Albert Escuer、M.A.S. Goher、Franz A. Mautner 等 4 位作者2000-04-27Inorganic Chemistry
Three new polynuclear copper(II) complexes, derived from the end-on azido bridging ligand and pyridine derivatives, have been synthesized, and their crystal structures have been determined by X-ray diffraction methods; they are the dinuclear compounds [Cu2(mu 1,1-N3)2(4-Etpy)4(mu-NO3)2] (1), and [Cu2(mu 1,1-N3)2(3-amp…
Lanthanide and Transition Metal ComplexesMagnetism in coordination complexesMetal complexes synthesis and properties
Isabelle Durussel、Y. Blouquit、Sandrine Middendorp 等 5 位作者2000-04-27FEBS Letters
Centrin and calmodulin (CaM) are closely related four-EF-hand Ca(2+)-binding proteins. While CaM is monomeric, centrin 2 is dimeric and binds only two Ca(2+) per dimer, likely to site IV in each monomer. Ca(2+) binding to centrin 2 displays pronounced negative cooperativity and a [Ca(2+)](0.5) of 30 microM. As in CaM,…
Protein Structure and DynamicsNuclear Structure and FunctionEnzyme Structure and Function
Patrick R. L. Malenfant、Jean M. J. Fréchet2000-04-27Macromolecules
The first conducting polythiophene, having only dendritic solubilizers, has been prepared using a Stille coupling approach. The use of second and third generation aliphatic ether convergent dendrons as a solubilizing platform facilitated the preparation of dendrimer-oligothiophene hybrid macromonomers having minimal s…
Conducting polymers and applicationsDendrimers and Hyperbranched PolymersOrganic Electronics and Photovoltaics
Jon‐Paul Strachan、Donal F. O’Shea、Thiagarajan Balasubramanian 等 4 位作者2000-04-27The Journal of Organic Chemistry
Chlorins provide the basis for plant photosynthesis, but synthetic model systems have generally employed porphyrins as surrogates due to the unavailability of suitable chlorin building blocks. We have adapted a route pioneered by Battersby to gain access to chlorins that bear two meso substituents, a geminal dimethyl…
Photodynamic Therapy Research StudiesPorphyrin and Phthalocyanine ChemistryMetal complexes synthesis and properties
Noriko Kanzaki、Kazuo Onuma、Gabin Treboux 等 5 位作者2000-04-27The Journal of Physical Chemistry B
The effect of magnesium and zinc on the growth kinetics of a hydroxyapatite (0001) face in pseudophysiological solutions was investigated. The growth rates of the (0001) face were measured under various concentrations of magnesium or zinc using Moire phase shift interferometry coupled with surface observation by atomi…
Calcium Carbonate Crystallization and InhibitionCrystallization and Solubility StudiesBone Tissue Engineering Materials
Anthony Roberts、Max Teubner2000-04-27arXiv
We investigate the effective conductivity ($σ_e$) of a class of amorphous media defined by the level-cut of a Gaussian random field. The three point solid-solid correlation function is derived and utilised in the evaluation of the Beran-Milton bounds. Simulations are used to calculate $σ_e$ for a variety of fields and…
Materials Sciencecond-mat.dis-nn
Anthony Roberts、Mark Knackstedt2000-04-27arXiv
We investigate the influence of fractal structure on material properties. We calculate the statistical correlation functions of fractal media defined by level-cut Gaussian random fields. This allows the modeling of both surface fractal and mass fractal materials. Variational bounds on the conductivity, diffusivity and…
Materials Sciencecond-mat.dis-nn
Xiaoqing Yu、Congjun Wu、Chui-Lin Wang 等 4 位作者2000-04-27arXiv
The extended SSH model and Bogoliubov-de Gennes(BdeG) formalism are applied to investigate the electronic properties and stable lattice configurations of C$_{36}$. We focus the problem on the molecule's unusual $D_{6h}$ symmetry. The electronic part of the Hamiltonian without Coulomb interaction is solved analytically…
Materials ScienceSoft Condensed Matter
K. H. Kim、M. Uehara、S-W. Cheong2000-04-27arXiv
High temperature (T) studies of La_{1-x}Ca_{x}MnO_{3} show that charge and phonon transport is significantly suppressed in a narrow doping region of x~1/2 and in a wide T range up to 900 K, which accompanies anomalous broadening of x-ray Bragg peaks. Contrarily, ferromagnetic (FM) correlation above Curie T is sharply…
Strongly Correlated ElectronsMaterials Science
Kazutaka Kondo、Mitsuru Sano、Akio Hiwara 等 9 位作者2000-04-27The Journal of Physical Chemistry B
Solutions of lithium hexafluorophosphate, LiPF 6, in propylene carbonate (4-methyl-1,3-dioxolan-2-one; denoted by PC hereafter) in the concentration range from 0.0 to 3.29 M (M = mol dm -3 ) have been studied regarding their conductivities, viscosities, and self-diffusion coefficients of PC by the NMR field gradient t…
NMR spectroscopy and applicationsPolymer Nanocomposites and PropertiesThermodynamic properties of mixtures
