Piero Carninci、Yoko Nishiyama、Arthur Westover 等 9 位作者1998-01-20Proceedings of the National Academy of Sciences
The advent of thermostable enzymes has led to great advances in molecular biology, such as the development of PCR and ligase chain reaction. However, isolation of naturally thermostable enzymes has been restricted to those existing in thermophylic bacteria. Here, we show that the disaccharide trehalose enables enzymes…
Protein Structure and DynamicsBacteriophages and microbial interactionsEnzyme Structure and Function
A. J. Williamson、Alex Zunger、A. Canning1998-01-20arXiv
Free standing InP quantum dots have previously been theoretically and experimentally shown to have a direct band gap across a large range of experimentally accessible sizes. We demonstrate that when these dots are embedded coherently within a GaP barrier material, the effects of quantum confinement in conjunction with…
Materials Science
Vincenzo Balzani、Sebastiano Campagna、Gianfranco Denti 等 6 位作者1998-01-20OpenAlex
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesigning Dendrimers Based on Transition-Metal Complexes. Light-Harvesting Properties and Predetermined Redox PatternsVincenzo Balzani, Sebastiano Campagna, Gianfranco Denti, Alberto Juris, Scolastica Serroni, and Margherita VenturiView Author Information Dipartimento di Chi…
Metal complexes synthesis and propertiesMolecular Junctions and NanostructuresDendrimers and Hyperbranched Polymers
C. K. Ong、Zhigang Song、K. H. Oh 等 5 位作者1998-01-19Applied Physics Letters
The variation of the relative permittivity of charged dielectrics with trapped charge density has been investigated by a time-resolved current method, in conjunction with a mirror image method employing a scanning electron microscope. The calculation is made by a mathematical expression derived from classical electrom…
High voltage insulation and dielectric phenomenaPower Transformer Diagnostics and InsulationElectrical and Bioimpedance Tomography
Julie A. Last、Andrew C. Hillier、Daniel E. Hooks 等 5 位作者1998-01-19Chemistry of Materials
Crystalline, molecularly thick organic films mimicking layer motifs observed in bulk crystals of conducting (ET) 2 X charge-transfer salts (ET = bis(ethylenedithiolo)tetrathiafulvalene, X = I 3, ReO 4 ) form on highly oriented pyrolytic graphite (HOPG) electrodes upon electrochemical oxidation of ET in electrolytes co…
Perovskite Materials and ApplicationsConducting polymers and applicationsOrganic and Molecular Conductors Research
C. Abadı́a、P. A. Algarabel、B. Garcı́a-Landa 等 7 位作者1998-01-19Journal of Physics Condensed Matter
Magnetization measurements along the main symmetry directions of the tetragonal structure, [100], [110] and [001], have been performed on several single crystals (R = Y, Tb and Ho), at applied high magnetic fields up to 12 Tesla and temperatures ranging from 4.2 to 300 K. From the measurements on the yttrium compound…
Magnetic properties of thin filmsMagnetic Properties and ApplicationsMagnetic Properties of Alloys
Ryu Abe、Kiyoaki Shinohara、Akira Tanaka 等 6 位作者1998-01-19Chemistry of Materials
Thin films composed of a layered titanate were prepared by a so-called soft-chemical method that took advantage of exfoliation of the layered material Cs x Ti (2 - x /4) □ x /4 O 4 . The exfoliated titanate sheets were easily oriented on a substrate by means of spin-coating. The prepared thin films had a layered struc…
Ferroelectric and Piezoelectric MaterialsPolyoxometalates: Synthesis and ApplicationsMicrowave Dielectric Ceramics Synthesis
James L. Hedrick、Kenneth R. Carter、Ralf P. Richter 等 9 位作者1998-01-19Chemistry of Materials
High-temperature polymeric foams were prepared using compositionally asymmetric microphase-separated block copolymers where the major component is thermally stable and the minor component is thermally labile. Upon thermal treatment, the dispersed phase undergoes thermolysis leaving pores the size and shape of which ar…
Epoxy Resin Curing ProcessesSynthetic Organic Chemistry MethodsSynthesis and properties of polymers
C. Masciovecchio、G. Monaco、Giancarlo Ruocco 等 9 位作者1998-01-19Physical Review Letters
The dynamic structure factor of the glass formers glycerol, o-terphenyl, and n-butyl-benzene has been studied by inelastic x-ray scattering across the liquid-glass transition. Data taken at selected temperatures in the $1--8{\mathrm{nm}}^{\ensuremath{-}1}$ momentum transfer ( $Q$) range show a propagating soundlike mo…
Material Dynamics and PropertiesGlass properties and applicationsTheoretical and Computational Physics
Anne E. Huber、Christopher Viney1998-01-19Physical Review Letters
Levan, which adopts a compact spherical conformation in aqueous solution, can form a liquid crystalline phase if DNA is also present. We propose that supramolecular rodlike structures, assembled by the noncovalent aggregation of levan around DNA, stabilize the lyotropic phase. We describe a geometric model for the agg…
Photosynthetic Processes and MechanismsLiquid Crystal Research AdvancementsPlant Reproductive Biology
