Jianzhao Liu、Ronghua Zheng、Youhong Tang 等 10 位作者2007-09-21Macromolecules
A group of hyperbranched poly(silylenephenylenes) ( hb -PSPs) were synthesized in high yields (up to 100%) by TaBr 5 -catalyzed polycyclotrimerization of A 2 -type monomers of silylenediynes [HC⋮C−C 6 H 4 −Si(C n H 2 n +1 ) 2 −C 6 H 4 −C⋮CH, n = 2, 4, 6]. The hb -PSPs are completely soluble in common organic solvents…
Organic Electronics and PhotovoltaicsLuminescence and Fluorescent MaterialsDendrimers and Hyperbranched Polymers
Steven C. Zimmerman、Jordan R. Quinn、Ewelina Burakowska 等 4 位作者2007-09-21Angewandte Chemie International Edition
Like a big crown (ether): Cross-linked glycerol-based nanoparticles have been synthesized by ring-closing metathesis (RCM) of polyallyl glycerol dendrimers or hyperbranched polymers (see scheme). In organic solvents, the polyether nanoparticles show modest ionophoric abilities.
Chemical Synthesis and AnalysisSynthetic Organic Chemistry MethodsDendrimers and Hyperbranched Polymers
Ignasi Salvadó‐Estivill、A. Brucato、Gianluca Li Puma2007-09-21Industrial & Engineering Chemistry Research
In this paper we present a two-dimensional (2-D) analysis of a narrow-slit, flat-plate, single-pass, flow-through photocatalytic reactor for air purification. The continuity equation for convection and diffusion in two dimensions, under un-steady-state conditions, was coupled with radiation field modeling and photocat…
TiO2 Photocatalysis and Solar CellsCatalytic Processes in Materials ScienceAdvanced oxidation water treatment
Xi’an Fan、Junyou Yang、Zhong Xie 等 8 位作者2007-09-21Journal of Physics D Applied Physics
Bi2Te3 plate-like crystals with homogeneous hexagonal morphology were rapidly synthesized using a microwave assisted wet chemical method in 30 min. These Bi2Te3 nanoplates possessed a fixed edge with a length of ~0.5–2 µm, and the thickness was less than ~100 nm. The n-type Bi2Te3 nanocomposites were prepared by conso…
Advanced Thermoelectric Materials and DevicesThermal properties of materialsThermal Radiation and Cooling Technologies
Liu Lü、Xiaoliang Xu、Wentao Liang 等 4 位作者2007-09-21Journal of Physics Condensed Matter
We report the first-order and high-order Raman scattering from core-shell CdSe/CdS nanocrystals and investigate the evolution of the longitudinal mode of CdSe (LO1) and CdS (LO2), and the surface mode of CdSe (SO1) and CdS (SO2) with increasing shell thickness (0-5.5 ML (monolayer)). We find that the shift of the LO2…
Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsSemiconductor materials and interfaces
Harish Kumar Yadav、K. Sreenivas、Ram S. Katiyar 等 4 位作者2007-09-21Journal of Physics D Applied Physics
We study the influence of Mn doping on the vibrational properties of rf sputtered ZnO thin films. Raman spectra of the Mn doped ZnO samples reveal two additional vibrational modes, in addition to the host phonon modes, at 252 and 524?cm?1. The intensity of the additional modes increases continuously with Mn concentrat…
ZnO doping and propertiesGas Sensing Nanomaterials and SensorsAcoustic Wave Resonator Technologies
Julienne Chaigneau、J. M. Kiat、Charlotte Malibert 等 4 位作者2007-09-21Physical Review B
We have performed a structural study of the morphotropic phase boundary system $(1\ensuremath{-}x)\mathrm{Bi}\mathrm{Sc}{\mathrm{O}}_{3\ensuremath{-}x}\mathrm{Pb}\mathrm{Ti}{\mathrm{O}}_{3}$ in which both $A$ and $B$ sites of the perovskite are randomly occupied. A ${M}_{A}$ monoclinic phase coexisting with a tetragon…
Ferroelectric and Piezoelectric MaterialsHigh-pressure geophysics and materialsElectronic and Structural Properties of Oxides
B. Hadjarab、A. Bouguelia、M. Trari2007-09-21Journal of Physics D Applied Physics
BaSnO 3 crystallizes in a cubic perovskite structure and exhibits insulating behaviour. It can be made conducting by reducing a small fraction of Sn 4+ into Sn 2+ under an O 2 -free atmosphere. This can be achieved through the solid solution Ba 1− x La x SnO 3−δ which is a mixed phase for x > 0.02, behaviour readily u…
Diamond and Carbon-based Materials ResearchMagnetic and transport properties of perovskites and related materialsElectronic and Structural Properties of Oxides
John P. Robinson、Henning Schomerus2007-09-21Physical Review B
We investigate the conductance of normal-conductor/graphene/normal-conductor (NGN) junctions for arbitrary on-site potentials in the normal and graphitic parts of the system. We find that a ballistic NGN junction can display insulating behavior even when the charge-carrier density in the graphene part is finite. This…
Advancements in Battery MaterialsGraphene research and applicationsQuantum and electron transport phenomena
A. Allenic、Wei Guo、Y. B. Chen 等 10 位作者2007-09-21Advanced Materials
The role of dislocations in stable p-type phosphorus-doped ZnO epitaxial films is investigated. It is shown that good p-type conductivity is always associated with a considerable increase in the density of dislocations, which can aid the formation of shallow complex acceptors and provide sinks for native donors.
