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。
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMetal-insulator transitions in La1-xTiO3, 0.0 .ltoreq. x .ltoreq. 0.33. structure-property correlationsM. J. MacEachern, H. Dabkowska, J. D. Garrett, G. Amow, Wenhe Gong, Guo Liu, and J. E. GreedanCite this: Chem. Mater. 1994, 6, 11, 2092–2102Publication Date (Print):Novembe…
Crystallography provides a major approach toward reaching an understanding of the relationship between crystal structure and material physical properties. The specific relationships of five highly structure dependent physical properties, namely piezoelectricity, pyroelectricity, ferroelectricity, ferroelasticity and o…
Brewster angle microscopy (BAM) and polarized fluorescence microscopy (PFM) were used to observe domains of a tilted condensed phase in coexistence with an isotropic liquid phase in Langmuir monolayers of pentadecanoic acid. The orientation of the molecular tilt direction inside the domains can be described as a ‘‘vir…
Summary X‐ray detection by energy‐dispersive spectrometry in the analytical electron microscope (AEM) is often limited by low collected X‐ray intensity ( P ), modest peak‐to‐background ( P/B ) ratios, and limitations on total counting time (τ) due to specimen drift and contamination. A new AEM has been designed with m…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of "Wheel-and-Axle"-Type Porphyrin Arrays Composed of Phosphorus PorphyrinsHiroshi Segawa, Kazuhiko Kunimoto, Kimihiro Susumu, Masahito Taniguchi, and Takeo ShimidzuCite this: J. Am. Chem. Soc. 1994, 116, 24, 11193–11194Publication Date (Print):November 1, 1994Publ…
Abstract Previous studies have demonstrated techniques by which model elastomers prepared by end linking poly(dimethylsiloxane) (PDMS) chains can be reinforced by the in-situ precipitation of silica from a base-catalyzed sol-gel conversion of tetraethoxysilane (TEOS). The present investigation extends this technique t…
We have investigated the electron affinity of (111) and (100) single crystalline surfaces of chemical-vapor-deposited diamond with additional treatments. For specimens exposed to hydrogen plasma (H treatment), the electron affinities are found to be negative from photoyield spectra using ultraviolet synchrotron radiat…
The stable Al-Cu-Co, Al-Ni-Co and Al-Ni-Fe decagonal quasicrystalline phases were studied by transmission electron microscopy and powder X-ray diffraction. These phases were found to be isotypic in all three alloy systems. Minor differences in the intensity distributions in their electron diffraction patterns can be a…
5-Formyltetrahydropteroylpolyglutamate (5-CHO-H4PteGlun) is the only reduced folate derivative that is stable to oxidation and alkaline pH. However, no metabolic role has been assigned to this folate derivative, and evidence for its existence in cells has been questioned. Recently, serine hydroxymethyltransferase was…
Silicon oxycarbide glasses were synthesized by the sol‐gel process using precursors such as methyl‐, propyl‐, and phenyltrimethoxysilanes. The final products contained 14–38 wt% carbon. A TEM study on the nanometer scale revealed that all of the materials were amorphous and monophasic, and that it was not possible to…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDesign and Synthesis of Functionalized Polyimides for Second-Order Nonlinear OpticsDong Yu and Luping YuCite this: Macromolecules 1994, 27, 23, 6718–6721Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994ht…
Donor doping, with La and Nb, has been used successfully to improve the leakage resistance of Pb(Zr,Ti)O 3 (PZT) films. Donor doping of Pb(Zr 0.5 Ti 0.5 )O 3 films has led to an improvement in the leakage resistance of over 2 1/2 orders of magnitude at elevated temperatures (T 100°C). The effect on leakage resistance…
From the phenomenological theory, the size effects on dielectric properties of ferroelectric thin films were calculated. When the spontaneous polarization is reduced in the surface layer, the mean susceptibility of the film increases with the decrease in film thickness and a size-driven phase transition will take plac…
Alkoxy‐substituted thiophenes have been shown to yield polymers with a reduced bandgap. An X‐ray investigation of two symmetrical pentoxy‐substituted 2,2′‐bithienyls is reported, and their structure and packing described. It is suggested that the extra rigidity and packing stability of the alkoxythiophene oligomers an…
This paper presents a method for the reliable extraction of structure-factor amplitude information from the least-squares integrated-intensity refinement of powder diffraction data. The inevitable overlap of Bragg reflections can lead to strongly correlated reflection intensities that can, in turn, produce unrealistic…
Conformational dynamics and relaxation of the torsional angle autocorrelation (ACF) function in bulk polybutadienes (PBD) have been studied over a wide temperature range via molecular dynamics simulations. All trans, all cis and 70 mol % trans were the configurations of the systems studied. Companion studies of these…
The coherent (111) twin boundary in BaTiO3 has been investigated using quantitative high-resolution transmission electron microscopy and spatially resolved electron-energy-loss spectroscopy (EELS). Lattice images under different defocusing conditions were obtained and compared with simulated images for different struc…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBrosted Acidity of a Superacid Sulfate-Doped ZrO2 SystemC. Morterra, G. Cerrato, F. Pinna, and M. SignorettoCite this: J. Phys. Chem. 1994, 98, 47, 12373–12381Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November…
A three-dimensional, electromechanical constitutive law has been formulated for electrostrictive ceramic materials. This fully coupled, phenomenological model relates the key state variables of stress, strain, electric field, polarization and temperature in a set of compact nonlinear equations. The direct and converse…
We have performed measurements of the surface impedance in the normal and superconducting states of the title compounds in the millimeter wave-frequency range (1--3 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$), and have evaluated the complex conductivity for different crystallographic orientations. Above the transition…