Materials Literature
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Polycrystalline samples of BaLaMnO4, oxygen deficient and oxygen excess BaLaMnO4 ± δ and the solid solution BaxSr1 − xLaMnO4 have been prepared and investigated. Magnetic susceptibility, powder X-ray diffraction and variable temperature powder neutron diffraction data are presented for these compounds. BaLaMnO4 and Ba…
Abstract This paper deals with the influence of interface between polyethylene and semiconducting electrode on the space charge formation and electrical breakdown. Low‐density polyethylene (LDPE) films attached with different semiconducting electrodes were subjected to the DC breakdown test, and corresponding space ch…
The critical divergence of the smectic-order correlation lengths parallel and perpendicular to the director, ${\ensuremath{\xi}}_{\ensuremath{\parallel},\ensuremath{\perp}}$, and the susceptibility, ${\ensuremath{\sigma}}_{0}$, near the nematic-to-smectic-A phase transition has been measured in a 5 T magnetic field. T…
Abstract Free‐standing poly( para ‐phenylene) (PPP) films have been electrosynthesized by direct oxidation of benzene on stainless steel electrode in mixed e1ectrolytes of boron trifluoride diethy1 etherate (BFEE) and trifluoroacetic acid (TFA). The oxidation potential of the monomer in these media is lower than those…
Abstract Metallocene polyethylene (mPE) fractions are recognized as being more homogeneous with respect to short‐chain branch (SCB) distribution as compared with unfractionated mPEs. Differential scanning calorimetry and polarized optical microscopy (POM) were used to study the influences of SCB content on the crystal…
Abstract The bisphenol 4,4″‐dihydroxy‐5′‐phenyl‐ m ‐terphenyl ( 4 ), containing a 1,3,5‐triphenylbenzene moiety, was synthesized from a pyrylium salt obtained by the reaction of benzaldehyde with p ‐methoxyacetophenone with boron trifluoride etherate as a condensing agent. Polymers were obtained from 4 by a nucleophil…
The perovskite oxide ${\mathrm{Sr}}_{2/3}{\mathrm{La}}_{1/3}{\mathrm{FeO}}_{3}$ has been found to switch its electronic ground state drastically at 23 GPa through measurements of ${}^{57}\mathrm{Fe}$ M\"ossbauer spectroscopy and powder x-ray diffraction up to 56 GPa. In the low-pressure region a first-order transition…
We present a first-principles calculation of the theoretical shear strength of the Al\ensuremath{\Sigma}3(112\ifmmode\bar\else\textasciimacron\fi{}) tilt boundary. Here we replace the usual \ensuremath{\gamma} surface (defined by rigid atomic translations parallel to the boundary) by a ``generalized \ensuremath{\gamma…
The original structure of calditol--that is, an open-chain branched nonitol--has recently been questioned by various research groups and cyclopentane-based structures have been proposed. To unambiguously clear up this confusion, four isomeric cyclopentane candidates 26-29 have been synthesized. Of these, compound 27 w…
We analyze the beating behavior of the magnetic quantum oscillations in a layered metal under the conditions when the cyclotron energy $\ensuremath{\Elzxh}{\ensuremath{\omega}}_{c}$ is comparable to the interlayer transfer energy t. Using a simple semiclassical model, we show that the positions of the beats in the int…
The preparation of a series of new macrocyclic carbodiazasilane molecules functionalized with the monoanionic [2,6-(CH2NMe2)2C6H3](-)[triple bond]N,C,N-pincer ligand has been accomplished. Palladation of these systems was possible through oxidative addition with [Pd(dba)2] affording exclusive formation of the meso dia…
Zirconia nanotubules, filled with crystalline cobalt rods (see Figure), were prepared in a reaction sequence of sol–gel crystallization of ZrO2 from zirconyl chloride octahydrate around a template of commercial porous anodic alumina, followed by electrodeposition of cobalt from CoSO4 solution and template removal with…
An AgI-promoted meso–meso coupling reaction has been extended to prepare discrete 100 nm long linear arrays of porphyrins. Oxidation of the resulting phenyl end-capped meso–meso linked porphyrins using a combination of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) and ScIII(OTf)3 directly produces fully π-conjugated…
Phenylphosphonic acid undergoes a topotactic reation with the available hydroxyls on the gibbsite sheet of kaolin and halloysite during reflux in a water–acteone mixture at 70 °C. The reaction occurs much more rapidly with halloysite than with kaolin and the number of hydroxyls consumed is much higher for the halloysi…
Abstract Fluoropolymers with adhesive and anticorrosive properties were investigated by blending statistical phosphonated copolymers with poly(vinylidene fluoride) (PVDF). In a first part, methacrylic monomers bearing dialkyl phosphonate and phosphonic acid groups were synthesized. Dimethyl(2‐methacryloyloxyethyl)phos…
Abstract Glycolide (GL) and ϵ‐caprolactone (CL) were copolymerized in bulk at relatively high temperatures using stannous octoate as a catalyst. To investigate the relationship among microstructure, thermal properties, and crystallinity, three series of copolymers prepared at various reaction temperatures, times, and…
A novel multilayer film is assembled from highly sulfonated polyaniline (SPAN) and diazoresin (DR) in aqueous solution via electrostatic attraction. Under UV irradiation, following the decomposition of diazonium group between the adjacent interfaces of the multilayer, the ionic bonds of the self-assembled film convert…
Temperature dependent nano-confined self-assembly has been observed for the crystallization of poly(ethylene oxide) (PEG) blocks within a hexagonally perforated layer in a PEO–polystyrene diblock cololymer. X-ray diffraction patterns in 2D wide and small angle X-ray scattering (WAXS/SAXS) do characteristically differ…
Abstract Symmetric polystyrene (PS)–poly(dimethylsiloxane) (PDMS) diblock copolymers were mixed into a 20% dispersion of PDMS in PS. The effect of adding the block copolymer on the blend morphology was examined as a function of the block copolymer molecular weight ( M n,bcp ), concentration, and viscosity ratio (η r )…
We have observed interference fringes of electrons in field emission patterns from multiwalled carbon nanotubes at 60 K. The observed fringe pattern is reproduced by calculations based on the formula of Young's interference of two beams. Three-beam interference has also been detected over short time periods. We discus…