Materials Literature
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An analysis on the conductance of multiwall carbon nanotubes (MWNT's) is presented. Recent experiment indicated that MWNT's are good quantum conductors. Our theory shows that tunneling current between states on different walls of a defect-free, infinitely long MWNT is vanishingly small in general, which leads to the q…
The tripodal ligand tris[4-(2-hydroxy-3-methoxyphenyl)-3-aza-3-buten]amine (LH(3)) is capable of coordinating to two different lanthanide ions to give complexes formulated as [LLnLn'(NO(3))(3)].x H(2)O. The stepwise synthetic procedure consists of introducing first a Ln(III) ion in the inner N(4)O(3) coordination site…
We report the two-photon-induced photoisomerization of 3-[1-(1,2-dimethyl-1H-indol-3-yl)-ethylidene]-4-isopropylidene-dihydrofuran-2,5-dione ( 1 ), a photochromic compound with λ max = 385 nm, using 775-nm femtosecond pulsed laser irradiation. The resulting photoisomer had λ max = 582 nm. The kinetic rate constant for…
Upon treating elemental sulfur with [AgSbF(6)], [AgAl(hfip)(4)], [AgAl(pftb)(4)] (hfip=OCH(CF(3))(2), pftb =OC(CF(3))(3)) the compounds [Ag(S(8))(2)][SbF(6)] (1), [AgS(8)][Al(hfip)(4)] (2), and [Ag(S(8))(2)](+)[[Al(pftb)(4)](-) (3) formed in SO(2) (1), CS(2) (2), or CH(2)Cl(2) (3). Compounds 1-3 were characterized by…
Chains change: Novel valence-ordering structures of the ground states of MMX chain compounds, [Pt2(RCS2)4I]∞ (1: R=nBu, 2: R=Et), are determined by low-temperature crystal-structure analyses to be -Pt2+-Pt3+-I−-Pt3+-Pt2+-I−-. Magnetic susceptibility measurements of 1 (see graph) revealed an abrupt drop in magnitude fr…
Molecular sieving to take your breath away: The breathing ionic crystal 1 is synthesized by the complexation of Keggin-type [α-SiW12O40]4− (red) polyoxometalate with a macro cation [Cr3O(OOCH)6(H2O)3]+ (green and white). The water of crystallization is easily removed from 1 by evacuation to form a guest-free phase 2.…
The distinctive features of well-defined, three-dimensional macromolecules with topologies designed to enhance solubility and amplify end-group functionality facilitated nanophase morphologies in mixtures with organosilicates and ultimately nanoporous organosilicate networks. Novel macromolecular architectures includi…
Big rings and nanocleavage: Whereas a variety of molybdenum oxide based nanoobjects can be obtained by self-assembly concomitant with a variety of modifications of a parent cluster system under alterable boundary conditions, drastic changes—comparable to a molecular-scissors-type activity—can even cause splitting of t…
The oxidation behavior of Ti3AlC2 powders has been investigated in air by means of simultaneous TGA-DSC, XRD, Raman spectra, SEM, EDS and BET specific surface measurement to understand the intrinsic oxidation behavior of this newly developed ternary compound. The starting and complete oxidation temperatures determined…
Interdependencies between experimental spectra, representing line or plane projections of electronic densities, are derived from their consistency and symmetry conditions. Some additional relations for plane projections are obtained by treating them as line projections of line projections. The knowledge of these depen…
The competition between the long range Coulomb attractive and the short range repulsive interaction in ionic nanocrystals creates an effective negative pressure, which causes the lattice parameter a to increase with decreasing nanoparticle size d. A simple ``Madelung model'' is used to predict the dependence of the la…
We calculate the inelastic light scattering from X-rays, which allows the photon to transfer both energy and momentum to the strongly correlated charge excitations. We find that the charge transfer peak and the low energy peak both broaden and disperse through the Brillouin zone similar to what is seen in experiments…
Photoemission from a single self-organized GaAs/AlGaAs quantum dot (QD) is temporally resolved with picosecond time resolution. The emission spectra consisting of the multiexciton structures are observed to depend on the delay time and the excitation intensity. Quantitative agreement is found between the experimental…
The approach to calculating the effective dielectric and magnetic response in bounded composite materials is developed. The method is essentially based on the renormalisation of the dielectric matrix parameters to account for the surface polarisation and the displacement currents at the interfaces. This makes it possi…
Chiral structures have been found as the lowest-energy isomers of bare $({\mathrm{Au}}_{28}$ and ${\mathrm{Au}}_{55})$ and thiol-passivated $[{\mathrm{Au}}_{28}({\mathrm{SCH}}_{3}{)}_{16}$ and ${\mathrm{Au}}_{38}({\mathrm{SCH}}_{3}{)}_{24}]$ gold nanoclusters. The degree of chirality existing in the chiral clusters wa…
In this paper, we show theoretically that there exists quasi-liquid on the edges and vertices of snow crystals between -4C and -22C, while the basal and prism faces have no quasi-liquid layers. Investigating the macroscopic theory of quasi-liquid and applying to the edges and vertices of the crystal, we find that the…
Synchrotron x-ray powder diffraction measurements have been performed on unpoled ceramic samples of $(1\ensuremath{-}x)\mathrm{Pb}({\mathrm{Mg}}_{1/3}{\mathrm{Nb}}_{2/3}){\mathrm{O}}_{3}\ensuremath{-}x{\mathrm{PbTiO}}_{3}$ (PMN-xPT) with $30%<~x<~39%$ as a function of temperature around the morphotropic phase bo…
Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for d…
Many potential applications have been proposed for carbon nanotubes, including conductive and high-strength composites; energy storage and energy conversion devices; sensors; field emission displays and radiation sources; hydrogen storage media; and nanometer-sized semiconductor devices, probes, and interconnects. Som…
Abstract The Nuclear Regulatory Commission (NRC) issues licenses for commercial power reactors to operate for up to 40 years and allows these licenses to be renewed for additional periods of 20 years. In 1995 the Commission issued Part 54 of Title 10 of the Code of Federal Regulations (10 CFR Part 54) specifying the r…