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Relaxation Mode Analysis of a Single Polymer Chain in a Melt

Katsumi Hagita、Hiroshi Takano2002-03-15Journal of the Physical Society of Japan

Relaxation modes and rates of a polymer chain in a melt are studied by Monte Carlo simulations of the bond fluctuation model, where only the excluded volume interaction is taken into account. Polymer chains, each of which consists of N segments, are located on an L × L × L simple cubic lattice under periodic boundary…

Polymer crystallization and propertiesMaterial Dynamics and PropertiesTheoretical and Computational Physics

Mössbauer and magnetization studies of Fe3BO5

Alexios P. Douvalis、A. Moukarika、T. Bakas 等 5 位作者2002-03-15Journal of Physics Condensed Matter

We report on magnetometry, resistivity and Mössbauer spectroscopy measurements on single-phase Fe 3 BO 5 in a wide temperature range from 4.2 to 620 K. Magnetically split Mössbauer spectra were observed below T N = 114 K, although a proportion of the Fe 2+ ions in the basal plane (crystallographic site Fe1) remain par…

High-pressure geophysics and materialsMagnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter Physics

Tetracyanide-Bridged Divanadium Complexes: Redox Switching between Strong Antiferromagnetic and Strong Ferromagnetic Coupling

Matthew P. Shores、Jeffrey R. Long2002-03-15Journal of the American Chemical Society

Reaction of [(Me3tacn)V(CF3SO3)3] (Me3tacn = N,N',N''-trimethyl-1,4,7-triazacyclononane) with LiCN in DMF results in oligomerization of cyanide to form [(Me3tacn)2V2(CN)4(mu-C4N4)]. The structure of this binuclear complex features a planar tetracyanide unit bridging two VIV centers via imido type linkages. The conjuga…

Magnetism in coordination complexesLanthanide and Transition Metal ComplexesOrganic and Molecular Conductors Research

Synthesis and Characterization of Phthalocyanines with Direct Si−Si Linkages

Nagao Kobayashi、Fumio Furuya、Gyeong-Chang Yug 等 6 位作者2002-03-15Chemistry - A European Journal

Several cofacial phthalocyanines (Pcs) with an Si-Si linkage were obtained by one-step condensation of 1H-isoindole-1,3(2H)-diimine with hexachlorodisilane as template in quinoline. They were characterized by gel-permeation chromatography, IR, NMR spectroscopy, and mass spectrometry, and cyclic voltammetry. The result…

Photosynthetic Processes and MechanismsPorphyrin and Phthalocyanine ChemistrySurface Chemistry and Catalysis

Sensitized Luminescence of Trivalent Europium by Three-Dimensionally Arranged Anatase Nanocrystals in Mesostructured Titania Thin Films

Karen L. Frindell、Michael H. Bartl、Alois Popitsch 等 4 位作者2002-03-15Angewandte Chemie

Die wohldefinierte Anordnung von Poren und Wänden aus Nanokristalliten in einem mesoporösen Titanoxid-Dünnfilm kann mit hohen Konzentrationen (bis zu 8 Mol-%) von Eu3+ unter Bildung eines rot photolumineszierenden Materials dotiert werden (siehe Bild). Die Photolumineszenz stammt von einem Energietransfer von den Band…

Luminescence Properties of Advanced MaterialsMesoporous Materials and CatalysisPolyoxometalates: Synthesis and Applications

Optical diffraction from a liquid crystal phase grating

C. V. Brown、Emmanouil E. Kriezis、Steve J. Elston2002-03-15Journal of Applied Physics

The finite-difference time-domain method has been used in the numerical analysis of the optical diffraction properties of a liquid crystal phase grating. The grating is formed using a nematic material that is switched using striped electrodes with a unity mark-space ratio. Three different surface pretilts have been in…

Photonic and Optical DevicesPhotonic Crystals and ApplicationsOptical Coatings and Gratings

Infrared spectra of Si-O overtones, hydrous species, and U ions in metamict zircon: radiation damage and recrystallization

Ming Zhang、Ekhard K. H. Salje、Rodney C. Ewing2002-03-15Journal of Physics Condensed Matter

Radiation damage and recrystallization in natural zircons have been studied by analysing Si-O stretching overtones/combinations, hydrous species, and U-ion spectra in the frequency region between 1200 and 11 000 cm -1 . The effects of radiation are characterized by a dramatic variation of intensity, a decrease in freq…

