P. Ganguly、P. S. Anil Kumar、P. N. Santhosh 等 4 位作者1994-01-10Journal of Physics Condensed Matter
The itinerant electron ferromagnetism in La 1-x Sr x CoO 3 (0.1<or=x<or=0.5) has been reinvestigated. AC magnetic susceptibility studies on these systems have been carried out for the first time. The nature of the susceptibility indicates the freezing of superparamagnetic clusters at low values of x (<0.3) and long-ra…
Magnetic and transport properties of perovskites and related materialsRare-earth and actinide compoundsAdvanced Condensed Matter Physics
F. Maury、N. Lorenzelli、M.H. Mathon 等 5 位作者1994-01-10Journal of Physics Condensed Matter
Samples of FeCu, FeCuMn, FeCuNi, and FeCuCr alloys containing 1.5 wt% of each solute have been electron irradiated around 290 degrees C or thermally aged at 500 degrees C for various times. It is known that such treatments induce Cu precipitation; the Cu depletion of the matrix is measured by the resistivity decrease…
Microstructure and Mechanical Properties of SteelsFusion materials and technologiesRare-earth and actinide compounds
Ping Sheng、Minyao Zhou、Zhao-Qing Zhang1994-01-10Physical Review Letters
We study phonon transport in random 3D lattices when the mean free path l becomes comparable to the lattice spacing a. Through numerical simulation, it is shown that in contrast to the electronic case, here the Ioffe-Regel criterion is inaccurate in the prediction of phonon localization. By using the Thouless criterio…
Quantum and electron transport phenomenaThermal properties of materialsRandom lasers and scattering media
K. A. Gschneidner、Hiroyuki Takeya、J. O. Moorman 等 4 位作者1994-01-10Applied Physics Letters
The low-temprature heat capacity and ac and dc magnetic properties of (Dy0.5Er0.5)Al2 have been studied as a function of magnetic fields up to ∼10 T. The magnetocaloric effect in (Dy0.5Er0.5)Al2 is 30% larger than that of the prototype material, GdPd. Magnetic measurements show that there is no measurable magnetic hys…
Physics of Superconductivity and MagnetismMagnetic and transport properties of perovskites and related materialsThermal Expansion and Ionic Conductivity
M. Heino、P. Hietaoja、Tommi Vainio 等 4 位作者1994-01-10Journal of Applied Polymer Science
Abstract The effect of viscosity ratio and processing conditions on LCP/PP blend morphology was studied. The viscosity ratio (η LCP /η PP ) was varied from 0.1 to 3.6 by using five different polypropylene grades as the matrix and two LCPs as the dispersed phase (20 wt %). The most spontaneous fiber formation was achie…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesRheology and Fluid Dynamics Studies
A. Peter Cox、Mark E. Newton、J M Baker1994-01-10Journal of Physics Condensed Matter
New ENDOR measurements on the single substitutional nitrogen centre in diamond are reported. The CW-ENDOR mechanism utilizes cross relaxation, and measurements have been made on both 14 N and 15 N, as well as the first detailed 13 C ENDOR study on the isotope at the natural abundance of 1.1%. The change in EPR intensi…
Diamond and Carbon-based Materials ResearchRadioactive element chemistry and processingAtomic and Subatomic Physics Research
Johan M. Felix、Paul Gatenholm、H. P. Schreiber1994-01-10Journal of Applied Polymer Science
Abstract Cellulose fibers have been surface‐modified by selected cold, microwave plasma treatments. Inverse gas chromatographic (IGC), XPS, and SEM analyses showed surface treatment to be incomplete, but, nevertheless, effective in controllably altering the acid/base interaction balance of fiber surfaces. Surface‐modi…
Polymer Nanocomposites and PropertiesHigh voltage insulation and dielectric phenomenaAdsorption, diffusion, and thermodynamic properties of materials
D. Kovalev、I. D. Yaroshetzkii、T. Muschik 等 5 位作者1994-01-10Applied Physics Letters
The visible luminescence of porous Si is known to contain at least two spectrally distinct emission bands with widely different response times. The orange-red luminescence component (1.5–1.9 eV) decays in times being of the order of 10 μs at room temperature. The blue-green band (2.3–2.6 eV) is very much faster with r…
Luminescence Properties of Advanced MaterialsSemiconductor materials and devicesSilicon Nanostructures and Photoluminescence
Takahiro Matsumoto、Jun Takahashi、Teruyuki Tamaki 等 6 位作者1994-01-10Applied Physics Letters
Porous silicon carbide has been fabricated using single crystal 6H-SiC that has a wider indirect band gap than silicon crystal. Intense blue-green luminescence has been observed at room temperature. The peak wavelength is around 460 nm, below the band gap of crystalline SiC. The luminescence intensity is about 100 tim…
Semiconductor materials and devicesThin-Film Transistor TechnologiesSilicon Nanostructures and Photoluminescence
R. Nagarajan、Chandan Mazumdar、Z. Hossain 等 9 位作者1994-01-10Physical Review Letters
We report here our discovery of bulk superconductivity at rather high ${\mathit{T}}_{\mathit{c}}$ in samples having nominal compositions ${\mathrm{YNi}}_{4}$${\mathrm{BO}}_{0.2}$ (${\mathit{T}}_{\mathit{c}}$\ensuremath{\approxeq}12.5 K) and ${\mathrm{YNi}}_{2}$${\mathrm{B}}_{3}$${\mathrm{O}}_{0.2}$ (${\mathit{T}}_{\ma…
Rare-earth and actinide compoundsIron-based superconductors researchSuperconductivity in MgB2 and Alloys
