Regina Palkovits、Christian von Malotki、Martin Baumgarten 等 10 位作者2009-09-24ChemSusChem
The direct low-temperature oxidation of methane to methanol is demonstrated on a highly active homogeneous molecular catalyst system and on heterogeneous molecular catalysts based on polymeric materials possessing ligand motifs within the material structure. The N-(2-methylpropyl)-4,5-diazacarbazolyl-dichloro-platinum…
Catalytic Processes in Materials ScienceCatalysis and Oxidation ReactionsMesoporous Materials and Catalysis
Yao‐Hung Tseng、Hsia Yu Lin、Ming‐Han Liu 等 5 位作者2009-09-24The Journal of Physical Chemistry C
A fabrication of ZnO hierarchical mesocrystal was achieved by a biomimetic method using gelatin as structure-directing agent. It was found that the ZnO−gelatin microcrystal with well-defined hexagonal twin plate shape is built by the stacking of nanoplates. The irregularly edged nanoplates can adjust themselves to eac…
Cephalopods and Marine BiologyCalcium Carbonate Crystallization and InhibitionPaleontology and Stratigraphy of Fossils
Jian‐Hui Lan、Dapeng Cao、Wenchuan Wang2009-09-24Langmuir
By using a multiscale theoretical method, which combines the first-principles calculation and grand canonical Monte Carlo (GCMC) simulation, we studied storage capacities of methane in 3D covalent organic frameworks (COFs) and their Li-doped compounds at T = 243 and 298 K. Our results predicted that, at T = 298 K and…
Membrane Separation and Gas TransportMetal-Organic Frameworks: Synthesis and ApplicationsCovalent Organic Framework Applications
Weifeng Bu、Sayaka Uchida、Noritaka Mizuno2009-09-24Angewandte Chemie International Edition
Core–corona composites were prepared by incorporating a hydrophilic polyoxometalate (POM) into poly(styrene-b-4-vinyl-N-methylpyridinium iodide) matrices in acidic aqueous solution (see scheme). On dispersal in toluene they self-assemble into micellar and vesicular morphologies (see TEM images), which can be controlle…
Polyoxometalates: Synthesis and Applicationsbiodegradable polymer synthesis and propertiesChemical Synthesis and Reactions
Sylvain Deville、Éric Maire、Audrey Lasalle 等 7 位作者2009-09-24Journal of the American Ceramic Society
This paper investigates the behavior of colloidal suspensions of alumina particles during directional solidification, by in situ high‐resolution observations using X‐ray radiography and tomography. This second part is focussed on the evolution of ice crystals during steady‐state growth (in terms of interface velocity)…
nanoparticles nucleation surface interactionsSolidification and crystal growth phenomenaMaterial Dynamics and Properties
J. Agostinho Moreira、A. Almeida、W. S. Ferreira 等 9 位作者2009-09-24arXiv
Eu1-xYxMnO3 exhibits, unlike other magnetoelectric systems, very distinctive features. Its magnetoelectric properties is driven by the magnetic spin of the Mn3+ ion, but they can be drastically changed by varying the content of Y3+, which it does not carry any magnetic moment. Though the x = 0.40 composition has been…
Materials ScienceStrongly Correlated Electrons
C. E. Pryor、M. E. Flatté、J. Levy2009-09-24arXiv
We calculate that the electron states of strained self-assembled Ge/Si quantum dots provide a convenient two-state system for electrical control. An electronic state localized at the apex of the quantum dot is nearly degenerate with a state localized at the base of the quantum dot. Small electric fields shift the elec…
Mesoscale and Nanoscale PhysicsMaterials Science
M Inglot、V K Dugaev2009-09-24arXiv
We consider a two-dimensional crystalline monolayer of carbon atoms with a single non-magnetic impurity. Using the Weyl Hamiltonian to describe electronic energy spectrum near the Dirac points, we calculate the wave function and energy of impurity states, as well as the induced magnetic moment associated with polariza…
cond-mat.otherMaterials Science
Bin Wang、Yanxia Xing、Lei Zhang 等 4 位作者2009-09-24arXiv
We report first principles investigation of time-dependent current of molecular devices under a step-like pulse.Our results show that although the switch-on time of the molecular device is comparable to the transit time, much longer time is needed to reach the steady state. In reaching the steady state the current is…
Materials ScienceMesoscale and Nanoscale Physics
Jing Li、Ian Appelbaum2009-09-24arXiv
By incorporating the proper boundary conditions, we analytically derive the impulse response (or "Green's function") of a current-sensing spin detector. We also compare this result to a Monte-Carlo simulation (which automatically takes the proper boundary condition into account) and an empirical spin transit time dist…
