Materials Literature
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By analogy with earlier studies on Eu 2+ phosphors the luminescence of the Ce 3+ ‐doped hexagonal aluminates, containing large, divalent or trivalent cations, was also studied in relation to the crystal structure of the host lattices. The u.v. band ascribed to the luminescence of Ce 3+ ions is found at a relatively sh…
The Mossbauer effect of the 21.53 keV transition of 151 Eu was utilised to study EuNi 5 , EuMg 2 and their hydrides. Measurements of isomer shift and hyperfine field were made at various temperatures between 77K and 2.6K. The experimental data were used to interpret the hydrogen absorption mechanism acting in these in…
The pitting resistances of four high strength, high ductility, stainless steels (TRIP steels) were compared with those of the two alloys most widely used in implants today: Type 316L stainless steel and a cast Co-Cr-Mo alloy (Vitallium). Each of the alloys in several metallurgical conditions was tested in a physiologi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMono- and biscarbonyl complexes of iron(II) tetraphenylporphyrinB. B. Wayland, L. F. Mehne, and J. SwartzCite this: J. Am. Chem. Soc. 1978, 100, 8, 2379–2383Publication Date (Print):April 1, 1978Publication History Published online1 May 2002Published inissue 1 April 1978http…
The epidermal cells which migrate over the wound surface of the amputated limb of the adult newt were examined using the scanning electron microscope. Specimens were prepared routinely for scanning electron microscopy or were embedded in Epon 812 for light microscopic observations. A cuff of epidermal cells was seen a…
The magnetic susceptibilities of YCo 2 and LuCo 2 at 4.2 and 77K, as determined from magnetisation measurements in fields up to 38 Tesla, are found to increase with field in an anomalous way.
Colour centres in vitreous silica are discussed in. terms of dangling bond defects on silicon and oxygen sites. Because of the large cation-anion electronegativity difference it is argued that neutral singly occupied states will be unstable, decomposing into empty positively charged silicon sp3 states and doubly occup…
Phenomenological theory of phase separation of a binary alloy at low temperatures is developed. The equation of motion for a structure function is derived. The damping coefficient is chosen to give a correct shape of the structure function at large wave numbers. On a scaling assumption we have a slow asymptotic decay…
A comparison of intravenous to intracarotid artery (ICA) administration of 14C-BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) was made in squirrel monkeys. Radioactivity was measured as soluble drug products and as RNA-, DNA-, and protein-bound radioactivity. The ICA administration of BCNU achieved 190% to 280% higher br…
Recommended levels of a number of metals for Great Lakes Water Quality Objectives were found to be very toxic to freshwater algae when these metals were present simultaneously in lake water and culture medium. The diatom tested was more sensitive to metal toxicity than the blue-green and green algae. Key words: metals…
Alternating current microcalorimetry was used to measure the specific heat of 4-$n$-pentylphenylthiol-4\ensuremath{'}-$n$-octyloxybenzoate in the nematic, smectic-$A$, and smectic-$C$ phases. Critical exponents were found to be consistent with the superfluid analogy of de Gennes for the nematic to smectic-$A$ transiti…
A frequency domain technique is demonstrated which permits the determination of the homogeneous linewidth and relaxation rates of inhomogeneously broadened transitions in crystals, liquids, and glasses. The density-matrix formalism is employed to explain the origins of the intensity-dependent dichroism and birefringen…
An ordered ilmenite phase of the compound MnSnO3 is evidenced from powder patterns. The hexagonal and rhombohedral unit-cell parameters are respectively: a = 5.358 (1), c = 14.505 (4) Å, Z = 6 and a = 5.740 (1) Å, α = 55.65 (2)°, Z = 2: Dm = 6.11, Dx = 6.12 g cm−3.
John D. Koppen, Distribution and Aspects of the Ecology of the Genus Tabellaria Ehr. (Bacillariophyceae) in the Northcentral United States, The American Midland Naturalist, Vol. 99, No. 2 (Apr., 1978), pp. 383-397
Mechanical injury or infection with Helminthosporium maydis race T or O enhanced peroxidase activity in leaves of two corn inbreds which differ in their susceptibility to the fungal race T. Increases in activity were found in the soluble fraction extracted from tissues with 20 mm phosphate buffer (pH 6), and in the io…
Abstract Neo acids are highly branched synthetic trialkyl acetic acids manufactured by reacting an olefin with high purity carbon monoxide under high pressure in the presence of an acidic‐type catalyst. The starting olefins for neopentanoic (C 5 , single isomer) and neodecanoic (C 10 , mixed isomers) acids are isobuty…
Practical procedure for evaluation of strength of coated fabrics with crack requires a formula which bears on expression of an inherent property of the materials in phenomenon of the crack extension.
A series of polyurethane elastomers based on an aliphatic diisocyanate and a polyether macroglycol was polymerized with various cross-link densities and OH/NCO ratios. Stoichiometries yielding between 8,600 and 12,900 gm/mole/crosslink and an OH/NCO ratio of 1.1 resulted in polymers with the low modulus, yet high stre…
Coefficients of linear thermal expansion are reported in the range from room temperature to 250 degrees C for six optical materials: Polytran potassium chloride and Polytran calcium fluoride-Harshaw; chemical-vapordeposited (CVD) zinc selenide and zinc sulfide-Raytheon; single-crystal germanium-Eagle-Picher; and lithi…
The general class of phase equivalent nonlocal potentials is examined using standard reaction matrix methods. The relationship between phase equivalent overlap matrices is derived and it is found that the matrices fall into four general classes.