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81.
Cristina Elena Ciomaga Mirela Airimioaei Valentin Nica Luminita M. Hrib Ovidiu F. Caltun Alexandra R. Iordan Carmen Galassi Liliana Mitoseriu Mircea N. Palamaru 《Journal of the European Ceramic Society》2012,32(12):3325-3337
Magnetoelectric composites of xNiFe2O4–(1 ? x)Pb(Zr,Ti)O3 with x = 2, 5, 10, 20, 30% were prepared by citrate–nitrate combustion using PZT-based template powders. In order to ensure a better connectivity of dissimilar phases, we have used chemical methods for preparation in situ composites, followed by adequate sintering procedure. The structural, microstructural and functional properties of di-phase magnetoelectric composites of NiFe2O4–PZT are reported. The XRD analysis is demonstrating the synthesis of pure ferrite phase directly on the ferroelectric templates. An excellent mixing was obtained in the composite powders, as proved by a detailed SEM analysis.The magnetic and dielectric behaviors of the ceramic composites vary with the ratio of the two phases. The dielectric behavior is greatly influenced by the magnetic phase. The magnetoelectric (ME) coefficient was measured as a function of applied DC magnetic field. The maximum ME coefficient (dE/dH) varies from 0.0011 mV/(cm Oe) to 0.5 mV/(cm Oe) with increasing of NF addition. 相似文献
82.
The temperature dependence has been determined for the wetting by molten aluminum of materials based on aluminum oxide (polycor and corundum). A temperature range has been identified in which the wetting increases significantly. There is no effect on the wetting characteristics of these oxide materials from the addition to the aluminum of up to 25% silicon, 33% copper, or 6% nickel. 相似文献
83.
Naftalevič’s Theorem states that, given a Blaschke sequence, it is possible to modify the arguments of its terms so as to
obtain an interpolating sequence. We prove a computable version of this theorem in that it possible, given a Blaschke sequence,
to computably modify the arguments of its terms so as to obtain an interpolating sequence. Using this result, we produce a
computable, interpolating Blaschke sequence that does not define a computable Blaschke product. This answers a question posed
by Matheson and McNicholl in a recent paper. We use Type-Two Effectivity as our foundation. 相似文献
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85.
A.L.G.A. Coutinho L.P. Franca F. Valentin 《Computer Methods in Applied Mechanics and Engineering》2011,200(25-28):2127-2130
We derive two stabilized methods for transient equations using static condensation of residual-free bubbles. The methods enhance the stability of the Discontinuous Galerkin method. 相似文献
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Diana Mardare Valentin NicaValentin Pohoata Dan MacoveiNicoleta Gheorghe Dumitru LucaCristian-Mihail Teodorescu 《Thin solid films》2011,520(4):1348-1352
Chromium-doped titanium oxide thin films were investigated in the as-deposited state and after thermal treatment (723 K for 3 h in air). X-ray diffraction data revealed an improvement in film crystallinity induced by the thermal treatment. Extended X-ray absorption fine structure data revealed similar atomic neighboring around Cr atoms in both as-deposited and annealed samples. A lattice contraction of ~ 2% is observed in the annealed samples. The 67% enhancement of the amplitude of the Cr 1 s X-ray absorption fine structure pre-edge peak after thermal treatment, which is a sign of “dipole-forbidden” 1 s → 3 d transitions, suggests strong alteration in the number of Cr 3 d vacancies, in spite of similar Cr local environment in the two kinds of investigated samples. We discuss here the Cr+ → Cr4+ and Cr2+ → Cr6+ changes induced by thermal treatment, and/or the evolution in local structures without inversion center.Refractive index dispersion spectra in the visible wavelength domain allowed us to compute the values of the dispersion energy, the single-oscillator energy and the coordination number of Ti atoms in both as-deposited and annealed samples. 相似文献
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