H. Van Swygenhoven、A. Caro1997-09-22Applied Physics Letters
We report molecular dynamics computer simulations of low temperature-high load plastic deformation of Ni nanophase samples with several mean grain sizes in the range of 3–5 nm. The samples are polycrystals nucleated from different seeds, with random location and orientation. Among the mechanisms responsible for the de…
Microstructure and mechanical propertiesHigh-Velocity Impact and Material BehaviorIon-surface interactions and analysis
D. B. Kacedon、R. A. Rao、Chang‐Beom Eom1997-09-22Applied Physics Letters
We have studied the magnetoresistive behavior of epitaxial thin films of the conductive ferromagnetic oxide SrRuO3 with different domain structures grown on both miscut (001) SrTiO3 and exact (001) LaAlO3 substrates. A strong anisotropic magnetoresistance (MR) has been observed in the single domain SrRuO3 thin film on…
Magnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter PhysicsElectronic and Structural Properties of Oxides
EA Evans、W. Rawicz1997-09-22Physical Review Letters
Sensitive micropipet methods have been used to measure the elastic stretch modulus and bending rigidity of biomembranes studded with water-soluble polymers. The fully extended lengths of the chemically grafted chains ranged from $10--50\ifmmode\times\else\texttimes\fi{}$ the length of the embedding membrane lipid. Con…
Lipid Membrane Structure and BehaviorPolymer Surface Interaction StudiesForce Microscopy Techniques and Applications
Peter H. Poole、Mahin Hemmati、C. Austen Angell1997-09-22Physical Review Letters
We conduct extensive molecular dynamics computer simulations of a rigid-ion model of liquid silica [L.V. Woodcock et al., J. Chem. Phys. 65, 1565 (1976)], evaluating thermodynamic and transport properties over a wide range of pressure and temperature. We find numerous similarities with behavior found in simulations of…
Phase Equilibria and ThermodynamicsMaterial Dynamics and PropertiesThermodynamic properties of mixtures
Jianwang Cai、Cong Wang、Baogen Shen 等 5 位作者1997-09-22Applied Physics Letters
The magnetic and magnetotransport properties of the perovskite La0.67Ca0.33Mn0.9Fe0.1O3 have been investigated, and the spin-glass behavior with a spin freezing temperature of 42 K has been well confirmed for this compound. A metal-to-insulator transition and colossal magnetoresistance have been observed near its spin…
Magnetic and transport properties of perovskites and related materialsAdvanced Condensed Matter PhysicsElectronic and Structural Properties of Oxides
S. Neser、Clemens Bechinger、P. Leǐderer 等 4 位作者1997-09-22Physical Review Letters
We study closely packed crystalline structures formed by slow lateral compression of a colloidal suspension of hard spheres in a thin wedge. In addition to the known sequence of structural transitions, a buckling mechanism was recently proposed to maximize the packing fraction $\ensuremath{\Phi}$ between one and two l…
Proteins in Food SystemsMaterial Dynamics and PropertiesPickering emulsions and particle stabilization
M. R. Jarvis、I. D. White、R. W. Godby 等 4 位作者1997-09-22arXiv
We study the behaviour of total-energy supercell calculations for dipolar molecules and charged clusters. Using a cutoff Coulomb interaction within the framework of a plane-wave basis set formalism, with all other aspects of the method (pseudopotentials, basis set, exchange-correlation functional) unchanged, we are ab…
Materials Science
M. Mobarak、H. Berger、Gian F. Lorusso 等 7 位作者1997-09-21Journal of Physics D Applied Physics
single crystals have been grown and characterized by experimental techniques such as high-resolution transmission electron microscopy, x-ray diffraction, x-ray photoelectron spectroscopy and optical and electrical measurements. The samples were prepared in single-crystal form from a melt. The structural analysis indic…
Semiconductor Quantum Structures and DevicesChalcogenide Semiconductor Thin FilmsSolid-state spectroscopy and crystallography
Bashir M. Suleiman、M. Gustavsson、Ernest Karawacki 等 4 位作者1997-09-21Journal of Physics D Applied Physics
The thermal conductivity and diffusivity of lithium sulphate have been measured simultaneously, using the transient plane source technique over the temperature range 300 - 900 K. The thermal conductivity decreases slowly up to about 640 K, whereupon a distinct rise occurs, indicating the onset of a pre-transitional be…
Solid-state spectroscopy and crystallographyThermal and Kinetic AnalysisX-ray Diffraction in Crystallography
S. Mahajna、Y.S. Horowitz1997-09-21Journal of Physics D Applied Physics
We describe the development of a comprehensive theory of thermoluminescence (TL) supralinearity and sensitization, the unified interaction model (UNIM), based on both radiation absorption stage and recombination stage mechanisms. The UNIM incorporates both the track interaction model (TIM) for heavy charged particles…
