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。
Protein geranylgeranyltransferase type-I (GGTase-I) transfers a geranylgeranyl group from the prenyl donor geranylgeranyl diphosphate (GGPP) to the cysteine residue of substrate proteins containing a C-terminal CaaX-motif (a sequence motif of proteins consisting of an invariant Cys residue fourth from the C-terminus).…
The electronic band structure and the local screening effects of the transition-metal perovskites ${\mathrm{La}}_{0.65}{A}_{0.35}\mathrm{Mn}{\mathrm{O}}_{3}$ ($A=\mathrm{Ba}\mathrm{and}\mathrm{Ca}$) have been examined across the coupled magnetic-metallic phase transition using the techniques of angle-resolved photoemi…
The molecule Bcl was generated by chlorination of B(s) with both MgCl2 and SrCl2 in a heated effusive beam source, and identified by mass spectrometry. Gaseous equilibria in the B–Mg–Cl and B–Sr–Cl systems were studied in the regions 1350–1600 K and 1760–1830 K, respectively, and the dissociation energy D0°(Bcl)=121.3…
Direct current (dc) resistivity studies have been made on two series of Ni–Zn–Sc ferrites with varying concentrations of zinc and scandium to estimate the effects of composition, temperature, and applied electric field. The resistivity has been found to increase with the increase in scandium/zinc content in both the s…
Optical and electrochemical properties of vanadium pentoxide (V2O5) films prepared by sol-gel method from organic and inorganic precursors were studied. The organic gel was obtained by hydrolysis and polycondensation of vanadium isopropoxide dissolved in isopropanol. The inorganic gel was prepared from aqueous solutio…
Magnetostriction measurements using high-pulsed magnetic fields up to 14 T and thermal expansion measurements under hydrostatic pressure up to 12 kbar have been performed in Hf1−xTaxFe2−y alloys with x=0.17 and 0.15 and y=0.02. These compounds have a first-order magnetic phase transition from an antiferromagnetic (AF)…
Magnetotransport properties were investigated for Sm1−xSrxMnO3 films that were prepared by the pulsed laser deposition technique. Application of a magnetic field causes a huge change in the resistivity for x=0.45, 0.50, and 0.55, in some cases exceeding five orders of magnitude. Measurement of the magnetization curve…
We present a detailed study of the dynamics of electronic wave packets in Fibonacci semiconductor superlattices, both in flat band conditions and subject to homogeneous electric fields perpendicular to the layers. Coherent propagation of electrons is described by means of a scalar Hamiltonian using the effective-mass…
Photoluminescence decay times and quantum yields were measured at 77 K in the spectra of two Si-doped diamond films grown by the chemical-vapor deposition technique. A decay time of 950 ps for both films and a quantum yield of 0.05 for one film were determined for the Si center zero-phonon optical transition at 737 nm…
Electrical resistivity ($\ensuremath{\rho}$) and Seebeck-coefficient measurements ($\ensuremath{\alpha}$) are reported for $\mathrm{Ni}{\mathrm{S}}_{2\ensuremath{-}x}{\mathrm{Se}}_{x}$ single crystals in the range $0<~x<~0.71$. There is a general trend toward increasing metallicity with increasing $x$. In the ra…
We study the nonradiative Auger decay of excitons in ${\mathrm{Cu}}_{2}$O, in which two excitons scatter to an excited electron and hole. The exciton decay rate for the direct and the phonon-assisted processes is calculated from first principles; incorporating the band structure of the material leads to a relatively s…
The first spectroscopic characterization of the VO2 radical is reported along with new results for V17O and tentative assignments for the VO3 and V+2 radicals. These vanadium radicals were investigated in neon matrices at 4 K by electron spin resonance utilizing conventional high temperature vaporization and pulsed la…
The infrared local mode at 1450 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$ in diamond, called H1a, has been studied in samples containing mixtures of $^{12}\mathrm{C}$ and $^{13}\mathrm{C}$ in several different ratios. It was previously associated with a nitrogen interstitial, assumed to be on a 〈001〉 split site [G. S…
We explore the application of the semiconducting phases of YBaCuO thin films as a bolometer for uncooled infrared detection. For this study, four different structures were built with different types of buffer layers: YBaCuO on a Si substrate with and without a MgO buffer layer, and on an oxidized Si substrate with and…
The spatial distributions of the cathodoluminescence (CL) emissions from thin ZnS films on GaAs(100) have been examined by the low-temperature CL measurement system combined with a transmission electron microscope (TEM). The correlation between these CL emissions and structural defects were studied by comparing the mo…
The atomic structure of the 2\ifmmode\times\else\texttimes\fi{}4 reconstructed GaAs (001) surface, prepared in optimized molecular beam epitaxy growth conditions, has been fully determined by in situ grazing incidence x-ray diffraction measurements. The structure involves only two dimers in the As top layer, in agreem…
We have proposed ReMnO3 (Re: rare earth) thin films for nonvolatile memory devices. We examine the growth mechanism of YMnO3 films on (0001)ZnO:Al/(0001) sapphire substrate using rf magnetron sputtering and pulsed laser deposition methods with oxide compound target. We have succeeded in obtaining (0001) epitaxial YMnO…
We have studied photoluminescence (PL) properties of surface-oxidized Ge nanocrystals with a 3.7 nm diameter. A difference between the absorption and PL excitation spectra and time-resolved PL measurements show that the site for the radiative recombination of excitons is different from that for the photogeneration of…
Neutron-scattering experiments have been performed on a LaMnO 3 single crystal. The spin waves exhibit two-dimensional anisotropic dispersion, that is, strong planar ferromagnetic coupling and weak antiferromagnetic interplane coupling with a finite gap. The critical exponent β of the order parameter is 0.25 ±0.01, wh…
Spin-resolved and high-energy-resolution x-ray-photoelectron spectra of the 3d, 4d, 4f, and 5p levels of ferromagnetic Gd are reported. The experimental spectra are compared with theoretical predictions for bulk Gd based on atomic multiplet calculations. The agreement is quite good when the Slater integrals are reduce…