Yuqing Wu、Bing Zhao、Weiqing Xu 等 6 位作者1999-05-19Langmuir
Near-infrared (NIR) Fourier transform (FT) surface-enhanced Raman scattering (SERS) spectra were measured for Langmuir−Blodgett (LB) and dipping films of azobenzene-containing long-chain fatty acids ( n A m H, n = 8, 12, m = 3, 5) on silver substrates prepared by silver mirror and nitric acid etched silver foil method…
Chalcogenide Semiconductor Thin FilmsGold and Silver Nanoparticles Synthesis and Applications
Antonio Montalbán、H. Meunier、Richard Ostler 等 6 位作者1999-05-19The Journal of Physical Chemistry A
We report on the efficient photooxidation of hexapropyl bis(dimethylamino) zinc porphyrazine. The process is shown to be autocatalytic. The triplet state of the seco -ZnPz sensitizes the formation of excited-state singlet oxygen with a quantum yield of 0.54 and subsequent cleavage of the pyrrole double bond occurs to…
Porphyrin and Phthalocyanine ChemistryProtein Interaction Studies and Fluorescence AnalysisPhotochemistry and Electron Transfer Studies
Phillip J. Stone、Roger A. Bennett、Michael Bowker1999-05-19New Journal of Physics
The re-oxidation of slightly reduced TiO 2 (110) surfaces by exposure to an oxygen pressure of ~2 × 10 -7 mbar in the temperature range 473-1000 K occurs by re-growth of TiO 2 overlayers by diffusion of Ti n + interstitials from the bulk. Starting with a (1 × 2) reconstructed surface, scanning tunnelling microscope im…
Semiconductor materials and devicesCatalytic Processes in Materials ScienceElectronic and Structural Properties of Oxides
Ione Cendoya、Ángel Alegría、J. M. Alberdi 等 7 位作者1999-05-19Macromolecules
In this work we have investigated how the dynamics of poly(vinyl methyl ether), PVME, changes by blending with deuterated polystyrene. The experimental techniques used were dielectric spectroscopy, quasielastic neutron scattering, and 13 C nuclear magnetic resonance. By means of these techniques, the dynamics of the p…
NMR spectroscopy and applicationsMaterial Dynamics and PropertiesThermodynamic properties of mixtures
Ann J. Stemmler、Jeff W. Kampf、Martin L. Kirk 等 5 位作者1999-05-19Inorganic Chemistry
The preparation and characterization of a series of encapsulated-lanthanide 15-metallacrown-5 complexes are reported. Planar ligands such as picoline hydroxamic acid (picha) or nonplanar alpha-amino hydroxamic acids (e.g., glycine hydroxamic acid (glyha)) led to one-step syntheses of metallacrowns in yields as high as…
Magnetism in coordination complexesMetal-Organic Frameworks: Synthesis and ApplicationsLanthanide and Transition Metal Complexes
H. M. Cataldo1999-05-19arXiv
The stability of a quasicrystalline structure, recently obtained in a molecular-dynamics simulation of rapid cooling of a binary melt, is analyzed for binary hard-sphere mixtures within a density-functional approach. It is found that this quasicrystal is metastable relative to crystalline and fluid phases for diameter…
Materials Sciencecond-mat.stat-mech
Arkady A. Karyakin、Maika Vuki、Lylia V. Lukachova 等 7 位作者1999-05-19Analytical Chemistry
An advanced potentiometric pH transducer based on processible polyaniline (PCPAn) is reported on. Both glassy carbon and screen-printed carbon electrodes modified with PCPAn by dip-coating exhibited a fully reversible potentiometric response of approximately 90 mV/pH unit over the range from pH 3 to 9. Such a signific…
Conducting polymers and applicationsAnalytical Chemistry and SensorsElectrochemical sensors and biosensors
Ramin Golestanian、Mehran Kardar、Tanniemola B. Liverpool1999-05-19arXiv
The effective elasticity of highly charged stiff polyelectrolytes is studied in the presence of counterions, with and without added salt. The rigid polymer conformations may become unstable due to an effective attraction induced by counterion density fluctuations. Instabilities at the longest, or intermediate length s…
Materials ScienceSoft Condensed Mattercond-mat.stat-mech
F. M. Munteanu、Yongmin Kim、C. H. Perry 等 5 位作者1999-05-19arXiv
The magnetophotoluminescence (MPL) behavior of a GaAs/Al(0.3)Ga(0.7)As single heterojunction has been investigated to 60T. We observed negatively charged singlet and triplet exciton states that are formed at high magnetic fields beyond the nu=1 quantum Hall state. The variation of the charged exciton binding energies…
Mesoscale and Nanoscale PhysicsMaterials Science
Yongmin Kim、F. M. Munteanu、C. H. Perry 等 7 位作者1999-05-19arXiv
Coulomb driven, magneto-optically induced electron and hole bound states from a series of heavily doped GaAs/Al(0.3)Ga(0.7)As single heterojunctions (SHJ) are revealed in high magnetic fields. At low magnetic fields (nu > 2), the photoluminescence spectra display Shubnikov de-Haas type oscillations associated with the…
