Materials Literature
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A microdomain structure was found in the alloy ${\mathrm{V}}_{41}$${\mathrm{Ni}}_{36}$${\mathrm{Si}}_{23}$ after rapid solidification. It behaves like a structural constituent giving electron diffraction patterns similar to those from a decagonal quasicrystal though its high-resolution electron microscopic image shows…
High-resolution x-ray scattering measurements have revealed a second critical length scale at the cubic-to-tetragonal transition in SrTi${\mathrm{O}}_{3}$, corresponding to very large correlation lengths of the order of 2500 \AA{} at ${T}_{c}+1$ K. The correlation length becomes substantially larger still after the sa…
The dielectric function $\ensuremath{\epsilon}(\mathbf{q},\ensuremath{\omega})$ of Li-intercalated graphite (Li${\mathrm{C}}_{6}$) with $\mathbf{q}\ensuremath{\parallel}c$ axis was deduced from inelastic x-ray scattering data and compared with $\ensuremath{\epsilon}(\mathbf{q},\ensuremath{\omega})$ of pristine graphit…
Abstract Postcrosslinking of such linear polyesters as poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) are known to be attractive means to improve their thermal resistances without sacrificing their melt processibilities. Effective melt‐blend‐type ultraviolet‐induced crosslinking agents were…
Abstract A polytheylene composite was prepared and tested. It was consisted of a high‐density polyethylene (HDPE) matrix and uniaxial gel‐spun high‐modulus PE fiber. Aided by the similarity between matrix and fiber, transcrystallization of HDPE melt on the PE fiber surface was generated. Nucleating agents were not emp…
Abstract A new class of high performance engineering resins, poly(aryl ether ketone)s, has emerged with a property balance not offered by existing polymeric materials. Blends of poly(aryl ether ketone)s with other polymers have not been described in the open literature, although several patents have revealed interesti…
Abstract The oxygen index test is a fundamental tool in basic research on polymer combustion and on mechanisms of fire retardance. Although the oxygen index should provide an evaluation of intrinsic flammability of polymeric materials, its response may depend on geometry of the specimen. This is shown by comparing the…
The temperature dependence of the yield-stress of mono- and poly-crystalline α-brasses containing 5 to 35 at% zinc in the range 4 to 300 K is analysed in terms of the kink-pair model of solid-solution hardening. The parameter W0 in the theoretical relation τ = τo exp (–mkT/W0), where m is a constant equal to about 25,…
The scattering of conduction electrons at grain boundaries in polycrystalline copper, molybdenum, and iron is studied. Linear functions of the specific electrical resistance versus concentration of grain boundaries are determined. Coefficients of conduction electron scattering kGB at grain boundaries as well as the sp…
The effect of crystallite sizes L smaller than 100 nm on the integrated Raman cross section Σc of the transverse optical (TO) mode of fcc silicon was studied experimentally in fully nanocrystallized thin films. The Σc/Σa (amorphous) ratio of this mode is shown to be 1 up to L=30 Å, and to decay exponentially down to 0…
Sr 2 Sb 2 O 7 cristallise dans Imma avec a=7,4557, b=10,3708 et c=7,6860 A, Z=4; affinement jusqu'a R=3,48%
We measured, via LIF, time-dependent concentrations of OH resulting from the reaction of O(3 P) with B2H6 and C2H6. The oxygen atoms were generated by titrating microwave discharged N2 /He with NO to the chemiluminescent end point. The operating pressures in the flow reactor ranged from 5 to 15 Torr; the mixtures cons…
In WO3 thin films the optical dispersion parameters (single-oscillator energy E0 and dispersion energy Ed developed by Wemple and DiDomenico [Phys. Rev. B 3, 1338 (1971)]) have been analyzed in the sample thickness range 100–1000 nm using the experimental results by Davazoglou and Donnadieu [Thin Solid Films 147, 131…
We have measured the reflectivity of ${\mathrm{Bi}}_{4}$${\mathrm{Ge}}_{3}$${\mathrm{O}}_{12}$ single crystals at 300 and 80 K from 4 to 40 eV. Beyond the first sharp peak at 4.57 eV, assigned to an excitonic transition, several other structures have been found between 5 and 10 eV, followed by a broad reflectivity ban…
Gelatin films glued to an O-ring are proposed as a new procedure to record interference patterns when a CO(2) laser is used as an infrared light source. With this method the unwanted effects given by asubstrate, on which the thin recording film is laid, are avoided. To characterize the medium, interferometric studies…
The ferromagnetic Ising model on the dual Penrose lattice is simulated by the Monte Carlo method. Using a phenomenological Monte Carlo renormalization group based on finite-size scaling, the critical temperature and the magnetic critical exponent are estimated as T c / J =2.150±0.006 and y H =1.88±0.02. It is shown th…
We present results of absorbance measurements in the range of 300--900 nm on submicrometer-size solid silver needles with aspect ratios near 7:1. The needles have parallel major axes and are formed on a transparent substrate. The needles are modeled as prolate spheroids with shapes determined from electron micrographs…
M\"ossbauer spectroscopy (MS) in $^{119}\mathrm{Sn}$ and $^{129}\mathrm{I}$ was employed to investigate the evolution and properties of the high-pressure amorphous-metallic phase of ${\mathrm{SnI}}_{4}$. Measurements were carried out at pressures up to 27 GPa using diamond-anvil cells. Both MS probes detect the onset…
In optical coating calculations, a 2 x 2 matrix formalism is generally used to describe the effect of each layer on the electromagnetic field. In current applications, the layers are considered homogeneous, and, therefore, the matrix used is restricted to this particular case. In this paper, a 2 x 2 matrix describing…
A time-domain light scattering study of acoustic and Mountain modes in glycerol is reported. By using light-scattering angles between 0.89° and 88.9°, a wide range of acoustic frequencies is sampled. The data also yield information about time-dependent density responses to stress and to heat (the latter is the time-de…