Materials Literature
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The properties of transition-metal oxides are related to the presence of elements with mixed valences, such as Mn and Co. Spatial mapping of the valence-state distribution of transition-metal elements is a challenge to existing microscopy techniques. In this letter, using the valence-state information provided by the…
The molecule of the title compound, C 32 H 18 N 8 , is slightly distorted at the corners. Two of the phenyl rings are located below the molecular plane while the other two are above the plane. This leads to a molecular symmetry of C i as opposed to D 2h , assumed for the free molecule. The crystal data are basically i…
Die Verbrückung von Gold(I)-zentren durch Bis(diphenylphosphanyl)methan(dppm)-Liganden sowie die Gegenwart aurophiler Schwefelzentren führen zur Bildung des vielkernigen Komplexkations [Au12(μ-dppm)6(μ3-S)4]4+ (siehe Bild) aus [Au2Cl2(dppm)] und H2S. Dieser Metalla-Makrobicyclus weist eine langlebige Lumineszenz im Mi…
Optical nonlinearity in host–guest liquid crystals was characterized by systematically investigating both the experimental diffraction beam pattern and the theoretical one originating in photothermal self-phase modulation. The experimental diffraction patterns were in very good agreement with the calculated results wh…
We propose one- and two-wavelength methods of absolute measurement of diffraction-grating spacings based on the Littman configuration for autocollimation. The one-wavelength method has been applied to measure the spacing of a grating with a nominal value of 2160grooves/mm . The grating spacing was measured to be 463.1…
The surface electronic structure in crystalline copolymer films of vinylidene fluoride (70%) with trifluoroethylene (30%) has been studied by photoemission and inverse photoemission as a function of alkali metal (sodium) doping. Sodium doping introduces at least two new states into the band (HOMO-LUMO) gap well away f…
We have applied optical second-harmonic generation to the spectroscopy of strained $\mathrm{Si}(100)\ensuremath{-}{\mathrm{Si}}_{0.85}{\mathrm{Ge}}_{0.15}\ensuremath{-}{\mathrm{SiO}}_{2}$ heterostructures, covering the full range of the fundamental critical-point interband transitions. By analyzing spectra from sample…
Photon-stimulated desorption of positive and negative hydrogen ions from hydrogenated diamond film and Di(100) surfaces and amorphized diamond surface has been studied for incident photon energies in the 280--340 eV range. From comparison between the ${\mathrm{H}}^{+}$ yield as a function of photon energy and the near…
Benztropine and its analogs are tropane ring-containing dopamine uptake inhibitors that produce behavioral effects markedly different from cocaine and other dopamine transporter blockers. We investigated the benztropine binding site on dopamine transporters by covalently attaching a benztropine-based photoaffinity lig…
The recent success of bulk synthesis of pure nanoscale silicon quantum wires (SiQW's) enables us to evaluate their photoluminescence (PL) characteristics under ultraviolet photoexcitation. Intensive multiple light emissions ranging from dark red to blue regions were revealed for as-grown and partially oxidized SiQW sa…
A lamellar multilayer grating of the nominal normal and lateral periods 8 and 800 nm, respectively, was obtained by etching a planar amorphous W/Si multilayer up to the substrate. The specular reflectivity, grating truncation rods of nonzero orders, and a reciprocal space map of the scattered intensity close to the to…
Decreases in both dark conductivity and photoconductivity after intense and prolonged photoirradiation have been observed in the narrow-band-gap amorphous ${\mathrm{Sb}}_{2}{\mathrm{Se}}_{3};$ they are similar to those observed in hydrogenated amorphous silicon $(a\ensuremath{-}\mathrm{S}\mathrm{i}:\mathrm{H})$ (the S…
The NCOCH2(CF2)6CH2OCN fluoromethylene cyanate ester monomer and resin are synthesized and characterized. The monomer is prepared by a large-scale bench-top synthesis, characterized by differential scanning calorimetry, infrared, 1H-, 13C-, 15N-, and 19F-NMR spectroscopies and analyzed for catalytically active impurit…
Optical excitation of half-leaky guided modes has been used to explore the director distortion of a homogeneously aligned nematic liquid crystal (BDH E7) under application of an in-plane electric field. Homogeneous alignment is realized by obliquely evaporated SiOx layers with an in-plane field being applied across a…
A novel approach for porphyrin modification is provided by ring-enlargement reactions. Treatment of dioxochlorins (see scheme) and tetraoxobacteriochlorins with diazomethane results in formation of the corresponding mono- and di(oxopyri)porphyrins.
Hochreaktiv sind die aus Alkalimetallaziden in situ gebildeten Alkalimetalloxide. Deren Umsetzung zu ternären Oxiden verläuft aber kontrolliert und bietet damit ein elegantes Syntheseverfahren für Alkalimetalloxometallate.
Thermal expansion, magnetization, and electrical-resistivity measurements of single crystalline ${\mathrm{La}}_{0.83}{\mathrm{Sr}}_{0.17}{\mathrm{MnO}}_{3}$ are presented. A first-order structural transition occurs at 300 K, transforming the high-temperature rhombohedral phase into an orthorhombic phase. The paramagne…
The thermal and catalytic degradation of mixed plastics containing poly(vinyl chloride) (PVC) was carried out at 360−430 °C under atmospheric pressure by semibatch operation. The boiling-point distributions of organic chlorine compounds in the oil obtained from the degradation of mixed plastics PE/PVC, PP/PVC, and PS/…
The oxidation kinetics of two kinds of polycrystalline nickel particles with an approximate median diameter of 5 μm but with different morphology, has been studied by thermogravimetric measurements in the temperature range 573–973 K. The oxidation was found to be thermally activated with an apparent activation energy…
Electron paramagnetic resonance (EPR) and photoluminescence (PL) spectroscopy have been used to examine the structure and optical properties of erbium-impurity complexes formed in float-zone Si by multiple-energy implants at 77 K of Er together with either O or F. After implantation a 2-\ensuremath{\mu}m-thick amorpho…