Materials Literature
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The Sso10b (or Alba) family of proteins is a conserved group of archaeal and eukaryotic proteins which are thought to play a role in both chromatin organization and RNA metabolism. We describe here the solution structure and properties of Sso10b2 from Sulfolobus solfataricus. NMR data including residual dipolar coupli…
The effects of Ti, B and O co-segregating on the α-Fe Σ5 [001] / (010) grain boundary are studied by a first-principles method, DMol. We found that (Ti+B) acts as an enhancer, but O can completely offset the beneficial effect of Ti. Based on the segregation energy analysis, it is also found that Ti can effectively pro…
YMnO 3 exhibits a ferroelectric transition at high temperature (≈900 K) and magnetic ordering at T N ≈70 K, where the dielectric constant shows an anomaly indicative of the magneto-dielectric effect. Here we report powder neutron diffraction experiments in this compound that show that the magnetic moment at saturation…
We demonstrate the synthesis of single-crystalline star-shaped ZnO microcrystals with six arms by a simple solution method. Microscopic and diffraction data reveal that the as-grown products have a wurtzite structure. Each arm of the ZnO microstars has a sharp tip of several nanometers. Under moderate optical excitati…
The physical origins of negative refractive index are derived from a dilute microscopic model, producing a result that is generalized to the dense condensed phase limit. In particular, scattering from a thin sheet of electric and magnetic dipoles driven above resonance is used to form a fundamental description for neg…
Crystallographic and magnetic properties of Co 2 Mn 1− x Fe x Sn and Co 2 Mn 1− y Cr y Sn Heusler alloys were studied using x-ray diffraction, scanning electron microscopy with energy dispersive x-ray analysis, magnetization measurements and Mössbauer spectroscopy. We found that the intermetallic compounds crystallize…
Ultrasmall P450scc cytochrome microcrystals are grown by classical hanging vapor diffusion and by its modification using homologous protein thin-film template displaying a long-range order. The nucleation and growth mechanisms of P450scc microcrystals are studied at the thin cytochrome film surface by a new microbeam…
Dimethyl terephthalate was polycondensed in bulk with a 300 mol % excess of 1,4-butanediol in bulk up to 250 °C. The following catalysts were used Bi 2 O 3, BiCl 3, Bi−subsalicylate, bismuth(III) acetate, ZnO, ZnCl 2, SnO, SnCl 2, Y 2 O 3, YCl 3, La 2 O 3, LaCl 3, Sb 2 O 3 /manganese(II) acetate, and Ti(OBu) 4 . The h…
Amyloid fibrils are self-associating filamentous structures formed from the 39- to 42-residue-long amyloid beta peptide (Abeta peptide). The deposition of Abeta fibrils is one of the most important factors in the pathogenesis of Alzheimer's disease. Abeta25-35 is a fibril-forming peptide that is thought to represent t…
We study the enthalpy of formation $\ensuremath{\Delta}H$ of spinel-type gallium oxynitrides ($\ensuremath{\gamma}$ galons) as a function of pressure. Formation of the ternary oxynitride from gallia $({\mathrm{Ga}}_{2}{\mathrm{O}}_{3})$ and gallium nitride (GaN) is endothermic at any pressure. $\ensuremath{\Delta}H$ i…
Deleterious gases such as CO and H(2)S can cause degradation of steel by reacting with the metal surface. Here we consider whether alloying the steel surface might be able to inhibit these damaging surface reactions by raising the barriers to molecular dissociation. We employ first-principles density functional theory…
The electronic structure of multiwalled carbon nanotubes (CNTs) has been investigated, depending on the growth temperature, using synchrotron X-ray photoelectron spectroscopy (XPS) and field emission measurements. The vertically aligned CNTs are grown via pyrolysis of ferrocene and acetylene in a broad temperature ran…
We study the trend of structural stability and magnetic moment for $\mathrm{Mn}X\phantom{\rule{0.3em}{0ex}}(X=\mathrm{N}$, P, As, and Sb) binary compounds in the NiAs and zinc-blende structures through first-principles spin-density-functional calculations. The exchange splitting and magnetic moment are generally lower…
We have comparatively investigated the photophysical properties of a series of meso-meso directly linked orthogonal porphyrin arrays (Zn, n = 1, 2, 3, 4, 6, 8, 9, 12, 16, 32, 48, 64, and 96) by ensemble average and single molecule fluorescence spectroscopy. In single molecule fluorescence study, we have recorded the f…
We have investigated the effects of nanometric grain size on magnetoresistance (MR), especially on its temperature-dependent behaviors of single-phase nanocrystalline granular La0.7Sr0.3MnO3 and La0.7Ca0.3MnO3 samples with an average grain size in the nanometric regime (12 and 17 nm). Most interestingly, we observed t…
The effect of aggregation on surfactant-suspended individual single-walled carbon nanotube (SWNT) Raman spectroscopy has been explored in the context of dielectrophoretic separation. The Raman spectra of individual surfactant-suspended HiPco SWNTs deposited on a substrate and the same suspension deposited via dielectr…
The influence of surface corrections on three-dimensional dislocation dynamics is investigated by considering a curved dislocation intersecting a plane free surface. The Boussinesq–Cerruti formalism is used to determine the image field for this problem to high accuracy. A heuristic method for simultaneously regularizi…
We consider equilibrium solutions of the Smoluchowski equation for rodlike nematic polymers with a Maier–Saupe excluded volume potential. The purpose of this paper is to present a new and simplified proof of classical well-known results: (1) all equilibria are axisymmetric and (2) modulo rotational symmetry, the numbe…
The paper presents numerical results from extensive molecular-dynamics simulations of the crystallization process of a single polyethylene chain with N=500 monomers. The development of the ordered structure is seen to proceed along different routes involving either the global reorganization of the chain or, alternativ…
An ac photopyroelectric calorimeter has been used to measure the thermal diffusivity and specific heat of the perovskite manganites RMnO 3 (R = La, Pr, Nd) close to their magnetic transitions. Taking into account that the inverse of the thermal diffusivity has the same critical behaviour as the specific heat, the crit…