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。
Monte Carlo simulations have been performed on a meso-scale polymer model for semiflexible chains and effective polymer-polymer interactions. Simulations were made for different chain lengths at dilute and semidilute concentrations. The correlation length and osmotic compressibility have been determined for the simula…
Formation of different crystallographic phases and their characteristic Raman and infrared spectra are studied in the manganite system La1−xBaxMnO3 for x in the range of 0⩽x⩽1, and with variations in oxygen stoichiometry. Synthesis of the end member LaMnO3 in pure argon environment leads to the formation of Jahn–Telle…
An aspartate kinase-deficient mutant of Thermus thermophilus, AK001, was constructed. The mutant strain did not grow in a minimal medium, suggesting that T. thermophilus contains a single aspartate kinase. Growth of the mutant strain was restored by addition of both threonine and methionine, while addition of lysine h…
The physical and electronic structure of the dispersed and $(2\ifmmode\times\else\texttimes\fi{}2)$ phases of K/graphite have been characterized by valence and core-level photoemission. Charge transfer from K to graphite is found to occur at all coverages, and includes transfer of charge to the second graphite layer.…
The conductance of carbon nanotubes with a vacancy is studied in a tight-binding model. We examine the Fermi energy ε dependence of the conductance and show it is quantized into zero, one, and two times the conductance quantum \(e^{2}/\pi\hbar\) depending on the type of vacancy in the half-filled case, i.e., ε= 0. In…
Magnetic anisotropy of La0.8Ca0.2MnO3 (LCMO) epitaxial thin films grown on (001) SrTiO3 and LaAlO3 a substrates exhibits strong correlation with substrate-induced strain states as determined by normal and grazing incidence x-ray diffraction. In a 250 Å thick LCMO (001)T film grown on SrTiO3 substrate, an in-plane biax…
X-ray reflectivity by rough multilayer gratings is treated in the framework of kinematical and dynamical theories. The kinematical scattering integral is calculated without the restrictions of the Fraunhofer approximation. The dynamical theory is presented by the matrix modal eigenvalue approach. In both theories we g…
The holmium and europium complexes of the tetraanion of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (H4DOTA), namely, sodium aqua(1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetato)-holmium(III) tetrahydrate, Na[Ho(C 16 H 24 N 4 O 8 )(H 2 O)].4H 2 O, and sodium aqua(1,4,7,10-tetraazacyclododecane-1,4,7,…
The Berreman 4×4 matrix method is extended in order to calculate the optical behavior of reflective liquid crystal displays. Expressions for the reflection matrix and the reflection coefficient are derived. Possibly present uniaxial and/or biaxial retarders can be included in the calculation. Conservation of energy an…
We report angle-resolved photoemission spectroscopy (ARPES) on a single Cu-O chain compound ${\mathrm{Sr}}_{2}{\mathrm{CuO}}_{3}$ with Ne I photons. In contrast with previous ARPES with higher-energy photons, the present result clearly shows two well-separated branches of dispersions near ${E}_{F}$ ascribable to spino…
Electronic structures of halogen bridged mixed-valence (MV) complexes ${\mathrm{Cs}}_{2}{\mathrm{Au}}_{2}{X}_{6} (X$=I, Br, and Cl) have been investigated by means of reflectivity measurements. We have observed five polarization-dependent optical transitions in the energy range of 0.6--5.5 eV. The lower-lying three ba…
The temperature (10--290 K) and magnetic-field (0--7 T) dependencies of optical spectra and their anisotropy have been investigated for a single crystal of ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}(x=0.4),$ which undergoes a charge and orbital ordering transition at ${T}_{\mathrm{co}}=235 \m…
We report the observation of a strongly coupled first-order charge-density wave (CDW) transition in a high-quality single crystal of the intermetallic compound ${\mathrm{Lu}}_{5}{\mathrm{Ir}}_{4}{\mathrm{Si}}_{10}.$ The first-order nature is ascertained by a very narrow and huge cusp (360 J/mol K) in the specific heat…
Suppression of the multiphoton fluorescence contribution to the hyper-Rayleigh (second-order nonlinear optical) scattering signal was recently achieved by intrinsic demodulation of the fluorescence at high amplitude-modulation (AM) frequencies [Olbrechts et al., Rev. Sci. Instrum. 69, 2233 (1998)]. These high AM frequ…
Dielectric surface flashover in vacuum is characterized by a three-phase development, as shown by current measurements covering the range from 10−4 to 100 A, assisted by x-ray emission measurements, high speed photography, and time-resolved spectroscopy. Further information is gained from a comparison of the flashover…
New dianhydrides containing t-butyl and phenyl pendant groups have been synthesized and used as monomers, together with commercial diamines, to prepare novel polyimides. The influence of the chemical structure of the monomers on their reactivity has been studied by quantum semiempirical methods. The polyimides have be…
As a contribution to the understanding of the thermodynamics of the glass transition phenomenon a series of molecules having the same steric character, but differing in the strength and nature of intermolecular interactions, has been investigated. The series is based on systematic changes of substituents on disubstitu…
Structural materials for first–wall and breeding-blanket components will be exposed to 14\3MeV neutrons, plasma particles and electromagnetic radiation. In magnetically confined systems, the operation mode will be quasi–continuous. Typical operation conditions for next–step devices and demonstration plants will be des…
The surface phonon mode of CdSe quantum dots in a glass matrix was investigated by Raman spectroscopy. The blueshift and broadening of the surface phonon frequency were observed as the quantum dot size was reduced. It was shown that the observed size-dependent blueshift and broadening are mainly caused by the lattice…
The transition from the dynamics of isolated molecules to that of a bulk liquid is observed for the first time by analyzing the dielectric relaxation $({10}^{\ensuremath{-}2}--{10}^{9}\mathrm{Hz})$ of ethylene glycol (EG) guest molecules confined to zeolitic host systems of different topology. Beyond a threshold chann…