K. Sümmerer、Β. Blank2000-02-14Physical Review C
New experimental data obtained mainly at the GSI/FRS facility allow one to modify the empirical parametrization of fragmentation cross sections. It will be shown that minor modifications of the parameters lead to a much better reproduction of measured cross sections. The most significant changes refer to the descripti…
Nuclear reactor physics and engineeringHigh-Velocity Impact and Material BehaviorNuclear and radioactivity studies
E. E. Narimanov、C. M. Varma2000-02-14arXiv
We develop a variational mean-field theory of the ferromagnetic transition in compounds like Lanthanum-Manganite within the framework of the Double-Exchange Model supplemented by modest disorder. We obtain analytical expressions for the transition temperature, its variation with the valence electron-density and its de…
Materials ScienceStrongly Correlated Electrons
D. Alfe`、G. D. Price、M. J. Gillan2000-02-14arXiv
We present a new technique which allows the fully {\em ab initio} calculation of the chemical potential of a substitutional impurity in a high-temperature crystal, including harmonic and anharmonic lattice vibrations. The technique uses the combination of thermodynamic integration and reference models developed recent…
Materials Sciencecond-mat.stat-mech
Vivek B. Shenoy、R. V. Kukta、Rob Phillips2000-02-14Physical Review Letters
We develop a finite-element-based nodal dislocation dynamics model to simulate the structure and strength of dislocation junctions in fcc crystals. The model is based on anisotropic elasticity theory supplemented by the explicit inclusion of the separation of perfect dislocations into partial dislocations bounding a s…
Microstructure and mechanical propertiesMetal and Thin Film MechanicsHigh Temperature Alloys and Creep
Philip G. Collins、Michael S. Fuhrer、Alex Zettl2000-02-14Applied Physics Letters
The electrical noise characteristics of single-walled carbon nanotubes have been investigated. For all three cases of individual isolated nanotubes, thin films of interconnected nanotubes, and bulk nanotube mats, anomalously large bias-dependent 1/f noise is found. The noise magnitude greatly exceeds that commonly obs…
Carbon Nanotubes in CompositesGraphene research and applicationsLow-power high-performance VLSI design
Dong-Yul Kim、Cynthia V. Stauffacher、Victor W. Rodwell2000-02-12Biochemistry
There are two classes of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase: the class I enzymes of eukaryotes and some archaea, and the class II enzymes of certain eubacteria. The activity of the class I Syrian hamster HMG-CoA reductase is regulated by phosphorylation-dephosphorylation of Ser871. Phosphorylati…
Protein Structure and DynamicsEnzyme Structure and FunctionPlant biochemistry and biosynthesis
Robert J. P. Corriu、Philippe Gerbier、Christian Guérin 等 4 位作者2000-02-12Chemistry of Materials
The preparation of β-SiC/MC (M = Ti, Nb, and Ta) nanocomposite ceramics by the pyrolysis under an inert atmosphere of precursors consisting in interpenetrating networks of poly[(dimethylsilylene)diacetylene], 1, and polymeric metal oxide is described. The precursors are obtained by in-situ precipitation of the desired…
Advanced ceramic materials synthesisAdvanced materials and composites
Thomas Gennett、Anne C. Dillon、J. Alleman 等 6 位作者2000-02-12Chemistry of Materials
Carbon single-wall nanotubes (SWNTs) are of great interest because of their expected novel electronic, mechanical, and adsorption properties. However, to test these properties and develop applications, it is necessary to isolate large aligned nanotube bundles. Here we demonstrate that SWNT samples may be converted fro…
Carbon Nanotubes in CompositesGraphene research and applicationsNanopore and Nanochannel Transport Studies
Samuel Achilefu、Ralf Wilhelm、Hermo N. Jimenez 等 5 位作者2000-02-12The Journal of Organic Chemistry
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTA New Method for the Synthesis of Tri-tert-butyl Diethylenetriaminepentaacetic Acid and Its DerivativesSamuel Achilefu, R. Randy Wilhelm, Hermo N. Jimenez, Michelle A. Schmidt, and Ananth SrinivasanView Author Information Discovery Research, Mallinckrodt, Inc., St. Louis, Misso…
Molecular Sensors and Ion DetectionSupramolecular Chemistry and ComplexesLanthanide and Transition Metal Complexes
Takeshi Serizawa、Satoshi Takehara、Mitsuru Akashi2000-02-12Macromolecules
Ultrathin cross sections of core−corona polymeric nanospheres, which were prepared by the free-radical polymerization of methacrylate-terminated poly(ethylene glycol) (MA-PEG) as a hydrophilic macromonomer and styrene (St) as a hydrophobic comonomer in a ethanol/water (4/1, v/v) mixed solvent, were observed by using t…
Nanoparticle-Based Drug DeliveryPolymer Surface Interaction StudiesAnodic Oxide Films and Nanostructures
Paul E. Anderson、N.M. Rodríguez2000-02-12Chemistry of Materials
