A.R. McWilliams、Derek P. Gates、Mark Edwards 等 7 位作者2000-08-30Journal of the American Chemical Society
The thionylphosphazene cation [NSO(NPCl 2 ) 2 ] + is a proposed intermediate in the thermal ring-opening polymerization of the cyclic thionylphosphazene NSOCl(NPCl 2 ) 2 ( 1 ) at 165 °C. The attempted generation of [NSO(NPCl 2 ) 2 ] + via halide abstraction from 1 with a variety of Lewis acids has been studied and the…
Synthesis and characterization of novel inorganic/organometallic compoundsSynthesis and properties of polymersSilicone and Siloxane Chemistry
Tebikie Wondimagegn、Abhik Ghosh2000-08-30The Journal of Physical Chemistry B
Nonlocal DFT provides an excellent description of the structural and conformational properties of metallohydroporphyrins and related complexes. The Ni(II) complexes are found to be strongly ruffled and the Zn(II) complexes planar, consistent with experimental results. The increased flexibility of the novel chlorophin,…
Porphyrin and Phthalocyanine ChemistryMetal-Catalyzed Oxygenation MechanismsPorphyrin Metabolism and Disorders
Franca Jones、Helmut Cölfen、Markus Antonietti2000-08-30Biomacromolecules
In a previous paper, it was shown that the functional polysaccharide kappa-carrageenan acts as an efficient stabilizer to prevent the precipitation of iron oxides and hydroxides up to very high pH values (Jones, et al. Colloid Polym. Sci. 2000, 278, 491-501). Here, this process was investigated for its application to…
Algal biology and biofuel productionCalcium Carbonate Crystallization and InhibitionGeochemistry and Elemental Analysis
Zhitong Yang、Oskar Liivak、Andreas Seidel 等 6 位作者2000-08-30Journal of the American Chemical Society
The high-performance mechanical properties of certain spider silks can be radically altered by the addition of water. For example, unconstrained silk fibers from the major ampullate gland of the golden orb-weaving spider, Nephila clavipes, contract to about half of their original length when immersed in water. In this…
Adhesion, Friction, and Surface InteractionsSilk-based biomaterials and applicationsSilkworms and Sericulture Research
Joachim Krug2000-08-30arXiv
Nucleation on top of two-dimensional islands with step edge barriers is investigated using scaling arguments. The nucleation rate is expressed in terms of three basic time scales: The time interval between deposition events, the residence time of atoms on the island, and the encounter time required for $i^\ast + 1$ at…
cond-mat.dis-nnMaterials Sciencecond-mat.stat-mech
Xiaoming He、T.N. Taylor、R. S. Lillard 等 5 位作者2000-08-29Journal of Physics Condensed Matter
Amorphous silicon carbonitride (a-SiCN) films were synthesized by ion enhanced radio-frequency (rf) magnetron sputtering from a Si 4 C target using a mixture of Ar and N 2 gases. The oxidation resistance of the films was investigated in an oxygen atmosphere over the temperature range of 0-1000 °C. X-ray photoelectron…
Metal and Thin Film MechanicsSemiconductor materials and devicesDiamond and Carbon-based Materials Research
Esther Belin‐Ferré、V. Fournée、Jean Dubois2000-08-29Journal of Physics Condensed Matter
This paper concentrates on a comparison of Al 3p occupied densities of states in crystalline and quasicrystalline Al-Cu-Fe intermetallics. This comparison is made quantitative by computing the two first moments of this partial distribution, which correspond to the partial contribution of Al atoms to the cohesive energ…
Intermetallics and Advanced Alloy PropertiesQuasicrystal Structures and PropertiesX-ray Diffraction in Crystallography
Kostya Trachenko、Martin T. Dove、Mark Harris 等 4 位作者2000-08-29Journal of Physics Condensed Matter
We present the results of a computational study of the low-energy dynamics of silica glass. Molecular dynamics simulation results show that parts of the glass structure can undergo large cooperative reorientations of SiO 4 tetrahedra. These motions involve reorientations of about 30 tetrahedra with an energy barrier o…
Material Dynamics and PropertiesGlass properties and applicationsPhase-change materials and chalcogenides
Shuji Munejiri、Fuyuki Shimojo、Kozo Hoshino2000-08-29Journal of Physics Condensed Matter
The structure of liquid sulphur at 400 K, below the polymerization temperature T p = 432 K, is investigated by first-principles molecular-dynamics simulations. The calculated structure factor is in excellent agreement with the experimental data. To investigate the microscopic mechanism of the photo-induced structural…
Glass properties and applicationsSolid-state spectroscopy and crystallographyThermal and Kinetic Analysis
Valérie Réat、R. Dunn、Michel Ferrand 等 6 位作者2000-08-29Proceedings of the National Academy of Sciences
A transition as a function of increasing temperature from harmonic to anharmonic dynamics has been observed in globular proteins by using spectroscopic, scattering, and computer simulation techniques. We present here results of a dynamic neutron scattering analysis of the solvent dependence of the picosecond-time scal…
Protein Structure and DynamicsMaterial Dynamics and PropertiesSpectroscopy and Quantum Chemical Studies
