Materials Literature
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The authors report a synthesis of unique superhard aggregated boron nitride nanocomposites (ABNNCs) showing the enhancement of hardness up to 100% in comparison with single crystal c-BN. Such a great hardness increase is due to the combination of the Hall-Petch and the quantum confinement effects. The decrease of the…
In this work, we develop a systematic and self-consistent approach to homogenize arbitrary nonmagnetic periodic metamaterials. The proposed method does not rely on the solution of an eigenvalue problem and can fully characterize the effects of frequency dispersion, magnetoelectric coupling, and spatial dispersion, eve…
Using an efficient strain-stress method, the first-principles elastic constants cij’s of α-Al2O3 and θ-Al2O3 have been predicted within the local density approximation and the generalized gradient approximation. It is indicated that more accurate calculations of cij’s can be accomplished by the local density approxima…
This article presents a general formulation of an atomistic Green's function (AGF) method. The atomistic Green's function approach combines atomic-scale fidelity with asymptotic treatment of large-scale (bulk) features, such that the method is particularly well suited to address an emerging class of multiscale transpo…
We propose, fabricate, and study a double-layer chiral planar metamaterial that exhibits pronounced circular dichroism at near-infrared wavelengths. The antisymmetric oscillation modes of the two coupled layers allow local magnetic-dipole moments and enhanced polarization effects compared with similar single-layer sys…
Mini-chromosome maintenance (MCM) proteins form ring-like hexameric complexes that are commonly believed to act as the replicative DNA helicase at the eukaryotic/archaeal DNA replication fork. Because of their simplified composition with respect to the eukaryotic counterparts, the archaeal MCM complexes represent a go…
We predict a spatially localized magnetic domain wall oscillator upon the application of an external magnetic field and a DC electric current. The amplitude and frequency of the oscillator can be controlled by the field and/or the current. The resulting oscillator could be used as an effective microwave source for inf…
Microstructure properties, phase transitions, and charge ordering in the LuFe2O4 materials have been extensively investigated by means of transmission electron microscopy (TEM). The (001) twins as a common defect frequently appear in the LuFe2O4 crystals along the c-axis direction, and the crystals across each boundar…
Abstract Liquid-phase deposition, LPD, method was used for the fabrication of copper ferrite (CuFe2O4) thin film from aqueous solution system of FeOOH–NH4·HF (aq.) and Cu source (Cu(NO3)2 or CuCl2) with H3BO3. SEM observation revealed that highly homogeneous thin film was formed on a substrate. In X-ray diffraction me…
Abstract Spherical microcapsules of silica-shelled octadecane are prepared in the presence of polyvinyl alcohol in an O/W emulsion. The silica shell forms via hydrolysis and condensation from tetraethyl silicate with acetatic acid as catalyst. The thermogravimetric curves show that the microcapsules have thermal stabi…
P(II) proteins have been shown to be key players in the regulation of nitrogen fixation and ammonia assimilation in bacteria. The mode by which these proteins act as signals is by being in either a form modified by UMP or the unmodified form. The modification, as well as demodification, is catalyzed by a bifunctional…
The forces between two adhering surfaces bearing highly extended polymer melt brushes as they are sheared past each other, and between a single melt-brush-bearing substrate sheared across an adhering bare solid surface, were studied using a mica surface force balance with a high shear-force resolution. The melt brushe…
The aqueous solubilization of carbon nanotubes (CNTs) with the aid of a block copolymer possessing one polyelectrolyte block (namely polystyrene-b-sodium (sulfamate/carboxylate polyisoprene)) is reported. The solubilization protocol, based on the co-dissolution of the copolymer and the CNTs, leads to the formation of…
Using confocal microscopy and small-deformation rheology, we demonstrate the formation of stable thermoreversible gelatin-based gels with colloidal fractal-type microstructure. The opaque particle gels were made by cooling of transparent mixed aqueous solutions of gelatin (1-3 wt %) and starch (7 wt %) from 40 to 24 d…
The reaction of the cyclotetraphosphazene, [N4P4Cl8], with the difunctional reagent, 2,2'-biphenol, in the presence of potassium carbonate in acetone produced the spiro-substituted derivatives, 2,2'-dioxybiphenylhexachlorocyclotetraphosphazene, bis(2,2'-dioxybiphenyl)tetrachloro-cyclotetraphosphazene, and tris(2,2'-di…
Isotactic poly(1-butene) (i-PB) fibrous membranes with fiber diameters on the order of microns were prepared from polymer solutions using mixed solvents via electrospinning. As demonstrated by FE-SEM, unexpected structures such as curled, twisted ribbon fibers and hollow hemisphere (HHS) on a string appeared depending…
It is hypothesized that a highly ordered, relatively defect-free dilute magnetic semiconductor system should act as a weak ferromagnet. Transition-metal-doped ZnO nanowires, being single crystalline, single domain, and single phase, are used here as a model system for probing the local dopant coordination environments…
Mesoporous aluminas with a uniform fibrous morphology were synthesized using a copolymer-controlled homogeneous precipitation method under hydrothermal conditions. Scanning electron microscopy, X-ray diffraction, solid-state magic-angle spinning nuclear magnetic resonance, transmission electron microscopy, thermogravi…
A new tiara Pd(II) thiolate complex, [Pd(SC12H25)2]6, has been synthesized and fully characterized by X-ray single crystal analysis, elemental analysis, MALDI, 1H NMR, powder XRD, IR, Raman, and UV/vis. It was found that, in each complex cluster, the six palladium atoms form a nearly planar hexagonal ring and the adja…
The effect of different mixing protocols on the charged nature and size distribution of the aqueous complexes of hyperbranched poly(ethylene imine) (PEI) and sodium dodecyl sulfate (SDS) was investigated by electrophoretic mobility and dynamic light scattering measurements at different pH values, polyelectrolyte conce…