Materials Literature
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OBJECTIVE: This study was designed to determine whether a mixture of iodinated contrast material and gadopentetate dimeglumine used during MR arthrography yields free gadolinium ion, a systemically toxic metal. MATERIALS AND METHODS: Mixtures of commercially available nonionic and ionic iodinated contrast agent, gadop…
The reactive pyrolysis−gas chromatography technique was applied to verify the branching and/or cross-linking structures in an industrially available PC sample and its thermally treated ones through identification of specific pyrolysis products directly reflecting the related abnormal structures. On the pyrograms of th…
This communication deals with the coordination-insertion ring-opening polymerization of 1,4-dioxan-2-one (DX) as initiated by aluminium triisopropoxide (Al(OiPr)3) either in bulk or in solution. First, polymerization of DX has been carried out in bulk at 100°C and compared to the ring-opening polymerization promoted b…
Relaxor ferroelectric single crystals ${0.65\mathrm{P}\mathrm{b}(\mathrm{M}\mathrm{g}}_{1/3}{\mathrm{Nb}}_{2/3}{)\mathrm{O}}_{3}{\ensuremath{-}0.35\mathrm{PbTiO}}_{3}$ have been studied in detail by high resolution micro-Brillouin scattering technique over a wide temperature range (-190--600 \ifmmode^\circ\else\textde…
We have developed a new technique called the slope nucleation method (SNM) for the growth of high-quality 4-dimethylamino-methyl-4-stilbazolium-tosylate (DAST) crystals. This technique combines the spontaneous nucleation and subsequent growth of a single crystal into one process. The SNM features the ability to contro…
An MgO crystal was thermochemically reduced (TCR) under extreme reducing conditions such that the concentration of anion vacancies $(F$ centers) was exceptionally large, $6\ifmmode\times\else\texttimes\fi{}{10}^{18}{\mathrm{cm}}^{\ensuremath{-}3}.$ Optical absorption measurements demonstrate that in addition to F cent…
The dioxomolybdenum(VI) fragment MoO2X2 has been confined within the ordered mesopores of pure siliceous hexagonal MCM-41 and cubic MCM-48 molecular sieves either by direct grafting (solvent impregnation) with MoO2X2(THF)2 or by using a spacer ligand [L = NC(CH2)2Si(OEt)3]. The materials have been characterised by ele…
Until modelling is complete, macromolecular structures are refined in the absence of a model for some of the atoms in the crystal. Techniques for defining positional probability distributions of atoms, and using them to model the missing part of a macromolecular crystal structure and the bulk solvent, are described. T…
Properties of disordered nematic elastomers and gels are theoretically investigated with emphasis on the roles of nonlocal elastic interactions and crosslinking conditions. Networks originally crosslinked in the isotropic phase lose their long-range orientational order by the action of quenched random stresses, which…
A new spectrometer for the study of energy-resolved momentum densities is described. The (e, 2e) spectrometer uses a symmetric configuration and uses incoming energies up to 50 keV. Energy resolution and momentum resolution are 1.8 eV and 0.1 a.u., respectively. Compared to previous spectrometers this spectrometer has…
Abstract The removal of hydrochloric acid utilizing magnesium-aluminum oxide (Mg–Al oxide), as prepared by the thermal decomposition of hydrotalcite (HT), was investigated. Cl− in hydrochloric acid can be removed almost 100% by adding 1.75 times the stoichiometric quantity of Mg0.70Al0.20O at 60 °C for 1 h. Mg2+ and A…
Ultrasonic degradation was shown to be a very effective method for creating homologous series of molar masses in order to establish structure-property relationships such as the Mark-Houwink equation and the RG-M relation. It was tested mainly for cellulose derivatives. The detection of the molar masses, the radii of g…
Abstract It was found that methyl-4,6-O-p-nitrobenzylidene-α-d-galactopyranoside (1) and methyl-4,6-O-benzylidene-α-d-mannopyranoside (2), which are scarcely soluble in apolar solvents, act as “supergelators” when they are enforcedly dissolved above their bp’s in a sealed tube. The minimum gelator concentrations (Cmin…
The effect of the addition of lauric acid and nisin to corn zein films on the water permeability and inhibition of bacterial growth was examined using two methods. A zone of inhibition test on solid media and a log reduction assay with the film exposed to a bacterial culture (Lactobacillus plantarum) in liquid media (…
Proteins and RNA undergo intricate motions as they carry out functions in biological systems. These motions frequently entail large-scale conformational changes that induce changes in the surface structure, or shape, of a molecule. This review describes the experimental characterization of large-scale shape changes in…
The core structure of an edge dislocation in aluminum is studied by molecular dynamics simulation with the glue potential. The edge dislocation of the $\frac{1}{2}[1\ifmmode\bar\else\textasciimacron\fi{}10](111)$ type is observed to dissociate into two partials separating from each other by a distance of 9 \AA{}. The…
Using a density-functional-based interface displacement model, we determine the effective interaction potential between two spherical particles which are immersed in a homogeneous fluid such as the vapor phase of a one-component substance or the A-rich liquid phase of a binary liquid mixture composed of A and B partic…
An apparatus suitable for pressure-jump experiments with variable pressure amplitude and a fast response time to facilitate time-resolved small-angle x-ray scattering at synchrotron facilities is described. The high pressure-jump apparatus is capable of performing bidirectional pressure jumps at a time resolution as h…
We report unambiguous evidence for ferroelectricity in a chiral bent-core liquid crystal. This evidence includes (i) a single current peak in the polarization reversal current, (ii) a strong dielectric response that is suppressed by applying a bias electric field, and (iii) strong optical second-harmonic generation in…
This review summarizes data for all known tricyanomethanide and dicyanamide compounds of copper(II), nickel(II) and cobalt(II). The possible bonding modes of [C(CN)3]− and [N(CN)2]− ions and their influence on infrared spectra are demonstrated. Preparative methods are briefly described and structural data for crystall…