Geological and Geochemical AnalysisHigh-pressure geophysics and materialsNuclear materials and radiation effects

Band-edge emission of undoped and doped ZnO single crystals at room temperature

Naoki Ohashi、Takashi Sekiguchi、K. Aoyama 等 8 位作者2002-03-15Journal of Applied Physics

Band-edge emission of ZnO at around room temperature was investigated by measuring the temperature dependence of cathodoluminescence spectra at 20–300 K. Undoped crystals grown by a vapor transport method and Al-doped crystals by flux method were employed to elucidate the effect of doping on luminescence properties. F…

ZnO doping and propertiesPerovskite Materials and ApplicationsGa2O3 and related materials

Pressure and temperature dependence of viscosity and diffusion coefficients of a glassy binary mixture

Arnab Mukherjee、Sarika Maitra Bhattacharyya、Biman Bagchi2002-03-15The Journal of Chemical Physics

Extensive isothermal-isobaric (NPT) molecular dynamics simulations at many different temperatures and pressures have been carried out in the well-known Kob–Andersen binary mixture model to monitor the effect of pressure (P) and temperature (T) on the dynamic properties such as the viscosity (η) and the self-diffusion…

Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesThermodynamic properties of mixtures

What density-functional theory can tell us about the spin-density wave in Cr

Stefaan Cottenier、Bart de Vries、Johan Meersschaut 等 4 位作者2002-03-15Journal of Physics Condensed Matter

The energy-versus-volume curve of the spin-density wave (SDW) in body-centred-cubic Cr is calculated with the density functional theory/full-potential linearized augmented plane wave (DFT/FLAPW) method using the generalized gradient approximation (GGA). The predicted ground state is not the SDW, in contrast to an earl…

Advanced Chemical Physics StudiesIron-based superconductors researchHeusler alloys: electronic and magnetic properties

Magnetic Resonance Imaging Detects a Specific Peptide−Protein Binding Event

Luis M. De Leon Rodriguez、Alfonso Bouzas Ortíz、Allison L. Weiner 等 7 位作者2002-03-15Journal of the American Chemical Society

DOTA was conjugated to the N-terminus of a 12-mer peptide by using standard peptide synthesis chemistry. The peptide, first isolated by phage display, maintained a high affinity for its protein-binding target, Gal-80, even with GdDOTA attached. The high affinity constant (KA = 5 x 105 M-1) combined with the high relax…

Advanced MRI Techniques and ApplicationsLanthanide and Transition Metal ComplexesRadiopharmaceutical Chemistry and Applications

Controlled Room Temperature Synthesis of CoFe2O4 Nanoparticles through a Block Copolymer Nanoreactor Route

Sufi R. Ahmed、Peter Kofinas2002-03-15Macromolecules

The synthesis and characterization of well-dispersed, CoFe 2 O 4 nanoparticles within a polymer matrix at room temperature are reported. Comparable inorganic synthetic methods require heating at high temperatures in order to produce this particular mixed-metal oxide composition. Our modification of prior reported temp…

Organometallic Complex Synthesis and CatalysisBlock Copolymer Self-AssemblySynthetic Organic Chemistry Methods

Effects of intentionally introduced hydrogen on the electrical properties of ZnO layers grown by metalorganic chemical vapor deposition

B. Theys、Vincent Sallet、François Jomard 等 6 位作者2002-03-15Journal of Applied Physics

Unintentionally doped ZnO layers grown epitaxially on a sapphire substrate have been exposed either to a hydrogen or deuterium plasma. Secondary ion mass spectroscopy measurements performed subsequently showed a rapid diffusion of hydrogen in these layers. Furthermore, the presence of hydrogen in the ZnO samples is fo…

ZnO doping and propertiesGas Sensing Nanomaterials and SensorsCopper-based nanomaterials and applications

Carbon nanotubes synthesized by Ni-assisted atmospheric pressure thermal chemical vapor deposition

G.S. Choi、Y. S. Cho、Sehwa Hong 等 6 位作者2002-03-15Journal of Applied Physics

A detailed systematic study on the growth morphology of carbon nanotubes (CNTs) on Si in atmospheric pressure thermal chemical vapor deposition was undertaken. The role of NH3 for vertical alignment of CNTs was investigated. The direct cause for the alignment was a dense distribution of the catalytic metal particles,…

