Liang Chen、J. Karl Johnson2005-03-28Physical Review Letters
Simulations show that CO2 adsorbed in the groove sites of carbon nanotubes displays unique quasi-one-dimensional behavior. Clusters containing only odd numbers of molecules are formed at finite CO2 coverages and low temperatures. The molecules are orientationally ordered with respect to the nanotube groove axis and az…
Phase Equilibria and ThermodynamicsZeolite Catalysis and SynthesisCarbon Nanotubes in Composites
Cinara Peverari、Ana Maria Pires、Rogéria Rocha Gonçalves 等 4 位作者2005-03-28Eclética Química
This work reports on the investigation of nanosized CeO 2 -ZnO systems prepared by Pechini'smethod. The structural and morphological characterization of CeO 2 -ZnO systems as well as thecharacterization of CeO 2 and ZnO separately, showed that the employed method result in powders withspheroidal particles whose size a…
Catalysis and Oxidation ReactionsPigment Synthesis and PropertiesCatalytic Processes in Materials Science
Michelle T. Casanova2005-03-28Australian Systematic Botany
Charophytes (family Characeae) are a cohesive group within the green algae. The genus Chara is abundant and diverse in a variety of Australian habitats. Approximately 37 taxa of Chara have been described on the basis of Australian collections. The current status of charophyte taxonomy is confused. RD Wood revised Aust…
Aquatic Ecosystems and Phytoplankton DynamicsFreshwater macroinvertebrate diversity and ecologyDiatoms and Algae Research
C.-X. Sheng、Z. Valy Vardeny、Alan Β. Dalton 等 4 位作者2005-03-28Physical Review B
Ultrafast relaxation of photoexcitations in semiconducting single-walled carbon nanotubes ($S$-NTs) were investigated using polarized pump-probe photomodulation (with 150 fs time resolution) and cw polarized photoluminescence (PL). Both annealed and unannealed thin NT films and ${\mathrm{D}}_{2}\mathrm{O}$ solutions o…
Mechanical and Optical ResonatorsCarbon Nanotubes in CompositesFullerene Chemistry and Applications
Min Feng、Anlian Pan、H. R. Zhang 等 9 位作者2005-03-28Applied Physics Letters
Strong photoluminescence (PL) is observed in nanostructured crystalline tungsten oxide thin films that are prepared by thermal evaporation. Two kinds of films are investigated—one made of nanoparticles and another of nanowires. At room temperature, strong PL emissions at ultraviolet-visible and blue regions are found…
Gas Sensing Nanomaterials and SensorsGa2O3 and related materialsTransition Metal Oxide Nanomaterials
L. Gómez、C. Gazza、H. Dacharry 等 5 位作者2005-03-28arXiv
We study the pressure dependence of the melting mechanism of a surface free Lennard-Jones crystal by constant pressure Monte Carlo simulation. The difference between the overheating temperature($T_{OH}$) and the thermodynamical melting point($T_M$) increase for increasing pressure. When particles move into the repulsi…
Materials Sciencecond-mat.stat-mech
S. Vionnet-Menot、C. Grimaldi、T. Maeder 等 5 位作者2005-03-28arXiv
A vast class of disordered conducting-insulating compounds close to the percolation threshold is characterized by nonuniversal values of transport critical exponent t, in disagreement with the standard theory of percolation which predicts t = 2.0 for all three dimensional systems. Various models have been proposed in…
cond-mat.dis-nnMaterials Science
Craig J. Fennie、Karin M. Rabe2005-03-28Physical Review B
The structure and polarization of the as-yet hypothetical Ruddlesden--Popper compound ${\mathrm{Pb}}_{2}\mathrm{Ti}{\mathrm{O}}_{4}$ are investigated within density-functional theory. Zone center phonons of the high-symmetry ${\mathrm{K}}_{2}\mathrm{Ni}{\mathrm{F}}_{4}$-type reference structure, space group I4/mmm, we…
Solid-state spectroscopy and crystallographyMultiferroics and related materialsFerroelectric and Piezoelectric Materials
Lixin He、Gabriel Bester、Alex Zunger2005-03-28arXiv
We show that a diatomic dot molecule made of two identical, vertically stacked, strained InAs/GaAs self-assembled dots exhibits an asymmetry in its single-particle and may-particle wavefunctions. The single-particle wave function is asymmetric due to the inhomogeneous strain, while the asymmetry of the many-particle w…
Materials Science
M. Mertinat、V. Tsurkan、D. Samusi 等 5 位作者2005-03-28Physical Review B
Transmission electron microscopy studies of [100], [110], and [111] oriented $\mathrm{Fe}{\mathrm{Cr}}_{2}{\mathrm{S}}_{4}$ single crystals at different temperatures reveal a structural transition at low temperatures indicating a cubic-to-triclinic symmetry reduction within crystallographic domains. The overall crysta…
