Sebastian Polarz、A. V. Orlov、Ferdi Schüth 等 4 位作者2006-09-27Chemistry - A European Journal
Transition-metal-oxide materials possessing ordered mesoporosity have recently attracted significant research interest due to their numerous potential applications. Among them, ordered mesoporous zinc oxide (ZnO) is a very tempting material because of the importance of ZnO in heterogeneous catalysis. Here, first resul…
Mesoporous Materials and CatalysisCatalytic Processes in Materials ScienceSupercapacitor Materials and Fabrication
Kerstin Schlufter、H.‐P. Schmauder、Susann Dorn 等 4 位作者2006-09-27Macromolecular Rapid Communications
Abstract Summary: Bacterial cellulose (BC), a unique type of cellulose, with high degree of polymerization of 6 500 could be dissolved easily in the ionic liquid 1‐ N ‐butyl‐3‐methylimidazolium chloride. For the first time, well‐soluble BC acetates and carbanilates of high degree of substitution (up to a complete modi…
Catalysis for Biomass ConversionIonic liquids properties and applicationsAdvanced Cellulose Research Studies
S. Pittalis、S. Kurth、N. Helbig 等 4 位作者2006-09-27arXiv
Current-spin density functional theory (CSDFT) provides a framework to describe interacting many-electron systems in a magnetic field which couples to both spin- and orbital-degrees of freedom. Unlike in usual (spin-) density functional theory, approximations to the exchange-correlation energy based on the model of th…
Materials Science
Robert van Leeuwen、Nils Erik Dahlen、Adrian Stan2006-09-27arXiv
We derive variational expressions for the grand potential or action in terms of the many-body Green function $G$ which describes the propagation of particles and the renormalized four-point vertex $Γ$ which describes the scattering of two particles in many-body systems. The main ingredient of the variational functiona…
Materials ScienceStrongly Correlated Electrons
Jesús F. Bermejo-Martín、Paula Ortega、Louis Chonco 等 11 位作者2006-09-27Chemistry - A European Journal
Novel amine- or ammonium-terminated carbosilane dendrimers of type nG-[Si{OCH2(C6H3)-3,5-(OCH2CH2NMe2)2}]x, nG-[Si{O(CH2)2N(Me)(CH2)2NMe2}]x and nG-[Si{(CH2)3NH2}]x or nG-[Si{OCH2(C6H3)-3,5-(OCH2CH2NMe3 +I-)2}]x, nG-[Si{O(CH2)2N(Me)(CH2)2NMe3 +I-}]x, and nG-[Si{(CH2)3NH3 +Cl-}]x have been synthesized and characterized…
Advanced biosensing and bioanalysis techniquesRNA Interference and Gene DeliveryDendrimers and Hyperbranched Polymers
T. Devolder、C. Chappert、J. A. Katine 等 5 位作者2006-09-27arXiv
We study the distribution of switching times in spin-transfer switching induced by sub-ns current pulses in pillar-shaped spin-valves. The pulse durations leading to switching follow a comb-like distribution, multiply-peaked at a few most probable, regularly spaced switching durations. These durations reflect the prec…
Strongly Correlated ElectronsMaterials Science
F. Dalla Longa、J. T. Kohlhepp、W. J. M. de Jonge 等 4 位作者2006-09-27arXiv
The role of photon angular momentum in laser-induced demagnetization of Nickel thin films is investigated by means of pump-probe time-resolved magneto-optical Kerr effect in the polar geometry. The recorded data display a strong dependency on pump helicity during pump-probe temporal overlap, which is shown to be of no…
Materials Science
Vasili Perebeinos、Phaedon Avouris2006-09-27Physical Review B
We investigate theoretically the efficiency of intramolecular hot-carrier-induced impact ionization and excitation processes in carbon nanotubes. The electron confinement and reduced screening lead to drastically enhanced excitation efficiencies over those in bulk materials. Strong excitonic coupling favors neutral ex…
Diamond and Carbon-based Materials ResearchMechanical and Optical ResonatorsCarbon Nanotubes in Composites
Ferenc Simon、Rudolf Pfeiffer、H. Kuzmany2006-09-27Physical Review B
The temperature dependence of optical excitation lifetime $1∕\ensuremath{\Gamma}$ and transition energies ${E}_{ii}$ were measured for bucky papers of single-wall carbon nanotubes (SWCNTs) and inner tubes in double-wall carbon nanotubes (DWCNTs) using resonant Raman scattering on the radial breathing mode. The tempera…
Mechanical and Optical ResonatorsCarbon Nanotubes in CompositesGraphene research and applications
Yu-xi Liu、C. P. Sun、Franco Nori2006-09-27arXiv
We study a coupling/decoupling method between a superconducting qubit and a data bus that uses a controllable time-dependent electromagnetic field (TDEF). As in recent experiments, the data bus can be either an LC circuit or a cavity field. When the qubit and the data bus are initially fabricated, their detuning shoul…
SuperconductivityMaterials Science
Victor Galitski、A. A. Burkov、S. Das Sarma2006-09-27arXiv
We develop a general scheme of deriving boundary conditions for spin-charge coupled transport in disordered systems with spin-orbit interactions. To illustrate the application of the method, we explicitly derive boundary conditions for spin diffusion in the Rashba model. Due to the surface spin precession, the boundar…
cond-mat.dis-nnMaterials Science
Yi Qi、H. Zheng、R. Ramesh 等 4 位作者2006-09-27arXiv
We report on linear and non-linear dielectric property measurements of BaTiO3 - CoFe2O4 (BTO-CFO) ferroelectro-magnetic nano-composites and pure BaTiO3 and CoFe2O4 samples with Scanning Near Field Microwave Microscopy. The permittivity scanning image with spatial resolution on the micro-meter scale shows that the nano…
Materials Science
Liliana Cseh、Georg H. Mehl2006-09-27Journal of the American Chemical Society
Nematic gold nanoparticles, covered with a monolayer of calamitic mesogens and short hydrocarbon chains, have been synthesized and investigated. The materials are chemically stable and exhibit nematic phase behavior at room temperature.
