Materials Literature
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We have performed first-principles calculations of hexagonal $C14\ensuremath{-}\mathrm{type}$ Laves phase Ti-Mn metals and their hydrides, namely, ${\mathrm{Ti}}_{1.0}{\mathrm{Mn}}_{2.0}{\mathrm{H}}_{3},$ ${\mathrm{Ti}}_{1.25}{\mathrm{Mn}}_{1.75}{\mathrm{H}}_{3},$ and ${\mathrm{Ti}}_{1.5}{\mathrm{Mn}}_{1.5}{\mathrm{H}…
A simple method for the synthesis of high purity single wall carbon nanotubes has been developed by using nickel formate as a precursor for the formation of nearly mono-dispersed nickel seed-nanoparticles as catalysts in the CVD growth process.
This paper presents the modeling of a current transformer by various methods with the FLUX3D software. The technique used is based on the finite element method coupled with electric circuits. A magnetic scalar potential reduced versus T 0 formulation ( T 0 ϕ − ϕ ) taking into account the electric circuits with an air‐…
The phase diagram of a polydisperse mixture of uniaxial rodlike and platelike hard parallelepipeds is determined for aspect ratios kappa=5 and 15. All particles have equal volume, and polydispersity is introduced in a highly symmetric way. The corresponding binary mixture is known to have a biaxial phase for kappa=15,…
The changes in composition and productivity of semi-arid C(4) grassland, anticipated with rising atmospheric CO(2), will depend on soil water and nutrient availability. The interactive effects of soil resource limitation and elevated CO(2 )on these grasses, furthermore, may vary among C(4) biochemical subtypes (NADP-M…
Foamed aluminium alloy containing 7 wt.-% of Si is investigated by μm-resolved X-ray computed tomography (CT) using synchrotron radiation. The foam is fabricated employing a powder metallurgical route. The evolution of foam microstructure is characterized by studying a series of samples representing different stages o…
Three kinds of CdII/CuII compounds of different nuclearity: tetranuclear [Cd2Cu2I4L4(dmso)2] 1, pentanuclear [Cd2Cu3Br6L4(dmso)2] 2 and hexanuclear [Cd4Cu2Cl6L6(H2O)2] 3, have been synthesised by the reaction of zerovalent copper and cadmium halides with non-aqueous (dmso, CH3CN) solutions of 2-dimethylaminoethanol (H…
The aim of this paper is to present a methodology for 2D and 3D characterization of different foams using X-ray microtomography with a resolution of 30 micrometer. 2D and 3D quantitative image analyses have been performed to obtain information about the cells. The main parameters of interest are the cell size, the cel…
Visible photoluminescence (PL) broad bands are observed in the Raman spectra of SiC nanoparticles (np-SiC) with diameters ranging from 10 to 25 nm. The phenomenon is studied versus the particle size, chemical composition, annealing, and oxidation treatments. In the case of quasistoichiometric np-SiC, excitation by 514…
Calculations based on density-functional theory show that the stability and magnetic properties of small Mn clusters can be fundamentally altered by the presence of nitrogen. Not only are their binding energies substantially enhanced, but also the coupling between the magnetic moments at Mn sites remains ferromagnetic…
A quantum mechanical model is used to derive a generalized Landau-Lifshitz equation for a magnetic moment, including fluctuations and dissipation. The model reproduces the Gilbert-Brown form of the equation in the classical limit. The magnetic moment is linearly coupled to a reservoir of bosonic degrees of freedom. Us…
The interaction of a fast electron with a photonic crystal is investigated by solving the Maxwell equations exactly for the external field provided by the electron in the presence of the crystal. The energy loss is obtained from the retarding force exerted on the electron by the induced electric field. The features of…
We show that the differences in the magnetic properties of Ni-Pd and Ni-Pt alloys arise mainly due to relativity. In particular, we find that the local magnetic moment of Ni increases with the addition of Pd in Ni-Pd while it decreases with the addition of Pt in Ni-Pt, as found experimentally, only if relativity is pr…
Based on an accurate first principles description of the energetics in H-bonded potassium-dihydrogen-phosphate crystals, we conduct a first study of nuclear quantum effects and of the changes brought about by deuteration. Tunneling is allowed only for clusters involving correlated protons and heavy ion displacements,…
Abstract Random copolyesters based on 1,4‐butanediol and different ratios between adipic and terephthalic units were synthesized from thermal polycondensation of the appropriate mixture of monomers or by melt transesterification of the mixture of homopolymers. 1 H NMR spectroscopy makes feasible the study of the avera…
We report on the dynamics of resonant energy transfer in monodisperse, mixed-size, and energy-gradient (layered) assemblies of CdSe nanocrystal quantum dots. Time-resolved and spectrally resolved photoluminescence directly reveals the energy-dependent transfer rate of excitons from smaller to larger dots via electrost…
We report atomistic simulations for both self- and transport diffusivities of light gases in carbon nanotubes and in two zeolites with comparable pore sizes. We find that transport rates in nanotubes are orders of magnitude faster than in the zeolites we have studied or in any microporous material for which experiment…
Abstract It is accepted that sulphate reducing bacteria (SRB) and certain general heterotrophic bacteria (GHB) can promote pit corrosion of topside and downhole equipment and cause formation damage in the reservoir including H2S souring. In order to inhibit microbial growth and hence minimise these damage mechanisms,…
The process of insertion of molecular oxygen and nitrogen into polyhedral oligomeric silsesquioxanes (POSS) has been investigated theoretically. Using ab initio methods, the N 2 interaction with the POSS has been described with restricted Hartree−Fock (RHF) with a triple-ζ basis set, while systems involving O 2 requir…
New types of reaction pathways have been identified during pulsed plasma polymerization of difunctional precursor molecules. Ethylene glycol dimethacrylate is found to give rise to a highly cross-linked polymeric network, while methacrylic anhydride undergoes cyclopolymerization. The deposited films have been characte…