Materials Literature
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Lanthanum‐modified lead titanate ceramics with a tetragonality of c/a = 1.028 to 1.000 were hot‐pressed and the dielectric, electromechanical, optical, and mechanical properties were investigated. With decreasing c/a , the Curie point, remnant polarization, coercive field, and electromechanical coupling factors decrea…
A review is given of research whose objective is to understand the principles governing corrosion beneath organic coatings. Eight subject areas of special interest are discussed: electrical properties of coatings, the nature of the metal substrate in determining coating performance, electrochemical processes which tak…
Magnetization measurements and X-ray diffraction experiments have been made on ε -Mn 3 Ga (71.4 at%Mn) having a triangular spin structure with a weak ferromagnetic component below 460 K. It has been found that the D0 19 -type hexagonal structure is slightly distorted to an orthorhombic structure below 170 K, and that…
The fragmentation response of explosive-filled cylinders of Armco iron and HF-1 steel with two heat treatments has been determined. The cylinders were filled with cast-in-place composition B explosive and detonated. At least 99% of the metal mass was recovered in all the experiments. The recovered fragments had both b…
The influence of annealing time (1–1000 hours), applied tensile stress (0–130 MPa), temperature (973–1073 K) and helium content (10–300 a.p.p.m.) on the size distribution and density of helium bubbles within the grains of AISI Type 316 stainless steel has been studied by TEM of α-implanted foil specimens. The results…
Bioactive porous structure coatings have received extensive attention because they can significantly improve the surface bioactivity of medical metal implants. However, traditional porous making technologies were restricted by the "upward growth" mode, with an obvious interface with the substrate, resulting in weak bo…
Thin films that are substantially amorphous arsenic sulfide have been prepared by spin deposition from solutions of n-propylamine or n-butylamine. These materials have been investigated by nuclear magnetic resonance, infrared absorption, and elemental analysis. A structural model is suggested based on As2S3 clusters s…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffects of temperature and pressure on alkyl nitrate yields in the nitrogen oxide (NOx) photooxidations of n-pentane and n-heptaneRoger Atkinson, William P. L. Carter, and Arthur M. WinerCite this: J. Phys. Chem. 1983, 87, 11, 2012–2018Publication Date (Print):May 1, 1983Pub…
ABSTRACT The cation composition of water in the Aquia aquifer of southern Maryland changes systematically in the direction of ground‐water flow. In the upgradient parts of the aquifer, calcium is the dominant cation in solution. Between 10 and 20 miles downgradient, calcium and magnesium are dominant. Between 20 and 3…
A series of nomograms that simplify determination of diagnostic X-ray shielding requirements with lead are presented. All recommendations of the NCRP, except that to "add one half value layer" in determining secondary barriers, were followed in the production of these curves. For secondary barriers, the shielding requ…
The amino acid sequence of a single polypeptide chain, B-4, from fowl feather barbs has been determined. The B-4 chain was found to consist of 96 amino acid residues and to have a molecular weight of 10206 in the S-carboxymethylated form. The N terminus of this protein was an N-acetylserine residue. The B-4 protein co…
A mechanism for the toughening of brittle matrices with ductile particles is presented. It is shown that the constraints imposed on the particles by the rigid matrix suppress plastic deformation of the particles at crack tips so that the main contribution to composite toughness comes from ligament formation in the mat…
We describe highly accurate (0.2-1%) intensity measurements for the inelastic scattering of 75-keV electrons in \ensuremath{\sim} 1000-\AA{}-thick polycrystalline aluminum films in the region of (0.0-3.1)-${\mathrm{\AA{}}}^{\ensuremath{-}1}$ transferred wave vector and (0-100)-eV energy loss. The work was performed on…
The kinetics of grain growth in fully dense Al 2 O 3 with and without MgO solute additions were measured. The MgO was found to retard boundary migration and to rkvelop more uniform microstructures. A grain‐growth mechanism involving solute partitioning of segregated ions (calcium and magnesium) between different bound…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCalixarenes. 10. OxacalixarenesBalram Dhawan and C. David GutscheCite this: J. Org. Chem. 1983, 48, 9, 1536–1539Publication Date (Print):May 1, 1983Publication History Published online1 May 2002Published inissue 1 May 1983https://pubs.acs.org/doi/10.1021/jo00157a033https://d…
Generalized relations relating multipole population parameters to d-orbital occupancies of transition-metal atoms are presented. The relations are cast in the form of a 15 × 15 matrix which reduces to smaller size for site symmetries higher than {\bar 1}. The matrix takes into account differences in normalization of d…
Abstract The impact fracture mechanisms of rubber‐toughened nylon are analyzed by measuring the energy dissipated in several different processes during notched fracture. An energy balance is thus established for the impact fracture. The stress‐whitened zone is shown to be the energy dissipation zone, having an energy…
Abstract The impact failure of blends of nylon 6,6 and low density polyethylene grafted with maleic anhydride (PEgMA) is discussed in terms of fracture morphology, composition, and particle adhesion and dispersion. Basic criteria for effective impact modification of these materials are developed. A numerical model for…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDioxygen and carbonyl binding to iron(II) porphyrins: a comparison of the "picket fence" and "pocket" porphyrinsJames P. Collman, John I. Brauman, Brent L. Iverson, Jonathan L. Sessler, Roger M. Morris, and Quentin H. GibsonCite this: J. Am. Chem. Soc. 1983, 105, 10, 3052–30…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanistic aspects of the catalytic reduction of dioxygen by cofacial metalloporphyrinsRichard R. Durand Jr., C. Susana Bencosme, James P. Collman, and Fred C. AnsonCite this: J. Am. Chem. Soc. 1983, 105, 9, 2710–2718Publication Date (Print):May 1, 1983Publication History P…