Materials Literature
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Using total energy and structure optimization calculations, we investigate the relative stability and the conversion mechanism between multiwall carbon nanotubes and graphitic scrolls. We suggest that axial segments of a nanotube and a scroll may coexist within the same tubular nanostructure, separated by a dislocatio…
First-principles calculations based on gradient corrected density functional theory are performed on $\mathrm{Mn}$-doped $\mathrm{ZnO}$ thin film. Magnetism and energetics are studied for two $\mathrm{Mn}$ concentrations and varying $\mathrm{Mn}$ configurations. It is found that in the dilute limit when $\mathrm{Mn}$…
In aqueous solutions and for high concentrations triblock copolymers are known to aggregate. As a critical volume fraction of micelles is reached they crystallize. We report on grazing incident small angle neutron scattering as an experimental tool to investigate the crystallization of spherical polymer micelles in th…
Catastrophic equipment failures continue to occur today due to ferroresonance even though this phenomenon has been extensively studied over the past ninety years. This paper is concerned with describing practical examples of ferroresonance in a high voltage transmission system. Methods of mitigating ferroresonance are…
Abstract The copolymers of acrylamide and acrylamide with pendant azobenzene (AzBA–AAm) were prepared by radical polymerization. The association constants of trans-AzBA–AAm copolymers with β-CD are larger than those of cis-AzBA–AAm copolymers. The trans-AzBA–AAm guest copolymer was found to form supramolecular gels wi…
Anomalous magnetic and electronic properties of the half-metallic ferromagnets (HMF) have been discussed. The general conception of the HMF electronic structure which take into account the most important correlation effects from electron-magnon interactions, in particular, the spin-polaron effects, is presented. Speci…
Starting from exact expression for the dynamical spin susceptibility in the time-dependent density functional theory a controversial issue about exchange interaction parameters and spin-wave excitation spectra of itinerant electron ferromagnets is reconsidered. It is shown that the original expressions for exchange in…
We report on large negative magnetoresistance observed in ferromagnetic thiospinel compound CuCrZrS$_{4}$. Electrical resistivity increased with decreasing temperature according to the form proportional to $\textrm{exp}(T_{0}/T)^{1/2} $, derived from variable range hopping with strong electron-electron interaction. Re…
We have produced magnetic patterns suitable for trapping and manipulating neutral atoms on a $1 μ$m length scale. The required patterns are made in Co/Pt thin films on a silicon substrate, using the heat from a focussed laser beam to induce controlled domain reversal. In this way we draw lines and "paint" shaped areas…
This article reviews basic theoretical features of Gilbert magnetization dynamics of a single domain magnetic film in the presence of Slonczewski spin-transfer torques, with and without thermal fluctuations taken into account. Rather than showing results of detailed numerical calculations, the discussion here is restr…
Atomic Force Microscopy (AFM) has become established as a powerful and a versatile tool for investigating local mechanical properties. In addition, it has been made possible to take advantage of the AFM tip-sample interaction, to perturb, and I turn, to modify the surface of soft samples, such as polymers. The accurat…
The first generation of luminescent semiconductor quantum dot (QD)-based hybrid inorganic biomaterials and sensors is now being developed. It is crucial to understand how bioreceptors, especially proteins, interact with these inorganic nanomaterials. As a model system for study, we use Rhodamine red-labeled engineered…
Based upon the Slater–Koster tight-binding calculations, we investigated electronic properties of the "metallic" single-walled carbon nanotubes (SWNTs) in detail. Our results show that tube curvature may produce an energy gap at the Fermi level for zigzag and chiral "metallic" SWNTs, and this effect decreases with the…
Crystal structures of lanthanide complexes with NTA (NTA = nitrilotriacetate) are reported. The complexes of <TEX>$[Ln(NTA)_2{\cdot}H_2O]^{3-}$</TEX> (Ln = Sm, Eu, Gd, Tb and Ho) crystallize in the orthorhombic space group Pccn. In the structures, the trivalent lanthanide ions are completely encapsulated via coordinat…
The pure product of 2,3-diaminophenazine was prepared by the enzyme-catalyzed reaction of ophenylenediamine-<TEX>$H_2O_2$</TEX>-horseradish peroxidase and characterized by UV/Vis spectroscopy, IR spectroscopy and NMR spectroscopy. The electrochemical behaviour of 2,3-diaminophenazine on the glassy carbon electrode was…
The point-like defects known as E' centers are the most abundant natural defects in silicon dioxide ( SiO 2 ) and have been identified as unpaired sp 3 dangling bonds. Their importance stems from the fact that they deeply affect the quality of electronic and optical devices. For this reason, particular attention has b…
The crystal structures of sparteinium tetrachlorocuprate monohydrate [(C 15H28N2)CuCl4·H2O], 1 and sparteinium tetrabromocuprate monohydrate [(C15H28N2)CuBr4·H2O], 2, were determined. The structures of 1 [orthorhombic, P212121, a = 8.3080(10) A, b = 14.6797(19) A and c = 16.4731(17) A], and 2 [orthorhombic, P212121, a…
Department of Chemistry Education, Pusan National University, Pusan 609-735, KoreaReceived October 24, 2003Key Words : Self-dopable, Conjugated polymer, 2-Ethynylpyridine, 2-Sulfobenzoic acid cyclic anhydride,PolyelectrolytePolyelectrolytes are among the important classess ofmacromolecules. These polyelectrolytes are…
We have used the vibrational density of state (DoS) derived from classical molecular dynamic (MD) simulations to investigate the origin of the generation-dependent stability of the hydrogen-bond-mediated self-assembly of supramolecular dendritic structures synthesized and characterized by Zimmerman and co-workers. In…
Three new methods for syntheses of modified oxa corroles bearing one meso free carbon in reasonably good yields are reported. The formation of the meso carbon bridge and the direct pyrrole-pyrrole linkage occur in a single step by a simple condensation and coupling with TFA as a catalyst with appropriate precursors. T…