Materials Literature
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The structure of crystallites (regions of coherent scattering — RCS), which comprise the grains of ultradisperse diamond (UDD) powder, was investigated by x-ray crystallography and coordination-sphere diffractometry. It was established that the RCS have an average size $$\bar L = 42 \pm 2{\AA}$$ and that these regions…
The Yafet-Kittel model for a two-sublattice ferrimagnet with an antiferromagnetic exchange interaction in one of the sublattices was developed to describe magnetic-field-induced phase transitions in the isotropic and Ising cases. Depending on the relative values of the exchange parameters of the inter-sublattice inter…
A simple method of data analysis, called the averaging technique, is presented which may be useful in long-term field measurements of temperature dependent thermal conductivity of insulating materials. Its mathematical basis is the integral statement, which follows from the heat conduction equation For lin ear depende…
With the fundamental work of Hofstadter on the combined effects of band structure and magnetic field on the electronic states in two dimensions (2D) as a starting point, we numerically study the effects on the Hofstadter butterfly of including a binary distribution of on-site potentials on a 2D lattice in the tight-bi…
La1−xSrxMnO3 is a perovskite-type magnetic material. LaMnO3 and SrMnO3 are antiferromagnetic insulators while the system becomes a ferromagnetic metal in a certain Sr concentration. In ∼0.2<x<∼0.5, it shows a so-called colossal magnetoresistance (CMR) which is a phenomenon of a huge resistivity drop when…
In a severe accident of light water reactors, the reactor coolant system (RCS) piping might be subjected to thermal loads caused by the decay heat of the deposited fission products and the heat transfer from the hot gases, with an internal pressure in some accident sequences. Tests on the RCS piping failure were perfo…
New statistical characteristics are suggested for analyzing nonwoven fabric irregularity. These characteristics are based on the concept of outliers of random field irregularity beyond (or beneath) a fixed level, and allow the area and volume of these outliers to be determined. Outlier statistics are studied and resul…
The surface and bulk magnetic structures of Sr-M-type single-crystal hexagonal ferrites (with the chemical formula SrFe 12− x Al x O 19 ) have been directly compared by simultaneous gamma, x-ray, and electron Mössbauer spectroscopy. It was found, that when the magnetic lattice of Sr-M hexagonal ferrites is slightly di…
Phosphorylating archaeal D-glyceraldehyde 3-phosphate dehydrogenases (GraP-DHs) share only 15-20% identity with their glycolytic bacterial and eukaryotic counterparts. Unlike the latter which are NAD-specific, archaeal GraP-DHs exhibit a dual-cofactor specificity with a marked preference for NADP. In the present study…
A new kind of large dispersion lower order blaze grating spectrometer is built. The design is based on the use of uncustomary large angles of incidence and diffraction approaching 80°. The double diffraction optical scheme is employed to fit the design conception. A set of compact size grating spectrometers of various…
Azimuthal anchoring energy was measured by a novel method for sample cells of several liquid crystals on various aligning layers. In this method, the deviation of director was measured and determined accurately, even in the case where the dispersion of the rotatory power is significant. The obtained azimuthal anchorin…
Two cardiotonic glycosides were isolated from Calotropois procera; one of them (1) is a new natural product. Their structures were elucidated by extensive application of one- and two-dimensional 1H and 13C NMR spectroscopy. Copyright © 1999 John Wiley & Sons, Ltd.
Anomalous lattice properties and structural phase transition of NaV 2 O 5 have been studied under hydrostatic high pressure at room temperature by using powder X-ray diffraction techniques. Upon compression the c -axis along the stacking direction of V 2 O 5 -layers contracts rapidly and the b -axis along the one-dime…
Les masses volumiques ρ(θ) de maltitol, glucose et sorbitol ont été mesurées par pycnométrie et par dilatométrie. Les variations de la masse volumique en fonction de la température sont linéaires dans la phase liquide et dans l'état vitreux. La viscosité de cisaillement a été mesurée sur 11 décades, par trois techniqu…
The oxidation of SiC whiskers, contained in alkoxide‐derived mullite‐based matrices and exposed in air at 1000–1350°C for up to 1000 h, has been studied by analytical TEM, high‐resolution SEM, and XRD. Silicon carbide whiskers were effectively protected from oxidation when embedded in a pure mullite matrix, but oxidiz…
The phase behavior of the system water/SephadexG25 in a wide range of water content Wc (g water/g dry Sephadex) has been investigated by differential scanning calorimetry. At low degree of hydration (Wc < 0.38), the system is homogeneous and is characterized by a glass transition whose temperature-composition dependen…
Hellgelbe Einkristalle von (Hg2)2P2O7 sind über chemischen Transport im Temperaturgradienten (500 °C → 450 °C, 23 d) mit Hg2Cl2 als Transportmittel zugänglich. Charakteristisch für die Kristallstruktur (P2/n, Z = 2, a = 9,186(1), b = 4,902(1), c = 9,484(1) Å, β = 98,82(2)°, 1228 symmetrieunabhängige von 5004 Reflexen,…
In this study, we developed a simple electromechanical, lumped parameter model to simulate the dynamic performance of a deformable mirror driven by electrostrictive actuators in an adaptive optics system. Positioned behind the mirror, the multilayered actuator array dynamically controls the mirror's surface shape for…
A pseudobinary thermodynamic analysis of the alumina/copper–oxygen eutectic bonding process yields a value of approximately 1076°C for the invariant temperature of the {Cu( ss ), Cu( L1 ), CuAlO 2 , Al 2 O 3 } equilibrium. This temperature, which is 11°C above the eutectic, corresponds to a critical temperature for st…
Vanadium dioxide (VO2) thin films deposited on (1010) sapphire are composed of two mixed monoclinic phases, namely M1 and M2. The M1 phase is unstable because of the existence of a larger misfit strain in the (102) VO2 film. The reduction of misfit strain in the film favours the formation of the M2 phase. The X-ray di…