Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
This article presents the technique for measuring an amplitude and a profile of a laser-generated stress pulse using a Doppler velocity interferometer velocity interferometer system for any reflector (VISAR). The compressive stress, produced by a laser pulse, moves target’s rear free surface. The velocity of this disp…
Mechanical properties of copper have been studied using effective-medium theory and Molecular-Dynamics simulations. At room temperature we calculate the tensile moduli of systems that are elongated along different crystal orientations. These moduli are in very good agreement with the experimental values, the differenc…
MurA (UDP-GlcNAc enolpyruvyl transferase), the first enzyme in bacterial peptidoglycan biosynthesis, catalyzes the enolpyruvyl transfer from phosphoenolpyruvate (PEP) to the 3'-OH of UDP-GlcNAc by an addition-elimination mechanism that proceeds through a tetrahedral ketal intermediate. The crystal structure of the Cys…
Other| February 01, 1998 Silanol groups in minerals and inorganic compounds Daniel Nyfeler; Daniel Nyfeler Universitaet Bern, Laboratorium fuer Chemische und Mineralogische Kristallographie, Bern, Switzerland Search for other works by this author on: GSW Google Scholar Thomas Armbruster Thomas Armbruster Search for ot…
Charge-state-dependent structural stability of oxygen vacancy in α-quartz is determined by using first-principles total-energy calculations. It is found that neutral and positively charged oxygen vacancies show bistability, and that a spontaneous structural transformation occurs for doubly positively and doubly negati…
We report time-resolved small angle X-ray scattering (SAXS) studies of the structural characteristics of the collapsed state of lysozyme from henegg white (HEL) obtained on initiating refolding by rapidly changing solvent conditions from 8 M to 1.1 M urea at pH 2.9. At this reduced pH the lifetime, of about one second…
The quantum efficiency of the 1.3 μm transition in Pr3+ doped oxyfluoride transparent glass ceramics is measured using a self-calibrating fluorescence ratio technique. The measured value of 8%±1% is much higher than expected for Pr3+ in an oxide glass, and is consistent with the incorporation of the Pr3+ ions into the…
Blend films of a commercial poly(vinyl alcohol) (a-PVA) derived from vinyl acetate and silk fibroin (SF) obtained from degummed silk were prepared by mixing the aqueous solutions of both samples. A plain weave structure was recognized only in the blend films, whereas no structure was found for the superimposed films o…
We extend our previous first-principles theory for perovskite ferroelectric phase transitions to treat also antiferrodistortive phase transitions. Our approach involves construction of a model Hamiltonian from a Taylor expansion, first-principles calculations to determine expansion parameters, and Monte-Carlo simulati…
We carry out a theoretical analysis for the spectra of plasmon polaritons in multiple semiconductor layers arranged in a quasiperiodical fashion. This quasiperiodicity can be of the type of so-called substitutional sequences. They are characterized by the nature of their Fourier spectrum, which can be dense pure point…
The mechanism of the electrical resistivity increase above the Curie temperature TC [so-called positive temperature coefficient of resistivity (PTCR) effect] in BaTi1−x−yNbxMnyO3 ceramics is studied with the temperature-dependent resistivity and electron paramagnetic resonance (EPR) data and the calculated energy leve…
The combination of x-ray Brillouin scattering data with coherent inelastic neutron scattering results in vitreous silica allows us to identify the scattering mechanisms for high-frequency sound waves in the glass. Below one THz, one has resonant scattering from low-frequency vibrations, above one THz Rayleigh scatteri…
Polarization properties of ceria‐based anodes dispersed with nanometer‐sized Ru catalysts, which we developed for medium‐temperature solid oxide fuel cells, were greatly improved by controlling the composition and microstructure. Among samaria‐doped ceria (SDC) anodes with compositions of (0 ≦ x ≦ 0.4) a SDC anode wit…
Nonisothermal electron transport in thin barrier heterostructures is investigated using Monte Carlo techniques. Particular attention is paid to the energy balance in thermionic emission, and the Joule heating in the barrier region. By introducing an energy relaxation length, an equation for the temperature distributio…
A series of styrene- d 8 /4-hydroxystyrene graft and block copolymers has been prepared by “living” radical and anionic techniques for use in interfacial strengthening studies at the polystyrene/poly(2-vinylpyridine), PS/PVP, interface. The following copolymers in which A and B segments represent poly(styrene- d 8 ) a…
Analytical and high‐resolution transmission electron microscopies were used to study the structure and chemistry of two‐grain boundaries and three‐grain junctions in polycrystalline alumina sintered with additions of between 0 and 10 wt% calcium silicate. Addition of calcium silicate greatly aided full densification a…
Multidimensional deuteron NMR provides powerful tools for studying molecular reorientation in supercooled liquids. We present results on selectively deuterated toluene-${d}_{5},$ which may be one of the molecularly most simple van der Waals glass formers. From two-time correlation functions the time scale of reorienta…
Transmission-electron-microscopy measurements characterizing the structure and charge-ordered states in ${\mathrm{LaSr}}_{2}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}$ are presented. The crystal structure of this phase has been identified as a well-defined 327 layered structure by high-resolution electron microscopy and image…
The positivity of the Patterson function is used as prior information for the decomposition of a powder diffraction pattern. An automatic procedure is described which, integrated with the Le Bail method, is able to provide estimates of |F| values that are often remarkably better than those obtained by application of s…
Small block copolymers consisting of a hydrophilic poly(ethylene glycol) block and a second, also hydrophilic, moiety which strongly interacts with alkaline earth ions were synthesized by diverse reaction sequences based on poly(ethylene glycol) monomethyl ethers (MW = 2000 and 5000 g/mol, respectively). These startin…