Benoı̂t Champagne、Éric A. Perpète、S. J. A. van Gisbergen 等 8 位作者1998-12-15OpenAlex
DFT schemes based on conventional and less conventional exchange-correlation (XC) functionals have been employed to determine the polarizability and second hyperpolarizability of π-conjugated polyacetylene chains. These functionals fail in one or more of several ways: (i) the correlation correction to α is either much…
Nonlinear Optical Materials ResearchSynthesis and Properties of Aromatic CompoundsSolid-state spectroscopy and crystallography
I. Forbeaux、J.-M. Themlin、J.M. Debever1998-12-15OpenAlex
When annealed at elevated temperatures under vacuum, silicon carbide surfaces show a tendency towards graphitization. Using the sensitivity of empty conduction-band states dispersion towards the structural quality of the overlayer, we have used angular-resolved inverse photoemission spectroscopy (KRIPES) to monitor th…
Graphene research and applicationsSilicon Carbide Semiconductor TechnologiesSurface and Thin Film Phenomena
Akira Onuki1998-12-14Journal of Physics Condensed Matter
Phase transitions in fluids can be drastically altered by shear flow and heat flow. We briefly discuss the mechanisms of shear effects in three very different fluids. They are near-critical fluids, semidilute polymer solutions in theta solvent, and highly supercooled liquids. As regards heat flow problems, we consider…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesAdvanced Thermodynamics and Statistical Mechanics
M. Todorovic、S. Schultz1998-12-14Applied Physics Letters
We present a high-sensitivity alternating gradient magnetometer. It uses inexpensive, commercially available, piezoelectric quartz tuning fork resonators as vibration amplitude sensors of a vibrating magnetic sample in an alternating gradient field. The technique exploits the high quality factor, high resonant frequen…
Magnetic properties of thin filmsMagnetic Properties and ApplicationsGeomagnetism and Paleomagnetism Studies
Peter R. Ashton、Derek W. Anderson、Christopher L. Brown 等 6 位作者1998-12-14Chemistry - A European Journal
An eight-member family of dendrimers has been built up by both convergent and divergent methodologies from an orthogonally-protected amino-tetraacid. Examination of the series by GPC, 1H NMR and computer modeling suggests that the three-directional fourth-generation dendrimer (right) has a globular, void-containing st…
Chemical Synthesis and AnalysisLuminescence and Fluorescent MaterialsDendrimers and Hyperbranched Polymers
Luigi Cavallo、Franca Fraternali1998-12-14Chemistry - A European Journal
New insights into dendritic boxes: various structural properties for the first five generations of a modified poly(propylene imine) dendrimer are examined. The simulations indicate that cavities, which are partly filled with terminal groups, are present so that guests can be incorporated. It is hypothesised that the l…
Luminescence and Fluorescent MaterialsSynthesis and Properties of Aromatic CompoundsDendrimers and Hyperbranched Polymers
L. H. Avanci、Lisandro Pavie Cardoso、S. E. Girdwood 等 6 位作者1998-12-14Physical Review Letters
Distortions produced in the unit cell of a nonlinear organic crystal under the influence of an applied electric field $E$ are investigated by using synchrotron x-ray multiple diffraction (MD). A typical MD pattern shows numerous $(\mathrm{hkl})$ secondary peaks and the position of each one is basically a function of t…
Nonlinear Optical Materials ResearchAcoustic Wave Resonator TechnologiesSolid-state spectroscopy and crystallography
Shigenobu Ogata、Timothy J. Campbell1998-12-14Journal of Physics Condensed Matter
The oxidation of an Al nanocluster with radius 100 ? placed in oxygen gas at room temperature is investigated by performing molecular dynamics simulations on parallel computers. The simulations take into account the effects of dynamic charge transfer between Al and O on the basis of electronegativity-equalization prin…
Graphene research and applicationsAdvanced Physical and Chemical Molecular InteractionsIon-surface interactions and analysis
Jin Yu、Yoshiharu Namba1998-12-14Applied Physics Letters
We present a well-validated model to predict the roughness on an atomic surface. Surface roughness equation is developed for atomic topography. The root-mean-square roughness σ is found to be proportional to the radii of the surface atoms or ions. Tables are provided for theoretical atomic surface roughness in pure me…
Force Microscopy Techniques and ApplicationsElectronic and Structural Properties of OxidesSurface and Thin Film Phenomena
Albertus P. H. J. Schenning、Jeffrey H. Lutje Spelberg、Dominicus H. W. Hubert 等 5 位作者1998-12-14Chemistry - A European Journal
Turnover numbers comparable to those of the enzyme itself in the catalytic epoxidation of alkenes are attained by a supramolecular cytochrome P450 mimic, in which an amphiphilic rhodium complex and a manganese porphyrin are incorporated in a dihexadecyl phosphate vesicle bilayer (shown schematically above). The electr…
Porphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation MechanismsOxidative Organic Chemistry Reactions