Gold and Silver Nanoparticles Synthesis and ApplicationsPickering emulsions and particle stabilizationMicro and Nano Robotics
Katsuyoshi Matsushita、Ryoko Sugano、Akiyoshi Kuroda 等 5 位作者2006-09-27arXiv
We investigate freezing characteristics of a finite dipolar hexagonal plate by the Monte Carlo simulation. The hexagonal plate is cut out from a piled triangular lattice of three layers with FCC-like (ABCABC) stacking structure. In the present study an annealing simulation is performed for the dipolar plate uniaxially…
Materials Sciencecond-mat.stat-mech
J. Reinisch、A. Heuer2006-09-27arXiv
Information about the nature of the low-temperature anomalies and in particular the properties of the tunneling systems in silica and lithium silica glasses are revealed via computer simulations. The potential energy landscape of these systems is systematically explored for adjacent pairs of local minima which may act…
Materials Sciencecond-mat.dis-nn
Patrick Huber、Viktor Soprunyuk、K. Knorr2006-09-27Physical Review E
The n-alkanes C12H26, C14H30, and C16H34 have been imbibed and solidified in mesoporous Vycor glass with a mean pore diameter of 10 nm. The samples have been investigated by x-ray diffractometry and calorimetric measurements. The structures and phase sequences have been determined. Apart from a reduction and the hyste…
Advanced NMR Techniques and ApplicationsZeolite Catalysis and SynthesisMesoporous Materials and Catalysis
Thomas Kreibich、Robert van Leeuwen、E. K. U. Gross2006-09-27arXiv
We present a general multi-component density functional theory in which electrons and nuclei are treated completely quantum mechanically, without the use of a Born-Oppenheimer approximation. The two fundamental quantities in terms of which our theory is formulated are the nuclear N-body density and the electron densit…
Materials Science
L. Brey、M. J. Calderón、S. Das Sarma 等 4 位作者2006-09-27Physical Review B
A mean-field approximation of a model for double perovskites that takes into account the coupling between itinerant electron spins and localized spins is developed. As in previously reported theoretical results, and contrary to experimental observation, the critical temperature is suppressed for large electron density…
Magnetic and transport properties of perovskites and related materialsPerovskite Materials and ApplicationsAdvanced Condensed Matter Physics
To Ngai、Helmut Auweter、Sven H. Behrens2006-09-27Macromolecules
Using stimulus-sensitive microgel particles as an emulsifier, we have prepared a new type of emulsion responsive to pH, ionic strength, and temperature changes. Each of these environmental changes can trigger a volume phase transition in poly( N -isopropylacrylamide) (PNIPAM) microgel particles containing some carboxy…
Pickering emulsions and particle stabilizationProteins in Food SystemsHydrogels: synthesis, properties, applications
Rajesh K. Kainthan、Edward B. Muliawan、Savvas G. Hatzikiriakos 等 4 位作者2006-09-27Macromolecules
Very high molecular weight ( M n up to 700 000) and narrowly polydispersed (PDI = 1.1−1.4) hyperbranched polyglycerols (HPG) were synthesized by ring-opening multibranching polymerization of glycidol using dioxane as an emulsifying agent. Broader molecular weight distributions with low molecular weight fractions were…
Advanced Polymer Synthesis and CharacterizationRNA Interference and Gene DeliveryDendrimers and Hyperbranched Polymers