Materials Literature
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Measurements of magnetic hysteresis loops in Cu-Al-Mn alloys of different Mn content at low temperatures are presented. The loops are smooth and continuous above a certain temperature, but exhibit a magnetization discontinuity below that temperature. Scaling analysis suggest that this system displays a disorder induce…
We study the Mott insulating phase of the one-dimensional Hubbard model using a local-density approximation (LDA) that is based on the Bethe Ansatz (BA). Unlike conventional functionals, the BA-LDA has an explicit derivative discontinuity. We demonstrate that as a consequence of this discontinuity the BA-LDA yields th…
This paper describes a method, discovered and refined by parallel screening, for the epoxidation of alkenes. It uses hydrogen peroxide as the terminal oxidant, is promoted by catalytic amounts (1.0-0.1 mol %) of manganese(2+) salts, and must be performed using at least catalytic amounts of bicarbonate buffer. Peroxymo…
Tube-shaped nanostructures (nanotubes) have a number of attributes that make them potentially useful for biomedical applications such as drug delivery/detoxification and enzyme immobilization. Template synthesis provides a route for preparing monodisperse nanotubes of nearly any size and composed of nearly any materia…
Surface modification of nanocrystalline metal oxide particles with enediol ligands was found to result in altered optical properties of nanoparticles. The surface modification results in a red shift of the semiconductor absorption compared to unmodified nanocrystallites. The optical shift is correlated to the dipole m…
A variety of novel hierarchical nanostructures with 6-, 4-, and 2-fold symmetries have been successfully grown by a vapor transport and condensation technique. It was found that the major core nanowires are single-crystal In 2 O 3 with 6, 4, and 2 facets, and the secondary nanorods are single-crystal hexagonal ZnO and…
Abstract The synthesis and characterization of some novel cationic siloxanes copolymers containing quaternary ammonium salt (QAS) groups in the backbone is reported in this article. One cationic oligomer having QAS in the backbone and reactive groups like 2,3‐epoxypropyl and 2‐hydroxy‐3‐chloropropyl (RCO) as well as 1…
We demonstrate an approach to connect nanowires consisting of ligand-stabilized Au 55 clusters with metal arrays prepared by using metal evaporation through a mask of monodispersed latex beads. The metal arrays serve as a model for micro- or nanoelectrodes, depending on the size of the beads. The silicon surfaces bear…
Dynamic manipulation of droplets could be achieved by light in a nematic liquid crystal (LC) doped with photochromic azobenzene derivatives. On irradiation of ultraviolet light, the trans→cis photoisomerization drives a directional motion of the droplets towards the cis-rich region and assembled close-packed two-dimen…
Intergrowth Bi4Ti3O12–PbBi4Ti4O15 single crystals were grown, and their dielectric and ferroelectric anisotropy were investigated along the a and c axes. Dielectric measurements revealed that the Curie temperature was 550 °C, which was lower than that of Bi4Ti3O12 (675 °C) and PbBi4Ti4O15 (570 °C). Remanent polarizati…
The optical properties of SrAlF 5 :Pr 3 + are studied. Emission measurements up to 1200 nm under blue-light excitation in the 3 P 2 level reveal a large number of emissions all originating from the 3 P 0 level and the 1 D 2 level. Under vacuum ultraviolet excitation in the 4f 1 5d 1 bands, emission from the 1 S 0 leve…
Small angle x-ray scattering (SAXS) measurements were performed on nanoporous methyl silsesquioxane films that were generated by the incorporation of a sacrificial polymeric component into the matrix and subsequently removed by thermolysis. The average pore radii ranged from 1 to 5 nm over a porosity range of ∼5–50%.…
The nonlinear step-growth copolymerization of a mixture of low- and high-molecular-weight diols, and a low-molecular-weight diisocyanate is addressed using a kinetic−probabilistic model. The kinetic model allows for the calculation of the concentrations of all species. Different reactivities for isocyanate functional…
Effective-medium theories for predicting conditionally averaged velocity field and hydrodynamic transport coefficients of monodisperse suspensions are extended to bidisperse suspensions. The predictions of the theory are shown to agree very well with the results of direct numerical simulations of bidisperse suspension…
We have investigated the effect of complexation of different phosphorus ligands on the stability, solid state structure, and spectroscopic properties (NMR, IR, UV-vis) of a 5,15-diphenyl-substituted ruthenium porphyrin, (MeOH)Ru(II)(CO)(DPP) 2 [DPP = 5,15-bis(3',5'-di-tert-butyl)phenyl-2,8,12,18-tetraethyl-3,7,13,17-t…
A new series of banana-shaped mesogens with ethylene links in the branches and laterally substituted are presented. They form B1, B2, B6 and B7-like phases. The B7-like and B2 phases are not miscible although identical crystallographic structures are deduced from X-ray studies. The switching in the B7-like phase is wi…
Cavitation bubble nucleation following the passage of an extracorporeal shock wave lithotripter pulse is investigated experimentally and numerically. In the experiments two configurations are considered: Free passage of the shock wave, and reflection of the shock wave from a rigid reflector. The nucleation and the ear…
Argon-ion irradiation has been used to form a tunnel barrier in multiwall carbon nanotubes and single quantum dots have been fabricated with this technique. The periodic Coulomb diamonds have been shown at 10 K and the periodic Coulomb oscillations have been observed up to around 80 K.
This paper describes the surface modification of CdSe nanoparticles (NPs) with amphiphilic and flexible poly(amidoamine) (PAMAM) dendrimers carrying different numbers of hydrophobic aliphatic chains. Although hydrophilic full generation dendrimers with primary amine termini caused aggregation of the CdSe particles, th…
The high-frequency permittivity of composites consisting of a lattice of ferromagnetic wires is investigated. Experimental results using free space or coaxial line microwave measurements are reported. It is shown that the dielectric response is strongly dependent on the magnetic properties of the wires. Negative real…