Materials Literature
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Platinum nanoparticles accomodating bifunctional thiolate ligands self-assemble into regular superstructures or organize around a large gold particle; the shape of the superstructures can be modulated by addition of water.
Nonrandom porous mullite ceramic preforms were fabricated by the indirect fused deposition process. MgO was added to commercial mullite powders as a sintering aid. The influence of porosity and the amount of MgO on the densification and mechanical properties was studied. The shrinkage and compressive strength of the p…
Characterisation of alumina supported catalysts was performed by TEM and XPS spectroscopy during formation of multiwalled carbon nanotubes from acetylene at 1000 K. TEM images showed that thick carbon fibres (outer diameter is around 20–40 nm) were generated on Fe/Al2O3 and Co/Al2O3 samples. The only sample producing…
Diffusion of hydrogen in the α-phase Pd– and Pd81Pt19–H systems was investigated at 298 K by electrochemical methods in an aqueous solution of H2SO4. Smooth or Pd-black covered specimens were used. The concentration of hydrogen in the metal matrix was gradually increased by control of the electrode potential; equilibr…
The investigation of the partitioning equilibrium in real polymer systems by Monte Carlo (MC) simulations is reported. In contrast to ideal chain treatments the factors such as flexibility and excluded volume in real chains, the finite concentration of macromolecules φ, and polymer adsorption on pore walls of the attr…
A deep understanding of the two-step, one-flask synthesis of meso-substituted porphyrins requires characterization of the acyclic oligomers, which typically constitute ≥50% of the products. We have employed laser desorption mass spectrometry (LD-MS) to obtain a qualitative yet high resolution view of the oligomer cont…
Equiaxed solidification of steel was investigated with emphasis on the nucleation on titanium nitride (TiN). Ferritic stainless steels bearing different amounts of titanium and nitrogen were remelted using a gas-tungsten-arc welding, and equiaxed grain formation was examined in the as-solidified welds. It was found th…
Supported mesoporous γ‐Al 2 O 3 membranes deteriorate and blister in steam‐containing environments at high temperatures. This deterioration led us to the development of a new type of supported γ‐Al 2 O 3 membrane with significantly improved stability under hostile conditions. Two measures were taken to achieve this re…
The crystal structure of yeast orotidine-5'-phosphate decarboxylase in complex with the postulated transition state analog, 6-hydroxyuridine-5'-phosphate, reveals contacts between this inhibitor and a novel quartet of charged residues (Lys-59, Asp-91, Lys-93, and Asp-96) within the active site. The structure also sugg…
2-D 31P dipolar recoupling magic angle spinning NMR has been used to determine the true symmetry of the low temperature structure of ZrP2O7 for the first time.
An epoxy monomer was cured in liquid crystalline phase with three different amines to form (LCT). The thermal transitions of the LCT were studied by differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarized optical microscopy (POM). Different curing features are observed depending on t…
Whereas lignocellulosic fibers have received considerable attention as a reinforcing agent in thermoplastic composites, their applicability to reactive polymer systems remains of considerable interest. The hydroxyl-rich nature of natural lignocellulosic fibers suggests that they are particularly useful in thermosettin…
Carbon aerogels are prepared by a sol-gel process. By controlling the mass ratio of reactants and the molar ratio of resorcinol to catalyst (R/C), carbon aerogels with different microstructures can be developed. The electrical conductivity is measured by the van der Pauw method. The results show that the electrical co…
The first derivative of the hitherto elusive tripyrrin 2 was prepared and characterized; the X-ray structural analysis of its trifluoracetato-palladium(II) complex 7 displays a highly flexible N3 ligand.
Appropriate matrix formation, turnover and remodeling in tissue-engineered small diameter vascular conduits are crucial requirements for their long-term patency and function. This complex process requires the deposition and accumulation of extracellular matrix molecules as well as the remodeling of this extracellular…
Single phase europium-activated gadolinium aluminum borate, was obtained by the evaporation of its nitrate solution, and calcination at 900 to 1100°C in air. All the solid solution was identified as the isomorphs of huntite. activated showed intense red emission with CIE chromaticity coordinates of (0.645, 0.330) unde…
Adhesion energies of Cu-low k dielectric interfaces, measured with the technique of four-point bending, show a correlation to chemical mechanical polish results. A limit of 5 J/m/sup 2/ is established, below which thin film delamination and cracking are observed. In general, spin-on polymer dielectrics exhibit better…
Tantalum(V) oxide (Ta2O5) powders were synthesized by a solvothermal reaction of tantalum pentabutoxide (TPB) in toluene at 473–573 K in the presence of water. Ta2O5 powder with a large surface area (>200 m2 g−1) was obtained at 473 and 523 K, and its X-ray diffraction patterns showed no clear peaks of crystallites, w…
The trans/cis ratio of the azobenzene-attached bipyridine ligands in a cobalt complex is reversibly altered by a combination of photoirradiation with a single UV light source and the reversible redox change between Co(II) and Co(III).
The photocolouration of five spiro[2H-1-benzopyran-2,2′-indoline] compounds (1–5) and two spironaphthopyranindolines (6, 7) to give the ring-opened merocyanine(s) and the subsequent thermal relaxation back to the closed form was studied. A trans-merocyanine but no cis-photoisomer were detected for 1–7 using λexc = 308…