Materials Literature
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We present results of computer simulations of polymer brushes (layers of polymer chains attached at one end onto an impermeable planar surface) under shear deformation at constant shear rate. As the first stage of calculations the behavior of a single brush was studied. The monomer density profile, the distribution of…
Evidence of a transformation from tetragonal to rhombohedral phases in a 80/20 mixture of lead ziconate titanate (PZT) (53/47) and lead magnesium niobate-lead titanate (PMN-PT) (65/35) was observed by x-ray diffraction, microstructural analysis, dielectric spectroscopy, and electrically-induced strain measurements. An…
We have measured the electrical resistivity and the Hall effect in D03-type (Fe1−xVx)3Al alloys with 0≤x≤0.38. When substituted by V, the electrical resistivity increases rapidly at low temperatures and shows an anomalous temperature dependence: an occurrence of a resistance maximum at or near the Curie point TC and a…
Synthesis of a monosubstituted ferrocene-based chiral Schiff’s base derivative with unusual mesomorphic behavior is reported namely the first metallomesogen which exhibits TGBA and blue phases apart from SC*, SA and N* phase transformations.
A novel and direct synthesis of hydroperoxy compounds from various types of conjugated olefins was established via cobalt(II) porphyrin-catalyzed hydroperoxygenation. The reaction of α,β,γ,δ-unsaturated carbonyl compounds, acrylic esters, α-substituted acrylic esters and styrene derivatives with molecular oxygen and t…
The reaction of p-bromo(triisopropyloxysilyl)benzene 2 with magnesium led to stable THF solutions of the corresponding Grignard reagent. The reaction of this latter with PCl3 or PhPCl2 allowed the preparation of phosphines 4 and 5 respectively. LiAlH4 reduction of 4 afforded phosphine 6. Compounds 4 and 6 have been tr…
The oxidation of 1-(substituted phenylazo)-2-hydroxynaphthalene-6-sulfonate dyes by oxoiron(IV) tetra(2,6-dichloro-3-sulfonatophenyl)porphyrin (OFeIVTDCSPP) in aqueous solution is first-order in the concentration of the dye and of the oxoiron(IV) species over the pH range 6.93–12.68. The pH dependence of the second-or…
Fluoroalcohols [1,1,1,3,3,3-hexafluoropropan-2-ol (HFP), 2,2,2-trifluoroethanol (TFE) and 2-fluoroethanol (FE)], acting as Lewis acids, stabilize the π-conjugated, colored merocyanine forms of spiropyran and spirooxazine photochromic compounds as metal ions do.
Ab initio static electronic dipole hyperpolarizabilities, β(0), were computed for 1-(1‘,X‘-dicarba-closo-dodecaborane-1‘-yl)-closo-dodecaborane dianion (X = 2, 7, 12). These dianions have relatively large β(0) values (3.6 × 10-30 cm5 esu-1) comparable to those for 4-nitroaniline in spite of their short transition wave…
The interaction between haematite powder and formic acid has been studied at atmospheric pressure by FTIR and under high-vacuum conditions by X-ray photoelectron spectroscopy (XPS) and mass spectroscopy (MS). At room temperature formic acid is adsorbed mainly molecularly whereas dissociative chemisorption is prevalent…
A series of metalloporphyrin-containing cyclic hosts has been prepared, which are electronically and geometrically programmed to recognize guests in a particular configuration. Electronic control is achieved by substituting the C–H meso positions with carbonyl groups, while geometric control is possible in the choice…
119 Sn solid state nuclear magnetic resonance, 119Sn Mössbauer, Fourier transform Raman and variable temperature single crystal UV–VIS absorption, emission and excitation spectra of some archetypal microporous layered tin sulfides, denoted (Et4N)2Sn3S7 (TEA-SnS-1), (C6H12N2H)2Sn3S7 (DABCOH-SnS-1), (NH4)0.5(Et4N)1 .5Sn…
The crystal structure of the title compound was determined at 250 K in space group I 4 bar 2m, a = 20.661(5) Å , c = 6.764(7) Å , Z = 8. The individual dithiadiazole rings form two sets of contrarotatory 4-member pinwheels clustered around a 4-fold rotation-inversion axis located halfway along the unit cell edges, des…
This paper presents an experimental study on the manufacture of low-density fine-cell high density polyethylene (HDPE) foams in extrusion using CO 2 as a blowing agent. The strategies adopted to produce low-density, fine-cell HDPE foams were to generate a large number of cells by a rapid pressure drop, to suppress cel…
Rate coefficients for the depletion of ground-state nitrogen atoms by O 2 have been measured using a high-temperature photochemistry reactor. The N atoms were generated by VUV flash photolysis of N 2 O, and the relative concentrations were monitored by resonance fluorescence. The data are best fitted by the expression…
This paper deals with analysis by FEM for iron losses considering vector magnetic properties. We define the tensor magnetic reluctivity and calculate it from the data measured with two-dimensional measurement method. This numerical method is applied to the direct magnetic loss analysis. As a result, it is shown that t…
Abstract Oxalate is one of the dominant low molecular weight organic anions in many soils under forest ecosystems. Through its complexation reactions with Fe and Al, both in solution and at mineral surfaces, oxalate increases the availability of nutrients such as P in these soils. This investigation was designed to st…
Three new perylene-3,4-dicarboximide chromophores5a–c have been synthesized. They are characterized by high extinction coefficients and excellent thermal and photochemical stability. They display liquid crystallinity and exhibit several discotic phases depending upon temperature and substitution pattern.
The gas-phase reactions of molybdenum oxide cluster ions Mo x O y + ( x = 1−3, y = 1−9) with small alcohols have been investigated using Fourier transform ion cyclotron resonance mass spectrometry. The product branch ratios are reported. The reactions of Mo x O y + with alcohols can be envisioned as proceeding via met…
The non-hydrolytic sol–gel route has been used in the solvent-free synthesis of binary inorganic oxides based on silicon, aluminium and titanium. Where necessary, iron(iii) chloride was used as a catalyst. Clear evidence for the formation of true, amorphous binary systems was obtained only in the case of aluminosilica…