Materials Literature
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The complete energy expression of a deformed single-walled carbon nanotube (SWNT) is derived in the continuum limit from the local density approximation model proposed by Lenosky et al. [Nature (London) 355, 333 (1992)] and is shown to be consistent with the classic shell theory by which Young's modulus, the Poisson r…
We have observed size effects in the structural phase transition of submicron vanadium dioxide precipitates in silica. The ${\mathrm{VO}}_{2}$ nanoprecipitates are produced by the stoichiometric coimplantation of vanadium and oxygen and subsequent thermal processing. The observed size dependence in the transition temp…
Hydrogen uptake capacities of 1.8 and 2.6 wt % were obtained on BN multiwalled nanotubes and bamboo-like nanotubes, respectively, under approximately 10 MPa at room temperature. The preliminary results show that chemical interactions mainly take place between hydrogen and BN. Taking into consideration the uniform semi…
An analytical solution is presented for the borehole problem of an elasto-plastic plane strain body containing a traction-free circular hole and subjected to uniform far field stress. A strain gradient plasticity theory is used to describe the constitutive behavior of the material undergoing plastic deformations, wher…
The microstructural evolution of a single crystal of yttria-stabilized zirconia (YSZ) implanted with Ti has been studied by cross-sectional transmission electron microscopy (TEM). The implantation of 180 keV Ti ions to a dose of 1×1017 ions/cm2 was completed at room temperature. After annealing at 1100 °C in an Ar atm…
The configuration of dislocation wall structures and the interactions between dislocations and dislocation walls play a significant role in the understanding of deformation processes in metals. Samples of single-crystal aluminum deformed by tensile-straining (15%) were analyzed using TEM. In tensile-deformed (15%) sin…
An original concept for the realization of a molecular photoswitch is proposed, based on photochrochromic oligothiophene-substituted chromenes. When optically excited, these compounds undergo a structural change passing from a neutral state (closed form) to a strongly polarized one (open form). This photochromism proc…
The electronic structure of the low-dimensional metal ${\mathrm{K}}_{0.3}{\mathrm{MoO}}_{3}$ has been studied by means of first-principles density functional calculations. The dispersion of the partially filled bands is found to be in good agreement with the presently available photoemission results. The Fermi surface…
A comprehensive NMR study is presented to elucidate the local coordination and spatial distribution of the alkali-metal cations in mixed alkali borate glasses [(M2O)x(Na2O)1−x]0.3(B2O3)0.7 (M = Li, K and x = 0.2, 0.4, 0.6, 0.8, 1.0). 11B MAS-NMR results indicate that the network structure in these glasses is constant…
Abstract Multiple melting peaks in some semicrystalline polymers such as poly(trimethylene terephthalate) (PTT) have caused some difficulty in estimating accurately the equilibrium melting points. PTT forms a miscible blend with amorphous poly(ether imide) (PEI); for comparison purposes, a miscible system of a fixed c…
Two silver(I) coordination polymers have been synthesised and single-crystal structural analysis shows that 1 is the first coordination network containing discrete silver clusters and organic N,N′-spacers. It displays an intense blue photoluminescence with three emission maxima.
[Ni4L3(H2O)2](ClO4)2.2H2O 1, the first tetranuclear NiII cluster showing triangle planar geometry, formed with a new carboxylic-functionalized 1,5-diazacyclooctane bridging ligand has been presented; the global magnetic coupling is ferromagnetic and anisotropic calculations have been made.
Abstract Poly(ethylene oxide/polylactide/poly(ethylene oxide) (PEO/PL/PEO) triblock copolymers, in which each block is connected by an ester bond, were synthesized by a coupling reaction between PL and PEO. Hydroxyl‐terminated PLs with various molecular weights were synthesized and used as hard segments. Hydroxyl‐term…
A stochastic dislocation dynamics (SDD) model is developed to investigate dislocation glide through dispersed obstacles. The model accounts for: 1) the dynamics of the flight process between successive meta-stable dislocations under various drag mechanism using discrete dislocation dynamics, and 2) thermal activation…
We analyze simple shear and torsion of single crystal copper by employing experiments, molecular dynamics simulations, and finite element simulations in order to focus on the kinematic responses and the apparent yield strengths at different length scales of the specimens. In order to compare torsion with simple shear,…
Measurements of the infrared phosphorescence of singlet molecular oxygen (1O2) at 1270 nm have been used to demonstrate the formation of 1O2 by the Radziszewski reaction between acetonitrile and hydrogen peroxide. The kinetics of the Radziszewski reaction either alone or in the presence of ketones have been studied by…
The position of the molecular orbitals of polyaniline, relative to the Fermi level, shifts with the doping of polyaniline by both charge donor and charge acceptor species. Sodium as an electron donor, when added to the polyaniline system, results in an increase in electron population in the polyaniline bands but a dec…
Abstract The dynamic mechanical behavior of uncrosslinked (thermoplastic) and crosslinked (thermosetting) acrylonitrile butadiene rubber/poly(ethylene‐ co ‐vinyl acetate) (NBR/EVA) blends was studied with reference to the effect of blend ratio, crosslinking systems, frequency, and temperature. Different crosslinked sy…
Abstract Correlation between the morphology and the impact toughness was studied for ternary‐phase polypropylene (PP)/glass bead (GB)/ethylene‐propylene rubber (EPR) composites containing 5–40 vol % of rigid filler at a fixed volume fraction ratio EPR/GB equal to 0.33. The three following types of phase morphology wer…
The crystalline symmetry of the solid solution formed by a relaxor and a ferroelectric material with formula: (1−x)Pb(Fe2/3W1/3)O3–xPbTiO3, with various x was investigated, at T=300 K. A continuous change from pseudocubic to tetragonal symmetry, with cell parameters dependent on the PbTiO3 amount, was found. In a larg…