Materials Literature
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(I) CdSrP 2 O 7 cristallise dans P2 1 /n avec a=5,414, b=8,615, c=12,878 A, β=90,01°, Z=4; affinement jusqu'a R=6,0%. (I) CdBaP 2 O 7 cristallise dans P1 avec a=5,641, b=7,038, c=7,624 A, α=78,55, β=89,83, γ=86,79°, Z=2; affinement jusqu'a R=6,0%. Ces deux composes existent a l'etat solide comme les dichromates, avec…
We study transmission \ensuremath{\Vert}${\mathit{t}}_{\mathit{N}}$\ensuremath{\Vert} and reflection \ensuremath{\Vert}${\mathit{r}}_{\mathit{N}}$\ensuremath{\Vert} of a plane wave (with wave number k>0) through a one-dimensional array of N \ensuremath{\delta}-function potentials with equal strengths v located on t…
(NH 4 ) 3 [H 6 RhMo 6 O 24 ]•6H 2 O cristallise dans P2,1c avec a=11,435, b=11,017, c=11,789 A, β=100,02, Z=2; affinement jusqu'a R=0,042. Le polyanion [H 6 RhMo 6 O 24 ] 3− , de symetrie D 3d , est de meme structure que [H 6 Cr II Mo 6 O 24 ] 3− . L'octaedre RhO 6 , situe sur un centre d'inversion, est de forme rhomb…
Reflection-absorption infrared spectroscopy (RAIRS) in the spectral region 1700--280 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ used to identify and characterize three forms of oxygen adsorbed on a polycrystalline silver ribbon. The high resolution of RAIRS allows us to interpret the spectra resulting from adsorption…
The photoionization efficiency spectra of nickel clusters containing adsorbed ammonia have been recorded near threshold. Ionization potentials (IPs) have been assigned for 97 selected Nin(NH3)m species, with n up to 56 atoms. We observe that nickel cluster IPs decrease upon ammonia adsorption, with the magnitude of th…
The absorption of H and D into a palladium sphere of precise radius and density is examined experimentally with use of pressure-volume-temperature measurements and control techniques to achieve the stepwise boundary condition and constant pressure assumed in the common solutions to Fick's second law. Measurements were…
Photoelectron diffraction and Auger-electron diffraction studies to date have involved the study of the elastically scattered or ``no-loss'' features in spectra. In this work, we consider the diffraction patterns associated with inelastically scattered electrons in plasmon satellites. Although very similar in most pea…
Electro-optic properties of thin polymeric films can be studied by incorporating the films into the spacer layers of transmission-mode Fabry–Pérot devices formed using metal mirrors. The metal mirrors, which also serve as electrodes, are used for the application of an electric field for poling the polymeric material a…
Sound velocity, υ s , has been measured to examine the thermodynamics of structural transitions in the liquid Se-Te system. The isothermal compressibility, κ T , deduced from υ s together with the thermal expansion coefficient, α P , the constant pressure specific heat, C P , and the density shows a broad maximum when…
The detailed quantitative speciation of phosphorus and selenium microstructures in phosphorus-selenium glasses is derived from combined $^{31}\mathrm{P}$ spin-echo and magic-angle-spinning NMR experiments. The results illustrate that the structure of these glasses differs from the chemically ordered or clustered struc…
Abstract Differential scanning calorimetry (DSC) and in situ small‐angle x‐ray scattering (SAXS) indicate that in an α ω‐methoxy‐poly(ethylene oxide) (MPEO) fraction (MW 3000) a transient nonintegral folding (NIF) crystal initially forms during crystallization throughout a wide range of crystallization temperatures. S…
Evidence for interaction between the N-N pair and interstitial O in N-doped Czochralski silicon has been presented by studying the annealing behavior of the corresponding IR absorption bands.
Diamond powders with grain diameters up to 0.3 μm were obtained by CO2 -laser-induced decomposition of C2H4 at low pressures and temperatures. C2H4 or mixtures of C2H4, H2, and SiH4 were irradiated in a gas-flow reactor with the 10P14 line (10.532 μm) of a grating-tunable CO2 laser with 50-W cw output power. Solid pro…
Selectively deuterated glycerol has been subjected to 2 H-NMR spin-lattice relaxation and quasi-elastic neutron scattering experiments. The measurements yield relaxation rates and a non-Gaussian Q -dependence of the Debye-Waller factor which are different for the two hydrogen sites. The data analysis shows that below…
Dense fluids of biaxial hard convex bodies exhibit a phase transition from an isotropic to a nematic (I–N) liquid–crystalline state. In the Onsager theory, the I–N transition is attributed to the tendency of pairs of molecules to minimize their excluded volume (or second virial coefficient, B2 ). In the present work,…
Measurements of the dynamics of NH(X3∑−, v =1–3), created in electron-irradiated N2/H2 and Ar/N2/H2 mixtures, have been performed. Time-resolved Fourier spectroscopy was used to observe NH(v→v–1) vibrational fundamental band emission. Time-dependent populations were then determined by spectral fitting. Subsequent kine…
Abstract The complex polymorphic behavior of syndiotactic polystyrene (s‐PS) in melt‐crystallized samples is altered by blending with poly (2,6‐dimethyl‐1,4‐diphenylene oxide) (PPO). In particular, to render the beta form in these blends, starting with samples containing the α or γ froms, requires much lower temperatu…
Abstract The synthesis and living cationic polymerization of 11‐[(4‐cyano‐4′‐biphenyl)oxy]‐undecanyl vinyl ether ( 6 – 11 ) are described. The mesomorphic phase behavior of poly( 6 – 11 ) with different degrees of polymerization was compared to that of 6 – 11 and of 11‐[(4‐cyano‐4′‐biphenyl) oxy] undecanyl ethyl ether…
We present calculations of the local frequency spectrum of 〈110〉-split-interstitial atoms in bcc metals with the use of the Green's-function method. The dumbbell vibrates with low-frequency resonant modes and high-frequency localized modes with little contribution from the host frequencies. In agreement with experimen…
A useful magnitude of angular selective transmittance of incident unpolarized light is demonstrated in obliquely deposited aluminum. Required deposition procedures and anisotropic optical properties are discussed. Angular selectivity is very strong at visible wavelengths but both experiment and theory indicate that a…