Hideaki Kikuchi、Hiroshi Iyetomi、Akira Hasegawa1998-12-14Journal of Physics Condensed Matter
We study the electronic properties of a series of tellurides with the antifluorite structure, and (M = Li, Na, K), to reveal the outstanding diffusivity of silver ions. We carry out first-principles density-functional calculations for these systems using the linearized augmented-plane-wave (LAPW) method, where the exc…
Advanced Chemical Physics StudiesAdvanced Condensed Matter PhysicsSolid-state spectroscopy and crystallography
T. Maruyama、M. Saitoh、Ikuo Sakai 等 6 位作者1998-12-14Applied Physics Letters
A 10-nm-thick PbZr0.25Ti0.75O3 thin film is epitaxially grown on a SrRuO3/BaTiO3/ZrO2/Si heterostructure substrate by reactive evaporation. Structural and electrical properties of the film are investigated. It is concluded that the film is ferroelectric and retains a native uniform upward polarization. Artificial down…
Ferroelectric and Piezoelectric MaterialsAcoustic Wave Resonator TechnologiesMicrowave Dielectric Ceramics Synthesis
Javier Guevara、A. M. Llois、Mariana Weissmann1998-12-14Physical Review Letters
We report calculations of the electronic and magnetic properties of small Co clusters, coated with Ag or Cu, performed with a parametrized tight-binding method. For a given number of Co atoms in a cluster, we obtain a large range of magnetization values, depending on the size and shape of the coating. The noble metal…
Magnetic properties of thin filmsRare-earth and actinide compoundsHeusler alloys: electronic and magnetic properties
M.P. Oude Wolbers、Frank C. J. M. van Veggel、Frank Peters 等 7 位作者1998-12-14Chemistry - A European Journal
Efficient intramolecular energy transfer (ET) from an excited chromophore to Nd3+ and Er3+ ions with subsequent emission in the near-infrared (hν2) is possible in novel compounds (1). These are made by covalent attachment of fluorescein to a calix[4]arene possessing a cavity at the lower rim in which the trivalent lan…
Supramolecular Chemistry and ComplexesLuminescence and Fluorescent MaterialsLanthanide and Transition Metal Complexes
Chang Y. Ryu、Martin E. Vigild、Timothy P. Lodge1998-12-14Physical Review Letters
A triblock copolymer that undergoes a thermotropic order-order transition between hexagonally packed cylinders ( $C$) and body-centered-cubic spheres ( $S$) is examined. Transmission electron microscopy provides real space images, and small-angle x-ray scattering the reciprocal space signature, of fluctuations with cu…
Material Dynamics and PropertiesTheoretical and Computational PhysicsBlock Copolymer Self-Assembly
Rahul Gupta、Matt Stevenson、Arthur Dogariu 等 8 位作者1998-12-14Applied Physics Letters
Low thresholds (∼500 W/cm2) for amplified spontaneous emission (ASE) are reported in films of soluble poly(paraphenylene vinylene)-based conjugated polymer blends. Efficient Förster energy transfer from the absorbing host polymer to the emitting guest polymer is observed. Emission in the blends originates predominantl…
Organic Electronics and PhotovoltaicsOrganic Light-Emitting Diodes ResearchLuminescence and Fluorescent Materials
Joachim Holzfuss、Matthias Rüggeberg、Andreas Billo1998-12-14Physical Review Letters
A single bubble in water is excited by a standing ultrasound wave. At high intensity the bubble starts to emit light. Together with the emitted light pulse, a shock wave is generated in the liquid at collapse time. The time-dependent velocity of the outward-traveling shock is measured with an imaging technique. The pr…
Ultrasound and Hyperthermia ApplicationsUltrasound and Cavitation PhenomenaElectrohydrodynamics and Fluid Dynamics
Sufi Zafar、Robert E. Jones、Bo Jiang 等 6 位作者1998-12-14Applied Physics Letters
In the literature, the Schottky emission equation is widely used to describe the conduction mechanism in perovskite-type titanate thin films. Though the equation provides a good fit to the leakage current data, the extracted values of the Richardson and dielectric constants are inconsistent with their experimental val…
Ferroelectric and Piezoelectric MaterialsMicrowave Dielectric Ceramics SynthesisElectronic and Structural Properties of Oxides
O. Lourie、H. Daniel Wagner1998-12-14Applied Physics Letters
Well-aligned bundles of single-wall carbon nanotubes under tensile stresses were observed to fracture in real-time by transmission electron microscopy. The expansion of elliptical holes in the polymer matrix results in a tensile force in bridging nanotubes. The polymer matrix at both ends of the bundles deforms extens…
Carbon Nanotubes in CompositesForce Microscopy Techniques and ApplicationsSmart Materials for Construction
Peihong Zhang、Paul E. Lammert、Vincent H. Crespi1998-12-14Physical Review Letters
Although the elastic properties of a carbon nanotube are nearly independent of wrapping indices, we show that the onset of plastic deformation depends very strongly on the wrapping index. An $(n,0)$ nanotube has an elastic limit nearly twice that of an $(n,n)$ tube with the same radius. Such great variation has import…
Carbon Nanotubes in CompositesGraphene research and applicationsBoron and Carbon Nanomaterials Research