Materials Literature
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Probability relationships between structure factors from related structures have allowed previously only for either differences in atomic scattering factors (isomorphous replacement case) or differences in atomic positions (coordinate error case). In the coordinate error case, only errors drawn from a single probabili…
Abstract Crack healing in poly(methyl methacrylate) (PMMA) by methanol treatment at 40°C–60°C has been investigated. It is found that the methanol treatment reduces the glass transition temperature in PMMA. Crack healing only occurs at an operating temperature higher than the effective glass transition temperature. Th…
Scanning transmission electron microscopy (STEM) of positive‐temperature‐coefficient (PTC) BaTiO 3 thermistors shows that the grain‐boundary oxygen content in as‐received (oxidatively cooled) materials is slightly enriched compared to quenched samples, and the acceptor‐rich space‐charge present at high temperatures is…
High stiffness and strength combiend with low weight are the advantages offered by carbon fibers in the manufacture of reinforced composites. Effective use of these materials depends on an understanding of structure–property relationships One method of help in this work in small angle X‐ray scattering (SAXS), where th…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLadder polymers: recent developments in syntheses, characterization, and potential applications as electronic and optical materialsLuping Yu, Mai Chen, and Larry R. DaltonCite this: Chem. Mater. 1990, 2, 6, 649–659Publication Date (Print):November 1, 1990Publication History…
For pt.II see ibid., vol.6, no.5, p.35 et seq. (1990). The question of how to relate the magnitude of the measured, effective, partial discharge (PD) to the size, shape, and position of the cavity within a solid dielectric system is addressed. The causes of cavities are examined, and a brief review of gas breakdown is…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of thiazole rings to enhance molecular second-order nonlinear optical susceptibilitiesC. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. KingCite this: Chem. Mater. 1990, 2, 6, 700–705Publication Date (Print):November 1, 1990Publication History Published online1 May 2002…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolymer-supported poly(amino acids) as new asymmetric epoxidation catalyst of .alpha.,.beta.-unsaturated ketonesShinichi Itsuno, Minako Sakakura, and Koichi ItoCite this: J. Org. Chem. 1990, 55, 24, 6047–6049Publication Date (Print):November 1, 1990Publication History Publis…
A model is proposed to relate segregation of dopants with the development of fine ceramic microstructures and electrical properties in polycrystalline donor‐doped BaTiO 3 . As the average dopant concentration is increased, the dopant concentration at the grain boundary increases compared with the bulk. This has two im…
Precipitation causes changes in the modes of plastic deformation and recrystallisation, as well as in the development of rolling and recrystallisation textures. The nature of these changes varies strongly with the size, shape, and density of the particles and, in particular, on whether the particles are cut by disloca…
Whereas xenogeneic collagen has provided a safe and effective biomaterial for numerous medical applications, there are few instances in which data permit the correlation of the immunologic profile of well-defined devices with their clinical sequelae. A major exception is the use of injectable bovine dermal collagen fo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLuminescent and redox-reactive building blocks for the design of photochemical molecular devices: mono-, di-, tri-, and tetranuclear ruthenium(II) polypyridine complexesGianfranco Denti, Sebastiano Campagna, Luigina Sabatino, Scolastica Serroni, Mauro Ciano, and Vincenzo Bal…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotophysical investigation of starburst dendrimers and their interactions with anionic and cationic surfactantsGabriella Caminati, Nicholas J. Turro, and Donald A. TomaliaCite this: J. Am. Chem. Soc. 1990, 112, 23, 8515–8522Publication Date (Print):November 1, 1990Publicati…
We compare specific-heat-spectroscopy and dielectric susceptibility measurements of salol (phenyl salicylate) near the glass transition. The specific-heat-spectroscopy measurements cover 5 decades in frequency; the dielectric susceptibility measurements cover 13 decades. Over their common range, both probes measure th…
The evolution of the cold deformation microstructure is described for medium to high stacking fault energy, single phase fcc metals. Macroscopic strain accommodation for polycrystalline metals is considered, and it is suggested that grains subdivide during deformation on a smaller and smaller scale, and that each volu…
The first‐principles orthogonalized linear combination of atomic orbitals (OLCAO) method for electronic structure studies has been applied to a variety of complex inorganic crystals. The theory and the practice of the OLCAO method in the local density approximation are discussed in detail. Recent progress in the study…
X-ray structures of the peripherally crowded porphyrins, (2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphinato) Zn(II)-3MeOH solvate (ZnOETPP·3MeOH) and (2,3,7,8,12,13,17,18-octamethyl-5,10,15,20-tetraphenylporphinato) Zn(II)-pyridine-2HCCl3 (ZnOMTPP·py·2HCCl3) are reported. Both molecules are severely nonpl…
Direct observations using scanning transmission electron microscopy (STEM) of the grain‐boundary chemistry of selectively doped SrTiO 3 and BaTiO 3 show the predominant solute segregation in both systems to be that of acceptors (negative effective charge). Appreciable donor segregation is not observed even at lattice…
One important mechanical property of dental ceramics is fracture toughness, KIC, which represents the serviceability in the oral cavity, such as the resistance to marginal fracture. KIC values of several dental ceramics, natural tooth enamel and industrial ceramics were examined by use of the indentation microfracture…
Summary Direct visual studies of foam flow in etched-glass micromodels containing residual oil demonstrate that foam decays as a result of breakage of pseudoemulsion films. Foam films collapse whenever nearby thin aqueous films separating gas bubbles and oil rupture. Consequently, surfactant formulation for foam insen…