Materials Literature
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On etudie les mecanismes d'absorption d'energie lors de la perforation de boucliers composites ceramiques, incluant la rupture de la ceramique, la deformation du materiau ductile servant de support et du projectile lui-meme, et l'energie cinetique des fragments residuels et du support
The high thermal conducting mechanism of AlN ceramics has been investigated by the relationship between microstructure and thermal conductivity of the samples which were obtained by pressureless-sintering at 1900°C for 1-24h with Y2O3 2 at% addition as a sintering aid. The thermal conductivity increased gradually with…
Replicate excitation spectra of the fluorescence emission at 680 nm from 30 cultures of freshwater algae have been compared to determine the most sensitive regions for the differentiation of algal species. Spectra were normalized in four different ways prior to analysis in order to simulate different experimental appr…
Well-resolved Mossbauer spectra were obtained for CoMo-doped barium ferrite with variable doping (0-33% Fe), heat-treatment temperature (825-1200 degrees C), and sample temperature (90-300 K). Substitution was observed to occur primarily on the 12-K site, with little or no lattice distortion. A fitting model using fiv…
A quasicrystal built with three types of tiles is related to the well-known octagonal tiling. The relationships between both tilings are investigated. More precisely, we show that the coordinates of the vertices can be obtained in two different but equivalent ways. The structure factor is calculated exactly. We emphaz…
The Mott–Littleton method is used mainly for ionic defects in polar crystals, yet it provides a powerful tool for small polarons. These electronic carriers, important in many halides and oxides, cause a substantial self-trapping distortion, and move by an incoherent thermally activated hopping motion.The Mott–Littleto…
The considerable nucleophilicity of the OH bridges in the new hydroxo complexes [(C6F5)2M(µ-OH)2M(C6F5)2]2–(M = Ni, Pd, Pt) is indicated by high field proton resonances and the formation of µ-pyrazolate derivatives from [(C6F5)Ni(µ-OH)2Ni(C6F5)2]2–.
Pure MgO samples having greatly different morphologies and lithium-promoted catalysts derived from these materials have been examined by electron microscopy. In addition, their ability to generate and react with gas-phase methyl radicals has been determined using e.s.r. in combination with a matrix-isolation technique…
Results of a laboratory evaluation of the contamination performance of silicone rubber and EPDM (ethylene propylenediene monomer) rubber polymers are presented. it is shown that due to significant material differences, these polymers cannot be evaluated using experimental conditions standardized for porcelain and glas…
To characterize the galvanic corrosion of supraconstructions consisting of Ni-Cr alloys that come in contact with titanium implants, the resultant substance loss was determined. The measurement of the released substance masses was conducted by analysis of the electrolyte solutions with the aid of atomic absorption spe…
Hg 2 Cl 2 , M = 472.1 Daltons, tetragonal, I 4/ mmm , a = 4.4795(5) Å, c = 10.9054(9) Å, V = 218.83(8) Å 3 , Z = 2, D c = 7.162 g cm −3 , λ (neutron) = 1.893 Å, R B = 0.026, R P = 0.043. The structure of Hg 2 Cl 2 was refined using the Rietveld profile fitting technique on neutron powder data. Parameters obtained were…
The thermal properties of phenyl 4-(4-alkoxybenzoyloxy) benzoates (1), 4-alkoxyphenyl 4-benzoyloxybenzoates (2), 4-(4-alkoxybenzoyloxy)benzoyloxyxylenes (3), and phenyl 4-(4-alkoxyphenoxycarbonyl)benzoates (4) have been examined. In spite of the structural similarity, the smectic nature of the series is quite differen…
The DC flux decay test has been proposed as an attractive method of extracting synchronous machine parameters. This test is an attractive alternative to the variable-frequency static impedance test. It is quicker and easier to perform and with carefully chosen short-circuit resistance can give good values for transien…
In an attempt to develop an oxygen semipermeable membrane with an asymmetric structure using mixed conductive perovskite-type oxides, preparation of a dense La0.6Sr0.4CoO3 (LSCO) film on a porous LSCO substrate was studied by means of sputtering- and spray deposition-techniques. No dense overlayer formed by the sputte…
The synthesis and some properties of µ-nitrido-bis[(phthalocyaninato)ruthenium], [{Ru(pc)}2N], are reported. Infrared spectra, structural, magnetic, and e.s.r. data identify this complex as a mixed-valence RuIII–RuIV dimer. It represents the first example of a ruthenium phthalocyanine complex containing the metal atom…
Nanocrystalline materials which can be plastically deformed at low temperatures have revolutionized the applications for ceramics. Two methods for the production of high‐tech ceramics with grain sizes of less than 1 pm are described and the quality of the materials, for example ZrO 2 powder (see figure), assessed. mag…
A three-dimensional finite element method using the A- phi formulation for analyzing time-periodic nonlinear magnetic fields with eddy currents has been developed. The CPU time of this method can be reduced to below that of the conventional step-by-step method, because the new method calculates the time-periodic pheno…
The structural integrity and substrate binding properties of the two genetically engineered domains of yeast phosphoglycerate kinase were investigated using one- and two-dimensional nuclear magnetic resonance techniques. Both domains were found to fold with regions of native-like structure, with the N-domain showing g…
Infrared spectra are reported of adsorbed products from exposure of Rh/Al2O3 at ca. 300 and 473 K to propene–NO mixtures, ethanoic acid, acetone and acrolein. Ethanoic acid was dissociatively adsorbed, giving ethanoate ions on alumina and a rhodium carbonyl species. The latter species was also formed from acrolein whi…
A crystal chemical investigation of the Ca 3 (PO 4 ) 2 -EuPO 4 system has pointed out the existence of a continuous solid solution of formulation Ca 3−x Eu 2x/3 (PO 4 ) 2 (0≤x≤3/7) and of whitlockite-type structure. The lattice evolution has been analyzed by X-ray diffraction and emission spectroscopy, the Eu 3+ ion b…