Materials Literature
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The fluorescence of thiol-capped CdTe nanoparticles have been measured using nanosecond laser spectroscopy. While the bandedge fluorescence intensity of CdTe nanoparticles has been found to increase linearly with excitation intensity at low intensities, an unusual decrease of fluorescence intensity with increasing exc…
The (Ba0.5Sr0.5)TiO3 (BST) thin films were deposited on the LaNiO3/Pt(111)/Ti/SiO2/Si [LNO/Pt(111)] and LaNiO3/Pt(200)/SiO2/Si [LNO/Pt(200)] substrates by metalorganic deposition process. The BST films directly grown on the Pt(200) and Pt(111) substrates exhibited random orientation. In case of the LNO/Pt(111) substra…
Urethanes are frequently used in biomedical applications because of their excellent biocompatibility. However, their use has been limited to bioresistant polyurethanes. The aim of this study was to develop a nontoxic biodegradable polyurethane and to test its potential for tissue compatibility. A matrix was synthesize…
A lattice spin-fermion model for diluted magnetic semiconductors (DMS) is investigated numerically, improving on previously used mean-field approximations. Curie temperatures are obtained varying the Mn spin x and hole n densities, and the impurity-hole exchange J in units of the hop-ping t. Optimal values are found i…
ZnGeN2, one of the II–IV–N2 compounds, has been grown directly on r-plane sapphire by remote-plasma enhanced metalorganic vapor phase epitaxy. Single crystalline ZnGeN2 was obtained at growth temperature of 775 °C. Epitaxial relationship is ZnGeN2(010)/α-Al2O3(10–12), ZnGeN2[100] ∥α-Al2O3[11–20], and ZnGeN2[001] ∥α-Al…
Fluorescence quenching of poly(phenylene ethynylene) (PPE) particles by a Cy-5 labeled oligonucleotide is 2 orders of magnitude more sensitive than direct excitation of the Cy-5 fluorophore.
The spontaneous polarization and the piezoelectric constants of ZnO and BeO are evaluated at the ab initio level with the CRYSTAL program that uses a Gaussian-type basis set. The results obtained with four different Hamiltonians, namely, Hartree-Fock (HF), local-density approximation (LDA), Perdew-Burke-Ernzerhof, and…
Abstract Structured soft‐core/hard‐shell hydrophobic latices form rigid and transparent films under ambient conditions without the need of coalescing aids. The studied films have a composite structure, with the majority of soft poly( n ‐butyl acrylate) dispersed in a continuous poly(methyl methacrylate) (PMMA) matrix.…
We recently reported that the orientations of nematic phases of 4-cyano-4‘-pentylbiphenyl (5CB), when supported on surfaces with nanometer-scale topography and oriented carboxylic acid groups, are strongly influenced by n -H 2 N(CH 2 ) 5 CH 3 bound to these surfaces. The changes in orientation of the liquid crystals w…
Detailed kinetic Monte Carlo--molecular dynamics (KMC-MD) simulations of hyperthermal energy (10--100 eV) copper homoepitaxy reveal a reentrant layer-by-layer growth mode at low temperatures (50 K) and reasonable fluxes (1 ML/s. where ML stands for monolayer). This growth mode is the result of atoms with hyperthermal…
A first-principles-based dynamic Monte Carlo simulation method is used to examine the effect of alloying Pd and Au on the kinetics of ethylene hydrogenation over well-defined Pd and Pd/Au surfaces. The surface reaction kinetics is a strong function of the adsorbate−metal and adsorbate−adsorbate interactions. An intrin…
Semicrystalline poly(oxy-2,6-dimethyl-1,4-phenylene), PPO, is the first example of a polymer that has the glass transition of the rigid amorphous fraction (RAF) above the melting temperature of the crystals. Such phase structure does not allow fast melting below the glass transition and hinders recrystallization. The…
We have fabricated a number of high-quality porous silicon optical microcavities operating in the near infrared that exhibit cavity resonances with subnanometer linewidths. This was achieved through the low temperature anodic oxidation of highly doped p-type silicon wafers. We have investigated the optical properties…
A newly designed donor-acceptor substituted molecular motor 1 allows unidirectional rotation driven by visible light and shows some unique photophysical properties.
We have investigated the supramolecular structure of helical ribbons formed during self-assembly of a β-sheet peptide using computer simulation. We tested a wide range of molecular packing geometries consistent with the experimental dimensions to identify the most stable structure, and then systematically changed the…
ZSM-5- and NaY-coated MCF materials as new acid catalysts for conversion of bulky molecules were prepared by the coating procedure using diluted clear zeolite gel solutions. The resulting materials have high acidity and improved steam stability as compared to that of the corresponding MCF aluminosilica. This could be…
The results of first-principles density-functional calculations of the bulk moduli and related structural and electronic properties of all III-V and IV binary zinc-blende structures are presented. The band types and other properties for all the known materials in these two classes are correctly estimated. In studying…
Femtosecond coherence spectroscopic study on porphyrin molecules has demonstrated that the oscillatory features residing at the transient absorption and fluorescence decay profiles are strongly correlated with the lifetimes of the excited states and the displacements of the minima of the potential energy surfaces that…
We propose a scheme for extending the model Hamiltonian method developed originally for studying the equilibrium properties of complex perovskite systems to include Langevin dynamics. The extension is based on Zwanzig's treatment of nonlinear generalized Langevin's equations. The parameters entering the equations of m…
ZnO quantum dots (QDs) were fabricated on SiO2/Si substrates by metalorganic chemical vapor deposition. The densities and sizes of dots were investigated by atomic force microscopy. Photoluminescence at 10 K showed the broad spectra with band tails up to about 3.55 and 3.65 eV for the as-grown and the annealed ZnO QDs…