I.J. Clifton、Linh X. Doan、Mark C. Sleeman 等 7 位作者2003-05-30Journal of Biological Chemistry
The proposed biosynthetic pathway to the carbapenem antibiotics proceeds via epimerization/desaturation of a carbapenam in an unusual process catalyzed by an iron- and 2-oxoglutarate-dependent oxygenase, CarC. Crystal structures of CarC complexed with Fe(II) and 2-oxoglutarate reveal it to be hexameric (space group C2…
Enzyme Structure and FunctionMetabolism and Genetic DisordersBiochemical and Molecular Research
Heiko Lammert、Magnus Kunow、Andreas Heuer2003-05-30Physical Review Letters
The available sites for ions in a typical disordered ionic conductor are determined. For this purpose we devised a straightforward algorithm which via cluster analysis identifies these sites from long time ionic trajectories below the glass transition. This is exemplified for a lithium silicate glass (Li2O)(x)(SiO2)((…
Material Dynamics and PropertiesLuminescence Properties of Advanced MaterialsGlass properties and applications
Alain Gibaud、David Grosso、B. Smarsly 等 10 位作者2003-05-30The Journal of Physical Chemistry B
Surfactant templated silica mesophases belong to the class of self-assembled materials that exhibit long range ordered two-dimensional (2D) hexagonal, three-dimensional (3D) hexagonal, or 3D cubic mesostructures when the composition of the initial deposited solution and its aging time have been optimized. Thin films o…
Photonic Crystals and ApplicationsAerogels and thermal insulationMesoporous Materials and Catalysis
Amir A. Farajian、Boris I. Yakobson、Hiroshi Mizuseki 等 4 位作者2003-05-30Physical review. B, Condensed matter
We theoretically investigate the mechanical deformations of armchair, zigzag, and zigzag-armchair kink nanotube structures, under severe bendings, within a tight-binding model. It is shown that the zigzag tube is stiffer than the armchair tube with the same diameter. The kink structure is found to be quite stable unde…
Mechanical and Optical ResonatorsCarbon Nanotubes in CompositesForce Microscopy Techniques and Applications
Zongtao Zhang、Douglas A. Blom、Zheng Gai 等 6 位作者2003-05-30Journal of the American Chemical Society
One-dimensional (1D) magnetic nanomaterials have attracted much attention recently because of their applications in magnetic recording and spintronics. Nevertheless, it remains a challenge to prepare free-standing magnetic nanowires in high yield. This Communication reports the successful high-yield synthesis of an in…
Anodic Oxide Films and NanostructuresMagnetic properties of thin filmsElectrocatalysts for Energy Conversion
E. Anglada、J. Junquera、J. M. Soler2003-05-30arXiv
We present an efficient method to mix well converged ab initio forces with simpler and faster ones in molecular dynamics. While the cheap forces are evaluated every time step, the converged ones correct the trajectory only every n time steps. For convenience, both types of forces are calculated with the same basic sch…
Materials Science
H. Kepa、G. Springholz、T. M. Giebultowicz 等 10 位作者2003-05-30arXiv
The magnetic properties of antiferromagnetic (AFM) EuTe epitaxial layers and short period EuTe/PbTe superlattices (SLs), grown by molecular beam epitaxy on (111) BaF$_2$ substrates, were studied by magnetization and neutron diffraction measurements. Considerable changes of the Néel temperature as a function of the EuT…
Materials Science
Stephen Hill、R. S. Edwards、Shaela I. Jones 等 5 位作者2003-05-30Physical Review Letters
We present detailed angle-dependent single crystal electron paramagnetic resonance (EPR) data for field rotations in the hard plane of the S=10 single molecule magnet Mn(12)-acetate. A clear fourfold variation in the resonance positions may be attributed to an intrinsic fourth-order transverse anisotropy (O(4)/(4)). M…
Electron Spin Resonance StudiesLanthanide and Transition Metal ComplexesMagnetism in coordination complexes
Qiang Sun、Karsten Reuter、Matthias Scheffler2003-05-30Physical review. B, Condensed matter
Combining density-functional theory and thermodynamics we compute the phase diagram of surface structures of rutile ${\mathrm{RuO}}_{2}(110)$ in equilibrium with water vapor in the complete range of experimentally accessible gas phase conditions. Through the formation of hydroxyl or waterlike groups, already lowest co…
nanoparticles nucleation surface interactionsAdvanced Condensed Matter PhysicsElectronic and Structural Properties of Oxides
Claus‐Dieter Ohl、Roy Ikink2003-05-30Physical Review Letters
Free gas bubbles in water with radii between 7 and 55 microm subjected to a shock wave exhibit a liquid jetting phenomenon with the jet pointing in the direction of the propagating shock wave. With increasing bubble radius, the length of the jet tip increases and a lower estimate of the averaged jet velocity increases…
Fluid Dynamics and MixingUltrasound and Cavitation PhenomenaCombustion and Detonation Processes