Carbon Nanotubes in CompositesGraphene research and applicationsDiamond and Carbon-based Materials Research

Raman spectra of fluorine-doped silica glasses with various fictive temperatures

Noriaki Shimodaira、Kazuya Saito、Akira J. Ikushima2002-03-15Journal of Applied Physics

We have demonstrated the change of the Raman spectra in F-doped silica glasses with various fictive temperatures, and have also presented a useful peak-deconvolution technique for evaluating the relative concentration of D1 and D2 bands that could be attributed to four- and three-membered ring structures. The intensit…

Luminescence Properties of Advanced MaterialsGlass properties and applicationsMineralogy and Gemology Studies

Compartmentalization of a Gadolinium Complex in the Apoferritin Cavity: A Route To Obtain High Relaxivity Contrast Agents for Magnetic Resonance Imaging

Silvio Aime、Luca Frullano、Simonetta Geninatti Crich2002-03-15Angewandte Chemie

Eine bemerkenswerte Relaxationsverstärkung von Wasserprotonen wurde in Lösungen nachgewiesen, die mit GdHPDO3A beladenes Apoferritin (siehe Abbildung) enthalten. Der Einschluss des Komplexes im Apoferritin (innerer Durchmesser: 7.5 nm, äußerer Durchmesser: 12.5 nm) erhöht die Anzahl dipolarer Wechselwirkungen zwischen…

Advanced MRI Techniques and ApplicationsLanthanide and Transition Metal ComplexesAdvanced NMR Techniques and Applications

Tight-binding calculations of the band structure and total energies of the various phases of magnesium

H. J. Gotsis、D. A. Papaconstantopoulos、Michael J. Mehl2002-03-15Physical review. B, Condensed matter

Tight-binding calculations for Mg in a variety of crystal structures are reported using the nonorthogonal tight-binding model with parameters selected to fit accurately first-principles results. These parameters correctly predict hcp to be the stable crystal structure. We have calculated electronic properties (band st…

Magnesium Alloys: Properties and ApplicationsBoron and Carbon Nanomaterials ResearchSuperconductivity in MgB2 and Alloys

Evidence for a polar biaxial SmA phase (CPA) in the sequence SmA–CPA–B2

Martin Schröder、Siegmar Diele、Natella Pancenko 等 5 位作者2002-03-15Journal of Materials Chemistry

The isobaric phase diagram of a binary system is presented where one mixing component is an achiral five-ring bent-core mesogen and the other is the electron acceptor compound 2,4,7-trinitrofluorenone (TNF). In the mixed phase region a SmA phase as well as a polar (antiferroelectric) biaxial SmA phase (CPA) are induce…

Liquid Crystal Research AdvancementsNonlinear Optical Materials ResearchPhotochemistry and Electron Transfer Studies

Diffusion-Limited, Aggregation-Based, Mesoscopic Assembly of Roughened Core-Shell Bimetallic Nanoparticles into Fractal Networks at the Air-Water Interface

Yongdong Jin、Shaojun Dong2002-03-15Angewandte Chemie International Edition

The concentration of the plating solution enables control over the fine-tuning of fractal patterns and also drastically affects the crystal growth of Ag/Au core–shell roughened nanoparticles through diffusion-limited aggregation. At low concentrations there are more open spaces in the well-ramified fractal pattern tha…

Gold and Silver Nanoparticles Synthesis and ApplicationsTheoretical and Computational PhysicsPickering emulsions and particle stabilization

Facile, Efficient Conjugation of a Trifunctional Lanthanide Chelate to a Peripheral Benzodiazepine Receptor Ligand

H. Charles Manning、Timothy S. Goebel、J.N. Marx 等 4 位作者2002-03-15Organic Letters

[reaction: see text] Receptor-mediated imaging and therapy of diseased tissue is rapidly gaining favor in the medical community. The synthesis and facile aqueous/organic coupling of a peripheral-type benzodiazepine receptor ligand to a cyclen-based fluorophore is described herein. The contrast agent QM-CTMC-PK11195, w…

Glioma Diagnosis and TreatmentMedical Imaging Techniques and ApplicationsLanthanide and Transition Metal Complexes