Materials Literature
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Magnetite particles with an average size of 39 nm and good monodispersity have been synthesized by coprecipitation at 70 °C from ferrous Fe 2+ and ferric Fe 3+ ions by a (N(CH 3 ) 4 OH) solution, followed by hydrothermal treatment at 250 °C. The magnetite nanoparticles before the hydrothermal step display an average s…
The ability of different correlation functions to shed some light onto the conformational dynamics of an amorphous polymer has been analyzed. The study has been performed on a polyethylene model polymer, which has been simulated at decreasing temperatures towards its glass transition, via the molecular dynamics techni…
The Jet Propulsion Laboratory (JPL), Pratt & Whitney Rocketdyne, and Teledyne Energy Systems, Inc., have teamed together under JPL leadership to develop the next generation of advanced thermoelectric space reactor power conversion systems. The program goals are to develop the technologies needed to achieve a space nuc…
Efficient resonant electron transfer from the surface bonding structure to the conduction band of quantum confined Si nanocrystals is observed by Si nanocrystals in a toluene suspension. Based on the electron transfer mechanism, the enhancement of photoluminescence originates from the band-to-band recombination in the…
Bioassay guided fractionation of the dichloromethane extract of the underground parts of Gethyllis ciliaris, using a cyclooxygenase-1 enzyme assay, has resulted in the isolation of the dihydroxydimethylbenzopyran-4-one isoeugenitol 1 (IC50 = 262 μM). The 90% methanolic extract yielded 9Z-octadec-9-enamide 3 and the no…
Novel aquocyanophthalocyaninatocobalt(III) (Phthalcon 11) nanocrystals were used as intrinsically conducting fillers in cross-linked epoxy composites. The prepared conductive composites had a percolation threshold φ c between 0.9 and 9 vol %. The φ c appeared to be strongly dependent on layer thickness. Modeling showe…
In situ reflection electron energy loss spectroscopy (REELS) and reflection high energy electron diffraction employing a 20keV electron beam at a 2° grazing angle were used to characterize the surface properties of molecular beam epitaxy (MBE) grown Al, Ga, and In metals on silicon and sapphire substrates. In our stud…
We studied the low-energy excitations in the meV region as well as the picosecond fast process in polystyrene thin supported films using inelastic and quasielastic neutron scattering in a temperature range from 11 to 430 K , covering the bulk glass transition temperature Tg. It was found that the mean square displacem…
A first-principles-based approach is developed and used to investigate $\mathrm{Pb}({\mathrm{Zr}}_{0.4}{\mathrm{Ti}}_{0.6}){\mathrm{O}}_{3}$ ultrathin films having different growth directions and subject to different boundary conditions. A wide variety of dipole patterns is found, including ferroelectric phases absent…
The scattering amplitude distribution of an yttria-doped ceria material (Ce0.93Y0.07O1.96, space group: Fm3m) has been investigated between 23 and 1434 degrees C by the maximum-entropy method (MEM) combined with a Rietveld analysis using neutron powder diffraction data. The refined unit cell and atomic displacement pa…
CO dissociation on rhomboidal faceted nanopyramids, produced on Rh(110) by fine-tuning of ion irradiation conditions, has been studied by high resolution core-level spectroscopy. We find that this morphology presents a large efficiency towards CO dissociation, a process which is inhibited on flat (110) terraces. We al…
To understand quantum mechanical transport in a ferromagnetic semiconductor, the knowledge of basic material properties such as the phase coherence length and corresponding dephasing mechanism are indispensable ingredients. The lack of observable quantum phenomena has prevented experimental access to these quantities…
Abstract In recent years, there has been increased interest in using microphase‐separated block copolymer thin films as submicrometer/suboptical masks in next generation semiconductor and magnetic media fabrication. With the goals of removing metastable defects in block copolymer thin film simulations and potentially…
The growth of carbon nanotubes from Ni catalysts is reversed and observed in real time in a transmission electron microscope, at room temperature. The Ni catalyst is found to be Ni3C and remains attached to the nanotube throughout the irradiation sequence, indicating that C most likely diffuses on the surface of the c…
A series of novel dendritic polyphenylazomethines (DPA) with asymmetric morphologies was synthesized. Their physical properties, such as encapsulating effect, molecular dynamics, and metal assembly, are strongly dependent on the entire conformation of the molecules. The most important property is layer-by-layer metal…
The pulsed magnetron sputtering of transparent conductive oxide (TCO) films from powder targets is a promising technique, which produces films with dense columnar, defect-free structures and optical and electrical properties comparable to other deposition techniques. The targets are formed from loosely packed oxide po…
We have identified a second RpoH homolog, RpoH(II), in the alpha-proteobacterium Rhodobacter sphaeroides. Primary amino acid sequence comparisons demonstrate that R. sphaeroides RpoH(II) belongs to a phylogenetically distinct group with RpoH orthologs from alpha-proteobacteria that contain two rpoH genes. Like its pre…
The structures of two cyanoaurate-based coordination polymers, M(mu-OH(2))(2)[Au(CN)(2)](2) (M=Cu, Ni), were determined by using a combination of powder and single-crystal X-ray diffraction techniques. The basic structural motif for both polymers contains rarely observed M(mu-OH(2))(2)M double aqua-bridges, which gene…
ADVERTISEMENT RETURN TO ISSUECommunication to the...Communication to the EditorNEXTMultiporous Material from Fibrillar Syndiotactic Polystyrene IntercalatesSudip Malik, Denis Roizard, and Jean-Michel GuenetView Author Information Institut Charles Sadron, CNRS UPR 22, 6 rue Boussingault, BP 40016, F-67083 Strasbourg Ce…
Diatoms are eukaryotic, unicellular algae that are well known for the intricate architecture of their silica-based cell walls. Species identification is mainly based on variations of their hierarchically organized silica structures. Particularly striking silica frameworks are found among diatoms that belong to the gen…