Advanced Condensed Matter PhysicsMagnetic and transport properties of perovskites and related materialsMultiferroics and related materials
Gustavo A. Carri、Richard Batman、Vikas Varshney 等 4 位作者2005-03-28arXiv
We study the mechanical and conformational properties of networks of helical polymers with a combination of Monte Carlo simulations based on the Wang-Landau algorithm and the Three-chain Model. We find that the stress-strain behavior of these networks has novel features not observed in typical networks made of synthet…
Soft Condensed MatterMaterials Science
I. I. Mazin、S. L. Molodtsov2005-03-28arXiv
The electronic structure and selected zone-center phonons in Yb graphite intercalation compound (YbC6) are investigated {theoretically} using density functional calculations and LDA+U approximation for Coulomb correlations in the f shell, and experimentally using angle-resolved photoemission. We find that both in LDA…
SuperconductivityMaterials Science
E. A. Henriksen、S. Syed、Y. Ahmadian 等 8 位作者2005-03-27arXiv
We report on the temperature dependence of the mobility, $μ$, of the two-dimensional electron gas in a variable density AlGaN/GaN field effect transistor, with carrier densities ranging from 0.4$\times10^{12}$ cm$^{-2}$ to 3.0$\times10^{12}$ cm$^{-2}$ and a peak mobility of 80,000 cm$^{2}$/Vs. Between 20 K and 50 K we…
Materials Science
Yair Kurzweil、Roi Baer2005-03-27arXiv
Today, most application of time-dependent density functional theory (TDDFT) use adiabatic exchange-correlation (XC) potentials that do not take into account non-local temporal effects. Incorporating such "memory" terms into XC potentials is complicated by the constraint that the derived force and torque densities must…
Strongly Correlated ElectronsMaterials Science
Kikuo Harigaya2005-03-27arXiv
Electronic states in nanographite ribbons with zigzag edges are studied using the extended Hubbard model with nearest neighbor Coulomb interactions. The nearest Coulomb interactions stabilize electronic states with the opposite electric charges separated and localized along both edges. Such states are analogous as nan…
Strongly Correlated ElectronsMaterials Sciencequant-phChemical Physics
V. Novosad、F. Y. Fradin、P. E. Roy 等 6 位作者2005-03-27arXiv
We report a high-resolution experimental detection of the resonant behavior of magnetic vortices confined in small disk-shaped ferromagnetic dots. The samples are magnetically soft Fe-Ni disks of diameter 1.1 and 2.2 um, and thickness 20 and 40 nm patterned via electron beam lithography onto microwave co-planar wavegu…
Materials Science
Iban Quintana、Arantxa Arbe、Juan Colmenero 等 4 位作者2005-03-26Macromolecules
By means of quasielastic neutron scattering, we have studied the hydrogen dynamics in glassy polyethersulfone, revealing the phenylene ring motions. The combination of a time-of-flight (TOF) and a backscattering spectrometer has allowed us to cover the microscopic and mesoscopic time scales (∼10 -13 −10 -9 s) in a mom…
Spectroscopy and Quantum Chemical StudiesSolid-state spectroscopy and crystallographyNMR spectroscopy and applications
Yanxia Jiang、Wei‐Zheng Weng、Di Si 等 4 位作者2005-03-26The Journal of Physical Chemistry B
Palladium clusters have been synthesized by the "ship-in-a-bottle" approach in the supercages of NaX and NaY faujasite zeolites. In comparison with CO adsorbed on a bulk Pd electrode, the same molecule adsorbed on the Pd clusters electrodes evoked an enhanced IR absorption (EIRA). The enhancement factors have been det…
Electrocatalysts for Energy ConversionCatalysis and Oxidation ReactionsCatalytic Processes in Materials Science
Abraham Arceo、Peter F. Green2005-03-26The Journal of Physical Chemistry B
It is well-known that a bulk, symmetric, A-b-B diblock copolymer forms a lamellar morphology, with period L, below an order-disorder transition (T(ODT)) temperature, for chiN < 10.5; chi is the Flory-Huggins interaction parameter and N is the degree of polymerization of the copolymer. The ordering temperatures of poly…
Block Copolymer Self-AssemblyRheology and Fluid Dynamics StudiesMachine Learning in Materials Science
Jayajit Das、Masaru Yoshida、Zachary M. Fresco 等 6 位作者2005-03-26The Journal of Physical Chemistry B
The molecular architecture of dendronized polymers can be tuned to obtain nanoscale objects with desired properties. In this paper, we bring together experiments and computer simulations to study the thermodynamic and dynamic properties of a single dendronized polymer chain. We find that, upon changing certain archite…
Liquid Crystal Research AdvancementsMaterial Dynamics and PropertiesTheoretical and Computational Physics