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。
We study the recombination mechanism of the visible photoluminescence (PL) S-band in p-doped porous Si layers by time-resolved photoluminescence. From the observed ‘‘stretched-exponential’’ PL decays we present a simple yet accurate evaluation method for lifetime distributions G(τ) and average recombination lifetimes…
The electron-electron correlation has been considered by using the local-spin-density approximation (LSDA) with on-site Coulomb interaction (LSDA+U) in the first-principles discrete variational cluster method. Based on the correction to LSDA, we have carried out the self-consistent electronic-structure calculations fo…
Abstract Phenylacetylenes having one or two trimethylsilyl groups at their benzene ring were synthesized, and polymerized by [Rh(cyclooctadiene) (PPh 3 ) 2 ]PF 6 , [Rh(norbornadiene)Cl] 2 , or WCl 6 to afford high molecular‐weight polymers in high yields. These poly(phenylacetylene)s were soluble in many kinds of solv…
Abstract When poly(butylene terephthalate) (PBT) is annealed, a second endotherm is often displayed in a subsequent scanning thermal analysis at a temperature below that of the original endotherm, and this new endotherm appears to grow with annealing at the expense of the original. This growth is not due to chemical c…
Soft-recovery plate impact experiments have been conducted to study the evolution of damage in polycrystalline Al2O3 samples. Examination of the recovered samples by means of scanning electron microscopy and transmission electron microscopy has revealed that microcracking occurs along grain boundaries; the cracks appe…
Periodic Hartree-Fock total-energy calculations on two-dimensional slabs have been used to study the symmetry-conserving relaxation of the nonpolar (101\ifmmode\bar\else\textasciimacron\fi{}0) surface of ZnO. We find that it is energetically favorable for the Zn-O surface dimers to tilt slightly (by 2.3 \ifmmode^\circ…
Rhombohedral Cr 2 Se 3 is an antiferromagnetic compound with antiferromagnetic AF(L) phase below 38 K (= T t ) and the antiferromagnetic AF(H) one between 38 K and 45 K (= T N ). Neutron diffraction studies for rhombohedral Cr 2 Se 3 are carried out at temperatures from 6 K to 77 K. The results show that the magnetic…
The transverse thermal conductivities of SiO2 thin films are determined as a function of film thickness. The results indicate that the apparent thermal conductivities of SiO2 thin films are much lower than the thermal conductivity of bulk SiO2. In addition, a slight decrease in the thermal conductivity is observed as…
Abstract The anisotropy of the thermal expansion of polyimide films was investigated . Out‐of‐plane or thickness direction coefficients of linear thermal expansion (CTE) were calculated from the difference between the coefficient of volumetric expansion (CVE) and the sum of the in‐plane or film direction coefficients…
A systematic study of Sn-doped lead zirconate titanate ceramics has been carried out as a function of Sn and Ti contents. Dielectric constant and remanent polarization measurements have been performed and compared to our recent transmission electron microscopy study. The dielectric maximum was found to be associated w…
We report on the optical band gap of the filled tetrahedral semiconductor LiZnAs [viewed as a hypothetical zinc-blende (ZnAs${)}^{\mathrm{\ensuremath{-}}}$ lattice partially filled with He-like ${\mathrm{Li}}^{+}$ interstitials]. The band-structure nature of LiZnAs is found to be direct with a forbidden gap of 1.51 eV…
Heavily doped polypyrrole-hexafluorophosphate, PPy(${\mathrm{PF}}_{6}$), undergoes a metal-insulator (M-I) transition at resistivity ratio ${\mathrm{\ensuremath{\rho}}}_{\mathit{r}}$=\ensuremath{\rho}(1.4 K)/${\mathrm{\ensuremath{\rho}}}_{\mathit{r}}$(300 K)\ensuremath{\approxeq}10: for ${\mathrm{\ensuremath{\rho}}}_{…
We have shown that sterically stabilized (Stealth) liposomes (SL), can accumulate in the extracellular space within tumors, and may improve pharmacokinetics and therapeutic efficacy of encapsulated doxorubicin (SL-DOX). When SL-DOX were incubated in vitro at different temperatures with 50% bovine serum, approximately…
We measured the D - E hysteresis loop of TGS (triglycine sulphate), and transformed it to the q - E hysteresis loop by a method proposed in this paper, where q is the volume fraction of reversed domains. The experimental result was compared with a theory based on the Avrami model by the present authors [H. Orihara, S.…
Abstract Structural changes of native and regenerated silk fibroin membranes were induced by immersion in water‐methanol solutions and examined as a function of immersion time and methanol concentration. X‐ray diffractometry and infrared spectroscopy data showed that transition from random coil to β‐sheet structure oc…
A process based on the Kratschmer-Huffman carbon arc method of preparing fullerenes has been used to generate carbon-coated cobalt and cobalt carbide nanocrystallites. Magnetic nanocrystallites are extracted from the soot with a gradient field technique. For Co/C composites, structural characterization by x-ray diffra…
The chemical composition of thin native oxide layers grown on GaAs and InAs by ultraviolet (UV)/ozone and thermal oxidation is investigated using x-ray-photoelectron spectroscopy. Core-level binding energies, core-level intensities, and valence-band spectra are compared with data for bulk crystalline binary or ternary…
Alcaligenes eutrophus NCIMB 11599 was cultivated to produce poly(3-hydroxybutyric acid) (PHB) from glucose by the automatic fed-batch culture technique. The glucose concentration of the culture broth was controlled at 10 to 20 g/L by two methods: using exit gas data obtained from a mass spectrometer and using an on-li…
Magnetic properties of La 1- x Sr x CoO 3 (0 ≤ x ≤0.5) have been studied by magnetization measurements in low magnetic fields. It has been found that there exist spin-glass (0< x ≤0.18) and cluster-glass (0.18 ≤ x ≤0.5) regions. Ferromagnetic long-range order previously reported does not take place. Spin-glass behavio…
Transition between the low- and high-density amorphous H2O was observed with a piston-cylinder apparatus from 77 K to 140 K, almost the glass-transition temperature of the amorphs. The transition was found to occur reversibly and abruptly at ∼135 K and ∼0.2 GPa with a volume change of 0.20±∼0.01 cm3/g and some hystere…