Materials Literature
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The crystal structure of baricite, the Mg-dominant analogue of vivianite, (Mg 1.70 Fe 2+ 1.30− x Fe 3+ x )(PO 4 ) 2 (OH) x ·(8− x )H 2 O, a 10.085(2), b 13.390(3), c 4.6713(9) A, β 104.96(3)°, V 609.4(1) A 3 , space group C 2/ m , Z = 2, ρ calc = 2.440 g/cm 3 , has been determined [automated single-crystal diffractome…
From the stem bark of Bowdichia virgilioides, lupeol, lupeol acetate, sitosterol, stigmasterol and methyl-3-[2-(1-hydroxymethylvinyl)-2,3-dihydrobenzo[b]furan-5-yl]-(E)-2-propenoate have been isolated. The latter is a new compound and it has been named as bowdenol. Their structures were elucidated with the aid of spec…
Two homologous series are synthesized by fixing a rigid 4-methyl phenyl azo group to resorcinol moiety. In series I one phenolic -OH group is alkylated whereas, in series II both the phenolic -OH groups are alkylated. Monoethers of series I having free lateral hydroxy group due to strong hydrogen bonding, exhibit nema…
The cyclotetramerisation products from the 1,8-diazabicyclo[5,4,0]undec-7-ene catalysed reaction of a 1:1 mol mixture of 3,6-didecylphthalonitrile and 3,4-dicynopyridine in the presence of zinc chloride have been isolated by chromatography. The fractions comprise zinc octadecylphthalocyanine and compounds in which one…
We investigate the low-energy geometries and the electronic structure of several aluminum based clusters, viz. ${\mathrm{Al}}_{4}{X}_{4},$ $(X=\mathrm{Li},$ Na, K, Be, Mg, B, and Si) by first principle Born-Oppenheimer molecular dynamics within the framework of density-functional theory. We present a systematic analys…
Epitaxial silver tantalate-niobate Ag(Ta, Nb)O3 (ATN) films have been grown on LaAlO3(001) MgO(001), and Al2O3(011_2) single crystals by pulsed ablation of stoichiometric AgTa0.38Nb0.62O3 ceramic target. Rutherford backscattering spectroscopy has revealed Ag0.9Ta0.42Nb0.58O3−δ composition of fabricated films. Micromet…
Oyster greening was first described in the seventeenth century as a natural phenomenon. However, it has recently been discovered that the diatom Haslea ostrearia Simonsen causes greening by synthesis of a blue pigment designated as ‘marennine’. This phenomenon, which involves massive proliferation of H. ostrearia in o…
An easy and effective method to prepare a new supported Mn(III)-porphyrin by immobilisation of Mn(III)-5,10,15, 20-Tetrakis(p-sulfonatophenyl)porphyrin, [Mn(TPPS)], on poly(4-styrylmethyl)pyridinium chloride (PSMP) is reported. This catalyst was found to be efficient for catalysing alkene epoxidation and alkane hydrox…
Nine elastic stiffness coefficients, c ij , of a mullite single crystal (2Al 2 O 3 ·SiO 2 ) are measured using acoustic resonance spectroscopy. The obtained values are similar to those of the structurally related aluminosilicate phase sillimanite (Al 2 O 3 ·SiO 2 ). Characteristic elastic properties of the two mineral…
A 4-aminophenylethynyl substituent has been grafted into the 4-position of the pyridine ring in dipicolinic acid to yield ligand L4 the pKa's of which are 8.77(5), 3.54(3), 2.58(1) and 1.01(3). Ligand L4 reacts with trivalent lanthanide ions to give stable triple-stranded helical complexes in water (logβ13 = 13.7(1) f…
The stress dependence of platinum hillock formation during post thermal cycling was investigated in Pt/Ti electrode stacks. Annealing temperatures were varied from room temperature (RT) to 650°C. High compressive stress was generated during electrode annealing by the Ti diffusion into the platinum layer followed by ox…
Eleven different tin carboxylates were used as initiators of the ring-opening polymerization of ε-caprolactone. All polymerizations were conducted with 2 M solutions in chlorobenzene at 80°C and time/conversion curves were determined up to 96–99% conversion. The following structure-reactivity relationships were found.…
The acid-induced intramolecular cyclization reaction of aromatic methylsulfinyls has proven to be a suitable synthetic tool for the preparation of ladder-type oligomers and polymers on the basis of thianthrene (= “9,10-dithiaanthracene”). This approach allows for the synthesis of tetrathiapentacene oligomers in high y…
This paper presents active shape control of composite beams using shape memory actuation. Shape memory alloy (SMA) bender elements trained to memorize bending shape were used to induce bending and twisting deformations in composite beams. Bending-torsion coupled graphite-epoxy and kevlar-epoxy composite beams with Tef…
Article Probenpräparation für die Rückstreuelektronen-Kikuchi-Beugung (Electron Backscatter Diffraction, EBSD) / Specimen Preparation for Electron Backscatter Diffraction — Part I: Metals was published on October 1, 2001 in the journal Practical Metallography (volume 38, issue 10).
A set of ZnO/Mg0.12Zn0.88O multiple quantum wells (MQWs) with well widths, Lw, varying from 6.91 to 46.5 Å has been grown by laser molecular-beam epitaxy. We estimated the Lw dependence of the radiative and nonradiative recombination times of localized excitons at 5 K. Suppression of quantum efficiency can be avoided…
Elastic and mechanical properties such as Young's modulus E , Poisson's ratio ν, Debye temperature θ D , Vickers hardness H v , fracture toughness K c , and fracture surface energies γ f of y CuO x ·(100− y )P 2 O 5 glasses ( y = 45, 50, 55) with different copper valence states, i.e., R (Cu + ) = Cu + /(Cu + + Cu 2+ )…
The low and glasslike thermal conductivity of metal-doped semiconductor clathrate compounds makes them potentially high-efficiency thermoelectric materials. The cause of this unique and remarkable property has been postulated to be due to resonant scattering of lattice phonons by localized vibrations of the dopants. W…
In situ consolidation of amorphous Si‐N‐C ceramics during pyrolysis of polymer precursor provides a way to consolidate bulk silicon nitride based ceramics at lower temperatures. Porosity evolution during polymer‐ceramic conversion has been investigated to clarify the densification process. A densification mechanism ba…
This paper is concerned with the lattice and grain boundary diffusivities that can be extracted from the tracer concentration depth profile resulting from diffusion of tracers from a thin film source in the presence of equally spaced parallel boundary slabs. We address this problem by mapping a grid over the phenomeno…