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。
A comprehensive perturbation formalism is developed in order to relate the rotating-frame spin-lattice relaxation time ${T}_{1\ensuremath{\rho}}$ to the relative motions of the nuclear spins in a crystal lattice. A general relaxation equation valid in the entire temperature region is derived, from which both the stron…
Fourteen year data for 90-10 and 70-30 cupronickel alloys exposed in sea water at the F. L. LaQue Corrosion Laboratory, Wrightsville Beach, North Carolina are reported. Corrosion rates for both alloys in quiet and flowing as well as in the tidal zone tended to become linear after the first 4 years' exposure. Initially…
The refractive index and the absorption coefficient for sputtered α-HgS films several μm thick were determined in the wavelength region from 0.5 to 2.5 μm by the analysis of transmission and reflection spectra. The results showed that the refractive index for as-deposited films decreased with increasing rf power densi…
Abstract Coarse, medium, and fine‐textured soils were studied in three different arid regions of Iran, namely Gazvin, Karaj, and Kooshkak alluvial plains, respectively. Six representative pedons including 33 samples were tested. X‐ray analyses indicated the clay mineral components of soils consist of some discrete ver…
Abstract Thick Bh horizons in siliceous sands of the North Carolina Coastal Plain have essentially no extractable iron, and very small quantities of calcium, magnesium, and potassium. Aluminum is the dominant cation and the exchange properties of the Bh horizons are dominated by Al and organic carbon. One to two grams…
The phase-Q structures of Na0.98K0.02NbO3 and Na0.90K0.10NbO3 have been determined at room temperature by the neutron powder profile refinement technique. Two different models were refined: orthorhombic, space group P21ma (No. 26, in cab setting) and monoclinic, space group Pm (No. 6, in the second setting). The latte…
The introduction of a phenomenological relaxation time to take collision into account in the longitudinal dielectric formulation raises some questions of principle. The author attempts to elucidate the method adopted to deal with these questions, presents a complete derivation of the RPA dielectric function by this me…
Conditions leading to surface brightening during ECM in passivating electrolytes were investigated by studying high rate transpassive nickel dissolution in acidified nitrate electrolytes under controlled hydrodynamic conditions. The experimental apparatus consisted of a flow channel cell in which constant electrolyte…
The MINDO/3 SCF MO method has been used to investigate the equilibrium geometries, electronic structure and ground state properties of ttf and tcnq and their uni- and di-valent ions. An analysis of the results indicates that both ttf+ and tcnq- have low energies of disproportionation and that electron addition or remo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCircularly polarized luminescence and energy transfer studies on carboxylic acid complexes of europium(III) and terbium(III) in solutionChun Ka Luk and F. S. RichardsonCite this: J. Am. Chem. Soc. 1975, 97, 23, 6666–6675Publication Date (Print):November 1, 1975Publication Hi…
Abstract Des mesures de RPE sur la lacune d'oxygène ayant piégé un électron (centre F + ) dans ZnO, and permis de déterminer les paramètres des interactions hyperfines magnétique et quadrupolaire électrique, avec un noyau Zn 67 adjacent à la lacune. Ceci dans les deux cas possibles de configuration: celui qui correspo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOxygen binding to iron porphyrinsJames P. Collman, John I. Brauman, and Kenneth S. SuslickCite this: J. Am. Chem. Soc. 1975, 97, 24, 7185–7186Publication Date (Print):November 1, 1975Publication History Published online1 May 2002Published inissue 1 November 1975https://pubs.…
Symmetry rules are derived for relating the convergent-beam electron-diffraction pattern symmetries to the three-dimensional symmetry of the structure. These rules are applied to a study of 2M biotite. As a result the space group is determined as C2, or number 5 in International Tables for X-ray Crystallography, where…
Abstract β-K4SiW12O40·9H2O is orthorhombic, with the space group Pnma and a=20.62(1), b=15.57(1), c=12.95(1) Å, Dm=4.88 g cm−3 and Dx=5.04 g cm−3 for Z=4. The crystal contains a discrete β-SiW12O404− polyanion, a geometrical isomer of the α-SiW12O404− with the well known Keggin structure. The idealized Keggin ion has…
Abstract Tetraphenylporphinatoiron(III) methoxide in the high-spin state S=5⁄2 gives rise to an absorption spectrum which has been assigned to that of low-spin iron(III) porphyrins. The excited states characteristic of the spectrum of high-spin iron(III) porphyrins are the configuration-interaction admixtures of the l…
The rate of in vitro enzymatic degradation of various materials based on collagen has been determined by a novel mechanochemical method, and has been compared with the extent of degradation resulting from subcutaneous implantation in guinea pigs. In vitro data correlate well with in vivo data. It is suggested that the…
Radiative transition probabilities from 3P0, 1I6, 1D2, and 1G4 levels of Tm3+ in glasses were calculated using the matrix elements obtained by intermediate coupling scheme and experimentally obtained intensity parameters. In the absence of self-absorption of fluorescence by the glass host, the fluorescence intensities…
The structures of films of 300Å‐15μ thick formed on (100), (110), and (111)Ni crystal faces at temperatures in the range 500°–800°C were investigated by electron microscopy and x‐ray diffraction. The oxide was initially polycrystalline but rearranged as the oxide thickened to major epitaxial relationships with the met…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuantitative chemical analysis of individual microparticles using the electron microprobe. TheoreticalJohn T. Armstrong and Peter R. BuseckCite this: Anal. Chem. 1975, 47, 13, 2178–2192Publication Date (Print):November 1, 1975Publication History Published online1 May 2002Pub…
Magnetic measurements which have been performed on single crystals of the Gd${\mathrm{Co}}_{2}$, Ho${\mathrm{Ni}}_{2}$, and Ho${\mathrm{Co}}_{2}$ Laves phases lead to a quantitative analysis of the crystal-field effects on energy and magnetization anisotropies. The anisotropy due to cobalt is negligible. Crystal-field…