Chemical modification of polymers. Borohydride reducing agents derived from anion exchange resins
Exchange of quaternary ammonium type anion exchange beads with NaBH4 leads to useful reducing agents possessing the advantage of easy work-up.
Materials Literature
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Dimensional Stability of Fused Silica, Invar, and Several Ultra-low Thermal Expansion Materials
We have measured length change vs time for several low thermal expansion materials maintained in evacuated environments at constant temperature (near 300 K). Materials were two types of fused silica, Cer-Vit, ULE, Zerodur, Invar, and super Invar. Δ L/L was measured over a period of 170 days to a precision of two to th…
Fracture Properties of Polycrystalline Lithia‐Stabilized β “‐ Alumina
The critical stress‐intensity factor, K 1C , and the fracture strength, σ f , have been investigated on both hot‐pressed and sintered lithia‐stabilized β ”‐alumina. The hot‐pressed material possessed a strong preferred orientation with many of the basal planes aligned perpendicular to the direction of hot‐pressing. Bo…
The Corrosion and Oxidation of Metals
"The Corrosion and Oxidation of Metals." British Corrosion Journal, 12(1), p. 5
Triassic blueschist from northern California and north-central Oregon
Research Article| November 01, 1977 Triassic blueschist from northern California and north-central Oregon Preston E. Hotz; Preston E. Hotz 1U.S. Geological Survey, Menlo Park, California 94025 Search for other works by this author on: GSW Google Scholar Marvin A. Lanphere; Marvin A. Lanphere 1U.S. Geological Survey, M…
V. One‐Electron Density Functions and Many‐Centered Finite Multipole Expansions
Abstract The one‐electron density function, ρ( r ), (in principle deduced from elastically scattered X‐ray intensities) is the probability distribution function of an electron, averaged over the positions of all other electrons. A partitioning of ρ( r ) into constituent parts is an intellectual exercise that does not…
High-temperature electrical conductivity and point defects in lead zirconate-titanate
The electrical conductivity and thermoelectric power of lead zitconate-titanate Pb(Ti0.47Zr0.53)O3 (PZT) have been studied at temperatures up to 1000°C in gaseous ambients with controlled partial pressures of both volatile components: lead oxide and oxygen. The experimental results show the small polaron conduction me…
Preparation, Structure, and Selected Catalytic Properties of the System LaMn 1‐x Cu x O 3‐y
Samples of LaMn 1‐x Cu x O 3‐y in the range 0≤x≤0.8 were prepared from freeze‐dried solutions of the nitrates. Samples with x≤0.6 were single‐phase perovskites. At higher values of x , the samples contained La 2 CuO 4 and CuO as well as the perovskite phase. Samples of LaMn 1−x ,Cu x ,O 3−y supported on ceramic monoli…
Combustion of PVC
The thermal decomposition and combustion mechanisms of PVC are examined.
Reduction of nitro-compounds
Nitro-compounds were reduced to amines in high yields by using palladium, platinum, or rhodium metal catalyst with formic, phosphinic, or phosphorous acid. With formic acid, nitro-compounds containing fluorine were reduced but not those containing chlorine, bromine, or iodine. With the other acids, nitro-compounds con…
Unstable intermediates. Part 178. The structure of intermediates formed in the radiolysis of thiols
A wide range of thiols have been exposed to 60Co γ-rays at 77 K both in the pure state and in dilute methanolic or aqueous glasses. Spectra assigned to RS· radicals had gz values (z is along the C–S bond) which varied with the environment, but which were all close to 2.158 in methanol. Dissociative electron capture at…
Structural Integrity in Severe Thermal Environments
The theory of structural stability of ceramics in severe thermal environments was explored via the use of precracking. It was shown that structural stability should be possible when an array of precracks is used, but that the precracks required for this purpose are relatively large. The approach is thus limited to sys…
Composite Materials: Testing and Design (Fourth Conference)
Description The Fourth Conference on Composite Materials: Testing and Design was held 3-4 May 1976 at Valley Forge, Pa. The American Society for Testing and Materials' Committee D30 on High Modulus Fibers and Their Composites sponsored the conference. J. G. Davis, Jr., National Aeronautics and Space Administration-Lan…
Natural and artificial heterogeneous nucleation in polymer crystallization
Abstract An outline is given of heterogeneous nucleation as the main starting point for crystallization of unoriented polymer melts and solutions. The influence of temperature history on nucleation is discussed. As little is known about naturally occurring nucleants, the nature of several types of artificial nucleatin…
Reaction of carbon tetrachloride with 5,10,15,20-tetraphenyl-porphinatoiron(II)[(TPP)Fe II ]: evidence for the formation of the carbene complex [(TPP)Fe II (CCl2)]
The reaction of 5,10,15,20-tetraphenylporphinatoiron(II)[(TPP)FeII] with carbon tetrachloride in the presence of an excess of reducing agent leads to a complex having properties consistent with the carbene, :CCl2, bound to FeII; this is believed to be the first example of a carbene complex of a metalloporphyrin.
Resonance Raman spectra and excitation profiles of tris(.alpha.-diimine) complexes of iron(II)
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTResonance Raman spectra and excitation profiles of tris(.alpha.-diimine) complexes of iron(II)R. J. H. Clark, P. C. Turtle, D. P. Strommen, B. Streusand, J. Kincaid, and K. NakamotoCite this: Inorg. Chem. 1977, 16, 1, 84–89Publication Date (Print):January 1, 1977Publication…
Calcium orthovanadate, Ca3(VO4)2-a new high-temperature ferroelectric
Ferroelectricity has been discovered in calcium vanadate. Large, transparent crystals have been grown by Czochralski pulling. Electrical 180° domains of millimeter dimensions are observed by etching as-grown crystals. The ferroelectric Curie temperature, Tc = 1383 K, has been determined from dielectric, thermal and py…
Void formation and electrical breakdown in epoxy resin
The long term behaviour of epoxy resin subjected to high alternating electrical stress was studied using optical magnifications of up to 1500, a scanning electron microscope, and a high sensitivity discharge detector. The formation of voids in initially void-free specimens was investigated when voltages of duration be…
Low co-ordination numbers in lanthanoid and actinoid compounds. Part 2. Syntheses, properties, and crystal and molecular structures of triphenylphosphine oxide and peroxo-derivatives of [bis(trimethylsilyl)-amido]lanthanoids
The preparation, properties, and n.m.r. spectra of 1 : 1 triphenylphosphine oxide adducts of [M{N(SiMe3)2}3](M = La Eu, or Lu) and dimeric peroxo-species [M2{N(SiMe3)2}4(O2)(PPh3O)2](M = La, Pr, Sm, Eu, or Lu) are described. The crystal and molecular structures of [La{N(SiMe3)2}3(PPh3O)](1) and [La2{N(SiMe3)2}4(O2)(PP…
29Si N.M.R. studies of aqueous silicate solutions
Silicon-29 n.m.r. spectra have been obtained for a number of aqueous solutions of sodium and potassium metasilicate. The assignment of peaks to various silicate species is discussed. Linewidth and spin–lattice relaxation time measurements are reported as a function of ageing of the solutions in sealed glass tubes, and…