Victor Borovkov、Isao Fujii、Atsuya Muranaka 等 8 位作者2004-10-13Angewandte Chemie International Edition
A sign of the times: A 1:1 tweezer complex consisting of an achiral bis(zinc porphyrin) and (R,R)-1,2-diaminocyclohexane has been characterized by X-ray crystallographic analysis (see picture, Zn red, N blue). This has enabled a full and unambiguous rationalization of the highly efficient transfer of chirality informa…
Photosynthetic Processes and MechanismsPorphyrin and Phthalocyanine ChemistrySupramolecular Chemistry and Complexes
John F. Dobson、Jun Wang、Bradley P. Dinte 等 5 位作者2004-10-13International Journal of Quantum Chemistry
Abstract We discuss dispersion forces, beginning with toy models that illustrate the limitations of various standard approaches. For metallic cohesion of very thin layers, we show that because the local density approximation (LDA) misses distant dispersion interactions, it also makes significant errors in the maximum…
Boron and Carbon Nanomaterials ResearchGraphene research and applicationsAdvanced Chemical Physics Studies
J. Müller、John M. Lupton、Andrey L. Rogach 等 6 位作者2004-10-13Physical Review Letters
We demonstrate a universal correlation between the spectral linewidth and position of the excitonic transition in the spectral jitter observed from single elongated colloidal quantum dots. Breaking the symmetry of electron and hole confinement as well as of the spatial directions for surface charge diffusion enables u…
Chalcogenide Semiconductor Thin FilmsSemiconductor Quantum Structures and DevicesQuantum Dots Synthesis And Properties
Xiaojuan Hao、Camilla Nilsson、Martin Jesberger 等 8 位作者2004-10-13Journal of Polymer Science Part A Polymer Chemistry
Abstract The synthesis and characterization of novel first‐ and second‐generation true dendritic reversible addition–fragmentation chain transfer (RAFT) agents carrying 6 or 12 pendant 3‐benzylsulfanylthiocarbonylsulfanylpropionic acid RAFT end groups with Z‐group architecture based on 1,1,1‐hydroxyphenyl ethane and t…
Dendrimers and Hyperbranched PolymersAdvanced Polymer Synthesis and CharacterizationSynthetic Organic Chemistry Methods
Dong Ha Kim、Prabhu Karan、Petra Göring 等 9 位作者2004-10-13Small
Porous alumina templates have been used to prepare dendrimer nanotubes with uniform size and orientation as well as high aspect ratios by a layer-by-layer deposition technique (see SEM image). The tubes may be released from or located in the template pores. Diffusion limitations arising from the pore geometry lead to…
Anodic Oxide Films and NanostructuresDendrimers and Hyperbranched PolymersPolymer Surface Interaction Studies
Leonid Ionov、Nikolay Houbenov、Alexander Sidorenko 等 6 位作者2004-10-13Langmuir
We report on a thin polyelectrolyte film (mixed polyelectrolyte brush) with a gradual change of the composition (ratio between two different oppositely charged surface-grafted weak polyelectrolytes) across the sample. The gradient of surface composition creates a gradient in surface charge density and, consequently, a…
Polymer Surface Interaction StudiesElectrostatics and Colloid InteractionsAnalytical Chemistry and Sensors
Nicolas Dacheux、Nicolas Clavier、Anne‐Charlotte Robisson 等 7 位作者2004-10-13Comptes Rendus Chimie
In the field of the immobilisation of high-activity-level and long-life radwaste (HAVL) for a deep underground repository, several phosphate matrices were already proposed as good candidates to delay the release of actinides in the near-field of such disposal. Among them, thorium phosphate–diphosphate (TPD), monazites…
Nuclear materials and radiation effectsRadioactive element chemistry and processingChemical Synthesis and Characterization
Jobu Matsuno、Y. Okimoto、Zhilai Fang 等 8 位作者2004-10-13Physical Review Letters
A single-crystalline film of ${\mathrm{S}\mathrm{r}}_{2}{\mathrm{C}\mathrm{o}\mathrm{O}}_{4}$ with square-lattice ${\mathrm{C}\mathrm{o}\mathrm{O}}_{2}$ sheets (${\mathrm{K}}_{2}{\mathrm{N}\mathrm{i}\mathrm{F}}_{4}$-type structure) was synthesized, and its electronic properties were characterized. The compound exhibit…
Advanced Condensed Matter PhysicsMagnetic and transport properties of perovskites and related materialsZnO doping and properties
L. Seetha Lakshmi、K. Doerr、K. Nenkov 等 6 位作者2004-10-13arXiv
For the first time,we report the effect of pentavalent subtitution at the Mn site of La(0.67)Ca(0.33)MnO(3). The ferromagnetic -metallic ground state modifies to a cluster-glass insulator beyond x=0.03. The observed suppression in the transition temperatures (39K/at.%) is the largest reported for the Mn site subtitute…
Materials Science
J. L. Cheng、M. W. Wu2004-10-13arXiv
The spin-dependent density of states and the density of spin polarization of an InAs-based two-dimensional electron gas with the Rashba spin-orbit coupling under an intense terahertz laser field are investigated by utilizing the Floquet states to solve the time-dependent Schrödinger equation. It is found that both den…