Materials ScienceMesoscale and Nanoscale Physics
Jeffrey R. Reimers、Lachlan E. Hall、Maxwell J. Crossley 等 4 位作者1999-05-18The Journal of Physical Chemistry A
Over 100 oligoporphyrin (porphyrin molecules fused to each other through rigid acene-type bridges) molecules have now been synthesized, their long rigid π-bonded structures making them very suitable as molecular wires while their synthetic flexibility offers the possibility of tailoring their structural and electronic…
Molecular Junctions and NanostructuresPorphyrin and Phthalocyanine ChemistrySurface Chemistry and Catalysis
Qinyu Wang、J. Karl Johnson1999-05-18The Journal of Physical Chemistry B
The amount of hydrogen adsorbed in arrays of single-walled carbon nanotubes has been studied as a function of the geometry of the array. The tube lattice spacing has been varied to optimize hydrogen uptake. Two different lattice geometries have been examined, namely, the triangular lattice and the square lattice. None…
Hydrogen Storage and MaterialsFuel Cells and Related MaterialsCarbon Nanotubes in Composites
J. B. Sokoloff、M. S. Tomassone、A. Widom1999-05-18arXiv
A sudden drop in mechanical friction, between an adsorbed nitrogen monolayer and a lead substrate, occurs when the lead passes through the superconducting transition temperature. We attribute this effect to a sudden drop at the superconducting transition temperature of the substrate Ohmic heating. The Ohmic heating is…
Materials Science
Ramin Golestanian1999-05-18arXiv
Using a generalization of the Poisson-Boltzmann equation, dynamics of counterion condensation is studied. For a single charged plate in the presence of counterions, it is shown that the approach to equilibrium is diffusive. In the far from equilibrium case of a moving charged plate, a dynamical counterion condensation…
cond-mat.stat-mechMaterials ScienceSoft Condensed Matter
Walter Kob、Jean-Louis Barrat1999-05-18arXiv
By means of molecular dynamics computer simulations we investigate the out of equilibrium relaxation dynamics of a simple glass former, a binary Lennard-Jones system, after a quench to low temperatures. We study both one time quantities and two-times correlation functions. Two-times correlation functions show a strong…
Materials Sciencecond-mat.dis-nn
H. Yasuhara、S. Yoshinaga、M. Higuchi1999-05-18arXiv
The experimentally predicted narrowing in the bandwidth of sodium is interpreted in terms of the non-local self-energy effect on quasi-particle energies of the electron liquid. The calculated self-energy correction is a monotonically increasing function of the wavenumber variable. The usual analysis of photo-emission…
Strongly Correlated ElectronsMaterials Science
Keith M. Beardmore、Niels Gronbech-Jensen1999-05-18arXiv
Using molecular dynamics (MD) simulation, we investigate the mechanical response of silicon to high dose ion-irradiation. We employ a realistic and efficient model to directly simulate ion beam induced amorphization. Structural properties of the amorphized sample are compared with experimental data and results of othe…
physics.comp-phMaterials ScienceChemical Physics
G. Scott1999-05-18Royal Society of Chemistry eBooks
As environmental performance becomes increasingly important, the development of man-made polymers and their associated benefits has been overshadowed by problems relating to their ultimate disposal. In the light of wider acceptance of polymers for use in high technology applications, Polymers and the Environment aims…
biodegradable polymer synthesis and properties
Tuo Li、Jooho Moon、A. Morrone 等 6 位作者1999-05-18Langmuir
Spherical nanosize Ag/SiO 2 composite particles have been synthesized within reverse micelles via metal alkoxide hydrolysis and condensation. The size of the particles and the thickness of the coating can be controlled by manipulating the relative rates of the hydrolysis and condensation reactions of tetraethoxysilane…
Surfactants and Colloidal SystemsGold and Silver Nanoparticles Synthesis and ApplicationsQuantum Dots Synthesis And Properties
Rufina G. Alamo、Man‐Ho Kim、María J. Galante 等 5 位作者1999-05-18Macromolecules
The molecular, thermodynamic, and kinetic factors that govern the formation and concentration of the α and γ polymorphs in metallocene-catalyzed isotactic poly(propylenes) have been studied with a set of polymers that have a wide range in molecular weight and defect contents. With these polymers it was possible to inv…
biodegradable polymer synthesis and propertiesPolymer Nanocomposites and PropertiesPolymer crystallization and properties