Materials Sciencecond-mat.other
G. Acbas、Myoung-Hwan Kim、M. Cukr 等 9 位作者2009-09-24Physical Review Letters
We employ Faraday and Kerr effect spectroscopy in the infrared range to investigate the electronic structure of Ga_{1-x}Mn_{x}As near the Fermi energy. The band structure of this archetypical dilute-moment ferromagnetic semiconductor has been a matter of controversy, fueled partly by previous measurements of the unpol…
ZnO doping and propertiesElectronic and Structural Properties of OxidesMagnetic and transport properties of perovskites and related materials
Kamal K. Saha、Wenchang Lu、J. Bernholc 等 4 位作者2009-09-24arXiv
We present a generalized approach for computing electron conductance and I-V characteristics in multiterminal junctions from first-principles. Within the framework of Keldysh theory, electron transmission is evaluated employing an O(N) method for electronic-structure calculations. The nonequilibrium Green function for…
Materials Science
Shengfeng Cheng、Binquan Luan、Mark O. Robbins2009-09-24arXiv
Molecular dynamics simulations are used to study contact between a rigid, nonadhesive, spherical tip with radius of order 30nm and a flat elastic substrate covered with a fluid monolayer of adsorbed chain molecules. Previous studies of bare surfaces showed that the atomic scale deviations from a sphere that are presen…
Materials ScienceSoft Condensed Matter
R. L. Silva、A. R. Pereira、W. A. Moura-Melo2009-09-24arXiv
We consider a nanodisk possessing two coupled materials with different ferromagnetic exchange constant. The common border line of the two media passes at the disk center dividing the system exactly in two similar half-disks. The vortex core motion crossing the interface is investigated with a simple description based…
Mesoscale and Nanoscale PhysicsMaterials Science
R. L. Silva、A. R. Pereira、W. A. Moura-Melo 等 7 位作者2009-09-24arXiv
We investigate the influence of artificial defects (small holes) inserted into magnetic nanodisks on the vortex core dynamics. One and two holes (antidots) are considered. In general, the core falls into the hole but, in particular, we would like to remark an interesting phenomenon not yet observed, which is the vorte…
Mesoscale and Nanoscale PhysicsMaterials Science
Guo Hong、Bo Zhang、Banghua Peng 等 8 位作者2009-09-24Journal of the American Chemical Society
By introducing the UV beam into our homemade chemical vapor deposition system, we had obtained a well aligned SWNT array on an ST-cut quartz substrate. After transfer onto a SiO(2)/Si substrate, the SWNT array was detected by Raman spectroscopy and electrical measurement, which showed that over 95% of the SWNTs were s…
Graphene research and applicationsNanotechnology research and applicationsCarbon Nanotubes in Composites
Nian Ji、Xiaoqi Liu、Jian-Ping Wang2009-09-24arXiv
A new model is proposed for the strong ferromagnetism associated with partially localized orbitals in the Fe16N2 metallic system which draws substantially from models of heavy fermion metals. The basic idea is that the spatially isolated Fe-N clusters generate non-uniform charge density and increase the d-d electron i…
Materials Science
Xiaoqi Liu、Yun-Hao Xu、Cecilia Sanchez-Hanke 等 4 位作者2009-09-24arXiv
The mystery of giant saturation magnetization of Fe16N2 has remained for 37 years. In this letter, X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) are used to study the electron states of Fe atoms in Fe16N2 and Fe8N films. Localized Fe 3d electron states, which are not expected from current…
Materials Science
Markku P. V. Stenberg、Rogério de Sousa2009-09-24Physical Review B
We propose a model for the pair of electromagnon excitations observed in the class of multiferroic materials $R{\text{MnO}}_{3}$ ($R$ is a rare-earth ion). The model is based on a harmonic cycloid ground state interacting with a zone-edge magnon and its twin excitation separated in momentum space by two times the cycl…
Multiferroics and related materialsFerroelectric and Piezoelectric MaterialsMagnetic and transport properties of perovskites and related materials
Ryan M. Hensarling、Vanessa A. Doughty、Justin W. Chan 等 4 位作者2009-09-24Journal of the American Chemical Society
Thiol-yne click chemistry is demonstrated as a modular platform for rapid and practical fabrication of highly functional, multicomponent surfaces under ambient conditions. The principle is illustrated using a postmodification strategy in which poly(propargyl methacrylate) brushes were generated via surface-initiated p…
Molecular Junctions and NanostructuresPolymer Surface Interaction StudiesNanofabrication and Lithography Techniques