to establish the spatial relationship between the nanoscale distribution of charged chemical defects and nanoscale polar domains for the perovskite-based relaxor materials lead magnesium niobate (PMN) and lead scandium tantalate (PST). The random fields are not set stochastically but…
The influence of the random field effects originating from charged chemical defects and nano-domain textures on the formation and dynamics of polar clusters is analyzed. The spatial distribution of the local fields is not totally random but contains some correlations in direction and strength. Polar clusters are class…
Molecular films of protein/polyion layers were assembled by means of alternate adsorption through electrostatic interaction. Glucose oxidase (GOD) and peroxidase (POD) were assembled in combination with sodium poly(styrenesulfonate) (PSS) and poly(ethyleneimine) (PEI), respectively. Enzyme activities of those films on…
The equilibrium shape of strained InAs quantum dots grown epitaxially on a GaAs(001) substrate is derived as a function of volume. InAs surface energies are calculated within density-functional theory, and a continuum approach is applied for the elastic relaxation energies.
Six-dimensional quantum dynamical calculations of the scattering of H_2 from a Pd(100) surface using a potential energy surface derived from density-functional theory calculations are presented. Due to the corrugation and anisotropy of the PES strong off-specular and rotationally inelastic diffraction is found. The de…
Ab initio molecular dynamics calculations of deuterium desorbing from Si(100) have been performed in order to monitor the energy redistribution among the hydrogen and silicon degrees of freedom during the desorption process. The calculations show that part of the potential energy at the transition state to desorption…
First principles calculations show that H overlayers induce a honeycomb vacancy reconstruction on Al(111). Above one ML H coverage, Al(111) facets into surfaces vicinal to (111), with {100} faceted single and double steps and vacancies on the {111} terraces. These H induced reconstructions are stable because H binds m…
Rod-coil block copolymers are self-assembling polymers that combine the physics of orientational ordering of rodlike polymers and the microphase separation of coil-coil block copolymers. Several new solid-state morphologies were observed in a series of anionically synthesized model poly(hexyl isocyanate-b-styrene) rod…
In the present paper we report studies on metal-polyaniline (PAn) Schottky junctions where PAn is doped with various dopants such as hydrochloric acid (HCl), formic acid (HCOOH), iodine (I2) and methylene blue (C16H18N3SCl). The I-V characteristics for the different Schottky junctions have been reported. Electronic pa…
Two-component polyurethane flame retardant coatings were prepared by blending 2,3-dibromo modified polyesters (2,3-DBPOs) and polyisocyanate. 2,3-DBPOs were synthesized by polycondensation of 2,3-dibromopropanoic acid, a flame retardant aliphatic carboxylic acid, with 1,4-butanediol, trimethylolpropane, and adipic aci…
The relaxation behavior of poly(phenylene sulfide) (PPS) RytonTM film has been studied as a function of annealing temperatures, Ta, ranging from 30°C to 140°C. Previously, this type of semicrystalline PPS film was shown to possess a very large fraction of constrained, or rigid, amorphous chains. Here we investigate re…
Effect of Viscosity ratio (ηEPR/ηPP), propylene (C3) content of (ethylene-propylene copolymer (EPR)), and peroxide/coagent treatment on polypropylene (PP)/EPR (80/20 by weight) melt blends were studied in terms of morphological, rheological, thermal, and mechanical properties. As the viscosity ratio increases from app…
The synthesis is described of some aromatic polyamides based on unsubstituted, and methyl-, carboxy-, and sulfo-substituted diamines by interfacial polycondensation. Some of them are crosslinked and some of them contain heterocyclic aromatic rings. Their chemical structures are characterized by IR and 13C solid-state…
The effect of press-drying temperature on the surface chemistry of chimicothernomechanical pulp fibers has been studied using electron spectroscopy for chemical analysis (ESCA). The chemical composition showed no significant variation for press-dried samples at temperatures between 25 and 140°C. On the other hand, ESC…
Homopolyamic acids and copolyamic acids were prepared from four dianhydrides and three diamines. Copolyimides could be arranged in sequence through different reaction processes, such as alternating, block, and random. Polyamic acids were subsequently converted into corresponding polyimides by the solid-phase imidizati…
The relationship between vulcanization reactivity and chemical structure was studied using a rheometer and DSC for natural rubber (SMR 5CV), butadiene rubber (BR 01), styrene-butadiene rubber (SBR 1501), and their blends. The overall rate of the vulcanization was SBR > BR > NR. This was the same trend as the number of…