David G. Cahill、Monica Katiyar、John R. Abelson1994-09-01OpenAlex
The thermal conductivity of sputtered a-Si:H thin films for a hydrogen content of 1--20 % and a film thickness of 0.2--1.5 \ensuremath{\mu}m is determined in the temperature range 80--400 K using an extension of the 3\ensuremath{\omega} measurement technique. The reliability of the method is demonstrated on 1-\ensurem…
Thermal properties of materialsQuantum, superfluid, helium dynamicsThermal Radiation and Cooling Technologies
M. Zgonik、P. Bernasconi、M. Duelli 等 9 位作者1994-09-01OpenAlex
The complete set of material parameters of a top-seeded solution-grown ${\mathrm{BaTiO}}_{3}$ crystal has been determined by numerically evaluating available measurements and using additional measurements presented in this work. The parameters were determined at room temperature and consist of the low-frequency clampe…
Ferroelectric and Piezoelectric MaterialsPhotorefractive and Nonlinear OpticsAcoustic Wave Resonator Technologies
O. Schweers、E. Schönbrunn、Alexander Marx 等 4 位作者1994-09-01OpenAlex
We have studied the conformation of tau protein and Alzheimer paired helical filaments (PHF) by several spectroscopic, scattering, and imaging methods revealing the overall shape and the conformation of the polypeptide backbone. Tau protein behaves in solution as if it were denatured; no evidence for compact folding w…
Alzheimer's disease research and treatmentsPrion Diseases and Protein MisfoldingSupramolecular Self-Assembly in Materials
E. Bauer1994-09-01OpenAlex
Low energy electron microscopy (LEEM) is a new technique for surface imaging, based on the wave nature of the electron. Although it makes use of electron lenses as in conventional electron microscopes it differs from them in that the electrons have energies of the order 1-100 eV when they interact with the surface. As…
Advanced Electron Microscopy Techniques and ApplicationsElectron and X-Ray Spectroscopy TechniquesSurface and Thin Film Phenomena
Glenn Martyna、Douglas J. Tobias、Michael L. Klein1994-09-01OpenAlex
Modularly invariant equations of motion are derived that generate the isothermal–isobaric ensemble as their phase space averages. Isotropic volume fluctuations and fully flexible simulation cells as well as a hybrid scheme that naturally combines the two motions are considered. The resulting methods are tested on two…
Protein Structure and DynamicsHigh-pressure geophysics and materialsMaterial Dynamics and Properties
Number Collaborative Computational Project1994-09-01OpenAlex
The CCP4 (Collaborative Computational Project, number 4) program suite is a collection of programs and associated data and subroutine libraries which can be used for macromolecular structure determination by X-ray crystallography. The suite is designed to be flexible, allowing users a number of methods of achieving th…
Enzyme Structure and Function
N. N. Berchenko、Yu. V. Medvedev1994-08-31Russian Chemical Reviews
Processes leading to the growth of intrinsic insulators (oxides, sulfides, and fluorides) on the surfaces of semiconductors of the III-V, II-VI, and IV-VI groups as well as their solid solutions are analysed with the aid of classical thermodynamics. Their phase compositions, found from the equilibrium phase diagram, a…
Semiconductor materials and devicesElectron and X-Ray Spectroscopy TechniquesSurface and Thin Film Phenomena
А.А. Федоров、Karen A. Magnus、M.H. Graupe 等 6 位作者1994-08-30Proceedings of the National Academy of Sciences
We determined the structures of Acanthamoeba profilin I and profilin II by x-ray crystallography at resolutions of 2.0 and 2.8 A, respectively. The polypeptide folds and the actin-binding surfaces of the amoeba profilins are very similar to those of bovine and human profilins. The electrostatic potential surfaces of t…
Protein Structure and DynamicsCellular Mechanics and InteractionsEnzyme Structure and Function
Darrin M. York、Alexander Wlodawer、Lee G. Pedersen 等 4 位作者1994-08-30Proceedings of the National Academy of Sciences
Proper treatment of long-range Coulombic forces presents a major obstacle to providing realistic molecular dynamics simulations of macromolecules. Traditional approximations made to lessen computational cost ultimately lead to unrealistic behavior. The particle mesh Ewald method accommodates long-range Coulombic force…
Protein Structure and DynamicsBacterial Genetics and BiotechnologyEnzyme Structure and Function
Jim P. Zheng、Hoi Sing Kwok1994-08-29Applied Physics Letters
The time-resolved photoluminescence of semiconductor nanocrystals was obtained as a function of laser excitation intensity at a low temperature. Exciton and biexciton recombination processes were clearly identified. At laser intensities lower than 3.3×105 W/cm2, only exciton recombination with a lifetime of 4 ns was o…
Semiconductor Quantum Structures and DevicesQuantum Dots Synthesis And PropertiesChalcogenide Semiconductor Thin Films
