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A new method to obtain a local parameterization for the exchange term in the many--body electronic problem is presented. The approach amounts to the introduction of a coordinate dependent electron effective mass. Numerical results for metallic clusters in the jellium model are compared with other standard methods.
The results of study on dynamic dielectric properties of some H-bonded crystals are presented. It is shown that relaxational soft modes are responsible for the ferroelectric phase transition in RbD2PO4, PbHPO4 and NH4HSeO4 and their contribution accounts for the static permittivity. Glass-like dielectric relaxation wi…
Abstract The electromic behavior of polyaniline‐poly(sodium acrylate) composite films (CPAn‐PAcNa) combined with a polycation bound to the disulfonated bathophenathroline ligand‐Fe complex (QDM‐BPDS‐Fe) was investigated in a LiClO 4 CH 3 CN non‐aqueous aprotic solution. The combination was achieved by chemial deposit…
Low-frequency Raman scattering spectra of potassium nitrate, KNO3 are observed as a function of temperature in a range from room temperature up to 130 K above the melting point Tm (606 K), including its order-disorder phase transition point at 403 K (Tc ). A central peak grows drastically with increasing temperature b…
The solid phases which appear when heating crystalline bis n-decyl and n-dodecyl ammonium tetra-chlorozincates (C10Zn and C12Zn for short) were studied using differential scanning calorimetry, X-ray diffraction and infrared and Raman spectroscopies. The unit-cell parameters of the different phases were determined. For…
We report the effects of matrix impedance on the electrical and optical properties of polymer dispersed liquid crystal (PDLC) samples. It was found that the impedance of a PDLC sample is a function of the applied dc bias and the frequency of the superimposed ac perturbation signal. Using the Randles equivalent circuit…
Recombinant human adenovirus serotype 2 proteinase (both native and selenomethionine-substituted) has been crystallized in the presence of the serotype 12, 11-residue peptide cofactor. The crystals (space group P3(1)21 or P3(2)21, one molecule per asymmetric unit, a = b = 41.3 angstrum, c = 197.0 angstrum) grew in sol…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMorphological Aspects of Secondary Crystallization in Poly(ether-ester) Multiblock CopolymersR. A. Phillips and S. L. CooperCite this: Macromolecules 1995, 28, 17, 5734–5744Publication Date (Print):August 1, 1995Publication History Published online1 May 2002Published inissue…
Abstract The electron spin resonance parameters of the Tl and Pb dimer centers produced by electron trapping at pairs of neighboring Tl + or Pb 2+ impurity ions in alkali chlorides are reanalyzed. The analysis which uses a consistent set of molecular parameters is based on the molecular modcl previously employed to de…
The mechanism governing oxygen transport in the vicinity of the growth interface with varying rates of crystal rotation was investigated both experimentally and computationally. Rotation induces a sweeping flow out of high oxygen content melt contributing to uniform radial oxygen concentration. At low rates of rotatio…
Abstract Sb 4 (P 2 Se 6 ) 3 und Bi 4 (P 2 Se 6 ) 3 können über eine chemische Transportreaktion mit Iod aus den Elementen dargestellt werden. Die Verbindungen kristallisieren isotyp in der monoklinen Raumgruppe P2 1 /n (Nr. 14) mit den Gitterparametern a = 2 077,7(4) pm, b = 749,35(5) pm, c = 949,49(8) pm, β = 91,25(1…
Heat capacities of ${\mathrm{La}}_{2}$${\mathrm{NiO}}_{4.094}$ single crystal were measured in 15--400 K with an adiabatic calorimeter. Four anomalies were found, as due to a phase separation concerning the excess oxygen composition at around 285 K, a glass transition over a wide temperature range of 150--300 K, a fir…
A series of ligands based upon 1,4,7-triazacyclononane, containing variable numbers of acetate vs methylenephosphonate ester or methylenephosphonate sidechains, has been synthesized and characterized as possible 31P NMR probes for monitoring [Mg2+]free. The diacetate monophosphonate and diacetate monophosphonate ester…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharacterization of Metal-Carbon Nanocrystals in the Gas Phase: FTICR Studies of V14C12+ and V14C13+Y. G. Byun, C. S. Yeh, Y. C. Xu, and Ben S. FreiserCite this: J. Am. Chem. Soc. 1995, 117, 32, 8299–8303Publication Date (Print):August 1, 1995Publication History Published on…
The syntheses of ligands and Cu(II) phthaiocyaninale complexes substituted with four {diaza and triaza) macrocycles are described and the compounds were characterized by elemental analyses, IR, 1H NMR, UV/VIS and thermogravimetric analysis.
Improvements in instrumentation for energy-dispersive X-ray microanalysis (EDX) and electron energy-loss spectroscopy (EELS) have underlined the need for suitable standards for measuring performance. We report the results from several laboratories that were supplied with a test specimen consisting of a thin film of ni…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotochromic Polysulfones. 1. Synthesis of Polymeric Polysulfone Carrying Pendant Spiropyran and Spirooxazine GroupsAbraham Warshawsky, Nava Kahana, Frida Buchholtz, Alex Zelichonok, Judith Ratner, and Valeri KrongauzCite this: Ind. Eng. Chem. Res. 1995, 34, 8, 2825–2832Publ…
Abstract The promoting effects of 2,4‐ionene on the cobalt(II) phthalocyaninetetracarboxylic acid‐[CoPc(COOH) 4 ] and cobalt(II) phthalocyanineoctacarboxylic acid‐[CoPc(COOH) 8 ] cata‐lyzed autoxidation of 2‐mercaptoethanol were studied. Dimerization of the CoPc(COOH) 4 catalyst, combined with the disappearance of the…
A new method of measuring the viscosity of liquid, which is named the double-wire torsion pendulum method in contrast to the conventional torsion pendulum method, is described in this paper. It was found that the damping factor αl changes nearly linearly with the kinematical viscosity η/ρ of the standard oil in the ra…
The mechanism of oxygen transport in the bulk silicon melt with and without crystal pulling were investigated experimentally and computationally. Crucible rotation rates were chosen as a parameter, and results suggest that rotation suppresses transport of oxygen from the crucible wall to the crystal growth interface,…