Michael Tiemann、Michael Fröba、Gert Rapp 等 4 位作者2000-04-26Chemistry of Materials
Mesostructured aluminophosphate/dodecyl phosphate composite materials were synthesized under aqueous and alcoholic conditions. The syntheses were monitored by temperature- and time-resolved in-situ small-angle X-ray scattering (SAXS). In the aqueous synthesis, a lamellar mesostructure is formed within the first few mi…
Mesoporous Materials and CatalysisLayered Double Hydroxides Synthesis and ApplicationsZeolite Catalysis and Synthesis
Zhidong Zhu、Martin Hartmann、Estelle M. Maes 等 5 位作者2000-04-26The Journal of Physical Chemistry B
A series of mesoporous siliceous MCM-41 (SiMCM-41) molecular sieves with silicon partially substituted by Al, Ti, and Zr were synthesized hydrothermally. A combination of electron spin resonance (ESR), diffuse reflectance UV−vis spectroscopy (UV−vis), Raman spectroscopy, and temperature-programmed reduction (TPR) was…
Metal-Organic Frameworks: Synthesis and ApplicationsMesoporous Materials and CatalysisCatalytic Processes in Materials Science
Igor F. Perepichka、A. F. Popov、Tatyana V. Orekhova 等 8 位作者2000-04-26The Journal of Organic Chemistry
2,4,5,7-Tetranitro-9-fluorenone (1b) reacts readily with n-butanethiol in dipolar aprotic solvents with selective substitution of nitro groups by butylsulfanyl groups in positions 2 and 7 (2, 3); the 2,5-isomer 4 was formed only as a minor product (<1%). Condensation of fluorenones 2-4 with malononitrile yielded 9-dic…
Organic Chemistry Cycloaddition ReactionsOrganic and Molecular Conductors ResearchPhotochemistry and Electron Transfer Studies
Zugang Mao、Susan B. Sinnott2000-04-26The Journal of Physical Chemistry B
Molecular dynamics simulations are used to study the flow of methane, ethane, and ethylene through carbon nanotubes at room temperature. The interatomic forces in the simulations are calculated using a classical, reactive, empirical bond-order hydrocarbon potential coupled to Lennard−Jones potentials. The simulations…
Nanopore and Nanochannel Transport StudiesZeolite Catalysis and SynthesisCarbon Nanotubes in Composites
Claudio Castellano、Joachim Krug2000-04-26arXiv
The roughness of vapor-deposited thin films can display a nonmonotonic dependence on film thickness, if the smoothening of the small-scale features of the substrate dominates over growth-induced roughening in the early stage of evolution. We present a detailed analysis of this phenomenon in the framework of the contin…
Materials Sciencecond-mat.stat-mech
G. Aichmayr、M. D. Martin、H. van der Meulen 等 9 位作者2000-04-26arXiv
We investigated the carrier and light trapping in GaInAs/AlGaAs single quantum well laser structures by means of time resolved photoluminescence and Raman spectroscopy. The influence of the shape and depth of the confinement potential and of the cavity geometry was studied by using different AlGaAs/GaAs short-period s…
Materials Science
D. E. Steinhauer、C. P. Vlahacos、F. C. Wellstood 等 8 位作者2000-04-26arXiv
We describe the use of a near-field scanning microwave microscope to image the permittivity and tunability of bulk and thin film dielectric samples on a length scale of about 1 micron. The microscope is sensitive to the linear permittivity, as well as to nonlinear dielectric terms, which can be measured as a function…
Materials Science
Mohammad L. Hassan、Roger M. Rowell、Naim A. Fadl 等 5 位作者2000-04-25Journal of Applied Polymer Science
This research was to investigate the conversion of bagasse into a thermomoldable material through esterification of the fiber matrix. For this purpose, bagasse fiber was esterified in the absence of solvent using succinic anhydride. The dimensional stability and mechanical properties of composites prepared from the es…
Natural Fiber Reinforced Composites
Susana Piçarra、Pedro T. Gomes、J. M. G. Martinho2000-04-25Macromolecules
ADVERTISEMENT RETURN TO ISSUEPREVNoteFluorescence Study of the Coil−Globule Transition of a Poly(ε-caprolactone) Chain Labeled with Pyrenes at Both EndsSusana Piçarra, Pedro T. Gomes, and J. M. G. MartinhoView Author Information Centro de Química-Física Molecular, Instituto Superior Técnico, 1049-001 Lisboa, Portugal,…
Advanced Cellulose Research Studiesbiodegradable polymer synthesis and propertiesAdvanced Polymer Synthesis and Characterization
Yawu Chi、Steven S.C. Chuang2000-04-25The Journal of Physical Chemistry B
NO and O 2 coadsorption on γ-Al 2 O 3 -supported Tb 4 O 7, La 2 O 3, BaO, and MgO has been investigated by in situ infrared spectroscopy coupled with temperature-programmed decomposition and desorption. BaO/γ-Al 2 O 3 and MgO/γ-Al 2 O 3 possess a higher NO x storage capability than Tb 4 O 7 /γ-Al 2 O 3 and La 2 O 3 /γ…
Catalytic Processes in Materials ScienceIndustrial Gas Emission ControlLuminescence Properties of Advanced Materials