Materials Literature
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Steady-state and time-resolved fluorescence data are used to examine the photophysical characteristics of a series of phenylacetylene dendrimers. Correlated excimer formation is observed in some solvents which is found to depend strongly upon initial excited-state placement within the dendrimer framework. The results…
A new preparation method for highly dispersed iron in mesoporous MCM-41 materials has been developed, employing a methanolic solution of iron(III) nitrate. In situ EXAFS and NO adsorption followed by IR spectroscopy suggest that the resulting iron is present mainly in the form of isolated cations bound to the internal…
Elastic and inelastic neutron-scattering experiments have been performed in a ${\mathrm{La}}_{0.94}{\mathrm{Sr}}_{0.06}{\mathrm{MnO}}_{3}$ untwinned crystal, which exhibits an antiferromagnetic canted magnetic structure with ferromagnetic layers. The elastic small q scattering exhibits a modulation with an anisotropic…
3D inorganic monoliths with sponge-like texture have been produced using polymer–gel templates. Colloidal suspensions of magnetite or titanium dioxide nanoparticles were diffused into swellable gels (see Figure) composed of acrylic acid–based copolymers, and possessing 3D channels. Hybrid composites were produced that…
Seven absorption group-bands (1D2, 1G4, 3F2, 3F3, 3H4, 3H5, 3F4) of Tm3+ in YVO4 single crystals have been observed in the orientation absorption spectra recorded in the spectral range from 200 to 4000 nm at 300K. The integrated absorption cross section for each group-band was accurately evaluated. On the assumption t…
Zinc oxide thin films have been grown on silicon (100) and sapphire (0001) substrates by pulsed laser deposition. The thin films deposited at different processing parameters were evaluated by x-ray diffraction, Raman spectroscopy, and atomic force microscopy (AFM). The influences of substrate temperature and laser flu…
Barium cerate crystals of 1.5 mm diameter could be grown from melt solutions containing barium chloride, barium oxide (from thermolysis of barium carbonate), and cerium(IV) oxide. The maximum size of the crystals is limited by the low solubility of cerium(IV) oxide in the barium chloride melt (ca. 0.1 Mol%). The flux…
Diamond-like carbon (DLC) films were deposited directly on GaAs substrates by a capacitively coupled 13.56 MHz glow discharge in a CH4 plasma. The deposition process for antireflective DLC coating deposition on GaAs was optimized. DLC films of different thicknesses were deposited to investigate IR spectral characteris…
Work has been performed to investigate the effect of pH on the performance of a tertiary amine possessing a single carboxylic acid group. The efficiency of this inhibitor and speed at which the efficiency increased were able to show a strong pH dependency, indicating that in such systems pH monitoring is important. Me…
Abstract Four-probe resistivity measurements were made on an organic semiconductor, β′-(BEDT-TTF)2ICl2 up to 10 Gpa by using a diamond anvil high-pressure cell. The activation energy was decreased with increasing pressure and the metallic phase appeared around 8 Gpa. When the pressure was kept around 10 Gpa, the resis…
The polycondensation of hyperbranched polymers, based on AB2 type monomers, was simulated using an off-lattice Monte Carlo method in order to investigate the polymerization kinetics and microstructures of hyperbranched polymers. The effects of temperature and activation energy of reaction on the conversion rate seem q…
We show an anomalous behavior in a diffractive lens in which the spot size at the focus reaches a minimum at a numerical aperture of ~0.5 and then increases significantly at higher values. Theoretical and experimental results are presented, along with a comparison with refractive aplanatic lenses, in which the anomaly…
In this paper, a shot-line model that describes the process of air-defence warhead explosion and the fragment dispersion was developed, in which natural fragment warheads, controlled fragment warheads, performed fragment warheads, multi-P-charge warheads, fragment focusing warheads and continuous rod warheads were inc…
Hexakoordinierte ReV-Phthalocyaninate (pc) und ReV-Tetraphenylporphyrinate (tpp) vom Typ [Re(O)(X)p] (p: pc, tpp) mit X = OCH3, ReO4, Cl/pc, F/pc, OH/tpp, [{Re(O)p}2(μ-O)] und (cat)trans[Re(O)2p] (cat: nBu4N, Et4N/tpp) sind isoliert und durch UV-Vis-NIR-, IR- und Resonanz-Raman(RR)-Spektren charakterisiert worden. Bei…
Abstract Four commercially available main‐chain LCPs, Xydar and Zenite series, are characterized by FTIR spectroscopy, DSC, polarized light microscopy (PLM), TGA, TGAFTIR, and elemental analysis. The FTIR spectrum of Zenite 8000B is found to be more similar to that of Vectra A950 than those of the other three LCPs. Xy…
The paramagnetic resonance and optical spectra of Co2+ ions in SrLaAlO4 single crystals are reported. The EPR spectrum shows one electronic transition consisting of eight hyperfine lines with anisotropic g-factor and nearly isotropic hyperfine interaction constant. A tetragonal distortion of the octahedral crystal fie…
Abstract The compression molding process for manufacturing of all‐thermoplastic honeycomb core sandwich components is studied with the aim of verifying a previously proposed model describing the instantaneous face‐core bonding during molding. Experiments are performed with glass/polypropylene (PP) faces and PP honeyco…
The inhibition efficiency of the HEDP‐Zn2+ system, in a wider concentration range of Zn2+ and HEDP (10, 50, 100, 150, 200 and 300ppm), in controlling corrosion of mild steel immersed in low chloride medium (Cl‐ = 60ppm) has been evaluated by weight‐loss study. Synergism parameters have been calculated between HEDP and…
It is known from earlier work that the activation energies of dislocation glide and diffusion-controlled climb of semiconductors with diamond and zinc-blende structures are correlated. It is shown in the present work in a semiempirical approach that both energies are proportional to Phillips’ homopolar band gap. A sin…
The transverse Ising model is considered in the static fluctuation approximation. This hinges on the replacement of the local field operator with its mean value; only the quadratic fluctuations of the local field are retained. The model is applied to ferroelectrics of the order-disorder type, such as monoaxial crystal…