Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The optical properties of a periodic structure characterized by a uniform rotation of the dielectric tensor about a given axis are theoretically analyzed. The electromagnetic wave is described as a superposition of elementary modes having the form of Bloch waves. Each elementary mode is represented by a sum of plane w…
The dynamics of ferroelectric phase transition of KH2PO4 (KDP) have been clarified by means of Raman scattering experiments. The locally and momentarily distorted PO4 tetrahedrons play the main role on the ferroelectric phase transition in KH2PO4. The broad mode below ∼150 cm-1 in x(yx)y spectrum above the transition…
Abstract The thermal oxidation of undoped trans ‐polyacetylene powder in dry air has been studied and the principal features of the mechanism have been developed. Thermogravimetric and differential thermal analysis reveal an exothermic process that first leads to a weight increase, followed by precipitous weight loss…
Abstract Detailed quantitative studies are reported on the kinetics of acetonitrile pyrolysis using an isothermal quartz tubular flow reactor at 720–1033 K and 1 atm. Pressure using flow rates, in nitrogen, of 2–200 ml min −1 . The pyrolysis of several other nitriles (acrylonitrile, propionitrile, methacrylonitrile an…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAlkali metal insertion in the pyrochlore structureD. W. Murphy, J. L. Dye, and S. M. ZahurakCite this: Inorg. Chem. 1983, 22, 25, 3679–3681Publication Date (Print):December 1, 1983Publication History Published online1 May 2002Published inissue 1 December 1983https://pubs.acs…
High damping materials find numerous uses in the field of vibration and noise reduction in more or less complex structures. The high damping required in such structures can be structural damping or materials damping, although the distinction is not always clear-cut. Damping depends on a number of external parameters s…
Actinide oxides used for nuclear reactor fuels have fluorite-type cubic structure. In this crystal structure, the self-diffusion coefficients of the constituent ions are closely related to its sublattice structure. Characteristics of the actinide oxides are reviewed with respect to self-diffusion and chemical diffusio…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn EXAFS study of the thermal decomposition of molybdenum trisulfideDeborah R. Huntley, T. G. Parham, R. P. Merrill, and M. J. SienkoCite this: Inorg. Chem. 1983, 22, 26, 4144–4146Publication Date (Print):December 1, 1983Publication History Published online1 May 2002Publishe…
Bone mineral and synthetic calcium-deficient carbonate apatite (CDCA), when defined in terms of their respective thermal stabilities and ignition products, are homologous. When heated to 550 degrees, they may have a structure similar to that of the mineral dahllite. When heated to temperatures greater than 550 degrees…
Micromechanisms of transgranular cleavage fracture in ferritic steels have been investigated, particular attention being paid to the dependence of cleavage fracture stress σf on grain size over the range from 3·5 to 34·3 μm. It is found that σf increases less than linearly with d−1/2, where d is the grain diameter, wh…
Kinetics of the anionic polymerization of ε-caprolactone (εCL) initiated with (CH3)3SiO−K+ and carried out in THF solution has been studied in the temperature range from 0 to 20°C by using a calorimetric method. From the kinetic results and from conductometric measurements of the dissociation constant of the living Po…
We recently reported the discovery of stable disclinations of strength ± 3/2 and ± 2 in mixtures of several nematogenic compounds with a non-mesomorphic compound having plate-like molecules. We describe here further detailed observations on these defects, particularly on pairs of high strength disclinations.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTImidazole complexes of low-spin iron(III) porphyrin .pi.-cation radical species. Models for the compound I .pi.-cation radical state of peroxidasesHarold M. Goff and Martin A. PhillippiCite this: J. Am. Chem. Soc. 1983, 105, 26, 7567–7571Publication Date (Print):December 1,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSpectroscopic properties, electronic levels, and crystal field parameters of pentakis(nitrato)europate(III) ionsJ. C. G. Buenzli, B. Klein, G. O. Pradervand, and P. PorcherCite this: Inorg. Chem. 1983, 22, 25, 3763–3768Publication Date (Print):December 1, 1983Publication His…
Correlation of octahedral ion electronegativity with band frequency appears to best account for observed OH stretch frequencies in the di- and trioctahedral minerals potassic mica, talc and saponite. The site of charge substitution in the octahedral layer or in the tetrahedral layer affects the band frequencies also.…
Abstract Spherical kaolinite has been synthesized for the first time from noncrystalline aluminosilicate material in hydrothermal experiments conducted between 150° and 250°C and under autogenous vapor pressure. Spherules, whose mean diameters depended on growth conditions (0.1–0.6 μ m), were formed surrounding the no…
Laser excited fluorescence and infrared absorption spectra of single crystals of praseodymium diluted with anhydrous lanthanum trichloride was examined. A number of new fluorescing levels have been observed, numerous additional crystal field components identified, and a more complete energy level scheme is presented.
Abstract Difficulty in controlling and determining the structural parameters of polymer networks has hindered experimental studies on the glass transition in crosslinked polymers. A series of wellcharacterized networks of poly(propylene glycol) having narrow network chain‐length distributions and average molecular wei…
Abstract The mechanism of action of ammonium polyphosphate (APP) and polyurea (PU) as flame retardant (FR) agents for polypropylene (PP) was examined. The APP–PU system behaves as an intumescent flame‐retardant (IFR) formulation. Comparison of the oxygen index (OI) measured on molded pellets and rods, values of the po…
Molecular dynamics calculations based on atom–atom potentials and rigid nonpolarizable ions are used to study the cubic rotator phases of ammonium bromide (NH4Br). The nature of the orientational order exhibited by the ammonium ions is characterized using tetrahedral rotor functions (Mμ, μ=1,7). The quantities 〈M2μ〉 a…