Yu. Rosenberg、V. Sh. Machavariani、A. Voronel 等 7 位作者2000-08-29Journal of Physics Condensed Matter
A correlation between precise x-ray powder diffraction patterns and atomic size mismatch in disordered mixed crystals (alloys and ionic crystals) is observed. The anisotropy of the elastic moduli has been taken into account for evaluation of the strain energy density of the mixed crystals revealed in x-ray powder diff…
Quasicrystal Structures and PropertiesX-ray Diffraction in CrystallographyThermodynamic and Structural Properties of Metals and Alloys
Y. Barad、Lu Yu、Z.‐Y. Cheng 等 5 位作者2000-08-28Applied Physics Letters
The linear electro-optic (EO) coefficients of Pb(Zn1/3Nb2/3)O3–PbTiO3 single crystals over a broad composition range were investigated at temperatures from −20 to 80 °C. The orientation effect on the EO coefficients was also examined. For crystals poled in the 〈001〉 direction, a large r33 was observed near the morphot…
Ferroelectric and Piezoelectric MaterialsPhotorefractive and Nonlinear OpticsMicrowave Dielectric Ceramics Synthesis
Daisuke Adachi、Shigeki Hasui Shigeki Hasui、Toshihiko Toyama 等 4 位作者2000-08-28Applied Physics Letters
We have studied structural and luminescence properties of nanostructured (NS-) ZnS:Mn which has potential applications in thin-film electroluminescence (TFEL) devices. As a NS-ZnS:Mn system, a ZnS:Mn/Si3N4 multilayer having thicknesses of 2.5 nm for ZnS and 0.6 nm for Si3N4 was prepared by a conventional rf-magnetron…
ZnO doping and propertiesQuantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin Films
Xinglong Wu、G. G. Siu、M. J. Stokes 等 6 位作者2000-08-28Applied Physics Letters
C 60 molecules were chemically coupled in the pores of porous Si through a coupling agent and then coated with a layer of Si, and followed by N2 annealing. X-ray diffraction results indicate that the fabricated samples contain β-SiC particles which may exist in the pores, in addition to Si, SiO2, and graphite. The pho…
Graphene research and applicationsDiamond and Carbon-based Materials ResearchFullerene Chemistry and Applications
Gauri Karve、Bipin Bihari、Ray T. Chen2000-08-28Applied Physics Letters
Neodymium-doped polyimide waveguides were studied for optical amplifier applications. Photoluminescence at 890 nm, 1.06 μm, and 1.33 μm from neodymium ions in the polymer matrix was observed. Optical gain of about 8 dB was measured at 1.06 μm in a 5-cm-long multimode channel waveguide. Phase separation was observed in…
Photonic and Optical DevicesSemiconductor Lasers and Optical DevicesSynthesis and properties of polymers
Gotthard Seifert、T. Köhler、Thomas Frauenheim2000-08-28Applied Physics Letters
Theoretical investigations (density-functional tight binding) about the changes of the properties of single-wall carbon nanotubes (SWNTs) by fluorination are reported. It is shown that a sidewall functionalization of SWNTs may lead to tubes with a wide variety of electronic properties, ranging from insulating over sem…
Carbon Nanotubes in CompositesGraphene research and applicationsFullerene Chemistry and Applications
Jean‐Yves Raty、Vitaliy Godlevsky、Philippe Ghosez 等 6 位作者2000-08-28Physical Review Letters
The local atomic order of semiconducting liquid GeTe is studied using first-principles molecular-dynamics simulations. Our work points out a high degree of alternating chemical order in the liquid and demonstrates the presence of a Peierls distortion close above the melting temperature. This distortion, absent in the…
Advanced Thermoelectric Materials and DevicesChalcogenide Semiconductor Thin FilmsPhase-change materials and chalcogenides
F. W. Wang、X. X. Zhang、Fengxia Hu2000-08-28Applied Physics Letters
Rare-earth intermetallic compounds (Tb1−xGdx)Al2, have been successfully fabricated and characterized. Large magnetic entropy change, ΔSM, was observed in these alloys. The maximum −ΔSM(=14.3 J/kg K) is achieved in the TbAl2 alloy at its Curie temperature, TC=105 K, with a 5 T magnetic field change. It is shown that t…
Advanced Thermoelectric Materials and DevicesMagnetic and transport properties of perovskites and related materialsRare-earth and actinide compounds
Tomofumi Kise、Takeshi Ogasawara、Masaaki Ashida 等 6 位作者2000-08-28Physical Review Letters
Ultrafast spin dynamics in ferromagnetic half-metallic compound Sr2FeMoO6 is investigated by pump-probe measurements of the magneto-optical Kerr effect. The half-metallic nature of this material gives rise to anomalous thermal insulation between spins and electrons and allows us to pursue the spin dynamics from a few…
Magnetic and transport properties of perovskites and related materialsMultiferroics and related materialsAdvanced Condensed Matter Physics
Dušan A. Pejaković、Jamie L. Manson、Joel S. Miller 等 4 位作者2000-08-28Physical Review Letters
The dynamic susceptibility study of photoinduced magnetism in a molecule-based magnet, ${\mathrm{K}}_{1\ensuremath{-}2x}{\mathrm{Co}}_{1+x}[\mathrm{Fe}(\mathrm{CN}{)}_{6}]\ifmmode \dot{}\else \.{}\fi{}y{\mathrm{H}}_{2}\mathrm{O}$ $(0.2\ensuremath{\le}x\ensuremath{\le}0.4,y\ensuremath{\sim}5)$, is reported. Upon excita…
Magnetism in coordination complexesOrganic and Molecular Conductors ResearchElectron Spin Resonance Studies