Materials Literature
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Dispersion experiments of the second-order nonlinear optical susceptibility are reported for two fundamentally important organic systems $p$-nitroaniline and 2-methyl-4-nitroaniline for which detailed quantum-mechanical calculations have been completed. The frequency-dependent measurements were performed by dc-induced…
The dynamics of concentration fluctuations in binary polymer mixtures AB, A and B being long and flexible chains, is studied near the critical point of unmixing. A ‘‘hydrodynamic’’ theory in close analogy to the treatments of Cahn–Hilliard and Cook for the dynamics of unmixing alloys is developed, and its validity is…
A quantum mechanical method based on the Kramers–Heisenberg dispersion relation is used to evaluate the dielectric response of small metal particles, and thereby to determine the influence of particle size on the widths of the plasmon resonance line shapes. Several different particle shapes are considered (sphere, cyl…
Most one-dimensional conductors are quite similar since the Fermi surface is a point and the electron energy dispersion relation near the Fermi surface is linear. It is pointed out that in polyacene the Fermi surface lies at the edge of the Brillouin zone, but that an accidental degeneracy between the valence and cond…
The position of the Fermi level ${E}_{F}$ relative to the valence-band maximum ${E}_{V}$ has been determined from accurate measurements of the Si $2p$ core-level position relative to ${E}_{F}$. As a reference, we use $p$-doped samples with a Ga overlayer and $n$-doped samples with a Cs + O overlayer where ${E}_{F}$ is…
The temperature dependence of the refractive indices of SrTiO 3 and TiO 2 was measured in the 450-1600 nm wavelength range and at temperatures from room temperature to 400 degrees C. The thermal coefficients of the refractive indices of those materials depend on temperature, and the coefficient to TiO 2 is larger than…
An analogy is drawn between continuum elastic theories of the blue phase of cholesteric liquid crystals and recent theories of frustration in configurational glasses. Both involve the introduction of a lattice of disclination lines to relieve frustration; the frustration is due to an intrinsic curvature in the natural…
uv photoemission and electron-energy-loss measurements of Si(111)-7 \ifmmode\times\else\texttimes\fi{} 7 between $T=15 \mathrm{and} 300$ K reveal significant temperature-dependent changes in the occupied surface states and their transitions which can be associated with electron-phonon coupling at the surface. Several…
Absorption and luminescence-excitation measurements show that the H3 vibronic centre in diamond (zero-phonon line at 2.463 eV) has a series of excited states which give rise to absorption lines between 3.2 and 3.6 eV. There is no luminescence produced by transitions from these higher excited states to the ground state…
<div class="section abstract"><div class="htmlview paragraph">The corrosion resistance of Zn-Ni alloy electroplated sheet steel (SZ) against perforation and cosmetic corrosion was investigated in cyclic corrosion tests and service corrosion environment.</div><div class="htmlview paragraph">Perf…
Conoscopic observations have been made on a mixture of potassium laurate, 1-decanol, and ${\mathrm{D}}_{2}$O in the discotic-uniaxial, biaxial, and cylindric-uniaxial nematic phases. The differences between the principal refractive indices have been measured, leading to a complete determination of the tensor order par…
Proximate chemical analysis was conducted on the carding, spinning and weave rooms of textile mills. The dust was found to be composed of inorganic, cellulosic and noncellulosic organics in carding and spinning. The percentage of noncellulosic organic (the component of cotton dust considered to be responsible for byss…
The Raman spectra of the ferroelastics KH3 (SeO3)2 and KD3 (SeO3)2 have been measured at several temperatures across the phase transition. Broad Rayleigh wings are observed in the B and B3g symmetry spectra. The Raman spectra indicate that the phase transitions are of an order—disorder type.
To clarify the stray light effect in a polarized component which contains information about the splay viscosity coefficient, Rayleigh scattering from a nematic, MBBA, is observed at a small scattering angle α'=8° by a highly accurate microcomputer-based photon correlation spectrometer. By tilting a homeotropically ali…
The crystal of gadolinium pentaphosphate belongs to the monoclinic system.The space group is P21/a.The crystal parameters are a=12.910(9), b=8.889(10), c=8.721(6)Å, β=90.53, z=4. The diffraction data have been col-lected by using PW-1100Four-Circle Diffractometer. The total number of inde-pendent diffraction amounts t…
Some experimental conditions which generate the dislocation-enhanced Snoek peak in Fe-C alloys are presented. The results indicate that the movement of non-screw dislocation segments is involved in the relaxation mechanism. The results are consistent with the movement of non-screw dislocations in a medium with a visco…
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Article Order-disorder transition in MgAl2O4 spinel at high temperatures up to 1700 °C was published on December 1, 1983 in the journal Zeitschrift für Kristallographie - Crystalline Materials (volume 165, issue 1-4).
A relaxation time of the order parameter in the ferroelectric phase of ammonium lithium sulfate has been determined by analyzing anomalous temperature dependence of the Brillouin peak intensity. It is shown that the anomalies of the elastic constants associated with the phase transition cannot be interpreted by a conv…
Samples from the upper Oligocene and lower Miocene of Holes 515B (Brazil Basin) and 516F (Rio Grande Rise) were examined for fossil marine diatom content. The preservation of the diatoms was poor and the species diversity low in both holes. However, it was possible to zone portions of the intervals studied using the z…