Luminescence Properties of Advanced MaterialsRadiation Detection and Scintillator TechnologiesSolid-state spectroscopy and crystallography
Shigeki Sakaguchi、Shin‐ichi Todoroki1997-09-20Applied Optics
The optical properties of GeO(2) glass were investigated to clarify its potentiality as an optical fiber material. Glass samples were prepared by the flame hydrolysis and the melting techniques, and their Rayleigh scattering and infrared absorption properties were examined. Optical fibers composed of a pure GeO(2) cor…
Photonic and Optical DevicesGlass properties and applicationsLaser Material Processing Techniques
Mohammed Faloss、Michael Canva、Patrick Georges 等 6 位作者1997-09-20Applied Optics
Significant improvements have been obtained for solid-state dye lasers with doped xerogels. By using longitudinal pumping with a frequency-doubled Q-switched Nd: YAG laser, we obtained as much as 86% slope efficiency and 5 x 10(5) pulses lifetime. Furthermore, newly prepared deoxygenated samples exhibited even greater…
Luminescence Properties of Advanced MaterialsGlass properties and applicationsSilicone and Siloxane Chemistry
F. Gittes、B. Schnurr、P. D. Olmsted 等 5 位作者1997-09-20arXiv
We describe a high-resolution, high-bandwidth technique for determining the local viscoelasticity of soft materials such as polymer gels. Loss and storage shear moduli are determined from the power spectra of thermal fluctuations of embedded micron-sized probe particles, observed with an interferometric microscope. Th…
Materials ScienceSoft Condensed Matter
B. Schnurr、F. Gittes、F. C. MacKintosh 等 4 位作者1997-09-20arXiv
We have developed a new technique to measure viscoelasticity in soft materials such as polymer solutions, by monitoring thermal fluctuations of embedded probe particles using laser interferometry in a microscope. Interferometry allows us to obtain power spectra of fluctuating beads from 0.1 Hz to 20 kHz, and with sub-…
Materials ScienceSoft Condensed Matter
Igor F. Lyuksyutov、Thomas Nattermann、Valery Pokrovsky1997-09-20arXiv
A theory of the hysteresis loop in ferromagnets controlled by the domain wall motion is presented. Domain walls are considered as plane or linear interfaces moving in a random medium under the action of the external ac magnetic field $H=H_0\sinωt$. We introduce important characteristics of the hysteresis loop, such as…
Materials Science
I. Pesneau、Marie‐France Llauro、M. Gr�goire 等 4 位作者1997-09-19Journal of Applied Polymer Science
PE and PBT are known to be incompatible polymers. A grafted copolymer PBT-EVA has been generated as a compatibilizer in situ during the processing operation by redistributive transesterification between PBT and EVA in the presence of dibutyl tin oxide (DBTO). This copolymer has been isolated by selective extractions f…
Polymer crystallization and propertiesPolymer Nanocomposites and PropertiesRecycling and Waste Management Techniques
Amir Ershad‐Langroudi、C. Maï、Gérard Vigier 等 4 位作者1997-09-19Journal of Applied Polymer Science
Hybrid systems based on 3-trimethoxysilyl propyl methacrylate, tetramethylorthosilicate, and methyl methacrylate were developed for moisture protection and strengthening of glass objects. The hydrophobic behavior of the hybrid was obtained by adding different fluorinated precursors to the hybrid solution. Experimental…
Surface Modification and SuperhydrophobicityAerogels and thermal insulationSilicone and Siloxane Chemistry
Jürgen Engel1997-09-19Science
In his Perspective, Engel discusses the diverse structural features of collagens, a ubiquitous fibrillar protein that forms the main support of skin and tendons. A unique example is reported in this issue by Coyne et al ., who describe the amino acid sequence of the specialized collagen that forms the byssal threads t…
Tendon Structure and TreatmentSilk-based biomaterials and applicationsMarine Biology and Environmental Chemistry
Kathryn J. Coyne、Xiaoxia Qin、J. Herbert Waite1997-09-19Science
To adhere to solid surfaces, marine mussels produce byssal threads, each of which is a stiff tether at one end and a shock absorber with 160 percent extensibility at the other end. The elastic extensibility of proximal byssus is extraordinary given its construction of collagen and the limited extension (less than 10 p…
Knee injuries and reconstruction techniquesSilk-based biomaterials and applicationsMarine Biology and Environmental Chemistry
K. M. Rabe、P. H. Citrin1997-09-18arXiv
The fcc-based structure of Yb2.75C60 is unique among metal-doped fullerene compounds, exhibiting long-range-ordered vacancies, significantly off-centered divalent Yb cations, and distorted, crystallographically inequivalent, orientationally ordered C60 anions. A simple electrostatic-energy analysis, which models the c…
Materials Science