Materials Literature
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In this letter we describe electronic measurements of a conjugated polymer of phenylenevinylene (PPV) with electrode spacings down to 20 nm; all measurements are made in a gated transistor geometry. With rectangular electrodes we find that the current is fit by an exponential in the applied electric field for spacings…
Highly colored and photoluminescent naphthalene bisimide dyes have been synthesized from 2,6-dichloronaphthalene bisanhydride 1 by means of a stepwise nucleophilic displacement of the two chlorine atoms by alkoxides and/or alkyl amines. The alkoxy-substituted derivatives are yellow dyes with green emission and low pho…
The synthesis of a gold nanoparticle (AuNP) coated with a well-defined polymer is reported. The AuNP coated with an initiator group for living radical polymerization was prepared by the simple one-pot reduction of tetrachloroaurate with sodium borohydrate in the presence of an initiator group-holding disulfide. The su…
In this Account we highlight the experimental evidence in favor of our view that carbon nanotubes should be considered as a new macromolecular form of carbon with unique properties and with great potential for practical applications. We show that carbon nanotubes may take on properties that are normally associated wit…
An exact solution for the capacitance of a three plate system is obtained and is used to quantify the error made by the inverse sum rule. Three finite, parallel disks are arranged as two capacitors in series. By treating the system as an electrostatic boundary value problem, exact solutions for the potential and capac…
A large scale computation of three‐dimensional eddy current problems is considered; their numbers of degrees of freedom are near one million. A parallel computing using the Hierarchical Domain Decomposition Method (HDDM) is introduced to compute large scale problems. A transformer model is considered as a numerical ex…
We report the synthesis and physico-chemical characterization, including molecular second order nonlinear optical properties by the EFISH technique, of three new heterocycle based push–pull chromophores. Two chromophores contain the five membered 1,3,4-oxadiazole ring, the third a thiophene ring. The chromophores also…
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…