Dinesh Mohan、A.V.R. Reddy2007-09-21Journal of Polymer Science Part B Polymer Physics
Abstract Novel diamic acids (DAAs) and poly(amide amic acid)s (PAAs) were prepared and their thermal cycloimidization to the corresponding imide form was investigated by thermogravimetric analysis under isothermal conditions at four different temperatures, that is, at 175, 200, 225, and 260 °C for 75 min. A general eq…
biodegradable polymer synthesis and propertiesEpoxy Resin Curing ProcessesSynthesis and properties of polymers
Changho Lee、Gyung-Joo Jang、Hoseop Yun2007-09-21Acta Crystallographica Section E Structure Reports Online
Zirconium germanium tetratelluride, ZrGeTe4, is isostructural with Hf0.85GeTe4 [Mar & Ibers (1993). J. Am Chem. Soc. 115, 3227–3238], but the Zr site in ZrGeTe4 is fully occupied and the compound is stoichiometric. ZrGeTe4 adopts a layered structural type. Each layer is composed of two unique one-dimensional chains o…
Crystal Structures and PropertiesPhase-change materials and chalcogenidesInorganic Chemistry and Materials
K. Sumithra、E. Straube2007-09-21The Journal of Chemical Physics
We present the results of scaling analysis of diblock copolymers adsorbed on stripe-patterned surfaces of various widths. Our previous studies [K. Sumithra and E. Straube, J. Chem. Phys. 125, 154701 (2006)] show that the adsorption of diblock copolymer on patterned surfaces yields two peaks in the specific heat capaci…
Material Dynamics and PropertiesTheoretical and Computational PhysicsBlock Copolymer Self-Assembly
Іgor V. Zatovsky、Nataliia Strutynska、В.Н. Баумер 等 5 位作者2007-09-21Acta Crystallographica Section E Structure Reports Online
Nonacalcium chromium(III) heptakis(orthophosphate) has been obtained from a melt in the system Cs2O–CaO–Cr2O3 using a polyphosphate flux. The three-dimensional framework is related to the whitlockite structure [β-Ca3(PO4)3] and is built up from CaO8 and CaO9 polyhedra sharing vertices, edges and faces, further connec…
Crystal Structures and PropertiesChemical Synthesis and CharacterizationX-ray Diffraction in Crystallography
I. M. Ghauri、Naveed Afzal2007-09-21Journal of Physics D Applied Physics
Neutron irradiation effects on the stress relaxation rate of Al–Cu–Mg alloy have been investigated. The specimens were exposed to 100 mC, Ra–Be neutron source of continuous energy 2–12 MeV for a period ranging from 4 to 16 days. Stress relaxation tests during the tensile tests at room temperature were performed at mul…
Microstructure and mechanical propertiesFusion materials and technologiesAluminum Alloy Microstructure Properties
P F Zhang、Xiucai Liu、Hengyong Wei 等 10 位作者2007-09-21Journal of Physics D Applied Physics
ZnO thin films were grown by metal-organic chemical vapour deposition using methanol as oxidant. Rapid thermal annealing (RTA) was performed in an ambient of one atmosphere oxygen at 900 °C for 60 s. The RTA properties of the films have been characterized using scanning electron microscopy, x-ray diffraction, x-ray ph…
ZnO doping and propertiesGas Sensing Nanomaterials and SensorsElectronic and Structural Properties of Oxides
Kankana De、S. Majumdar、S. K. Giri2007-09-21Journal of Physics D Applied Physics
We report on the effect of Fe substitution in the self doped manganite, La 0.87 Mn 1− x Fe x O 3 in the composition range 0 ⩽ x ⩽ 0.15. The electrical resistivity (ρ) and dc magnetization were measured as a function of temperature, field and time. The metal to semiconducting transition is clearly observed for x ⩽ 0.02…
Magnetic and transport properties of perovskites and related materialsRare-earth and actinide compoundsAdvanced Condensed Matter Physics
Dunmin Lin、K. W. Kwok、H.L.W. Chan2007-09-21Journal of Physics D Applied Physics
Lead-free ceramics (1- x )K 0.5 Na 0.5 (Nb 0.925 Ta 0.075 )O 3 - x LiSbO 3 have been prepared by an ordinary sintering technique. Our results reveal that Li + and Sb 5+ diffuse into the K 0.5 Na 0.5 (Nb 0.925 Ta 0.075 )O 3 lattices to form a solid solution with a perovskite structure. The introduction of LiSbO 3 into…
Ferroelectric and Piezoelectric MaterialsAcoustic Wave Resonator TechnologiesMicrowave Dielectric Ceramics Synthesis
Pathikumar Sellappan、Vikram Jayaram、Atul H. Chokshi 等 4 位作者2007-09-21Journal of the American Ceramic Society
Amorphous powders of Al 2 O 3 —37.5 mol% Y 2 O 3 (yttrium aluminum garnet (YAG)) were prepared by coprecipitation, decomposed at 800°C, and hot‐pressed uniaxally at low temperature (600°C) and a moderate pressure (750 MPa). Optimum conditions yielded microstructures with only 2% porosity and partial crystallization of…
Luminescence Properties of Advanced MaterialsGlass properties and applicationsSolid State Laser Technologies
A. Luque、Javier Aldazabal、J.M. Martínez–Esnaola 等 4 位作者2007-09-21Fatigue & Fracture of Engineering Materials & Structures
ABSTRACT Mode I crack growth along some grain boundaries of copper embrittled by solute segregation shows strong anisotropy. For instance, growth along the direction on the symmetrical tilt boundary has been reported to occur by intergranular brittle fracture, whereas growth along the opposite sense occurs in a ductil…
Microstructure and mechanical propertiesMetal and Thin Film MechanicsMetal Forming Simulation Techniques
Hideto Yoshida、Tetsuya Uchiyama、Seiji Takeda2007-09-21Japanese Journal of Applied Physics
The swing and rotation of growing carbon nanotubes (CNTs) have been observed in situ for the first time by environmental transmission electron microscopy. We have also observed that a CNT grows discontinuously when the CNT comes in contact with a substrate. This means that the van der Waals force between the CNT and t…
Carbon Nanotubes in CompositesFullerene Chemistry and ApplicationsNanotechnology research and applications
Yu-Yun Peng、Tsung-Eong Hsieh、Chia‐Hung Hsu2007-09-21Journal of Physics D Applied Physics
The dielectric confinement effect on the blue shift Δ E g ( a ) of the ZnO quantum dots (QDs) embedded in the SiO 2 matrix is evaluated by applying a multi-shell two-electron system model. The experimental measurement and the calculations of various dielectric structures indicate that the composite matrix structure pr…
ZnO doping and propertiesQuantum Dots Synthesis And PropertiesCarbon and Quantum Dots Applications
Young Hwan Kim、Don Keun Lee、Hyun Gil 等 5 位作者2007-09-21Chemistry of Materials
Three-dimensional superlattice is easily obtained by a one-step hydrothermal process in the presence of double capping layers, a short length capping layer (aromatic carboxylic acid), and a long length capping layer (sodium oleate). The formation of layers on TEM images corresponds to a view of the 111 plane in FCC.
