Materials Literature
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A very mild method for the preparation of various 2‐diazo‐1,3‐carbonyl compounds in the presence of environmentally attractive solid acids such as clays in a heterogeneous manner in moderate to good yield is reported.
We investigated the phenomenon of photoinduced nematic-isotropic (N-I) transition for different concentrations of a long-chain alkane, viz., octadecane (OD), and a host liquid crystalline material having a small quantity (4.5 mol %) of a photoactive azo compound. As expected, the N-I transition temperature diminishes…
We discuss how the curvature of a substrate influences wetting by a nematic liquid crystal concentrating on the surface of a spherical particle. Our investigation is based on Landau-de Gennes free energy formulated in terms of second-rank nematic order parameter Q(ij). We review the method to treat wetting transitions…
The purification of single-wall carbon nanotubes synthesized by alcohol catalytic chemical vapor deposition (ACCVD) was performed for the first time. Subsequent use of aqueous solutions of sodium hydroxide and hydrochloric acid removed the main impurities, such as the support zeolite and the catalyst metal particles,…
Polarization gratings were recorded in amorphous As2S3 chalcogenide thin films in three orthogonal recording configurations. The analysis of polarization discrimination properties of such vector gratings revealed a poor performance. It was shown that the main reason for this is the presence of nondesired scalar modula…
The influence of the bias-voltage on the anisotropic part of the nematic surface energy is analyzed. The experimental data show a strong dependence of the anchoring strength on the bias-voltage when the electrodes of the nematic cell are covered with WO3. The observed dependence can be interpreted taking into account…
Abstract The miscibility and crystallization behavior of poly(ethylene oxide)/poly(vinyl alcohol) (PEO/PVA) blends were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and polarizing optical microscopy. Because the glass‐transition temperature of PVA was near the melting poi…
A ferromagnetic insulating (FM-I) state in ${\mathrm{Pr}}_{0.75}{\mathrm{Ca}}_{0.25}{\mathrm{MnO}}_{3}$ has been studied by neutron scattering experiment and theoretical calculation. The insulating behavior is robust against an external magnetic field, and is ascribed to neither the phase separation between a ferromag…
Solid-state magic angle spinning nuclear magnetic resonance (MAS NMR), X-ray diffraction (XRD), and scanning electron and transmission electron microscopy (SEM and TEM) are used to study thermal degradation of a Si−Al−C−O ceramic precursor in nitrogen. A polysilane (PS) and aluminum acetylacetonate (AlAce) in the weig…
Mesogenic compounds belonging to the two well-known -cyanophenyl, and -isothiocyanatophenyl homologous series, which distinctly differ in the molecular polarity (-C identical with N, 5D; -N=C=S, 2.5D), show an essential difference in the pretransitional dielectric behavior in the vicinity of the isotropic to nematic (…
Conservation of water molecules was identified by a cluster analysis of seven crystal structures of alanine racemase from Bacillus stearothermophilus. A total of 47 clusters of consensus water sites were determined and found to be highly localized, as indicated by their low mobilities. These clusters are located in th…
The crystal and magnetic structure as well as elastic, magnetic, and electrotransport properties of ${\mathrm{La}}_{0.88}{\mathrm{MnO}}_{x}$ $(2.82<~x<~2.96)$ manganites have been investigated as a function of oxygen content by x-ray, neutron diffraction, Young's modulus, magnetization, and resistivity measureme…
We present a comparative study of the charge-ordered states in orthorhombic and monoclinic forms of $\ensuremath{\theta}\ensuremath{-}(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}\ensuremath{-}\mathrm{T}\mathrm{T}\mathrm{F}{)}_{2}{\mathrm{TlZn}(\mathrm{SCN})}_{4}$ $[\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}\ensuremath{-}\m…
We have performed ferroelectric field effect experiments using an epitaxial heterostructure composed of ferroelectric Pb(Zr0.2Ti0.8)O3 and superconducting Nb-doped SrTiO3. The films were prepared on (001) SrTiO3 substrates by off-axis radio-frequency magnetron sputtering and pulsed-laser deposition. By switching the p…
Abstract With the aim of selecting a precursor of a polyhedral oligomeric silsesquioxane (POSS) reacted with aromatic diamines for its incorporation into an epoxy network, to generate an organic–inorganic hybrid material containing POSS, a polyhedral oligomeric silsesquioxane (glycidylisobutyl–POSS) was reacted with t…
We present measurements of the line tension and the viscous drag of a disclination line in nematic liquid crystal via observation of thermal fluctuations of the line position. Fourier analysis of the displacement of a disclination line due to thermal fluctuations was used to obtain the amplitudes and the relaxation ra…
A high-density electron emission more than 20 mA/cm2 was achieved from a cold cathode fabricated by simple plasma etching nanocraters onto a graphite substrate. The magnitude of the field enhancement factor was about 30 000, which is similar to that for the highest reported performance for carbon nanotube. The perform…
A novel aliphatic polyester containing a malonate group in the main chain was prepared by one-pot reaction of malonyl dichloride with ethylene glycol in the presence of triethylamine. The NMR, IR, and UV−vis studies revealed that the polymer partially underwent intra- and intermolecular Knoevenagel type self-condensat…
Kinetically constrained models (KCMs) are models of glass formers based on the concept of dynamic facilitation. This concept accounts for many of the characteristics of the glass transition. KCMs usually display a combination of simple thermodynamics and complex glassy dynamics, the latter being a consequence of kinet…
Abstract Thermal stability of polyvinyl chloride (PVC) based montmorillonite composites with either sodium montmorillonite (MMT) or alkyl ammonium ion modified montmorillonite (OMMT) were investigated by thermogravimetric analysis. The apparent activation energies associated with the first thermal degradation stage we…