Materials Literature
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New poly(azomethine urethanes) (PAMU) with linear structures were prepared in the conventional literature manner by reacting 4,4′-methylene bis(4-hydroxybenzylideneaniline) and 4,4′-methylene bis(2-hydroxybenzylideneaniline) as azomethine bisphenols, with various diisocyanates such as 4,4′-methylene bis(4-isocynatophe…
Some aspects of thermal fracture mechanics of ceramics with temperature-dependent properties are studied. It is first shown that the square-root singular field still prevails in the crack tip region. However, the size of the K-dominant zone may be influenced by the effect of temperature-dependent properties. Then the…
The crack propagation behavior in piezoelectric lead zirconate titanate (PZT) ceramics is studied. The crack propagation in piezoelectric ceramics under pure mechanical loading is considered in which a mode I mechanical loading is applied by means of Vickers indentation. Anisotropy in crack propagation is characterize…
Abstract Films of PEO and PEO blends were efficiently crosslinked by exposure to ultraviolet radiation with high‐pressure mercury lamp. Photochemical crosslinking proceeded in the presence of photoinitiator such as benzophenone or pentaerythritol triacrylate. PEO networks obtained by UV irradiation in the presence of…
An experimental study of the hexacyanoferrate (II)/(III) couple at a platinum disc electrode in hydrochloric acid, in alkali metal, ammonium and tetraalkylammonium chlorides solutions is carried out. Diffusion coefficients, equilibrium potentials and transfer rate constants are determined. Our results complete those p…
ABSTRACT The burial-diagenetic trends of illite/smectite (I/S) mixed-layer clays in the Beaufort-Mackenzie Basin have been established from detailed studies of 215 core and drill-cutting samples from 22 exploratory wells onshore and offshore. Illitization in the Beaufort-Mackenzie Basin is characterized by four types…
Abstract The chemical structure of polyolefins grafted with maleic anhydride (MA) has been the subject of much speculation, but thorough experimental studies are rare. MA with 99% 13 C in the double bond was synthesized and grafted onto PE, EPM and PP in the melt and solution. 1D INADEQUATE 13 C NMR spectroscopy was u…
Previously, a series of plate impact experiments have provided evidence for the appearance of failure waves in glasses under uniaxial compression. Presented herein is a continuation of research, performed on K9 crown glass and ZF1 dense flint glass at varied shock stresses with a goal to uncover the failure wave sourc…
Polyethylene (PE) film was implanted with 1000-keV Ar+ ions to a fluence of 5 × 1014 ions/cm2 under high vacuum conditions (2.5 × 10−6 torr) and the film surface was investigated by means of microhardness and microwear measurements, and FTIR/ATR, Raman, and XPS techniques. Ion implantation significantly increased the…
A local-nonequilibrium model of the diffusion of a solute during the rapid solidification of a binary alloy is considered. The model has two characteristic parameters: the diffusion velocity through the interface V Di and the diffusion velocity in the bulk of the liquid phase V D . The influence of local nonequilibriu…
The mechanical properties of dynamic vulcanizates depend very much on the attractive forces between the thermoplastic and rubber phases. Both in situ and separately formed block and graft copolymers were successfully used to intensify these inter facial interactions in a polymer system of polypropylene and nitrile rub…
Abstract In many areas of plastics processing the temperature is a decisive process control parameter. Infrared sensors that detect the heat radiation from molten plastic have a response time in the range of milliseconds. Thus in many processes they offer the only possibility to measure time dependent temperatures wit…
Determination of chemical structure by means of XPS through least-squares fitting of core lines is a widely used method. We present a model for the description of XPS core lines from polymers under simultaneous consideration of the lineshape and the inelastic background. For proper consideration of the background, a m…
Azurin from Pseudomonas putida is a blue copper protein which functions as an electron carrier. Two crystal forms of azurin were grown, one in the presence and the other in the absence of zinc acetate; each belongs to space group P21 and contains two molecules per asymmetric unit. The zinc-free crystals have cell dime…
Adhesive strength of Atmospheric Pressure Glow (APG) plasma-treated polypropylene was studied for various gas mixtures by a scratching test. An explanation of the high adhesive strength obtained after He/N2 APG plasma treatment was given. Formation of carbonyl, alcohol, carboxylic and primary amines was investigated b…
In ${\mathrm{Nd}}_{2}{\mathrm{Fe}}_{17\mathrm{\ensuremath{-}}\mathrm{\ensuremath{\delta}}}{X}_{\ensuremath{\delta}}$ ($X=\mathrm{Al},$ Si, Ti, V, Cr, Mn, Co, Ga, Nb, Mo, W, and $\ensuremath{\delta}=0, 0.5$) the $X$ atoms substitute for Fe without changing the crystal structure. Neutron-diffraction measurements show th…
Dihydrofolate reductase (DHFR) from the hyperthermophilic bacterium Thermotoga maritima was cloned and expressed in Escherichia coli. Sequence determination of the reported dyrA gene was repeated, and a corrected version deposited in the nucleotide sequence databank (accession number Y11021). Ultracentrifugational ana…
Poling of calcium and zirconium modified lead titanate pyroelelectric thin films has been studied. Poling temperature and electrical field were optimized to achieve high figure of merits. It was found that thermal activation is important to obtain highly poled films. Defect-dipole complexes are supposed to play a majo…
Porous silicon (PS) light emitting diodes (LEDs) were fabricated from p + n Si wafers by photoanodization. The maximum external quantum efficiency (η ext ) of electroluminescence (EL) from PS-LED up to 0.8%, which is the highest ever reported for PS-LEDs with solid state contact, was achieved under pulsed operation wi…
The elucidation of the role that injected cations play in the creation of electrochromic (EC) color centers in hydrated films is presented. The electron and cation contributions to the lattice distortion upon film coloration have been evaluated. The evolution of the fundamental absorption edge and vibrational bands of…