Materials Literature
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A new pentadentate N-isobutyrylsalicylhydrazidate ligand (H(3)ibushz, C(11)H(14)N(2)O(3)) and a self-assembly synthesis of the first 24-azametallacrown-8, [Fe(8)(C(11)H(11)N(2)O(3))(8)(CH(3)OH)(8)].0.5CH(2)Cl(2).7.5CH(3)OH.3.5H(2)O, have been reported. Eight Fe(III) ions and eight deprotonated ibushz(3)(-) ligands con…
Stacking-fault tetrahedra (SFT) are typical vacancy clusters in fcc metals. SFT have been, however, considered to be unstable in aluminum because of its high stacking-fault energy, until the recent finding of SFT in thin aluminum foils subjected to a tensile fracture. This study confirmed that SFT form in aluminum fol…
Abstract The influence of surface chemistry and boron doping density on the redox chemistry of Fe(CN) $\rm{ {_{6}^{3-/4-}}}$ at CVD polycrystalline diamond electrodes is considered. It is demonstrated that for this couple both the doping density and the surface chemistry are important in determining the rate of charge…
Finite difference schemes, named Compact Finite Difference Schemes with Spectral-like Resolution, have been used for a less crude approximation of the analytical hardness definition as the second-order derivative of the energy with respect to the electron number. The improved computational schemes, at different levels…
In the present work, quantification of the overall gas−liquid mass-transfer coefficient ( K L a ) in the sonochemical reactors (two different types viz. ultrasonic horn and ultrasonic bath) has been done using the dynamic method. The effect of operating parameters such as the power density into the system, gas flow ra…
A recent survey of the Cambridge Structural Database, CSD [Allen (2002). Acta Cryst. B58, 380-388], shows that the percentage of incorrect assignments of the space group Cc has remained at about 10% since the last survey in 1997.
Abstract Preparation of conductive polymer–coated fabrics was carried out by admicellar polymerization. By this method, a thin layer of conductive polymers (polypyrrole, polyaniline, and polythiophene) was formed on cotton and polyester fabrics by a surfactant template. The effects of monomer concentration, oxidant to…
We demonstrate the use of aqueous-based layer-by-layer (LbL) processing and in situ nanoreactor chemistry for creating polyelectrolyte multilayer (PEM) nanocomposites in which the concentration of a nanoparticle species is modulated throughout the depth of the film in a complex way. Using the in situ growth of silver…
Liquid crystalline behavior has been found in a series of low-molecular-weight 9,10-disubstituted anthracenes. In particular, nematic mesomorphism is displayed by derivatives bearing at least a 4‘-pentylbiphenyl-4-ylethynyl group, showing that the presence of this substituent induces a mesophase despite the broad cent…
Abstract Free Sulfate is a major parameter affecting gypsum crystallization during phosphoric acid production. Gypsum crystal size, shape and filtration rate are significantly affected by the concentration of free sulfate. It is, therefore, important to evaluate the effectiveness of different sulfate levels from 1.5%…
Abstract Nanocomposites of poly(vinyl chloride) (PVC) and nano‐calcium carbonate (CaCO 3 ) particles were prepared via melt blending, and chlorinated polyethylene (CPE) as an interfacial modifier was also introduced into the nanocomposites through preparing CPE/nano‐CaCO 3 master batch. The mechanical properties, morp…
Ultrathin Al2O3 layers on alloys are used as templates for model catalysts, tunneling barriers in electronic devices, or corrosion-resistant layers. The complex atomic structure of well-ordered alumina overlayers on NiAl110 was solved by surface x-ray diffraction. The oxide layer is composed of a double layer of stron…
We report a combined top-down/bottom-up hierarchical approach to fabricate massively parallel arrays of aligned nanoscale domains by means of the self-assembly of asymmetric polystyrene-block-poly(ethylene-alt-propylene) diblock copolymers. Silicon nitride grating substrates of various depths and periodicities are use…
We present density functional perturbation theory for electric field perturbations and ultra-soft pseudopotentials. Applications to benzene and anthracene molecules and surfaces are reported as examples. We point out several issues concerning the evaluation of the polarizability of molecules and slabs with periodic bo…
Using a combination of density-functional perturbation theory and the itinerant coherent potential approximation, we study the effects of atomic relaxation on the inelastic incoherent neutron scattering cross sections of disordered Ni$_{50}$Pt$_{50}$ alloys. We build on previous work, where empirical force constants w…
A functional $E_{xc}[ρ(\r,ε)]$ is presented, in which the exchange and correlation energy of an electron gas depends on the local density of occupied states. A simple local parametrization scheme is proposed, entirely from first principles, based on the decomposition of the exchange-correlation hole in scattering stat…
We present results of magneto-optical measurements and theoretical analysis of shallow bound exciton complexes in bulk ZnO. Polarization and angular dependencies of magnetophotoluminescence spectra at 5 T suggest that the upper valence band has ${\ensuremath{\Gamma}}_{7}$ symmetry. Nitrogen doping leads to the formati…
Several strategies have been used to increase the biostability of medical-grade polyurethanes while maintaining biocompatibility and mechanical properties. One approach is to chemically modify or replace the susceptible soft segment. Currently, poly(carbonate urethanes) (PCUs) are being evaluated as a replacement of p…
Inorganic glasses normally exhibit a network of interconnected, covalent-bonded, structural elements that has no long-range order. In silicate glasses, the network formers are based on SiO4 tetrahedra interconnected through oxygen atoms at the corners. Conventional wisdom implies that alkaline and alkaline-earth ortho…
We have developed the tight-binding theory to study electronic and optical properties of type-II heterostructures CA/C'A' grown from the zinc-blende semiconductors CA and C'A' along the crystallographic direction [001]. The sp^3s* nearest-neighbor tight-binding model with allowance for the spin-orbit interaction is us…