Gold and Silver Nanoparticles Synthesis and ApplicationsQuantum Dots Synthesis And PropertiesCopper-based nanomaterials and applications
Takahito Muraki、Ken‐ichi Fujita、M. Kujime2007-09-21The Journal of Organic Chemistry
A series of dendritic ligands with a 2,2'-bipyridine core was synthesized through the coupling of 4,4'-dihydroxy-2,2'-bipyridine with poly(aryl ether) dendrons. The corresponding dendritic Cu(OTf)2 catalysts were used for Diels-Alder and three-component condensation reactions. The dendritic Cu(OTf)2-catalyzed Diels-Al…
Chemical Synthesis and AnalysisClick Chemistry and ApplicationsDendrimers and Hyperbranched Polymers
Kazuaki Z. Takahashi、Kenji Yasuoka、Tetsu Narumi2007-09-21The Journal of Chemical Physics
Molecular dynamics simulations of a Lennard-Jones (LJ) liquid were applied to compare the isotropic periodic sum (IPS) method [X. Wu and B. R. Brooks, J. Chem. Phys. 122, 044107 (2005)], which can reduce the calculation cost of long-range interactions, such as the Lennard-Jones and Coulombic ones, with the cutoff meth…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesThermodynamic properties of mixtures
Tiejun Zhu、Fan Yan、Xinbing Zhao 等 6 位作者2007-09-21Journal of Physics D Applied Physics
The amorphous partial crystallization method has been applied to fabricate Ge–Te based bulk in situ thermoelectric amorphous/nanocrystal composites. High-resolution transmission electron microscopy showed that nanocrystals of only 4–8 nm were formed by nanoscale phase separation from the semiconductor amorphous matrix…
Advanced Thermoelectric Materials and DevicesChalcogenide Semiconductor Thin FilmsPhase-change materials and chalcogenides
Kevin T. Early、Kevin McCarthy、Nathan I. Hammer 等 7 位作者2007-09-21Nanotechnology
We report time-resolved single molecule fluorescence imaging of individual CdSe quantum dots that are functionalized with oligomeric conjugated organic ligands. The fluorescence intensity trajectories from these composite nanostructures display both a strong degree of blinking suppression and intensity fluctuations wi…
Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsNanocluster Synthesis and Applications
Steven C. Zimmerman、Jordan R. Quinn、Ewelina Burakowska 等 4 位作者2007-09-21Angewandte Chemie
Wie riesige Kronenether: Vernetzte, auf Glycerin basierende Nanopartikel wurden durch Ringschlussmetathese (RCM) aus Polyallylglycerin-Dendrimeren oder hyperverzweigten Polymeren synthetisiert (siehe Schema). In organischen Lösungsmitteln weisen die Polyether-Nanopartikel passable Ionophorfähigkeiten auf.
Luminescence and Fluorescent MaterialsDendrimers and Hyperbranched PolymersFerrocene Chemistry and Applications
M. M. Da Silva、Alfredo R. Vaz、Stanislav A. Moshkalev 等 4 位作者2007-09-21ECS Transactions
Dual beam FIB (focused ion beam)/SEM (scanning elelctron microscope) systems are commonly used for imaging, selective etch and deposition of materials like platinum. The paper presents the results of electrical characterization of platinum thin films deposited by focused ion beam. For measurements, two types of test s…
Electron and X-Ray Spectroscopy TechniquesIon-surface interactions and analysisSurface and Thin Film Phenomena
Giovanni Morello、M. Anni、P. Davide Cozzoli 等 6 位作者2007-09-21Nanoscale Research Letters
Abstract Time Resolved Photoluminescence (TRPL) measurements on the picosecond time scale (temporal resolution of 17 ps) on colloidal CdSe and CdSe/ZnS Quantum Dots (QDs) were performed. Transient PL spectra reveal three emission peaks with different lifetimes (60 ps, 460 ps and 9–10 ns, from the bluest to the reddest…
Quantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin FilmsNanocluster Synthesis and Applications