Materials Literature
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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…
This paper studies, in the Einstein model, the influence of thermal motion on diffraction by aperiodic structures. In particular, it shows that in a quasicrystal thermal motion reduces the intensity of the Bragg peaks by a Debye-Waller factor in the same way as in a crystal. The result applies to a large class of aper…
Abstract Die Bedeutung nichtlinearer optischer Phänomene ist schon seit geraumer Zeit bekannt, doch seit Mitte der achtziger Jahre hat das Interesse an der Suche nach und der Entwicklung von Materialien mit nichtlinearen optischen Eigenschaften, die als kommerzielle Bauelemente eingesetzt werden können, explosionsarti…
Abstract Changes in the thermal transition and stiffness of ionomers occuring during aging or water absorption were investigated. Ionomers used in this study are Na, K, Mg, and Zn salts of poly(ethylene‐ co ‐methacrylic acid) (EMAA), whose methacrylic acid unit is 5.4 mol %. It was found that ionomer stiffness is subj…
In the course of glutamate fermentation by Acidaminococcus fermentans glutaconate coenzyme A-transferase catalyzes the transfer of CoAS- from acetyl-CoA to (R)-2-hydroxyglutarate, forming (R)-2-hydroxyglutaryl-CoA. Glutamate (E) 54 of the beta-subunit was postulated to be directly involved in catalysis by formation of…
The chromophyte algae are a large and biologically diverse assemblage of brown seaweeds, diatoms, and other golden algae classified in 13 taxonomic classes. One subgroup (diatoms, pedinellids, pelagophytes, silicoflagellates, and certain enigmatic genera) is characterized by a highly reduced flagellar apparatus. The f…
Abstract Reactions taking place in a system consisting of a diepoxide (DGEBA, diglycidylether of bisphenol A) and a diisocyanate (TDI 80 : 20, toluene diisocyanate), catalyzed by a tertiary amine (BDMA, benzyldimethylamine), were followed by differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), and ch…