ZnO doping and propertiesCopper-based nanomaterials and applicationsElectronic and Structural Properties of Oxides
Rienk Eelkema、Kiminori Maeda、Barbara Odell 等 4 位作者2007-09-21Journal of the American Chemical Society
A cucurbituril-encapsulated oligoaniline rotaxane is synthesized in high yield by reductive amination in aqueous acid. Spectroscopic and electrochemical measurements show that encapsulation by cucurbit[7]uril increases the thermodynamic and kinetic stability of the radical cation of the threaded oligoaniline. This rad…
Supramolecular Chemistry and ComplexesConducting polymers and applicationsLuminescence and Fluorescent Materials
Zhenrong Zhang、Qingfeng Ge、Shao‐Chun Li 等 6 位作者2007-09-21Physical Review Letters
We report the first measurements and calculations of the intrinsic mobility of bridge-bonded oxygen (BBO) vacancies on a rutile TiO2(110). The sequences of isothermal (340-420 K) scanning tunneling microscope images show that BBO vacancies migrate along BBO rows. The hopping rate increases exponentially with increasin…
Catalytic Processes in Materials ScienceMachine Learning in Materials ScienceElectronic and Structural Properties of Oxides
Antoine Carré、Ludovic Berthier、Jürgen Horbach 等 5 位作者2007-09-21The Journal of Chemical Physics
We show that finite-range alternatives to the standard long-range pair potential for silica by van Beest et al. [Phys. Rev. Lett. 64, 1955 (1990)] might be used in molecular dynamics simulations. We study two such models that can be efficiently simulated since no Ewald summation is required. We first consider the Wolf…
Material Dynamics and PropertiesGlass properties and applicationsSpectroscopy and Quantum Chemical Studies
N. M. R. Peres、Eduardo V. Castro2007-09-21Journal of Physics Condensed Matter
We present an exact algebraic solution of a single graphene plane in transverse electric and perpendicular magnetic fields. The method presented gives both the eigenvalues and the eigenfunctions of the graphene plane. It is shown that the eigenstates of the problem can be cast in terms of coherent states, which appear…
Graphene research and applicationsMetamaterials and Metasurfaces ApplicationsQuantum and electron transport phenomena
Jung-Jin Kim、Keisuke Kobayashi、Eiji Ikenaga 等 9 位作者2007-09-21Physical Review B
We have investigated the valence-band density of states and core levels of the amorphous and crystalline ${(\mathrm{Ge}\mathrm{Te})}_{1\ensuremath{-}x}{({\mathrm{Sb}}_{2}{\mathrm{Te}}_{3})}_{x}$ $(x=0--1∕3)$ pseudobinary compounds using hard x-ray photoemission spectroscopy. In the valence-band spectra, the crystallin…
Chalcogenide Semiconductor Thin FilmsCrystal Structures and PropertiesPhase-change materials and chalcogenides
Ning Jin、Mohammed Ibrahim、Thomas G. Spiro 等 4 位作者2007-09-21Journal of the American Chemical Society
The relatively stable oxoMn(V) porphyrins generated by oxidation of Mn(III) porphyrins in alkaline solutions using peroxides are unambiguously identified as trans -dioxo species. Raman spectra revealed symmetric O Mn V O stretching frequencies between 741 and 744 cm -1 for five porphyrin complexes while the IR of diox…
Photosynthetic Processes and MechanismsPorphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation Mechanisms
Thushari Jayasekera、J. W. Mintmire2007-09-21Nanotechnology
We study the transport properties of multiterminal graphene nanodevices using the Landauer-Buttiker approach and the tight binding model. We consider a four-terminal device made at the crossing of a zigzag and armchair nanoribbons and two types of T-junction devices. The transport properties of graphene multiterminal…
Graphene research and applicationsQuantum and electron transport phenomenaMolecular Junctions and Nanostructures
Jiong Ma、Ji-Yao Chen、Yù Zhang 等 7 位作者2007-09-21The Journal of Physical Chemistry B
The process and mechanism of photochemical instability of thiol-capped CdTe quantum dots (QDs) in aqueous solution were experimentally studied. After laser irradiation, the corresponding Raman bands of the Cd-S bond decreased obviously, indicating bond breaking and thiol detachment from the QD surfaces. Meanwhile, a p…
Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsNanocluster Synthesis and Applications
Najeh Al‐Salim、Aidan G. Young、Richard D. Tilley 等 5 位作者2007-09-21Chemistry of Materials
CdSe x S y nanocrystals were synthesized in eight solvents that have different coordinating properties, trioctylphosphine oxide, trioctylphosphine, triphenylphosphine, oleylamine, hexadecylamine, dioctylamine, trioctylamine, and 1-octadecene at 230−300 °C. These nanocrystals exhibited high photoluminescence, which cou…
Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsCopper-based nanomaterials and applications
A. Stroppa、K. Termentzidis、J. Paier 等 5 位作者2007-09-21arXiv
We present a detailed study of the adsorption of CO on Cu, Rh, and Pt (111) surfaces in top and hollow sites. The study has been performed using the local density approximation, the gradient corrected functional PBE, and the hybrid Hartree-Fock density functionals PBE0 and HSE03 within the framework of generalized Koh…
Materials Science