Materials Literature
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We propose a density functional for anisotropic fluids of hard body particles. It interpolates between the well established geometrically based Rosenfeld functional for hard spheres and the Onsager functional for elongated rods. We test the new approach by calculating the location of the nematic–isotropic transition i…
FULLPAT is a quantitative X-ray diffraction methodology that merges the advantages of existing full-pattern fitting methods with the traditional reference intensity ratio (RIR) method. Like the Rietveld quantitative analysis method, it uses complete diffraction patterns, including the background. However, FULLPAT can…
An automated system for mounting and dismounting pre-frozen crystals has been implemented at the Stanford Synchrotron Radiation Laboratory (SSRL). It is based on a small industrial robot and compact cylindrical cassettes, each holding up to 96 crystals mounted on Hampton Research sample pins. For easy shipping and sto…
This paper discusses the development status of the memory cell element of OUM (Ovonic Unified Memory) - a chalcogenide-based, phase-change nonvolatile semiconductor memory technology at the 180 nm technology node. The device structure and characterization of the memory element will be reviewed. The key characteristics…
BaMgAl 10 O 17:Eu 2+ phosphors are synthesized by solid-state calcining of BaCO 3, Al 2 O 3, MgO, and Eu 2 O 3 with AlF 3 as a flux. The structural and optical properties of the blue phosphor are investigated as a function of the europium concentration in BaMgAl 10 O 17 using the neutron and the X-ray powder diffracti…
In this paper, it is pointed out that the light transmission anomalies observed for thin-film metallic gratings can be explained entirely in terms of dynamical diffraction theory. Surface plasmons are an intrinsic component of the diffracted wave field and, as such, play no independent causal role in the anomalies, as…
The novel morphology of BN nanotubes with a collapsed structure has been discovered by a metal-catalyzed treatment. The collapse causes the dramatic enlargement of a specific surface area of BN nanotubes and remarkably enhances the hydrogen storage capacity of BN nanotubes.
High solubility of SWNTs and MWNTs in water is obtained by organic functionalisation; derivatisation with N-protected glycine is also easily achieved.
An extension to the Steinmetz equation is proposed, to enable estimation of hysteresis losses in magnetic core materials with nonsinusoidal flux waveforms. The new formulation is shown to avoid anomalies present in previous modified-Steinmetz-equation calculations of loss with nonsinusoidal waveforms. Comparison with…
Gold-based catalysts have been of intense interests in recent years, being regarded as a new generation of catalysts due to their unusually high catalytic performance. For example, CO oxidation on Au/TiO(2) has been found to occur at a temperature as low as 200 K. Despite extensive studies in the field, the microscopi…
A new program has been developed for ab initio crystal structure determination from powder diffraction data (X-ray and neutron). It uses global-optimization algorithms to solve the structure by performing trials in direct space. It is a modular program, capable of using several criteria for evaluating each trial confi…
A kind of amphiphilic polymer, ES-1, is transferred onto solid substrates as so-called “reversed duckweed” polymeric Langmuir−Blodgett (LB) films. Their orientations, structures, and phase-transition behaviors were studied in detail by infrared (IR) transmission and reflection−absorption (RA) spectroscopy. The IR stud…
Crystal and magnetic structures of complex manganese oxides ${\mathrm{Sr}}_{2}{\mathrm{GaMnO}}_{5+\ensuremath{\delta}}$ $(\ensuremath{\delta}\ensuremath{\simeq}0.01,0.52)$ and ${\mathrm{Ca}}_{2}{\mathrm{GaMnO}}_{5+\ensuremath{\delta}}$ $(\ensuremath{\delta}\ensuremath{\simeq}0.05)$ were studied by neutron powder diffr…
Abstract The effect of siloxane chain length on surface segregation of poly(methyl methacrylate)‐grafted poly(dimethyl siloxane) (PMMA‐ g ‐PDMS)/poly(2‐ethylhexyl acrylate‐ co ‐acrylic acid‐ co ‐vinyl acetate) [P(2EHA‐AA‐VAc)] blends was investigated. The blends of PMMA‐ g ‐PDMS with P(2EHA‐AA‐VAc) showed surface segr…
Abstract Polyurethane prepolymers prepared from toluene 2,4‐diisocyanate, toluene 2,6‐diisocyanate, and polypropylene glycol with a ratio between the isocyanate and hydroxyl groups equal to 2 were analyzed by 1 H nuclear magnetic resonance (NMR) spectroscopy in acetone‐d 6 . Different temperatures and concentrations w…
Changes upon oxidization of carbon nanotubes (CNTs) in structure and Raman spectra are investigated using geometry optimizations and frequency calculations with density functional theory and ONIOM(MO:MO) methods. Macrocycles consisting of six and 12 fused C 6 hexagon units, C 24 H 12 and C 48 H 24 or [6]- and [12]-cyc…
Abstract Poly( L ‐lactide), that is, poly( L ‐lactic acid) (PLLA), poly(ε‐caprolactone) (PCL), and their blend (50/50) films containing different amounts of poly( L ‐lactide‐ co ‐ε‐caprolactone) (PLLA‐CL), were prepared by solution casting. The effects of added PLLA‐CL on the enzymatic hydrolysis of the films were inv…
Water-processable molecular complexes between dextran sulfate (DSA) and polyaniline derivatives (PANIs) have been synthesized by chemical polymerization of corresponding achiral monomer in the presence of DSA. The formation of the macromolecular complex was proved by the FTIR and UV−vis spectra. Interestingly, chiral…
X-ray crystal structures, solid-state photoluminescence, and Kurtz−Perry powder second harmonic generation (SHG) efficiencies of two novel noncentrosymmetric polymeric adducts of CuI with 4-acetylpyridine, a double-stranded “stair” and a single-stranded “chain”, are reported, the latter being a rare example of a [CuX(…
Epitaxial films of cuprous oxide, Cu 2 O, are electrodeposited from aqueous solution onto single-crystalline Si(001). The epitaxial growth of Cu 2 O onto Si is an unexpected result, because there is a strong driving force for the oxidation of Si to form a native amorphous SiO 2 layer. The Cu 2 O films are single-cryst…