Materials Literature
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In samples of isotactic polypropylene, the influence of the nucleation agent chinacridine permanent red E3B on the crystallization rate and content of α and β modifications and on the rate and mechanism of the β → α transition was investigated using x-ray diffraction, DSC microcalorimetry, and electron microscopy. It…
The effects of water‐soluble polymers and benzoic acid derivatives on green and sintered Al 2 0 3 compacts were studied for two types of alumina powder. The percent of theoretical density achieved by each Al 2 0 3 sediment was dependent primarily on the concentration of water‐soluble polymeric dispersant rather than o…
Ductal infiltrating carcinoma (d.i.c.) of human breast is a highly invasive neoplasm characterized by enhanced deposition of collagen. Paradoxically, enhanced collagen deposition is not correlated with inhibition of the migration of tumour cells into the host tissue. d.i.c. is characterized by the reappearance of 'emb…
Abstract The nature, crystallochemistry, organization and surface properties of soil clays derived from the most representative sedimentary formations of France are described, using qualitative and quantitative mineralogical methods and high resolution transmission microscopy (HRTEM). The main results show that soil c…
This paper describes experimental and theoretical studies of the distribution of crystal-field sites occupied by ${\mathrm{Cr}}^{3+}$ ions in silicate glasses. The effects of this site-to-site disorder on the optical band shape of $^{4}$${\mathit{T}}_{2}$${\ensuremath{\rightarrow}}^{4}$${\mathit{A}}_{2}$ and $^{2}$E${…
Abstract The crystallization behavior of poly(phenylene sulfide) (PPS) has been examined by differential scanning calorimetry as a function of melt temperature, residence time in the melt, and the presence of a liquid crystal polymer. The results suggest that the thermal history of the sample plays an important role i…
The present study analyzes high-dispersion echelle spectra of five stars located along the main sequence of M67 using the model atmospheres of Kurucz (1979). An average iron abundance of the cluster, relative to the sun, of -0.04 or - 0.12 is derived from the observed equivalent widths of up to four weak Fe II lines i…
A two‐dimensional model of a corrosion pit was developed with use of a finite‐element method which accounted for multiple species in solution, reaction equilibria, migration, and surface kinetics. The model was used to simulate the dissolution of a hemispherical corrosion pit on nickel in . Concentration profiles show…
Abstract The objective of this investigation was to determine the elemental composition and mineralogy of the smectitic and illitic phases in interstratified smectite‐illite from a typical upper Midwestern agricultural soil. A sample of soil clay (<2‐µm fraction) from the Ap horizon of a Webster (fine‐loamy, mixed,…
The electronic structure and optical properties of ${\mathrm{KTiOPO}}_{4}$ have been calculated using a first-principles self-consistent method. It is shown that the electronic structure is characterized by localized molecular units of ${\mathrm{TiO}}_{6}$ and ${\mathrm{PO}}_{4}$. Effective-charge calculation shows K…
A second-order density-functional theory is used to study the isotropic-nematic transition in a system of hard ellipsoids of revolution. The direct pair-correlation functions of the coexisting isotropic liquid that enter in the theory as input information are obtained from solving the Ornstein-Zernike equation using t…
An essential feature of surface stabilized ferroelectric liquid crystal displays (SSFLCD) is their bistability. Experiments and theory show however that this bistability can be destroyed by ionic charges building up at both electrodes. In this article a better understanding of the ion concentration distribution and th…
Dielectric properties of alkaline-earth-substituted PbZrO 3 ceramics up to microwave frequencies were investigated. Although there were no preferable characteristics in the Ba- or Sr-substituted system, the ceramics in a (PbCa)ZrO 3 system showed not only high dielectric constants in the range of 100 to 118, but also…
The paper summarizes recent studies on absorption, luminescence, nonlinear optical effects and electro-absorption on wide-gap II-VI nano-crystals embedded in a glass matrix.
Formation of a decagonal quasicrystal in Al 70 Pd 30- x Mn x alloys ( x =8-20) and its structure were examined by X-ray powder diffraction, electron diffraction and high-resolution electron microscopy. The decagonal quasicrystal is formed as a coexisting phase with an icosahedral phase in the composition range of x =1…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of added block copolymer on the phase-separation kinetics of a polymer blend. 2. Optical microscopic observationsDong Won Park and Ryong Joon RoeCite this: Macromolecules 1991, 24, 19, 5324–5329Publication Date (Print):September 1, 1991Publication History Published on…
Die Addition eines tertiären Radikals an ein elektronenarmes Alken erwies sich als entscheidender Schritt bei der Synthese der quaterdirektionalen Kaskadenpolymere 1 und 2 , die keine Heteroatome im Initiatorkern, in den Verzweigungszentren oder in den Repetiereinheiten haben. Lediglich die Peripherie ist hochfunktion…
Photoluminescence and absorption experiments performed on Schott commercial and experimental CdSSe-doped glasses reveal the existence of a pair of narrow electronic states close to the electronic bands. According to a study of the luminescence as a function of the size of the semiconductor spheres, we tentatively inte…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and characterization of diblock copolymer films containing self-assembled polyacetylene structuresRandall S. Saunders, Robert E. Cohen, and Richard R. SchrockCite this: Macromolecules 1991, 24, 20, 5599–5605Publication Date (Print):September 1, 1991Publication Hist…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelf-assembly and patterns in binary mixtures of SI block copolymer and PPOTakeji Hashimoto, Kohtaro Kimishima, and Hirokazu HasegawaCite this: Macromolecules 1991, 24, 20, 5704–5712Publication Date (Print):September 1, 1991Publication History Published online1 May 2002Publi…