Materials Literature
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The room-temperature direct allowed energy gap E g =3.425 eV was obtained for single crystals of GeS 2 which have an orthorhombic structure. The far-infrared transmission spectrum was measured with unpolarised light in the range of 100-250 cm -1 . The reflectivity spectrum was obtained, also with unpolarised light, in…
The following investigation concerns the identification of mechanisms responsible for the blue emission obtained with bismuth-doped lanthanum phosphate LaPO 4 (Bi). Observations of absorption, excitation and fluorescence spectra, together with measurements of the decay time from liquid He up to room temperature are pr…
A set of total cross sections for scattering of electrons by Ne, Ar, Kr and Xe has been evaluated over the energy range of about 20 to 3000 eV by means of the analysis of experiments and theories on total cross sections for elastic scattering, ionisation and excitation, and on differential cross sections for elastic a…
The reflectivity of magnetite (Fe 3 O 4 ) has been measured in the spectral energy range between 0.03 and 12 eV. The optical constants have been determined by means of a Kramers-Kronig analysis. The interband transition spectrum can be interpreted by O 2p to Fe4s transitions and be Fe3d n to 3d n-1 4s orbital promotio…
The effect of neurophysin-hormone interaction on the environment of the single tyrosine of bovine neurophysin (Tyr-49) and on that of the tyrosine of oxytocin and vasopressin was studied by fluorescence; tyrosine-free peptides were used to determine effects on Tyr-49, and acetylated neurophysin was used to determine e…
Abstract With published and estimated entropies and enthalpies of formation, we have estimated free energies of formation of schuetteite (Hg 3 O 2 SO 4 ) and corderoite (Hg 3 S 2 Cl 2 ) at 298°K. These estimates were compared with others based on the solubility of schuetteite and conditions of vapor phase synthesis of…
X-ray-scattering investigation of stoichiometric silver $\ensuremath{\beta}$-alumina reveals a clear phase transition between the high-temperature conducting-ions quasiliquid sublattice, and a lowtemperature crystalline state. Preliminary, structural analysis of the low-temperature crystalline order confirms the type…
Abstract The computer program GEOCHEM is adapted and being developed for soil solutions from the REDEQL2 program originally created by Morel and Morgan at Caltech. GEOCHEM differs from REDEQL2 in its inclusion of 1) data for a few hundred additional soluble complexes and solids that are relevant to trace metal studies…
Abstract Kinetic results of published laboratory studies of calcite dissolution and precipitation in the system CaO-MgO-Na 2 O-K 2 O-CO 2 -H 2 SO 4 - HCl-H 2 O are used to test the surface mechanism model of Plummer, Wigley, and Parkhurst (1978; Amer. Jour. Sci. 278, 179-216). This mechanism model includes: 1) three s…
The dependence of the spreading process of extrinsic grain boundary dislocations (EGBD's) on grain boundary state and misorientation, and spreading kinetics in austenitic steel is investigated. Spreading of EGBD's at non-equilibrium grain boundaries obtained by successive cold rolling and annealing treatments at a tem…
Molybdenum disulfide has been prepared in an unusual poorly crystalline form, termed the "rag" structure, consisting of several stacked but highly folded and disordered S-Mo-S layers. This previously unknown structure demonstrates the flexible and macromolecular nature of the layered transition metal dichalcogenides.…
Addition of acetate to a stationary phase culture of Escherichia coli in glycerol mineral salts medium containing phosphorus-32-labeled orthophosphate results in rapid loss of isocitrate dehydrogenase activity and concomitant incorporation of phosphorus-32 into the enzyme. This is the first example of protein phosphor…
This paper reports photoinduced optical anisotropy (dichromism and birefringence) and color adaptation in oxide glasses containing silver and halogens. The effects are found in both photochromic and fixed-tint glasses. In certain of the photochromic glasses there is memory, such that after thermal fading redarkening b…
Wideline 1H NMR studies have been carried out in various hydrated layered chalcogenides of the type A+x(H2O)y [TaS2]x− at temperatures from 148 to 300 K, where A=Na, K, NH4, Cs, and Ca. Some measurements have been made at 77, 363, 398, and 425 K, respectively, and a sample with Nb instead of Ta has also been examined.…
We have directly measured thermally induced changes in surface and bulk energy-band dispersions of copper by examining angle-resolved photoemission from Cu(111) and Cu(100) surfaces for temperatures from 25 to 500\ifmmode^\circ\else\textdegree\fi{}C. Polarized synchrotron radiation was used as the photon source. Obser…
The elastic and diamagnetic properties of some p-disubstituted phenylcyclohexanes (PCH) are investigated by studying the elastic deformation of a nematic layer under the influence of electric and magnetic fields. The elastic constants kii (i=1, 2, 3) and the anisotropy Δχ of the diamagnetic susceptibility are obtained…
X-ray photoemission spectroscopy (XPS) measurements are reported for Zr${\mathrm{H}}_{1.65}$ and Zr metal. The valenceband measurements are compared with available band-theory density-of-states calculations for the metal and hydride. The hydride spectrum differs significantly from the metal spectrum. Most important, a…
The 21.2 eV photoelectron spectra of metal-free phthalocyanine and some metal-containing phthalocyanines MPc (M=Mg,Fe,Co,Ni,Cu, and Zn) have been obtained for the gaseous molecules. Comparison of these spectra reveals that the uppermost occupied orbitals are ringlike, and not metal-3d-like, in all cases. Identificatio…
Secondary-electron energy distribution curves (EDC's) and the total secondary-electron yields relative to such for gold have been measured for seven semiconductors for which electron-electron scattering losses within the emitter were considered dominant and for nine insulators (alkali halides) for which electron-phono…
An investigation of the photoluminescence decay in plasma-deposited amorphous Si: H is presented. The relative contribution of radiative and nonradiative transitions are shown in undoped samples with efficiencies varying over two orders of magnitude. In high-efficiency samples the 10-K radiative rate spans nearly six…