Materials Literature
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The environmentally benign polymerization of aniline provided polyaniline with an emeraldine structure by using iron(III) and ozone which is easily converted from oxygen in air. The influence of the reaction temperature upon the molecular weight of the polyaniline in this system is different from that in the polymeriz…
We demonstrate that it is possible to achieve exceptionally fine control over the anchoring of liquid crystals via the use of semi-fluorinated self-assembled monolayers of varying spacer length. We use this approach to map the detailed shape of an anchoring transition surface in thermodynamic phase space and to explor…
Huygens's principle is used to derive equations for tracing the extraordinary ray in a uniaxial crystal when the crystal axis is normal to the refracting surface. Snell's law is used to trace ordinary rays that lead to an array of ordinary spherical wavelets centered on the refracting surface. Each spherical wavelet i…
This paper reviews studies on the optical properties of dielectric nanocrystals doped by rare-earth and transition-metal ions. Manifestations of small nanocrystal size in the optical properties of impurity ions are considered. Two types of phenomena are discussed: (i) those associated with modification of the vibratio…
The frequency of the R‐line luminescence from Cr 3+ ions in aluminum oxide is known to be sensitive to chromium concentration, stress, and temperature. In this work, the effect of simultaneously doping aluminum oxide with both Cr 3+ and other ions (Fe, Ti, Ni, or Y) on the R‐line frequency and intensity at room temper…
A model for the combined processes of quiescent and flow-induced crystallization of polymers is presented. This modeling should provide the necessary input data, in terms of the structure distribution in a product, for the prediction of mechanical properties and shape- and dimensional-stability. The model is partly ba…
Abstract The initial oxidation of Zr1Nb alloy in oxygen, water and hydrogen peroxide at room temperature has been studied by angle‐resolved x‐ray photoelectron spectroscopy (ARXPS). The clean surface of alloy has been prepared either by scraping under ultrahigh (10 −10 mbar) vacuum or by argon ion sputtering. The four…
The boron sillenite, up to now known as the 12:1 compound Bi24B2O39 in the system Bi2O3 – B2O3 andcrystallizing in the space group I23, melts incongruently at 655 °C only about 25 K above the eutectic tie line and corresponding to a steep liquidus line. Single crystals with dimensions larger then 1 cm 3 have been succ…
The orientation of the crystalline δ nanoporous phase in syndiotactic polystyrene films, obtained by different procedures, have been characterized. For both solution cast and biaxially stretched films a high degree of uniplanar orientation, corresponding to the tendency of the ac crystallographic planes, to be paralle…
Measurements of the temperature dependence of the thermal conductivity $\ensuremath{\kappa}(T)$ of the antiferromagnetic perovskites ${\mathrm{SmNiO}}_{3},$ ${\mathrm{CaMnO}}_{3},$ ${\mathrm{LaMnO}}_{3},$ and ${\mathrm{YCrO}}_{3}$ are compared to that of the nonmagnetic perovskite ${\mathrm{LaGaO}}_{3}.$ Whereas ${\ma…
New highly stable benzo-fused m-trifluoromethylphenyl porphyrazines and their complexes with Mg and In were synthesized by cross-condensation of phthalonitrile and bis(m-trifluoromethylphenyl)fumaronitrile. Their 1H and 13C NMR spectra were recorded and described. The Q- and B-bands in the UV/Vis spectra of the metal…
Mixed magnetic systems $({\mathrm{CH}}_{3}{)}_{2}{\mathrm{CHNH}}_{3}\mathrm{Cu}({\mathrm{Cl}}_{x}{\mathrm{Br}}_{1\ensuremath{-}x}{)}_{3}$ are good candidates for experimental studies of the effect of bond randomness in both the Haldane state and the singlet dimer state. We investigated the magnetization process in the…
We have studied the optical anisotropy of porphyrin layers with different thicknesses deposited onto gold substrates by the Langmuir−Schaefer technique. In coincidence with the Soret band of the molecule, the optical spectral line shape as determined by reflectance anisotropy spectroscopy exhibits a characteristic, la…
Abstract A comparative study of the crystallization and orientation development in injection molding isotactic and syndiotactic polypropylenes was made. The injection molded samples were characterized using wide angle X‐ray diffraction (WAXD) techniques and birefringence. The injection molded isotactic polypropylene s…
New poly(arylene ether amide)s with trifluoromethyl pendent groups were prepared via nucleophilic nitro displacement reaction of AB-type monomers. 4-Nitro-3-trifluoromethyl-[N-(4-hydroxyphenyl)]benzamide (3) and 4-nitro-3-trifluoro-methyl-[N-(3-hydroxyphenyl)]benzamide (4) gave polymers with weight-average molecular w…
Abstract Quantitative XPS data complemented by low‐energy electron diffraction (LEED) and scanning tunnelling microscopy (STM) results of the very first stages of oxidation of an NiAl(001) single‐crystal surface are reported. The thickness, stoichiometry and alloy composition at the oxide/alloy interface and, when pos…
This paper presents the image analysis algorithms developed for a microscopy system that specifically evaluates cotton properties from longitudinal views. The system uses a motorized stage to transport a sample slide to grab sequential images of fiber segments, transversely scans the detected fibers in the images, and…
Abstract In this research work, a comparative x‐ray photoelectron spectroscopy (XPS) analysis has been performed on three allotropic carbon materials i.e. amorphous carbon films, graphite crystals and chemically vapour deposited (CVD) diamond films. These studies have shown that XPS is one of the most powerful techniq…
β-octamolybdate [Mo 8 O 26 ] clusters have been assembled, under hydrothermal conditions, into a variety of interesting one-dimensional structures.
Let us start with a very basic question that most students would ask when they first hear the terms “nonlinear optics ” or “optical nonlinearity”: