Materials Literature
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This paper describes the chemical composition and the morfological nature of pulverized coal ashes, as well as their physical characteristics. Their influences —actions and effects— on the main properties and behaviour of cements and concretes, and the more adequate conditions for their efficient use un them are also…
The charge density in α-Al2O3 has been refined with respect to X-ray structure factors [complete spheres for both Mo Kα and Ag Kα radiations with (sin θ/λ)max = 1.19 and 1.495 Å-1 respectively] and electric-field gradient tensors at both atomic sites, using Hirshfeld- type deformation functions. Atomic charges from a…
Derek Hull 1981 Cambridge: Cambridge University Press x + 246 pp price £22.50 (£7.95 paperback) This book is based on a lecture course for final-year materials science and materials engineering students at Liverpool University. The author's declared aim is to encourage the use of composite materials by bridging the ga…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAnnelides. 7. Discotic mesophases obtained from substituted metallophthalocyanines. Toward liquid crystalline one-dimensional conductorsChristian Piechocki, Jacques Simon, Antoine Skoulios, Daniel Guillon, and Patrick WeberCite this: J. Am. Chem. Soc. 1982, 104, 19, 5245–524…
Abstract New five complexes of the type of [RuL3−x(dmby)x]X2(x=1,2,3, L=2,2′-bipyridyl or 1,10-phenanthroline, dmby=3,3′-dimethyl-2,2′-bipyridyl, X=halide ion) have been synthesized in order to investigate the effects of two methyl groups of dmby on the absorption and emission spectra, luminescence quantum yields, and…
These proceedings of EXPLOMET 90, the International Conference on the Materials Effects of Shock-Wave and High-Strain-Rate Phenomena, held August 1990, in La Jolla, California, represent a global and up-to-date appraisal of this field. Contributions (more than 100) deal with high-strain-rate deforma
The dielectric, piezoelectric and elastic properties of 0.91(PbZn 1/3 Nb 2/3 )O 3 –0.09PbTiO 3 single crystals have been investigated as functions of temperature and applied electric field. Two multiple phase transitions at 68°C and 178°C, the crystal changing from the rhombohedral ferroelectric phase to tetragonal fe…
The low-energy part (<20 meV) of the ground-state magnetic excitation spectra of Ho 2 Co 17 and Ho 2 Fe 17 were found to consist of three modes: (i) a highly dispersive transition-metal mode; (ii) a non-dispersive local mode and (iii) a weakly dispersive mode degenerate with the local mode at the zone boundary. These…
By using an elastic body approximation, lattice vibrations of a small particle are discussed. Consideration of both vector fields and a scalar field yields the proper vibrational modes. Eigenfrequencies of the elastic vibrations are derived by considering circumstances surrounding a small particle: matrix effect, surf…
A comprehensive reference on micelles and vesicles as membrane models. Describes the properties of different membrane mimetic agents and emphasizes such applications as those in enzymology, reactivity control, and solar energy. Includes thorough data tabulations and references to original research publications.
This paper reports an x-ray diffraction study of structures and restacking transitions within the $B$ phases of heptyloxybenzylidene-heptylaniline. The system evolves from a hexagonal close-packed structure, through intermediate orthorhombic and monoclinic phases, to a simple hexagonal structure. The monoclinic phase…
Standing waves of x rays have been used to determine the positions of bromine atoms in submonolayer coverages on a (111) silicon surface. In addition to the bromine position normal to the crystal surface its components relative to a plane inclined to the surface are also measured. This information suffices to establis…
The authors report X-ray photoemission measurements of core level shifts in TaS 2 , Fe 1 3/TaS 2 , Mn 1 4/TaS 2 and Ni 1 3/TaS 2 . The shifts are related to charge transfer from the intercalate 3d ions to the host band structure, and have implications concerning observations of charge density wave amplitudes.
Optical absorption and ESR spectra of reduced vanadium centres in Ca 2 NaMg 2 V 3 O 12 are reported. The spectra are interpreted as arising from tetrahedrally coordinated V 4+ and octahedrally coordinated V 3+ . The ESR and optical data are correlated using molecular orbital (MO) theory. The composition of the flux-gr…
Mice will replace the tip of a foretoe when it is amputated distal to the last interphalangeal joint. Amputation of the digit more proximal to the joint does not result in regrowth of the foretoe. Though this growth shares certain similarities with the epimorphic regeneration of amphibian limbs, the two processes are…
New information on the magnetic ordering of the iron ions in bismuth ferrite BiFeO 3 was obtained by a study with a high-resolution time-of-flight neutron diffractometer. The observed splitting of magnetic diffraction maxima could be interpreted in terms of a magnetic cycloidal spiral with a long period of 620+or-20 A…
It is pointed out that in fluorescent and Raman scattering by molecules in or near a small particle, large enhancements in the scattered signals are obtained when both the incident and the fluorescent frequencies coincide with eigenfrequencies of the particle. Numerical results are presented for spherical particles wi…
Bend-contour patterns are used to investigate the structure features of crystals of hexagonal selenium and tellurium grown in thin amorphous condensates of Se, SeTe, CuTe. The results are compared with microinterferometry data. Two bend effects are revealed: a hitherto unknown continuous bending, progressing with cr…
Photoemission involving an intermediate core-hole \ensuremath{\rightarrow} bound-valence transition shows a strong resonance enhancement as the photon energy is tuned through the intermediate-state transition energy. We have studied the effects of electronic relaxation in both intermediate and final states on the line…
The changes of the vibrational amplitudes of molecules in a crystal lattice, due to interaction between the optically induced dipoles, are shown to account for the nonlinear refractive index of a crystal. The general expressions for the fourth- and sixth-rank tensors, ${\ensuremath{\chi}}_{\mathrm{ijkl}}(\ensuremath{-…