Materials Literature
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The structure of synthetic YbFeMnO(4) has been refined by single-crystal X-ray diffraction. Space group R3m, a = 3.4580 (1), c = 25.647 (3) A, V = 265.59 (3) A(3), Z = 3. Yb is in octahedral coordination, whereas Fe and Mn are disordered on a single crystallographic type of trigonal bipyramid, in which the cation is o…
Guest host systems composed of various types of esters of (2-hydroxypropyl) cellulose and the chromophore coumarin 334 were characterized with respect to the absorption and emission properties as a function of the concentration of the chromophore and the nature of the esters. The results were compared with the ones ob…
A palette of computational techniques are employed for the analysis and reduction of a detailed 53-species methane-air mechanism including nitrogen chemistry in a perfectly stirred reactor (PSR). The analysis of the mechanism for a PSR operating at an equivalence ratio φ = 0.5, inlet temperature Tin = 400°C and pressu…
Polycrystalline ${\mathrm{La}}_{0.5}{\mathrm{Sr}}_{0.5}{\mathrm{MnO}}_{3\ensuremath{-}\ensuremath{\delta}}$ thin films deposited on quartz wafers at 680 \ifmmode^\circ\else\textdegree\fi{}C and various oxygen pressures P by pulsed laser deposition are prepared. The effects of oxygen nonstoichiometry on the microstruct…
Soluble zinc salts added to cement mix water are generally agreed to retard hydration. The role of zinc in clinker is, however, less well-established. Experiments are reported on clinker stimulants and real industrial clinker meals, the latter doped with 1·5 wt% ZnO. Contrary to findings in the literature, relatively…
The kinetics and mechanism of analcime formation from precursor Na-clinoptilolite (Cpt-Na) and Na-mordenite (Mor-Na) were investigated from 125-225 °C, pressures up to 34.5 MPa, and pH = 9.2-10.7. By using batch and flow-through experimental methodologies, compositions of solids and solutions were monitored to track r…
The effect of side chain substitution on the 35 CI NQR and crystal structure of amides of the type N-(2,6-dichlorophenyl)-amides, 2,6-Cl 2 C 6 H 3 -NHCO-R (R = H or CH 3_y X y where X = CH 3 or CI and y = 0, 1, 2 or 3), has been studied by measuring the 35C1 NQR spectra and determining the crystal structures of the co…
The structural, electrical, and optical properties of crystalline Si codoped with Er and O by molecular beam epitaxy (MBE) have been investigated in detail. Si:Er:O layers (∼250 nm thick) have been grown by MBE, realizing uniform dopant concentrations in the range 8×1018–1.5×1020 cm−3 for Er and up to 5×1020 cm−3 for…
Mesoporosity combined with organic polymer functionality and hydrophobicity could give rise to promising new materials with applications in host–guest chemistry and biosensor devices. The synthesis of polymer–silica hybrid mesoporous materials with pore sizes of 3–6 nm is described, in which materials with large speci…
Two diastereomeric carboxylic acids, 2(S)-[2(R)-methylhexyloxy]propionic acid and 2(S)[2(S)-methylhexyloxy]propionic acid, were prepared from ethyl (S)-lactate and (R)-1-iodo2-methylhexane or (S)-1-iodo-2-methylhexane in the presence of Ag2O. From these acids two liquid crystals, 2 and 3, whose configurations are (S,…
Abstract Two series of pillared clays were prepared from a purified montmorillonite (95%) from La Serrata of Nijar, Spain, and polycations of Al and Zr using various methods. The effect of both the pillaring cation and the procedure of preparation on the physicochemical characteristics of the resulting materials was s…
We have investigated the effect of hydrostatic pressure on direct optical transitions of the layered semiconductor γ-InSe by photoreflectance (PR) spectroscopy (T = 300 K). In addition, electroreflectance (ER) measurements were performed at ambient pressure. Six structures are resolved in the ER spectra in the energy…
Vimentin is a class III intermediate filament protein widely expressed in the developing embryo and in cells of mesenchymal origin in the adult. Vimentin knock-out mice develop and reproduce without any obvious defect. This is an unexpected finding in view of the high degree of conservation of the vimentin gene among…
In this paper we employ a relatively simple theory to show how a nematic disclination line can act as a nucleation site for the growth of the isotropic phase. With this theory we are able to find analytical expressions for the critical temperature of nucleation and the behaviour of the core radius as a function of tem…
The three-dimensional structures of human and rabbit liver cytosolic recombinant serine hydroxymethyltransferases (hcSHMT and rcSHMT) revealed that E75 and Y83 (numbering according to hcSHMT) are probable candidates for proton abstraction and Calpha-Cbeta bond cleavage in the reaction catalyzed by serine hydroxymethyl…
This paper describes the isolation, identification and analgesic activity of a new biflavonoid from Rheedia gardneriana leaves, which correspond to I3-naringenin-II8-4'-OMe-eriodictyol (GB-2a-II-4'-OMe) (1), with a methoxyl group in position 4 of ring-II. Its structure was determined by spectroscopic data and confirme…
The role of Fe oxides on the availability and dynamics of phosphorus (P) is poorly understood in calcareous soils. We ascertained its role in laboratory and plant growth experiments on substrates prepared by mixing calcium carbonate (calcite) sand (CCS, 0.2-0.5 mm) and Fe oxide (ferrihydrite)-coated quartz sand (FOCS,…
Transmission electron microscopy (TEM) and thermal (DTA-TG) analyses of lazurite, (Na,Ca) 8 [Al 6 Si 6 O 24 ](SO 4 ,S) 2 , indicate three forms: cubic, modulated, and orthorhombic. Cubic lazurite contains mainly [Na 3 Ca·SO 4 ] 3+ clusters that are disordered together with the O1 and O2 oxygen atoms, and no satellite…
We report a phenomenon occurring in field-responsive suspensions: shear-induced anomalous stresses. Competition between a rotating field and a shear flow originates a multiplicity of anomalous stress behaviors in suspensions of bound dimers constituted by induced dipoles. The great variety of stress regimes includes n…
In a search for sharp features in the electronic density of states (DOS) of quasicrystals, a systematic comparative study of the DOS in the vicinity of Fermi energy ${E}_{F}$ was performed in icosahedral ${\mathrm{Al}}_{72.4}{\mathrm{Pd}}_{20.5}{\mathrm{Mn}}_{7.1},$ ${\mathrm{Al}}_{62}{\mathrm{Cu}}_{25.5}{\mathrm{Fe}}…