Materials Literature
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The elastic structure factor of an unpinned charge-density wave (CDW) is derived. Both phase and amplitude excitations are studied. Phase modes cause a reduction of the intensity of CDW satellite peaks of any order. Amplitude modes, however, do not alter appreciably the intensity of the first-order CDW satellite. In f…
We present a thorough investigation of nonradiative energy-transfer processes in various rare-earth ($R$) pentaphosphates ($R{\mathrm{P}}_{5}{\mathrm{O}}_{14}$). Using time-resolved fluorescence spectroscopy, different crystals with high and low concentration of the interacting ${R}^{3+}$ ions were investigated. It tu…
Morphological instability occurring during high-velocity Si crystal growth from an impurity containing melt is examined in detail. The experimental conditions are achieved by annealing an ion-implanted Si layer with pulsed laser radiation. Computer modeling is employed to understand the heat flow and impurity diffusio…
The feasability of using poly(α-hydroxy-acid)s (poly-(glycolic acid), poly(L-lactic acid), L and D-lactic acid stereocopolymers and copolymers of glycolic and L- and D-lactic acids) for processing bioresorbable bone plates, screws, nails etc..., is questioned in regard to the requirements for effective applications an…
We modify Knauss and Wilson's approach to the theory of lattice thermal conductivity of anharmonic crystals and show that the Zwanzig-Mori projection-operator method then gives a result similar to that obtained from Green's-function methods.
A tristability is observed in the electric-field-induced liquid-crystal (LC) cholesteric-to-nematic phase transformation. The stable memory associated with the tristability has a potential application to display devices. The N-C relaxation characteristics, which determine the tristability, are found to be related to t…
In the previous paper [J. Chem. Phys. 70, 4199 (1979)] the high-spin ⇄ low-spin transitions were studied by using the model based on the static treatment of intramolecular distortion, in which the discontinuous spin transitions may be induced by the Jahn–Teller effect. In the present paper the intramolecular distortio…
Measurements of low-temperature specific heat $C$, thermal conductivity $\ensuremath{\kappa}$, and dielectric dispersion have been made on crystalline samples of the superionic conductor ${\mathrm{Li}}_{3}$N, the oxygen conductor ${\mathrm{Y}}_{2}$${\mathrm{O}}_{3}$-stabilized Zr${\mathrm{O}}_{2}$, and the relaxation…
We have investigated phosphorescence, thermoluminescence, and photostimulated luminescence in manganese activated zinc silicate phosphors, both with and without arsenic doping. Both phosphorescence and photostimulated luminescence intensities are found to decay as the reciprocal of the time, a result which requires a…
Observed 7-eV satellites in the x-ray---photoemission spectra of U${\mathrm{Ga}}_{2}$ and other $B$-group compounds are shown to be due to two-hole final states as confirmed by existing Auger data. The presence of these satellites is an indication for a weak $\mathrm{fd}$ hybridization and, when compared to uranium---…
Detailed polarised Raman spectra have been recorded at 300K of single crystals of the layered compound (NH 3 (CH 2 ) 2 NH 3 )CdCl 4 . The Raman-active external and internal modes associated with the linked layer-forming CdCl 6 octahedra and the cation chains, have been assigned on the basis of the polarisation data, m…
Abstract Oxidmischkristalle vom Perowskit‐Typ wie z.B. La, ‐xCaxYO3 ‐a oder Srlrog ° In0‐1O3 ‐o, besitzen, wie qualitativ mit einer elektrochemischen Methode bestätigt wird, in H, ‐Atrnosphäre bei hohen Temp. Protonenleitfähigkeit.
Abstract The literature on the corrosion of copper alloys in seawater published from 1975 to-date has been reviewed. The main topics covered are (i) the formation and nature of protective films (ii) velocity considerations (iii) corrosion in clean and polluted seawater with particular reference to sulphide pollution (…
Abstract In view of the increased frequency of grooving corrosion in electric resistance welded(ERW) steel pipes used for water pipes, case histories and factors affecting its occurrence have been investigated. Two types of grooving corrosion are observed in 68 case studies of troubled pipes, the continuous and discon…
The geometric structures of the clean 2\ifmmode\times\else\texttimes\fi{}1 reconstructed and the hydrogen-stabilized (1\ifmmode\times\else\texttimes\fi{}1)2H Si(100) surface have been studied by means of ion channeling and blocking. The latter surface appears to be contracted by 0.08\ifmmode\pm\else\textpm\fi{}0.03 \A…
An alternative [2] generalized Nyquist stability criterion is proposed for L2systems. It is shown that the properties of a system transfer function matrix\hat{G}(s)associated with its invertibility in the restricted space of transfer function matrices can be deduced from simple encirclement conditions in the complex p…
Abstract The reaction at the interfacial region of Cu/SiO 2 and Fe/SiO 2 heated in the high vacuum of an ESCA spectrometer has been studied. Copper spread slightly into SiO 2 at 500–800°C in the metallic oxidation state. Cupric oxide formed on SiO 2 changed to cuprous oxide or cuprous oxide plus copper metal and sligh…
The rare-earth oxysulfide La10S14O, doped with cerium, emits a bright luminescence band peaking around 6350 Å at room temperature. This red emission is quenched by copper impurities inadvertently present in insufficiently purified La10S14O. The Cu impurity in turn brings forth an emission band peaking around 7200 Å. T…
The paper describes the development and application of a hot-line insulator tester for the detection of defective suspension insulators. Concern over the quality of porcelain insulators and increasing line outage rates has renewed interest in programmed field testing of insulators. Field tests identified a need for a…
Brillouin scattering spectra of perovskite-type crystal CsPbCl 3 have been measured above its cubic-tetragonal phase transition temperature, T c =47^° C . The three elastic constants c 11 , c 12 and c 44 were determined in a wide temperature range. The result agrees quite well with that of the previous ultrasonic meas…