Materials Literature
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Abstract Deprotonated N ‐phenyl, N ′, N ′‐dialkylthiourea (PhtuR 2 ) complexes of Cu(I) and Cu(II) have been isolated and the existence of a Cu(III) complex inferred from electrochemical measurements. The crystal structure of Cu(I)[(C 6 H 5 )NC(S)N[(C 2 H 4 ) 2 O]] (space group P l̄, Z = 24, a = 10.487(9), b = 28.961(…
A high-yield six-step synthesis of sequirin D (1a), a naturally occurring norlignan, is described. Michael addition of deoxyanisoin (2) to acrylonitrile gives a ketonitrile (3), which on Wolff–Kishner reduction is reduced and hyrolysed in situ to 4,5-bis-p-methoxyphenylpentanoic acid (4). Cyclodehydration of (4) with…
In aqueous dimethylformamide solution meso-αααα-tetra(o-maleamoylphenyl)porphyrin undergoes rapid metal incorporation (CuII, ZnII, CoII, and NiII) by a mechanism featuring rate-determining intramolecular transfer of the metal ion from the carboxylate binding site to the porphyrin nucleus.
The fact that the polarization-related electrostrictive coefficients Q in the relaxor type ferro-electrics are almost an order of magnitude smaller than in most normal ferroelectric perovskites can be explained under the assumption that the temperature dependence of the soft-mode TO phonon frequency is given as ω2 TO…
—This paper summarizes experimental results obtained during the study of the production of nitrogen oxides in a well stirred reactor burning hydrocarbons. First, the particular problem of NO and NO2 probing has been addressed, and it has been shown experimentally that NO → NO2 conversion actually occurs within the pro…
The metal-insulator transition in Ti2O3 is described as a bandcrossing transition, an electron-hole gas forming when its free energy becomes greater than the gap.
The 13C n.m.r. spectrum of high-spin chloro(5,10,15,20-tetraphenylporphyrinato)iron(III) has been unambiguously assigned using porphyrins isotopically enriched at selected positions. The unexpected linewidth of the resonances of the porphyrin core carbons is explained by the dipolar interaction of the carbon nuclei wi…
The fatigue properties associated with the β1\ ightleftarrowsβ1′ transformation pseudoelasticity cycling of Cu–Al–Ni alloy single crystals have been investigated by cyclic loading tests and fractographic observations. Fatigue life is surprisingly short even under 100 MPa of applied stress, although the static fracture…
A phenomenological theory separating an isochronal data of temperature dispersion of the complex dynamic modulus function of PET into α, β, and γ relaxation mechanisms (αI, αII, β, γI, γII, and γIII) was proposed on the basis of the following three assumptions: (1) additivity for assessing the contribution of each rel…
The thermal decomposition and the glass transition temperature of poly-p-tert-butylstyrene (PptBuS) were studied with a (DSC-2) differential scanning calorimeter. The undecomposed and decomposed polymers were analyzed by gel permeation chromatography for molecular weight distributions and by DSC-2 for changes in the p…
A tripod field is used as model for a general anisotropic fluid. The elastic energy density is expanded as invariant polynomial in the components of the contortion tensor. Surface energy terms are derived from compatibility conditions for the tripod field. The model is applied to cholesteric liquid crystals of large a…
Skinfold thickness measurements on 626 normal subjects of both sexes between the ages of 5 months and 73 years demonstrated a tri-phasic relationship between loss of skin thickness and age. Measurements for infants of either sex were indistinguishable and high, falling rapidly to levels which only changed slightly ove…
In order to find a sulfide solid electrolyte with high ionic conductivity, the electrical conductivities of alkaline earth sulfides and CaS doped with a rare earth sulfide or a titanium group sulfide were measured by the ac bridge-complex impedance plot method at 1073–1673 K. From the dependence of the conductivity on…
Abstract
The circular dichroism (c.d.) spectra corresponding to 7F0→5D1.2 and 7F1→5D0,1,2 transitions of the europium oxydiacetate crystal are reported. The electric dipole and magnetic dipole contributions to the total transition moment are separated for the principally magnetic dipole allowed 7F0→5D1 transition as well as fo…
The susceptibility of polymeric insulating materials to breakdown by ‘treeing’ has impeded their utilisation as insulation for high voltage cables. This review surveys the results of tests used to investigate tree initiation and propagation and discusses factors which affect the resistance of materials to breakdown by…
Abstract Bei den Bemühungen um die Erschließung neuer, regenerierbarer Rohstoffquellen für die Chemie kann die Stärke eine besondere Rolle insofern spielen, als sie als natürliches Polymeres durch Konversion und Modifizierung den Anforderungen, die sich aus einer Verwendung als Rohstoff oder Zwischenprodukt biotechnis…
An algorithm to evaluate depth-dose distributions produced by plane-parallel electron beams normally incident on two- or three-layer slab absorbers has been developed. It is based on a simple model of electron penetration across the interface, and makes use of empirical equations previously formulated as well as ones…
By a PdSO4–heteropolyacid(H3PMo6W6O40)catalyst system in the liquide phase cyclo-olefins, particularly cyclopentene and cyclohexene, are oxidized to the corresponding ketones.
A comprehensive analysis is given for water proton relaxation rates, T–11. and T–12, measured in solutions of Mn–EDTA2–. Protons of water molecules hydrogen-bonded to co-ordinating carboxylate oxygen atoms of EDTA make a significant contribution to overall relaxation rates. After allowing for these secondary solvation…