Materials Literature
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[structure: see text]. New poly(phenylene ethynylene)s (PPEs) and poly(phenylene vinylene)s (PPVs) that are highly emissive in solution and thin films were prepared utilizing palladium-catalyzed cross-coupling between new 1,4-diiodo-2,3-dialkoxybenzene- and iptycene-containing monomers. The absorption and emission spe…
Using an ab initio local density approximation (LDA) method, we have studied the structural properties and the electronic band structures of several tin-based clathrate materials. We find that the pure type-I $({\mathrm{Sn}}_{46})$ and type-II $({\mathrm{Sn}}_{136})$ clathrate frameworks are metastable, expanded-volum…
The study objectives were to quantify the time- and magnitude-dependence of flow-induced alignment in vascular smooth muscle cells (SMC) and to identify pathways related to the orientation process. Using an intensity gradient method, we demonstrated that SMC aligned in the direction perpendicular to applied shear stre…
Several types of sugar-installed poly(ethylene glycol)/poly(DL-lactide) (sugar-PEG/PLA) block copolymers were synthesized. The synthesized block copolymer forms a core-shell type polymeric micelle in aqueous media possessing sugar molecules on its surface. Specific recognition of lectin proteins with the sugar molecul…
We report on the fabrication of field emission microcathodes which use carbon nanotubes as the field emission source. The devices incorporated an integrated gate electrode in order to achieve truly low-voltage field emission. A single-mask, self-aligned technique was used to pattern the gate, insulator and catalyst fo…
A quantum statistical theory of spin-dependent tunneling through asymmetric magnetic double barrier junctions is presented which describes $both$ ballistic and diffuse tunneling by a single analytical expression. It is evidenced that the key parameter for the transition between these two tunneling regimes is the elect…
We show through a variational calculation that in a large range of parameters the paramagnetic to ferromagnetic transition in colossal magnetoresistance compounds is accompanied by a collapse of polaronic lattice disorder in addition to that of spin disorder. The spin-lattice disordered state is shown to be localized…
In this comment, we give a simple analytical proof for the even-odd behavior of the conductance of atomic wires.
Ce travail experimental vise a mesurer l'impact du mouvement relatif solide / liquide sur la croissance de grains equiaxes en chute libre. Pour cela, nous avons developpe un dispositif rendant possible le suivi tridimensionnel et in situ de cristaux equiaxes sedimentant dans un liquide surfondu. Les experiences ont et…
In this work, the hazardous properties of solvent base adhesive wastes generated in the footwear manufacturing process have been studied. The characterisation procedures and criteria used are those contained in the legal documents European Union Council Decision 94/904/CE and October 13th Spanish Ministerial Order. Th…
When a surface of a silicon wafer, on which a nanometer-thin SiO 2 layer is selectively formed, is observed by a scanning electron microscope (SEM), the brightness of the SEM image at the SiO 2 portion is stronger than that of the bare Si portion, and the brightness increases with the increasing thickness of the SiO 2…
Four thermoplastic elastomers having the structure of poly(ether-ester-imide)s, PEEIs, were prepared and characterized. The hard segments were synthesized from 1,4-dihydroxybutane and from an imide dicarboxylic acid based on 1,6-diaminohexane and trimellitic anhydride. Poly(tetramethylene oxide)-1000, poly(ethylene ox…
<abstract language="eng">The compounds 5-nitro-8-quinolinol and 5,7-dinitro-8-quinolinol were obtained by nitration of the chelant 8-quinolinol. The compounds were characterized through EA, MNR, XRD, IR, TG, DTA and DSC. It was verified through thermal analysis that the compounds show consecutive processes of sublimat…
Reducing-atmosphere treatment at 400°C for 10 min was performed on sol–gel-derived Pb(Zr,Ti)O 3 (PZT) thin films, which were spin-coated on a LaNiO 3 /Pt/Ti/SiO 2 /Si substrate and annealed. The reducing atmosphere does not produce any significant change of the preferred orientation perovskite structure of these ferro…
Heteropoly acid entraped in nano silica matrix was prepared by the microemulsions method. The primary particle size was less than 400nm and it decreased with the content of the heteropoly acid. When these silica particles were blended with sulfonated polyethersulfone, the HPA could be effectively immobilized in aqueou…
Molecular mobility in sorbitol and maltitol is studied in order to understand their differences near the junction between the α and β relaxations. The molecular dynamics simulations performed on the polyols in their bulk state give support to the 13C NMR results and imply that the mobility of a carbon atom located at…
Supramolecular side chain liquid crystalline polymers were prepared from poly(3-carboxypropylmethylsiloxane) (PSI100) and azobenzene derivatives through intermolecular hydrogen bonding (H-bonding) between the carboxylic acid groups in the PSI100 and the imidazole rings in the azobenzene derivatives. The existence of H…
The effect of oxygen content on the electrical transport properties of La0.4Ca0.6MnO3—y was studied. Upon decreasing oxygen content, the lattice parameters a, b and c of the samples increase and the electrical resistivity of the samples also increases abruptly, contradicting what is expected in terms of Mn4+/Mn3+ rati…
The stress and displacement fields in an edge‐cracked sheet specimen made of a solid propellant and subjected to a uniform displacement along its upper and lower faces was studied. The solid propellant was simulated as a hyperelastic material with constitutive behaviour described by the Ogden strain energy potential.…
Sol-gel colloidal suspensions were used to elaborate ZnGa2O4 films by spin coating on glass and MgO substrates. Those films were annealed at 600 °C (10°/min) for l h in air and showed good mechanical resistance as well as very good transparency. XPS spectra recorded from 0 to 1200 eV indicated that the films contained…