The notion of using support materials to achieve high dispersions of metal particles has been extended to the synthesis of carbon nanofibers from the catalyzed decomposition of ethylene. By using this approach it has been possible to generate nanofibers whose widths are dictated by the dimensions of the supported meta…
Advancements in Battery MaterialsCarbon Nanotubes in CompositesGraphene research and applications
Tomohiro Sato、Hiroshi Watanabe、Kunihiro Osaki2000-02-12Macromolecules
Solidlike and liquidlike linear viscoelastic responses were observed at low and high temperatures ( T ) for polystyrene−polyisoprene−polystyrene (SIS) triblock copolymers dissolved in an I-selective solvent, n -tetradecane (C14). These SIS systems behaved as thermoreversible physical gels, with the microphase-separate…
Polymer crystallization and propertiesAdvanced Polymer Synthesis and CharacterizationBlock Copolymer Self-Assembly
Liming Dai、Albert W. H. Mau2000-02-12The Journal of Physical Chemistry B
Surface and interface play an important role in controlling the properties of a broad range of materials. With the recent development of various advanced surface analytical techniques, our understanding of material surfaces and interfaces has been significantly increased, as with our ability to control and even to tai…
Carbon Nanotubes in CompositesConducting polymers and applicationsPolymer Nanocomposite Synthesis and Irradiation
Akikazu Matsumoto、Hidenobu Higashi2000-02-12Macromolecules
The alternating copolymer of alkyl sorbates with oxygen was prepared by photopolymerization or thermal polymerization in the presence of oxygen. Methyl sorbate provided an alternating copolymer with oxygen on exposure to sunlight at room temperature. The yield and molecular weight of the obtained polymers depended on…
Advanced Polymer Synthesis and CharacterizationRadical Photochemical ReactionsLuminescence and Fluorescent Materials
Masamichi Tsuboi、Mika Suzuki、Stacy A. Overman 等 4 位作者2000-02-12Biochemistry
Raman spectra of oriented alpha-helical protein molecules exhibit a prominent band near 1340-1345 cm(-)(1), the intensity of which is highly sensitive to molecular orientation. Polarization of the 1340-1345 cm(-)(1) marker is evident in Raman spectra of alpha-helical poly-L-alanine (alphaPLA) and alpha-helical poly-ga…
Protein Structure and DynamicsProtein purification and stabilityEnzyme Structure and Function
Martin Müller、C. Czihak、H. Schober 等 5 位作者2000-02-12Macromolecules
We present inelastic neutron scattering (INS) experiments on various types of cellulose revealing the universal nature of the disordered regions from the point of view of low-energy dynamics. Using INS in combination with the deuteration of polar groups technique, we have studied the dynamic response of hydroxyl group…
Advanced Cellulose Research StudiesPolysaccharides and Plant Cell WallsLignin and Wood Chemistry
Jacob J. Piet、Peter N. Taylor、Harry L. Anderson 等 5 位作者2000-02-12Journal of the American Chemical Society
The excess polarizability volumes, Δ V p, of the relaxed S 1 and T 1 excited states of several covalently bridged zinc porphyrin dimers and their corresponding monomers have been measured using the flash photolysis time-resolved microwave conductivity technique. Δ V p (S 1 ) increases from close to zero for a diaryl-s…
Photosynthetic Processes and MechanismsPorphyrin and Phthalocyanine ChemistryPhotochemistry and Electron Transfer Studies
Hideaki Yokoyama、Thomas E. Mates、Edward J. Krämer2000-02-12Macromolecules
The structure of asymmetric poly(styrene- b -2-vinylpyridine) (PS-PVP) diblock copolymers allowed to order in a thin film is observed by a combination of secondary ion mass spectrometry and scanning force microscopy. The surface/interface-induced ordering persists over a surprisingly long range (more than 1 μm). The 2…
Theoretical and Computational PhysicsBlock Copolymer Self-AssemblyNanopore and Nanochannel Transport Studies
Jing Wu、Jerold M. Schultz、Fengji Yeh 等 5 位作者2000-02-12Macromolecules
Poly(vinylidene fluoride) (PVDF) fibers spun at different take-up speeds (10.6−61.0 m/min) were subjected to stretch−hold deformation at room temperature and in-situ simultaneous synchrotron small- and wide-angle X-ray scattering measurements. Crystal transformation from α to β form and morphological changes in lamell…
Advanced Sensor and Energy Harvesting MaterialsPolymer crystallization and propertiesAdvanced Cellulose Research Studies
Marc Husemann、Michael E. Morrison、Didier Benoit 等 8 位作者2000-02-12Journal of the American Chemical Society
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTManipulation of Surface Properties by Patterning of Covalently Bound Polymer BrushesMarc Husemann, Michael Morrison, Didier Benoit, Jane Frommer, C. Mathew Mate, William D. Hinsberg, James L. Hedrick, and Craig J. HawkerView Author Information Center for Polymeric Inte…
Polymer Surface Interaction StudiesMolecular Junctions and NanostructuresNanofabrication and Lithography Techniques