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151.
GDOES,XPS, and SEM with EDS analysis of porous coatings obtained on titanium after plasma electrolytic oxidation
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Krzysztof Rokosz Tadeusz Hryniewicz Steinar Raaen Patrick Chapon Łukasz Dudek 《Surface and interface analysis : SIA》2017,49(4):303-315
In the paper, the glow discharge optical emission spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy results of a commercial purity titanium grade 2 after plasma electrolytic oxidation (PEO), also known as micro arc oxidation (MAO), are presented. The PEO treatment was performed in the electrolyte containing concentrated (85%) phosphoric acid with copper nitrate at the voltage of 450 ± 10 V for 1 min. For the electrolyte, copper nitrate addition from 300 to 600 g/l was used. Porous coatings of specific properties were obtained. The measurements results allow to state that the copper and nitrogen ions can be introduced into the surface layer formed on pure titanium by the plasma electrolytic oxidation. The distributions of these elements were detected to depend on the electrolyte composition, with the highest amounts revealed in the coating created in the electrolyte containing 600 g Cu(NO3)2 in 1 l H3PO4. Three sub‐layers of the coating, displayed in this work by two models, were developed in the study. The analysis performed shows that under the PEO treatment in each of the electrolytes used, the formation of coating with the top sub‐layers always enriched in copper compounds was found. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
152.
Andrzej Dudek Christian Reiher Andrzej Ruciski Mathias Schacht 《Random Structures and Algorithms》2020,56(1):122-141
We study the existence of powers of Hamiltonian cycles in graphs with large minimum degree to which some additional edges have been added in a random manner. It follows from the theorems of Dirac and of Komlós, Sarközy, and Szemerédi that for every k ≥ 1 and sufficiently large n already the minimum degree for an n‐vertex graph G alone suffices to ensure the existence of a kth power of a Hamiltonian cycle. Here we show that under essentially the same degree assumption the addition of just O(n) random edges ensures the presence of the (k + 1)st power of a Hamiltonian cycle with probability close to one. 相似文献
153.
Andrzej Dudek 《Discrete Mathematics》2010,310(10-11):1524-1530
154.
155.
Ideals and atoms are studied by various authors from different point of views. In different algebras there are studied different
ideals, but obtained results are similar. Below we present a new method of study of ideals in BZ-algebras. Using this method we describe the connection between ideals of various types.
Supported by Natural Science Foundation of China (Grant No. 60775038). 相似文献
156.
Anne-Lise Adenot-Engelvin Christophe Dudek Olivier Acher 《Journal of magnetism and magnetic materials》2006
In this paper, we focus on metamaterials based on ferromagnetic composite combined with an inductive pattern. CoFeSiB amorphous ferromagnetic glass-coated microwires and thin films are involved in the composite. The inductive pattern is a coiling of Copper wire with a varying number of loops. We derived the microwave permeability of the ferromagnetic material inside the inductive pattern through a Landau–Gilbert model of gyromagnetism. In agreement with experimental results, the engineering of resonance frequency of the sample is achieved through the number of loops of the coiling. 相似文献
157.
Sven Thorwirth Michael C. McCarthy John B. Dudek Patrick Thaddeus 《Journal of Molecular Spectroscopy》2004,225(1):93-95
The carbon chain molecules vinylcyanoacetylene and cyanovinylacetylene have been investigated between 8 and 41 GHz by Fourier transform microwave spectroscopy of a supersonic molecular beam. Owing to the high spectral resolution of the present technique, significantly more accurate rotational and centrifugal distortion constants have been derived for both molecules. In addition, the dipole moments have been calculated at the B3LYP/cc-pVTZ level of theory. Because these carbon chains are similar in structure and composition to known astronomical molecules and because of their high polarity, both species are good candidates for radioastronomical detection. 相似文献
158.
Lucjan Chmielarz Małgorzata Rutkowska Piotr Kuśtrowski Marek Drozdek Zofia Piwowarska Barbara Dudek Roman Dziembaj Marek Michalik 《Journal of Thermal Analysis and Calorimetry》2011,105(1):161-170
Hydrotalcite-like materials containing apart from magnesium and aluminum also copper, cobalt, nickel, and iron were prepared
by a co-precipitation method. Thermal transformations of hydrotalcite-like materials were studied by thermal analysis methods
as well as XRD, UV–vis–DRS, and XPS measurements of the samples calcined at various temperatures (600, 700, and 800 °C). Calcined
hydrotalcites, especially those containing cobalt and copper, were found to be active and selective catalysts of N2O decomposition. It was shown that an increase in the calcination temperature significantly activated the Co-containing catalysts.
Promotion of the samples with potassium resulted in activation of the hydrotalcite-based catalysts. 相似文献
159.
We consider two relations on a ∩-semigroup of partial functions on a given set: the inclusion of domains and semiadjacency
(i.e., the inclusion of the image of the first function in the domain of the second). These are characterized from an abstract
point of view via a system of elementary axioms, i.e., conditions expressed in the language of pure predicate calculus with
equality. 相似文献
160.
The effect of the composition of reacting mixtures on the crystallinity of zeolite ZSM-5 was investigated. The mixture of ethanol and ammonia was used as a templating agent. The quantitative determination of the phase composition of the obtained preparations was made on the ground of X-ray diffraction. The ZSM-5 zeolite of ab.90% phase purity, contaminated with mordenite, quartz and amorphous material, was obtained. 相似文献