Materials Literature
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Traditional analysis of reactions catalyzed by supported metals involves the structure of the metallic particles. However, we report here that for the class of nanostructured gold- or platinum-cerium oxide catalysts, which are active for the water-gas shift reaction, metal nanoparticles do not participate in the react…
Abstract This method shows the superiority of designing DWDM filters by using the idea of simulated annealing algorithm. By applying this method, the spectral transmittance and reflectance curves of these filters all effectively achieve their desired optical performances. Although the design procedure is concentrated…
We report muon spin rotation measurements of the local magnetic susceptibility around a positive muon in the paramagnetic state of the quasi-one-dimensional spin 1/2 antiferromagnet dichlorobis (pyridine) copper (II). Signals from three distinct sites are resolved and have a temperature dependent frequency shift which…
Nonlinear optic (NLO) polymer based electro-optic devices have been achieving world record low half wave voltages and high frequencies over the last 2-3 years. Part of the advancement is through the use of relatively more conductive polymers for the cladding layers. Based on the current materials available for these c…
Abstract Magnetic composite nanoparticle of Au/γ-Fe2O3 was synthesized in an aqueous phase using gamma-ray. Connection between gold and γ-Fe2O3 was confirmed by the magnetic separation technique. TEM observation shows that 5-nm gold particles were dispersed on 20-nm γ-Fe2O3 particles. The nanoparticles adsorbed a wate…
Abstract A series of α,ω-bis(meso-porphyrinyl)oligoacetylenes were systematically prepared. The exciton interaction between the porphyrins gradually decreased with increasing number of acetylenes, whereas the interaction between the porphyrin and the oligoacetylene unit appeared.
This paper reviews the role of alloying elements in aluminium and alloy fabrication on performance during surface treatment and surface finishing. Such elements may be present in solid solution as fine segregates, strengthening phase and equilibrium phases. For surface treatment and finishes, which generally proceed i…
This paper deals with single-step, orientation-selective immobilization of human erythrocyte membranes on bare silica beads with different topographies: 1) solid (nonporous) silica beads with a diameter of 3 microns and 2) porous silica beads with a diameter of 5 microns. Erythrocyte membranes were immobilized onto be…
We present coupled cluster ab initio calculations for the Mg–He and Ca–He van der Waals potential energy curves. Our calculations employ large atom-centred basis sets, diffuse interbond functions and a fully iterative treatment of single, double and triple excitations in the coupled cluster calculation, and also inclu…
Measurements of the specific heat on the system ${\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}(x<~0.10)$ are reported. Particular attention is paid to the effect that doping the parent compound with electrons by substitution of La for Ca has on the magnetic ground state. The high- $(T>40$ K) temperature data reveal that d…
Abstract Surface‐wave propagation along a metamaterial slab with negative permittivity and permeability is analyzed. The dispersion relations are determined for the TM and TE (odd and even) modes. The Brillouin diagrams are drawn and show that, for odd modes after cutoff, there is an initial frequency range for which…
Abstract Liquid‐crystalline (LC) polyesters based on hexanediol or butanediol, dimethyl 4,4′‐biphenyldicarboxylate, and a sugar‐based diol, isosorbide or isomanide, were prepared with conventional melt polymerization. 1 H NMR spectroscopy confirmed that 50 mol % of the charged sugar diol was successfully incorporated…
Density-functional methods are used to analyze the scaling of discrete oligomeric \ensuremath{\pi}-electron conducting molecules towards idealized isolated polymer chains, treated in periodic boundary conditions. The band gaps of a series of conjugated oligomers of incrementally increasing lengths exactly fit a nearly…
We investigate the effect of counterion fluctuations in a single polyelectrolyte brush in the absence of added salt by systematically expanding the counterion free energy about Poisson-Boltzmann mean field theory. We find that for strongly charged brushes, there is a collapse regime in which the brush height decreases…
A new type of the single-molecule magnet [Mn_4 O_3 Cl_4 (O_2 CEt)_3(py)_3] forms dimers. Recent magnetic hysteresis measurements on this single-molecular magnet revealed interesting phenomena: an absence of quantum tunneling at zero magnetic field and tunneling before magnetic field reversal. This is attributed to a s…
We propose a model of transport in thick-film resistors which naturally explains the observed nonuniversal values of the conductance exponent t extracted in the vicinity of the percolation transition. Essential ingredients of the model are the segregated microstructure typical of thick-film resistors and tunneling bet…
This paper concentrates on the degradation characteristics of hydroxyapatite (HA) coatings on orthopaedic Ti-6Al-4V alloy while immersed in Ringer's salt solution, which were investigated by electrochemical impedance spectroscopy. Electrochemical impedance spectroscopy measurements were used to in situ characterize th…
We present an exactly solvable non-linear elastic model of a volume collapse transition in an isotropic solid. Integrity of the lattice through the transition leads to an infinite-range density-density interaction, which drives classical critical behavior. Nucleation is forbidden within a pressure window leading to in…
A model for a Heisenberg antiferromagnet on a pyrochlore lattice with exchange and dipole-dipole interactions is studied via mean-field theory. In treating the dipoles by use of the Ewald method, a soft (critical) mode with a unique ordering wave vector is selected for all strengths of the dipole-dipole coupling. For…
We investigate the electronic properties of nanocrystalline cerium oxide $({\mathrm{CeO}}_{x})$ films, grown by various techniques, and we establish universal relations between them and the film structure, composition, and morphology. The nanocrystalline ${\mathrm{CeO}}_{x}$ films mainly consist of ${\mathrm{CeO}}_{2}…