Materials Literature
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We report two fluorophores, N -(1-pyrenylmethyl)-1-pyrenebutanamide and N -(1-pyrenylmethyl)-1-pyreneacetamide, that exhibit temperature-dependent emission spectra over the temperature range of 20−100 °C. The fluorophores are readily synthesized via a one-pot process and can be used in dilute form (<1 μM) for measurin…
We have examined various structures of carbon nitride with 1:1 stoichiometry and determined that for this stoichiometry ${\mathrm{sp}}^{2}$ bonding of nitrogen is energetically preferable to ${\mathrm{sp}}^{3}$. We found the zinc-blende and rocksalt phases to be mechanically unstable. They relax to a rhombohedral phas…
The C 1s X-ray absorption spectra (XAS) of poly(diallyl phthalate), poly(diallyl isophthalate), and poly(ethylene terephthalate) (PET) have been recorded using transmission detection. The phthalate segments of these polymers are isomers with different patterns of substitution (ortho, meta, para) of the methyl carboxyl…
The static and dynamic magnetic properties of nanocrystalline ${\mathrm{BaFe}}_{10.4}$${\mathrm{Co}}_{0.8}$${\mathrm{Ti}}_{0.8}$${\mathrm{O}}_{19}$ M-type doped barium ferrite were studied in detail to clarify the effect of interactions on the magnetic relaxation of an assembly of small particles. The logarithmic appr…
[Ph3PCuH]6 is an efficient catalyst for the dehydrogenative coupling between the tertiary hydrosilanes Ph3SiH, Ph2MeSiH, Me2PhSiH, or Et3SiH and water or acetic acid to give silanols or silyl acetates.
The macrocyclic ligand DO2A (1,4,7,10-tetraazacyclododecane-1,7-bis(acetic acid)) was prepared and used as a building block for four new macrocyclic ligands having mixed side-chain chelating groups. These ligands and their complexes with Mg(II), Ca(II), and Ln(III) were studied extensively by potentiometry, high-resol…
The melting behavior of semicrystalline samples of PEEK crystallized from the glassy state was investigated by differential scanning calorimetry (DSC) and simultaneous time-resolved small-angle (SAXS) and wide-angle (WAXS) X-ray diffraction. The long spacing L and the invariant were computed from the Lorentz SAXS inte…
Four members of the even-even nylon 2 Y series, for Y = 6, 8, 10, and 12, have been crystallized in the form of chain-folded lamellar single crystals from 1,4-butanediol and studied by transmission electron microscopy (imaging and diffraction), x-ray diffraction, and thermal analysis. The structures of these 2 Y nylon…
Periphytic diatom samples from a metal-contaminated Rocky Mountain river in Colorado, U.S.A. were analyzed on two occasions for the presence of morphological abnormalites. Samples were collected from natural (rocks) and artificial (tiles) substrates at 12 sites displaying a range of metal concentrations. Members of th…
Abstract Two nitronyl nitroxide derivatives bearing imidazole and benzimidazole ring were prepared and their hydrogen-bonded structures and magnetic properties were characterized.
Abstract Synthesis of hyperbranched polycarbosilanes by hydrosilylation of triallylsilane is reported. Soluble high molecular weight polymer was obtained in an uncontrolled bulk reaction. Addition of 2‐(10‐decen‐1‐yl)‐1,3‐oxazoline (i) afforded control over degree of polymerization (DP) and (ii) resulted in hyperbranc…
The effect of composition on mullite formation was investigated using submicrometer composite particles that consisted of α‐alumina cores and amorphous silica coatings. Powders with varying alumina/silica ratios were prepared by varying the thickness of the silica coating. The mullitization behavior was monitored usin…
The genome of Methanopyrus kandleri was found to harbour a gene, fwuB, predicted to encode the catalytic subunit of a tungsten formylmethanofuran dehydrogenase with an active site selenocysteine, and a second gene, fwcB, encoding a tungsten formylmethanofuran dehydrogenase with an active site cysteine. Northern blot a…
Crystallized luminescent calcium molybdate (CaMoO 4 ) film has been prepared on a molybdenum substrate in an alkaline solution containing calcium ions by active electrochemical dissolution of molybdenum at room temperature (25°C). The dissolution rate became faster with an increase of pH value. A high concentration of…
In the literature there exist many theories that provide predictions for the rheological properties of concentrated colloidal suspensions, some in excellent agreement with existing experimental data. However, the manner in which hydrodynamic interactions are included differs greatly among the various approaches. Here…
We have measured the low-field magnetoresistance of molecular-beam-epitaxy-grown tetragonal ${\mathrm{La}}_{0.7}$ ${\mathrm{Ca}}_{0.3}$ ${\mathrm{MnO}}_{3}$ films as a function of temperature, and both magnitude and direction of the applied magnetic field. We observed low-field anisotropic hysteresis that depends on t…
ABSTRACT Biodegradable films were prepared from rice bran, and their water vapor and oxygen permeabilities, mechanical properties and solubilities were studied. No differences in apparent water vapor permeability (WVP app ) were observed between rice bran films cast at pH 9.5 (RBfilm 9.5) and those cast at pH 3.0 (RBf…
A series of mesoporous titanosilicate TiMCM-41 molecular sieves with variable amounts of framework titanium have been hydrothermally synthesized using H 2 O 2 as a phase stabilizer. Some structurally analogous materials containing framework zirconium (ZrMCM-41), aluminum (AlMCM-41), or only silicon (MCM-41) have also…
Donor−acceptor systems where the rate of radiationless electronic energy transfer is influenced by the electronic structure of the intervening medium are studied. In this paper we report the observation of mediated energy transfer in a series of geometrically well-defined porphyrin dimers. The dimers consist of a free…
Lead zirconate titanate based composites containing silver particles were fabricated from commercially available PZT and Ag 2 O powder mixtures. Densification behavior and mechanical and dielectric properties were evaluated as a function of the volume fraction of silver. No unwanted reaction phases between the PZT mat…