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。
A new structural model of an Al 72 Ni 20 Co 8 decagonal quasicrystal is constructed on the basis of high-angle annular dark-field images and high-resolution electron microscope images. The model is composed of two types of atom clusters with about a 0.4 nm radius as basic structural units, which are similar to the uni…
Carrier-type reversal $(p$ to $n)$ has been observed, in ${\mathrm{Pb}}_{x}{\mathrm{Ge}}_{42\ensuremath{-}x}{\mathrm{Se}}_{48}{\mathrm{Te}}_{10}$ glasses $(0<~x<~20)$ at 8 at. % of lead. dc electrical resistivity (\ensuremath{\rho}) and activation energy for electrical conduction $(\ensuremath{\Delta}E)$ are fou…
We report a comprehensive charge transport study of ion-implanted rigid rod and ladder polymers $p$-phenylenebenzobisoxazole, $p$-phenylenebenzobisthiazole, and benzimidazobenzophenanthroline. The three pristine materials are strong and stable polymers with a room temperature conductivity ${\ensuremath{\sigma}}_{\math…
We report photoluminescence (PL) data on amorphous ${\mathrm{SiO}}_{2}$ in the spectral range of the \ensuremath{\alpha} (4.3 eV), \ensuremath{\beta} (3.1 eV), and \ensuremath{\gamma} (2.7 eV) emissions excited with synchrotron radiation. Differently prepared and treated samples are compared. Neutron irradiation gives…
The recently developed coupled cluster cubic response approach is applied to the calculation of frequency-dependent second hyperpolarizabilities for Ne, Ar, N2, and CH4. A basis set investigation is performed for the static hyperpolarizabilities at the Hartree-Fock and the coupled cluster singles and doubles level (CC…
We studied the electronic structure of ${\mathrm{CaMnO}}_{x}$ $(2.66<~x<~3.00)$ using x-ray photoemission and O $1s$ x-ray-absorption spectroscopy. Analyzing the spectra of the two end members with the configuration-interaction cluster model, we have determined all the main parameters of the electronic structure…
The growth of thin silicate−organic films at the air−water interface of surfactant solutions has been studied in situ by X-ray and neutron reflectivity to a resolution of ca. 5 Å. Surfactant in the solution and the air−water interface itself are involved in directing the growth and final structure of the films. Hexade…
We have observed a significant change of absorption spectrum in the visible region by the irradiation of an intense laser pulse in a double-exchange ferromagnet ${(\mathrm{N}\mathrm{d}}_{0.5}{\mathrm{Sm}}_{0.5}{)}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{MnO}}_{3}$ $(x=0.4)$ thin film. In the ferromagnetic state, t…
We present atomically resolved scanning tunneling microscopy images of single-wall carbon nanotubes (SWNT's) embedded in a crystalline nanotube rope. Although they may be interpreted as of a chiral nanotube, the images are more consistently explained as an achiral armchair tube with a quenched twist distortion. The ex…
The line shape of the one phonon Raman peak has been used extensively in the literature to estimate the crystallite size in porous silicon. However it has been shown that the line shape obtained on top surface experiments depends on the excitation wavelength. Because the porosity depends on depth, previous results are…
The Mooney scorch times of three rubber blends [epoxidized natural rubber (ENR) 50/SMR L, ENR 50/styrene butadiene rubber (SBR), and Standard Malaysian Rubber SMR L/SBR] were studied in the temperature range of 120–160°C using an automatic Mooney viscometer. N-Cyclohexyl-2-benzothiazyl sulfenamide was used as the acce…
Alternating current impedance, Fourier transform Raman/infrared (IR), and luminescence excitation (continuous and time-resolved) measurements have been conducted on solutions of poly(propylene glycol) (MW 4000) complexed with Eu[N(CF3SO2)2]3 salt, EuTFSI3, along with differential scanning calorimetry (DSC) studies. Fr…
To identify key parameters which influence the efficiency of nonenzymatic template-directed oligonucleotide reactions, a kinetic study of oligoguanylate synthesis on a polycytidylate (poly(C)) template has been performed. This oligomerization is satisfactorily described by three kinetic processes: (i) dimerization to…
We report measurements of the resistivity, thermopower, thermal conductivity, Hall coefficient, and magnetic susceptibility of ${\mathrm{RuAl}}_{2}$ over a wide temperature range. Room-temperature sound velocity measurements are also reported. We find that at low temperature ${\mathrm{RuAl}}_{2}$ behaves as a low carr…
Iron samples of different thicknesses have been submitted to laser shocks of short duration. Transmitted wave measurements have been performed by means of polymeric piezoelectric transducers. The records indicate a decrease of the elastic precursor amplitude with increasing propagation distance, as well as a stress re…
Nonlinear optical properties of a fixed molecular dimer, 2,2′-diamino-7,7′-dinitro9,9′-spirobifluorene (ANSF), have been investigated in solution by the degenerate four-wave mixing technique. It has been observed that the orientationally averaged second molecular hyperpolarizability of ANSF in THF is enhanced ten time…
Dynamically vulcanized poly(vinyl chloride)/epoxidized natural rubber (PVC/ENR) thermoplastic elastomers (TPEs) were prepared with a Brabender plasticorder coupled with a mixing attachment by melt mixing. The blends were prepared at 150°C at a rotor speed of 50 rpm. Curatives concentration was steadily increased from…
It has recently been shown that well-ordered ${\mathrm{Fe}}_{3}{\mathrm{O}}_{4}(111)$ films can be prepared epitaxially on clean Pt(111) surfaces; various techniques have indicated that these multilayer films are chemically identical to bulk single crystals. We have studied the electronic structure of such an ordered…
Angle-resolved photoemission spectroscopy (ARPES) measurements on ${\mathrm{NiS}}_{2\ensuremath{-}x}{\mathrm{Se}}_{x}$ single crystals show the evolution of a narrow band near the Fermi level, which develops in the vicinity of the correlation-driven metal-insulator transition. To model the metal-insulator transition,…
We show that epd (gapB) mutants lacking an erythrose 4-phosphate (E4P) dehydrogenase are impaired for growth on some media and contain less pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP) than their epd+ parent. In contrast to a previous report, we found that gapA epd double mutants lacking the glycer…