Materials Literature
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Exponential polynomials are the building bricks of spectral synthesis. In some cases it happens that exponential polynomials should be extended from subgroups to whole groups. To achieve this aim we prove an extension theorem for exponential polynomials which is based on a classical theorem on the extension of homomor…
All articles of this category A "3 + 1" methodology has been developed for the synthesis of novel porphyrin analogues with carbon rings in place of one or more of the usual pyrrole units. This approach involves the acid catalyzed condensation of a tripyrrolic intermediate (tripyrrane) with dialdehydes, followed by oxi…
A diatom biostratigraphic study of the Maruyama Formation in the Makarov and Dolinsk areas of the southern part of Sakhalin Island indicates that its geologic time span ranges from ca. 14 Ma to 3.5 Ma or possibly younger, which is much longer than previous estimates (e.g. 9.5-5.3 Ma by Ingle, 1992). A middle Miocene a…
Effects of the Jahn-Teller (JT) distortion and the strong electron-electron correlation on the electronic structure of perovskite oxides ${\mathrm{LaMnO}}_{3}$ are studied by using the linear muffin-tin orbital method. Results show that the Jahn-Teller distortion has evident influence on the electronic structure and i…
It was found that an amorphous Mg62Ni33Ca5 alloy absorbs a large amount of hydrogen at 323 K and the hydrogen content is much larger than that of the corresponding crystalline alloy. The maximum absorption concentration of hydrogen at 323 K is 2.3 mass% in the amorphous phase and 1.3 mass% in the crystalline state. Th…
A detailed finite-difference approximation of equations of the model for crystal pattern formation in a solidifying binary alloy is given. The stability of the numerical scheme obtained is investigated and the criterion of von Neumann for computing stability is defined. A solution of the finite-difference equations si…
The main tendencies in the formation of local magnetic moments and hyperfine magnetic fields at Fe nuclei in Fe-Sn and Fe-Si alloys at low metalloid concentrations are analyzed on the basis of “first-principles” calculations. The results of calculations are compared with experimental data. The main differences between…
Austenitic stainless steels are currently known to have irradiation-assisted stress corrosion cracking (IASCC) susceptibility when exposed to critical neutron irradiation in pure water environment at high temperatures. Since the radiation induced segregation (RIS) at grain boundaries (GBs) has been considered as a pre…
An extended and generalized Flory–Huggins model for calculating the heats of mixing and predicting the phase stability and spinodal diagrams of binary polymer–polymer mixtures is presented. In this model, the interaction parameter is considered to be a function of both temperature and composition. It is qualitatively…
Electrochemical impedance spectroscopy was used to assess the corrosion behavior of the weld zones and surface conditions of a laser-clad nickel aluminum bronze immersed in a 3.5% neutral saline solution. The zones and conditions examined included: (i) as-cast base material; (ii) laser-clad material with the high temp…
The thermal properties of blends of polycarbonate (PC) and poly(ε-caprolactone) (PCL) were investigated by differential scanning calorimetry (DSC). From the thermal analysis of PC-PCL blends, a single glass-transition temperature (Tg) was observed for all the blend compositions. These results indicate that there is mi…
We report magnetization and magnetoresistance studies of the geometrically frustrated spinel compound LiMn2O4 near its charge ordering temperature. The effect of a 7 T magnetic field is to very slightly shift the transition in the resistivity to lower temperatures resulting in large negative magnetoresistance with sig…
New delafossite-type CuInO2 was synthesized by ion exchange reaction of CuCl with α-NaFeO2-type NaInO2 or with α-LiFeO2-type LiInO2. According to the XRD, after 144 h the main product obtained at 623 K was CuInO2 in either starting material. Lattice parameters of CuInO2 derived from NaInO2 or LiInO2 as determined by R…
Both conjugated polymers and guest-host organic materials have been investigated as potential candidates for optical switching applications. The non-linear optical properties have been charactrized and their suitability compared with the standard switching criteria. Copyright © 2000 John Wiley & Sons, Ltd.
A guideline for a stable π-extended Wurster type redox system is proposed and two new acceptor molecules having a pyrene π-system were prepared and structurally characterised. 3,8-Bis(3′,5′-di-tert-butylphenyl)-13,13,14,14-tetracyano-1,6-pyrenoquinodimethane gave an electron transfer complex with Mn(TPP) (H2TPP = m-te…
The role played by sorbed water molecules present within poly(ethylene terephthalate) film at the moment of uniaxial drawing on the appearance and the percentage of the strain-induced crystalline (SIC) phase is investigated by birefringence, X-ray diffraction, and differential scanning calorimetry measurements. We sho…
The magnetic properties of Nd-Fe-B alloy magnet powders produced by the HDDR process were found to depend strongly on the hydrogen pressure. Anisotropic magnet powder is obtained by treatment at low hydrogen pressure, whereas isotropic magnet powder is obtained at high hydrogen pressure. Since the reaction rate is det…
Chiral-twisted iron(III) porphyrin dimers were self-assembled to high-molecular-weight polynuclear species through the intermolecular formation of μ-oxo dimers.
High temperature oxide melt solution calorimetry is a versatile technique for studying the energetics of formation, solid solution mixing, phase transition, and order/disorder in complex perovskites. The methodology is described and examples of both present and possible future applications given. The stability of the…
Yttrium niobate doped with Bi was prepared using a solid‐state reaction technique and its luminescence behavior was investigated under ultraviolet and low‐voltage electron excitations and with the first‐principle calculations. The optimization of the photo‐and cathodoluminescent properties was studied with control of…