Magdalena Oledzka、Kandalam V. Ramanujachary、M. Greenblatt1998-01-19Chemistry of Materials
The synthesis, structure, and electronic properties of a series of new quaternary layered sulfides, NaCuMS 2 (M = Mn, Fe, Co, Zn) are reported. The synthesis was accomplished by sulfurization of a mixture of oxide or sulfide and carbonate precursors of the corresponding metals by nitrogen gas charged with CS 2 . All o…
Magnetic and transport properties of perovskites and related materialsIron-based superconductors researchElectronic and Structural Properties of Oxides
N. Nassrallah-Aboukaïs、A. Boughriet、J. Laureyns 等 7 位作者1998-01-19Chemistry of Materials
By a simple washing of vaterite with ultrapure water, it transforms rapidly into cubic calcite. When the solid is washed with Cu 2+ solutions, the transformation depends on the concentrations of the copper solutions applied in the process. For concentrations of 10 - 4 mol dm - 3, a certain delay in the transformation…
Metal Extraction and BioleachingCalcium Carbonate Crystallization and InhibitionMinerals Flotation and Separation Techniques
Philippe Boullay、Ram Seshadri、F. Studer 等 6 位作者1998-01-19Chemistry of Materials
Using a combination of microscopy, powder X-ray diffraction, and model building, we recently reported evidence for the first misfit layer oxide, Tl 0.41 (Sr 0.9 O) 1.12 CoO 2 (Boullay et al. Chem. Mater. 1996, 8, 1482). In this work, we present a more detailed structural characterization from an additional high-resolu…
Physics of Superconductivity and MagnetismMagnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter Physics
Itaru Honma、Hao Zhou1998-01-19Chemistry of Materials
Self-assembled functional molecules in mesostructured materials (MM) are synthesized directly either by coassembly of dye-bound surfactant of ferrocenyl TMA with silicate or by Pc (phthalocyanine) molecules doped within C 16 TMA micelles assembled with oxides framework such as vanadia (VO x ), MoO 3, WO 3, and SiO 2 t…
Mesoporous Materials and CatalysisPorphyrin and Phthalocyanine ChemistryPolyoxometalates: Synthesis and Applications
Yaw‐Terng Chern、Hann‐Chyan Shiue1998-01-19Chemistry of Materials
This work synthesizes new diamantane-based polyimides by reacting 4,9-bis(4-aminophenyl)diamantane ( 4 ) with various aromatic tetracarboxylic dianhydrides. Poly(amic acid)s have high inherent viscosities of 0.74−1.36 dL/g. The polyimide 7 d can be soluble in o -chlorophenol, chloroform, and THF. Their cast films have…
Dielectric materials and actuatorsSynthesis and properties of polymersTribology and Wear Analysis
L. Groenendaal、Monique J. Bruining、Eric Hendrickx 等 7 位作者1998-01-19Chemistry of Materials
The Pd-catalyzed cross-coupling reaction involving organostannanes (Stille reaction) is applied to prepare a series of N - t -BOC-protected D−π− A oligopyrroles. After purification, oligomers with one to four pyrrole units inserted between a 4-nitrophenyl and a 4-methoxyphenyl group are isolated in yields between 20 a…
Porphyrin and Phthalocyanine ChemistryNonlinear Optical Materials ResearchPhotochemistry and Electron Transfer Studies
David A. Hall、M M Ben-Omran、Paul J. Stevenson1998-01-19Journal of Physics Condensed Matter
The high-field dielectric properties of a commercial cobalt-doped piezoceramic were determined by analysis of P - E (polarization-electric field) hysteresis loops. Measurements recorded under a continuous high AC field (amplitude ) established that the material underwent a diffuse ferroelectric phase transformation at…
Ferroelectric and Piezoelectric MaterialsAcoustic Wave Resonator TechnologiesDielectric materials and actuators
Sandra Dirè、R. Campostrini、Riccardo Ceccato1998-01-19Chemistry of Materials
The pyrolytic transformation of hybrid gels, obtained by hydrolysis−condensation of diethoxydimethylsilane and zirconium n -propoxide mixtures with different Si/Zr ratio, has been studied using TG−GC−MS coupled techniques, FTIR spectroscopy, and N 2 adsorption analysis. The starting gels have been described as nanocom…
Advanced ceramic materials synthesisAerogels and thermal insulationSilicone and Siloxane Chemistry
Kiwing To、Hyoung Jin Choi1998-01-19Physical Review Letters
Conformation of a flexible linear polymer (polyacrylic acid, PAA) in a binary mixture ( $\mathrm{water}+2$,6-lutidine, LW) near the critical point of LW is studied using dynamic light scattering (DLS) by which the diffusivities of the polymer molecules and the critical composition fluctuation of the LW are measured. T…
Material Dynamics and PropertiesTheoretical and Computational PhysicsSpectroscopy and Quantum Chemical Studies
Yadong Li、Xiangfeng Duan、Hongwei Liao 等 4 位作者1998-01-19Chemistry of Materials
A self-regulation hydrothermal reaction to synthesize nanocrystalline zinc gallate (ZnGa2O4) complex oxides was proposed: The Zn2+ ion concentration and the pH value of the solution and the nucleation and growth of ZnGa2O4 were well auto-controlled under these simple hydrothermal conditions.
Quantum Dots Synthesis And PropertiesLuminescence and Fluorescent MaterialsCarbon and Quantum Dots Applications