Materials Literature
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We have measured the photoconductivity of insulative SrTiO 3 single crystal whose band-gap is 3.2 eV. We have found that the dependence of resistivity on temperature shows metallic conduction under white light irradiation and the resistivity drops rapidly below 105 K. This temperature at which a giant photoconductivit…
The absolute detection efficiency (ADE) of microchannel plates for neutral sodium and potassium atoms is measured in the low keV energy range. It is shown that ADE is primarily a function of the particle energy. This result is compared to measurements made by other authors for ionic particles.
A new technique for measuring the electro-optic coefficient of nonlinear optical polymer is described. In an attenuated-total-reflection experiment the refractive index of the poled polymer is changed because of the Pockels effect. This change causes a shift of the angular position of the surface plasmon modes that co…
Samples of rapeseed oils were oxidized at isothermal conditions in the cell of a pressure differential scanning calorimeter (PDSC). The experiments were carried out under 1400 kPa oxygen pressure at a temperature in the range of 113—144 °C. From resulting PDSC exotherms the times to reach the peak maximum (τmax) were…
Abstract Methods for the incorporation of phosphate and phosphonate units into the side groups of phosphazenes, at both the high polymeric and cyclic trimer levels, are described and evaluated. Halogenated organophosphates were used as the phosphorylating agents and were allowed to react with hydroxyl‐ or lithio‐funct…
Infrared-to-visible upconversion emission enhancement through thermal effects in Yb3+-sensitized Pr3+-doped fluoroindate glasses excited at 1.064 μm is investigated. A twentyfold increase in the 485 nm blue emission intensity as the sample temperature was varied from 20 to 260 °C was observed. The visible upconversion…
Cu(I) (Cu + ) ion catalysts anchored onto various oxides (SiO 2 ·Al 2 O 3, Al 2 O 3, and SiO 2 ) were prepared by the combination of an ion-exchange method and a thermovacuum treatment. XAFS (X-ray absorption fine structure) investigations revealed that Cu + ions exist as linear two-coordinate Cu + on SiO 2 ·Al 2 O 3,…
Optical absorption of single-crystal, cerium-doped lutetium oxyorthosilicate has been carefully measured in the temperature interval 10--300 K. Prominent Gaussian absorption peaks occur at $3.432\ifmmode\pm\else\textpm\fi{}0.002\mathrm{eV}$ (peak a), $3.502\ifmmode\pm\else\textpm\fi{}0.002\mathrm{eV}$ (peak b), $4.236…
A series of m-terphenyl-based ligands bearing three coordinating oxyacetate and two amido or two sulfonamido groups, (1a-b)H3 and (2)H3, respectively, have been synthesized and characterized. The structures of the corresponding neutral complexes have been studied using 1H-NMR spectroscopy and luminescence experiments.…
The difference in threshold between sonoluminescence (SL) and sonochemical luminescence (SCL) has been investigated. The intensity of both SL from distilled water and SCL from a luminol solution in a rectangular glass cell was measured while changing the driving frequency and voltage applied to the transducer. The sec…
ABSTRACT: Power measurements (input power to ultrasound generator, input power to transducer, and ultrasonic power entering the treatment medium) were compared to the inactivation effect of ultrasound under pressure (manosonication, MS) treatments on Listeria monocytogenes ATCC 15313 in pH 7 citrate‐phosphate buffer.…
The syntheses of two novel iptycene monomers, 1,4-diiodotriptycene ( 5 ) and 2,3-diiodo-4,9-dihydro-4,9-benzonaphtho[2,3, c ]thiophene ( 10), are described herein. These monomers were subsequently copolymerized with a number of diethynylphenyl monomers via a Sonogashira−Hagihara coupling to afford both regiodefined po…
The crystal structure and magnetic ordering of the Mn spins in polycrystalline NdMnO3 have been investigated by means of neutron diffraction and ac magnetic susceptibility measurements. The compound crystallizes into an orthorhombic symmetry of space group Pbnm. Three peaks were observed in the temperature dependence…
The purpose of this study was to identify and correlate the microstructural and luminescence properties of europium‐doped Y 2 O 3 (Y 1– x Eu x ) 2 O 3 thin films deposited by metallorganic chemical vapor deposition (MOCVD), as a function of deposition time and temperature. The influence of deposition parameters on the…
A fine strontium ferrite powder with high coercivity was successfully prepared by forming hydroxide precursor particles in the continuous ethanol‐based phase of a microemulsion consisting of iso‐octane, NP9, and an ethanol solution containing Sr 2+ and Fe 3+ cations at a molar ratio of 1:12. The microemulsion‐derived…
The correct positions of the deuterium (D) atoms of many of the bound waters in the protein concanavalin A are revealed by neutron Laue diffraction. The approach includes cases where these water D atoms show enough mobility to render them invisible even to ultra-high resolution synchrotron-radiation X-ray crystallogra…
This communication provides an overview of the literature on the biocorrosion of steel in marine media, influenced by the presence of sulphate-reducing bacteria (SRB). Electrochemical aspects, microbial interactions within biofilms, the significance of medium composition and the role of iron sulphides, and hydrogen ef…
Antiferroelectric liquid crystals with a fluorinated terminal chain are reviewed. Their mesomorphism, interlayer spacing, spontaneous polarization and AF-F switching properties are described. Mixtures with an induced antiferroelectric phase are shown.
Literature data show that for MCM-41 silica made in the presence of alkyltrimethylammonium bromide (ATAB) surfactants, the best quality materials in terms of framework order are those obtained with surfactants having 12−16 carbon atom alkyl chains. Lower molecular weight surfactants seem to be more difficult to self-o…
GaMnAs layers with Mn contents from 0.05% to 7% were grown by low temperature molecular beam epitaxy. At substrate temperatures lower than 300 °C and in this composition range a uniform ternary GaMnAs compound can be grown without MnAs precipitation. Reflection high energy electron diffraction intensity oscillations r…