Hideto Tsuji、Yoshito Ikada、Suong‐Hyu Hyon 等 5 位作者1994-01-10Journal of Applied Polymer Science
Abstract To obtain poly(lactic acid) (PLA) complex fibers, spinning was performed by wet and dry methods from 5–10 g/dL chloroform solutions of poly(D‐lactic acid) (PDLA) and poly(L‐lactic), both with a viscosity‐average molecular weight of 3 × 10 5 . The dope was extruded from a monohole nozzle into coagulation baths…
biodegradable polymer synthesis and propertiesMicroplastics and Plastic PollutionCarbon dioxide utilization in catalysis
C. Jin、R. E. Haufler、Robert L. Hettich 等 8 位作者1994-01-07Science
Laser radiation (XeCl laser, 308-nanometer wavelength) focused into a cell containing Mo(CO)(6) vapor produced ultrafine particles in the extended waist of the laser beam. Negative ion mass spectrometry revealed molybdenum carbide cluster ions with a stoichiometry MonC4n (n = 1 to 4). The MonC4n(-) (n = 2 to 4) ions a…
Advanced Chemical Physics StudiesDiamond and Carbon-based Materials ResearchIon-surface interactions and analysis
Yehouda Harpaz、Nadia elMasry、A.R. Fersht 等 4 位作者1994-01-04Proceedings of the National Academy of Sciences
The structural basis for the stability of N termini of helices has been analyzed by thermodynamic and crystallographic studies of three suitably engineered mutants of the barley chymotrypsin inhibitor 2 with Ser, Gly, or Ala at the N-cap position (residue 31). Each mutant has a well-organized shell of hydration of the…
RNA and protein synthesis mechanismsMicrobial Metabolic Engineering and BioproductionEnzyme Structure and Function
Wendell A. Lim、A.E. Hodel、Robert T. Sauer 等 4 位作者1994-01-04Proceedings of the National Academy of Sciences
The dense packing observed in protein interiors appears to be crucial for stabilizing the native structure--even subtle internal substitutions are usually destabilizing. Thus, steric complementarity of core residues is thought to be an important criterion for "inverse folding" predictive methods, which judge whether a…
Protein Structure and DynamicsGlycosylation and Glycoproteins ResearchEnzyme Structure and Function
Sergey Leikin、D C Rau、V. Adrian Parsegian1994-01-04Proceedings of the National Academy of Sciences
We report direct measurements of force vs. separation between self-assembled proteins. These forces are observed between collagen triple helices in native and reconstituted fibers. They are a combination of a short-range repulsion, which varies exponentially over at least five decay lengths, and an inferred, longer-ra…
Protein Structure and DynamicsCellular Mechanics and InteractionsCollagen: Extraction and Characterization
P.P. Proulx、G. Cormier、J. A. Capobianco 等 5 位作者1994-01-03Journal of Physics Condensed Matter
An investigation of low-frequency inelastic scattering (LOFIS) and pre-resonant Raman spectroscopy has revealed the role of the modifying cations, Ba 2+ , Zn 2+ and Pb 2+ on the bonding properties of the Eu-O bond in Ba(PO 3 ) 2 , Zn(PO 3 ) 2 , and Pb(PO 3 ) 2 glasses. Analysis of the results has shown that the electr…
Luminescence Properties of Advanced MaterialsGlass properties and applicationsPhase-change materials and chalcogenides
M. H. S. Gradwell、W. J. McGill1994-01-03Journal of Applied Polymer Science
Abstract The interaction of sulfur, ZnO, stearic acid, and the three sulfenamide accelerators N ‐cyclohexylbenzothiazole sulfenamide (CBS), 2‐(4‐morpholinothio) benzothiazole (MOR), and 2‐ t ‐butylaminobenzothiazole sulfenamide (TBBS) were investigated by differential scanning calorimetry in the absence of rubber. In…
Synthesis and properties of polymersSulfur-Based Synthesis TechniquesThermal and Kinetic Analysis
James M. Farley、Prasadarao Meka1994-01-03Journal of Applied Polymer Science
Abstract The effects of corona‐discharge treatment (CDT) of commercial polyethylene (PE) Linear low‐density PE (LLDPE) were studied with special emphasis on the heat‐seal behavior of treated films. A range of treat levels, representative of those used in industry, was obtained by varying the applied power to a commerc…
Surface Modification and SuperhydrophobicityHigh voltage insulation and dielectric phenomenaElectrostatic Discharge in Electronics
G.M. Yang、S. Bauer‐Gogonea、G. M. Sessler 等 7 位作者1994-01-03Applied Physics Letters
Electron beams with an energy of 10 keV were employed for selectively poling only the lower part of a typical nonlinear optical guest/host polymer at a temperature of 90 °C. The resulting dipole orientation was examined by means of electro-optical measurements and thermally stimulated depolarization, while the nonunif…
Advanced Fiber Laser TechnologiesNonlinear Optical Materials ResearchPhotorefractive and Nonlinear Optics
M. H. S. Gradwell、W. J. McGill1994-01-03Journal of Applied Polymer Science
Abstract The thermal decomposition of three sulfenamide accelerators N ‐cyclohexylbenzothiazole sulfenamide (CBS), 2‐(4‐morpholinothio) benzothiazole (MOR) and 2‐ t ‐butylaminobenzothiazole sulfenamide (TBBS) were investigated by differential scanning calorimetry. The sulfenamides decompose rapidly at 210–220°C, yield…
Synthesis and properties of polymersThermal and Kinetic AnalysisChemical Reactions and Mechanisms