Materials Literature
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We have performed a first-principles electronic-structure study of a planar structural form of a hypothetical ${\mathrm{C}}_{3}$${\mathrm{N}}_{4}$ solid and compared its energy to a fully three-dimensional form. We use a mixed basis of pseudoatomic orbitals and low-kinetic-energy plane waves to determine the single-pa…
The growth of ultrathin platinum films on a rutile ${\mathrm{TiO}}_{2}$(110) surface has been studied using low-energy ion scattering and x-ray photoelectron spectroscopy. In the temperature range between 160 and 420 K, Pt grows in three-dimensional islands on the ${\mathrm{TiO}}_{2}$ surface with the size of the isla…
We have developed a theory of one-phonon Raman scattering in semiconductor microcrystallites and quantum dots. In particular, we have given a complete description of the phonon modes of spherical structures embedded in another material, which includes a correct treatment of the mechanical and electrostatic matching co…
Light-emitting diodes (LEDs) of poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene) were fabricated using high surface area hole-injecting network electrodes made in situ from blends of polyaniline (PANI) in low molecular weight polyester resin. Due to the high interface area between the PANI network and the…
Band calculation results show that Heusler compounds Fe 2 MnZ (Z=Al,Si,P) have a band gap near the Fermi energy for one spin direction. Except for Fe 2 MnSi, the compounds does not have a half-metallic character because there is a slight density of states at the Fermi energy in the minority-spin state. An analysis of…
We have measured the frequency dependence of the conductivity and the dielectric constant of various samples of porous Si in the regime 1 Hz to 100 kHz at different temperatures. The conductivity data exhibit a strong frequency dependence. When normalized to the dc conductivity, our data obey a universal scaling law,…
Nanocrystallite Ge (nc-Ge) embedded in a glassy ${\mathrm{SiO}}_{2}$ matrix is fabricated and examined by x-ray photoelectron spectrometry, Raman spectrometry, and high-resolution transmission-electron microscopy. The precipitation and growth of nc-Ge are found to be related to a thermodynamical reduction of ${\mathrm…
Octacalcium phosphate (OCP) has been advocated to be a precursor of biomineral s. Tn this report , we aimed at investigating OCP hydrolysis and the interaction of OCP and its hydrolyzates (apatitic products) with bovine serum albumin (BSA). A batch of synthetic OCP was allowed to hydrolyze either (a) in deionized wate…
Two site-directed mutants of isocitrate dehydrogenase (IDH) of Escherichia coli have been studied by site-directed mutagenesis kinetic and structural studies. Substitution of phenylalanine for tyrosine at position 160 (Y160F) showed 0.4% of the kcat of wild-type with isocitrate as substrate, while the Km for isocitrat…
Abstract Metallized polymer films were prepared from polyacrylonitrile or poly(vinyl alcohol) silver chelate solution by heat treatment. These metallized film exhibited low surface resistivity around 10 0 Ω/cm 2 . The surface of these conductive films was proved to be metallized using X‐ray analysis. The metal adhered…
Abstract Using polycaprolactone (PCL) fibers drawn with various draw ratios, the effects of draw ratio on enzymatic degradation were studied in order to understand the influence of fine structure on biodegradation. Degradability of PCL fibers as monitored by total organic carbon (TOC) formation or weight loss decrease…
Antiferroelectric PbZrO3 thin films have been fabricated by a multi-ion-beam sputtering technique at a substrate temperature as low as 415 °C. Single crystal perovskite PbZrO3 films oriented along the a axis could be epitaxially grown on (100)MgO, (100)Pt/MgO substrates using a PbTiO3 buffer layer. The PbZrO3 films ac…
We use a combination of numerical simulations and laboratory experiments to study the time-dependent collective diffusion coefficient $D(q, t)$ in concentrated colloidal suspensions. At short times, the particle configuration is frozen, and $D(q, t)$ probes the temporal and spatial evolution of hydrodynamic interactio…
In this letter we report large magnetoresistance (MR) in ceramic samples of La1−xSrxMnO3 (0.1≤x≤0.4) in the temperature range 4.2 K≤T≤350 K in fields up to 6 T. We find that a large negative and isotopic MR exists for the whole composition range studied and the absolute value of resistivity change on application of ma…
Lead zirconate titanate, Pb(ZrxTi1−x)O3 or PZT, thin films grown on RuO2 electrodes by the sol-gel process have excellent resistance to polarization fatigue, but they generally have two drawbacks. The films have high leakage currents and large property variation. In this letter we show that the use of a thin Pt layer…
Ferroelectric SrBi2Ta2O9 thin films were synthesized on Pt/Ti/SiO2/Si substrates using a solution deposition process, and structural and electrical properties were investigated. The spin-on films crystallized during firing above 700 °C. The films showed high diffraction peaks of (105) and (200), while little peaks fro…
Homoepitaxial diamond films grown by chemical vapor deposition from 12C and 13C containing gases have been studied by Fourier transform infrared spectroscopy. A sharp absorption band observed at 3123 cm−1 is attributed to a CH vibrational absorption. It resembles the previously observed 3107 cm−1 absorption band in na…
The surface of an azoaromatic polymer film is optically altered to produce local highly efficient diffraction gratings. The gratings obtained are stable but can be erased by heating the polymer above its glass transition temperature and no permanent damage of the film is observed. Multiple gratings can be simultaneous…
The introduction of an off-diagonal spin–orbit interaction element in the Hamiltonian matrix representing the close-lying B 1Π and c 3Σ+ states of ScF allows us to interpret the anomalies previously observed, i.e., the large Λ-type doubling in B 1Π and the large spin-splitting in c 3Σ+ at v=0, both of which decrease r…
A guided ion beam tandem mass spectrometer is used to measure the kinetic energy dependence of the V+(5D) + CO2 reaction and a reverse pathway, VO+(3∑−) + CO. Two intermediates along these reaction pathways, V+(CO2) and OV+(CO), are examined by threshold collision-induced dissociation experiments with Xe. Thermochemic…