J. K. Krüger、J. Schreiber、Ricardo Jiménez 等 10 位作者1994-08-29Journal of Physics Condensed Matter
Frozen-in trans and gauche conformational disorder of symmetrical difluorotetra-chloroethane (DFTCE) produces the tendency of this plastic crystal to form an orientational glassy state on cooling below T g =86 K. To throw light upon the freezing mechanism in DFTCE neutron diffraction and Brillouin scattering as well a…
Material Dynamics and PropertiesPhotochemistry and Electron Transfer StudiesSpectroscopy and Quantum Chemical Studies
Márk Windisch、M. Krajčı́、J. Häfner1994-08-29Journal of Physics Condensed Matter
The electronic structure has been calculated for large approximant crystals (up to 51752 atoms in the periodically repeated cell) to icosahedral AlCuLi quasicrystals. The results show that a deep structure-induced pseudogap at the Fermi energy is a generic property of the quasicrystal and its crystalline approximants.…
Quasicrystal Structures and PropertiesX-ray Diffraction in Crystallography
Carlos Pecharromán、Juan Eugenio Iglesias1994-08-29Journal of Physics Condensed Matter
A method for determining the infrared dielectric constant function of an isotropic material from measurement of the reflectance from powdered samples has been implemented. The method is based on an expression for the average dielectric constant of a heterogeneous system, which shows percolation features. The results o…
Glass properties and applicationsSolid-state spectroscopy and crystallographyOptical and Acousto-Optic Technologies
Manabu Ihara、Hiroshi Komiyama、Tatsuya Okubo1994-08-29Applied Physics Letters
Diamond was deposited on substrates pre-etched with diamond powder using either a microwave plasma chemical vapor deposition method or a hot-filament-assisted chemical vapor deposition method. Density of residual diamond dust (i.e., number of diamond particles per unit area on the surface of a substrate) on the pre-et…
Metal and Thin Film MechanicsDiamond and Carbon-based Materials ResearchAdvanced materials and composites
F. Garwe、Andreas Schönhals、Mario Beiner 等 5 位作者1994-08-29Journal of Physics Condensed Matter
Dynamic dielectric and mechanical responses in the splitting region of PnBMA are analysed with the help of two Havriliak-Negami-function fits. The alpha and beta processes in the Arrhenius diagram are parallel to each other over a wide temperature range, and do not merge.
Material Dynamics and PropertiesPolymer Nanocomposites and PropertiesGlass properties and applications
T. Schaub、Daniel E. Bürgler、H.‐J. Güntherodt 等 4 位作者1994-08-29Physical Review Letters
For the first time the surface structure of an icosahedral quasicrystal could be resolved in direct space by scanning tunneling microscopy. The surface was found to form terraces with their normals being parallel to a fivefold axis. On the terraces fivefold stars and pentagonal holes were observed. Both the step heigh…
Quasicrystal Structures and PropertiesAdvanced Mathematical Theories and ApplicationsMineralogy and Gemology Studies
Tsann Lin、D. Mauri、N. Staud 等 6 位作者1994-08-29Applied Physics Letters
Dc magnetron sputtered Ni-Mn and Ni-Mn-Cr films are demonstrated to exhibit strong and thermally stable antiferromagnetism, as well as high corrosion resistance. For a 25.2 nm thick 53.3 Ni-46.7 Mn (in atomic percent) film deposited on top of a 28.5 nm thick 81 Ni-19 Fe film, a unidirectional anisotropy field (HUA) of…
Magnetic properties of thin filmsShape Memory Alloy TransformationsMagnetic Properties and Applications
V. B. Neustruev1994-08-29Journal of Physics Condensed Matter
This review presents the state of the art of the study of germanium-related colour centres in silica glass and silica-based fibres. Most attention is concentrated on the dominant colour centres such as the Ge-related oxygen-deficient centres and paramagnetic Ge(n) centres, all of them having ultraviolet absorption ban…
Glass properties and applicationsPhotonic Crystals and ApplicationsSilicon Nanostructures and Photoluminescence
J.C. Fontecilla-Camps、Rafael de Llorens、Marie‐Hélène Le Du 等 4 位作者1994-08-26PubMed
The crystal structure of the complex between ribonuclease A and d(ApTpApApG) has been solved by x-ray crystallography using the molecular replacement method. The model includes, besides the enzyme, the d(ApTpApA) 5'-segment (A1T2A3A4) and 68 solvent molecules. The R-factor for the strongest 87% of the measured data th…
Protein Structure and DynamicsDNA Repair MechanismsEnzyme Structure and Function
Ian Farnan、Jonathan F. Stebbins1994-08-26Science
The atomic-scale dynamics of the glass-to-liquid transition are, in general, poorly understood in inorganic materials. Here, two-dimensional magic angle spinning nuclear magnetic resonance spectra collected just above the glass transition of K(2)Si(4)O(9) at temperatures as high as 583 degrees C are presented. Rates o…
High-pressure geophysics and materialsMaterial Dynamics and PropertiesGlass properties and applications