H. B. Nie、S. Y. Xu、S. J. Wang 等 8 位作者2003-05-30arXiv
TaN thin film is an attractive interlayer as well as a diffusion barrier layer in [FeN/TaN](n) multilayers for the application as potential write-head materials in high-density magnetic recording. We synthesized two series of TaN films on glass and Si substrates by using reactive radio-frequency sputtering under 5-mto…
Materials Science
H. B. Nie、S. Y. Xu、J. Li 等 5 位作者2003-05-30arXiv
We studied the in-plane magnetic anisotropy of rf (radio frequency) sputtered [(FeTaN)/(TaN)](n) multilayers synthesized on Si substrates. In the multilayers where n=5, the FeTaN thickness is fixed at 30 nm and the thickness of TaN, t(TaN), is varied from 0 to 6.0 nm, we observed a clear trend that, with increasing t(…
Materials Science
H. B. Nie、X. X. Zhang、A. B. Pakhomov 等 7 位作者2003-05-30arXiv
A study of magnetic hysteresis and Giant magnetoimpedance (GMI) in amorphous glass covered Co-Si-B and Co-Mn-Si-B wires is presented. The wires, about 10 microns in diameter, were obtained by glass-coated melt spinning technique. Samples with positive magnetostriction (MS) have a rectangular bistable hysteresis loop.…
Materials Science
Bang‐Gui Liu2003-05-30Physical review. B, Condensed matter
It is predicted with the accurate full-potential density-functional method that the zinc blende (ZB) CrSb phase is a robust half-metallic (HM) ferromagnet with a magnetic moment of $3.000{\ensuremath{\mu}}_{B}$ per formula. Its HM gap reaches 0.774 eV and persists to be nonzero even when it is compressed by $21%.$ Bec…
Heusler alloys: electronic and magnetic propertiesIron-based superconductors research2D Materials and Applications
G. Raschke、Stefan Kowarik、T. Franzl 等 8 位作者2003-05-30OpenAlex
A method for biomolecular recognition is reported using light scattering of a single gold nanoparticle functionalized with biotin. Addition of streptavidin and subsequent specific binding events alter the dielectric environment of the nanoparticle, resulting in a spectral shift of the particle plasmon resonance. As we…
Gold and Silver Nanoparticles Synthesis and ApplicationsAdvanced biosensing and bioanalysis techniquesBiosensors and Analytical Detection
Rajamani Lakshminarayanan、Suresh Valiyaveettil2003-05-29Crystal Growth & Design
Calcite crystals with interesting morphologies were synthesized using various oligomers of silicate in solution. The crystals were grown by adding an appropriate amount of sodium silicate to a supersaturated calcium bicarbonate solution at room temperature. The morphology of nucleated calcite crystals changed signific…
Building materials and conservationClay minerals and soil interactionsCalcium Carbonate Crystallization and Inhibition
Gianmario Martra、Salvatore Coluccia、Michel Che 等 6 位作者2003-05-29The Journal of Physical Chemistry B
This paper is the continuation of a study of Ni II −(CO) n complexes formed on amorphous silica. Both Ni and CO are used as successive probes of the local structure and reactivity of the silica surface. An isolated tricoordinated Ni II 3c ion in a single oxidation state is characterized with CO as a probe of the coord…
Catalysis and Oxidation ReactionsGlass properties and applicationsLuminescence Properties of Advanced Materials
Sergei Tretyakov、Stanislav I. Maslovski、Igor S. Nefedov 等 4 位作者2003-05-29Microwave and Optical Technology Letters
Abstract As shown by N. Engheta, electromagnetic fields in two adjacent slabs bounded by two metal walls can satisfy the boundary conditions, even if the distance between the two walls is much smaller than the wavelength. This is possible if one of the slabs has a negative permeability. Here we show that these subwave…
Terahertz technology and applicationsPhotonic Crystals and ApplicationsMetamaterials and Metasurfaces Applications
Shaofeng Ran、Dufei Fang、Igors Šics 等 6 位作者2003-05-29Review of Scientific Instruments
Simultaneous measurements of Raman spectroscopy and synchrotron two-dimensional (2D) wide-angle x-ray diffraction (WAXD) have been successfully demonstrated for in situ study of an anisotropic system: isotactic polypropylene (iPP) fiber under tensile deformation. A fiber-optic probe was used to remotely deliver the in…
Polymer crystallization and propertiesMaterial Dynamics and PropertiesPolymer Nanocomposites and Properties
Aldo Eloízo Job、Neri Alves、María Zanín 等 7 位作者2003-05-29Journal of Physics D Applied Physics
The dielectric strength of films made from poly(ethylene terephthalate) (PET) coated with a thin layer of polyaniline (PANI) was studied. The PANI layer was deposited on the PET films by the ` in situ ' chemical polymerization method. The PANI layer of the PANI/PET films was undoped in NH 4 OH 0.1 M solution and re-do…
Conducting polymers and applicationsDielectric materials and actuatorsAdvanced Sensor and Energy Harvesting Materials