Materials ScienceMesoscale and Nanoscale Physics
A. Stroppa、M. Peressi2004-10-13arXiv
Accurate ab-initio pseudopotential calculations within density functional theory in the LDA approximation have been performed for structural properties and stability of ZnSe/GaAs(001) defected heterostructures. There is a strong experimental evidence that ZnSe/GaAs heterostructures with minimum stacking fault density…
Materials Science
Søren L. Frederiksen、Karsten W. Jacobsen、Kevin Brown 等 4 位作者2004-10-13Physical Review Letters
Using a Bayesian approach a general method is developed to assess error bars on predictions made by models fitted to data. The error bars are estimated from fluctuations in ensembles of models sampling the model-parameter space with a probability density set by the minimum cost. The method is applied to the developmen…
Machine Learning in Materials ScienceNuclear Materials and PropertiesMicrostructure and mechanical properties
Juan C. Fierro‐Gonzalez、Bruce C. Gates2004-10-13The Journal of Physical Chemistry B
Mononuclear gold complexes in zeolite NaY were synthesized from initially physisorbed Au(CH 3 ) 2 (C 5 H 7 O 2 ) and characterized in reactive atmospheres by X-ray absorption and infrared spectroscopies. Under conditions of CO oxidation catalysis at 298 K and 760 Torr in a flow reactor, the gold remained as mononuclea…
Electrocatalysts for Energy ConversionCatalysis and Oxidation ReactionsCatalytic Processes in Materials Science
Saïd Barazzouk、Surat Hotchandani、K. Vinodgopal 等 4 位作者2004-10-13The Journal of Physical Chemistry B
Electrophoretically deposited single-wall carbon nanotube (SWCNT) films on optically transparent electrodes are photoelctrochemically active and generate photocurrent upon visible excitation. A low photon-to-current conversion efficiency of 0.15% suggests that most of the photogenerated charge carriers are lost in the…
Carbon Nanotubes in CompositesMechanical and Optical ResonatorsTransition Metal Oxide Nanomaterials
Nathaniel L. Rosi、C. Shad Thaxton、Chad A. Mirkin2004-10-13Angewandte Chemie International Edition
Microorganisms point the way: The silica cell walls of various diatoms were covalently functionalized with DNA by using straightforward chemical procedures and then used as templates for the sequence-specific assembly and 3D hierarchical arrangement of prefabricated DNA-modified gold nanoparticles. The DNA was used to…
Protist diversity and phylogenyPaleontology and Stratigraphy of FossilsDiatoms and Algae Research
Weidong Sheng、Shun-Jen Cheng、Pawel Hawrylak2004-10-13arXiv
We report on a multiband microscopic theory of many-exciton complexes in self-assembled quantum dots. The single particle states are obtained by three methods: single-band effective-mass approximation, the multiband $k\cdot p$ method, and the tight-binding method. The electronic structure calculations are coupled with…
Mesoscale and Nanoscale PhysicsMaterials Science
Z. X. Ye、Qiang Li、Y. F. Hu 等 8 位作者2004-10-13arXiv
Magnetic instability in both ultra-pure and carbon-doped MgB2 films is investigated by magneto-optical imaging, transport and bulk magnetization measurements. In the carbon-doped MgB2 thin film, familiar dendritic flux-jump patterns were observed at low temperature as reported in previous experiments. In the ultra-pur…
Materials ScienceSuperconductivity
Igor I. Smolyaninov2004-10-13arXiv
A new far-field optical microscopy technique capable of reaching nanometer-scale resolution has been developed recently using the in-plane image magnification by surface plasmon polaritons. This microscopy is based on the optical properties of a metal-dielectric interface that may, in principle, provide extremely larg…
Materials ScienceStrongly Correlated Electrons
Vinod Chandra、S. Ramasesha、Diptiman Sen2004-10-13Physical Review B
We propose a model which could explain some of the unusual magnetic properties observed for the one-dimensional helical spin system $\mathrm{Co}{(hfac)}_{2}\mathrm{N}\mathrm{I}\mathrm{T}\mathrm{Ph}\mathrm{O}\mathrm{Me}$. One of these properties is that the magnetization shows some plateaus if a magnetic field is appli…
Quantum many-body systemsMagnetism in coordination complexesTheoretical and Computational Physics
S. V. Zaitsev-Zotov、V. E. Minakova2004-10-13arXiv
Light illumination of thin crystals of CDW conductor TaS$_3$ is found to result in dramatic changes of both linear ($G$) and nonlinear conduction. The increase of $G$ is accompanied by suppression of the collective conduction, growth of the threshold field $E_T$, and appearance of the switching and hysteretic behavior…
Strongly Correlated ElectronsMaterials Science