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。
Transparent TeO2-based glass ceramics consisting of nanocrystalline particles such as 15K2O.15Nb2O5.70TeO2 have been prepared, and the effect of surface layers on the second harmonic (SH) intensity has been examined using the Maker fringe method. An enhanced second harmonic generation (SHG) with fine fringe patterns h…
Die Entstehung komplexer Morphologien in lebenden und nicht belebten Systemen ist für Wissenschaftler, die den Ursprung und die Entwicklung von Form und Struktur erforschen, ein großes Rätsel. Während der vergangenen Jahre machten Biologen einerseits und Physiker andererseits bahnbrechende Fortschritte bei der Erkläru…
Nanosized metal-oxide-based composites—novel supramolecular entities—have been assembled and even cross-linked under one-pot conditions. The supramolecular entity (see picture) consists of a paramagnetic icosahedral capsule of the type {MoFe} as a host which encloses a potential electron-reservoir noncovalently bonded…
Photo- and radioluminescence, decay kinetics, and thermoluminescence are reported for a set of Ce3+-doped phosphate glasses. The presence of Gd3+ ions in the glass host matrix at concentrations above 20% enhances the energy transfer towards the Ce3+ emission centers, which results in a remarkable enhancement of the ra…
We report on the observation of stimulated emission in ZnO/MgxZn1−xO superlattices well above room temperature. Two kinds of superlattices grown by laser molecular-beam epitaxy showed clear systematics on the quantum subband levels in absorption and spontaneous emission spectra. Stimulated emission with excitonic orig…
A red phosphor, Li-doped Gd2O3:Eu3+ with high cathodoluminescent brightness was developed. In contrast to Gd2O3:Eu3+ which showed an irregular shape of agglomerated fine particles (the mean particle size <0.5 μm), the morphology of Li doped Gd2O3:Eu3+ crystals was quite regular and pseudospherical (the mean par…
Multiphoton photoelectron spectroscopy reveals the multiple excitation of the surface plasmon in silver nanoparticles on graphite. Resonant excitation of the surface plasmon with 400 nm femtosecond radiation allows one to distinguish between photoemission from the nanoparticles and the substrate. Two different previou…
Recently, an electromagnetic metamaterial was fabricated and demonstrated to exhibit a “left-handed” (LH) propagation band at microwave frequencies. A LH metamaterial is one characterized by material constants—the permeability and permittivity—which are simultaneously negative, a situation never observed in naturally…
At concentrations as low as 0.3 wt % a novel family of bis-urea dicarboxylic acids gel water (see picture). The aggregation state (vesicles, gel, or fibers) depends on the pH, the ionic strength, and the molecular weight of the gelator. In this way, the gelation properties of an aqueous system are controlled by the mo…
The emergence of complex form in living and nonliving systems remains a deep question for scientists attempting to understand the origins and development of shape and structure. In recent years, biologists and physicists have made significant advances in explaining fundamental problems in fields such as morphogenesis…
The real part of the refractive index n(omega) of a nearly transparent and passive medium is usually taken to have only positive values. Through an analysis of a current source radiating into a 1D "left-handed" material (LHM)-where the permittivity and permeability are simultaneously less than zero-we determine the an…
New Ba(DPM) 2 -amine (DPM=dipivaloylmethane) adduct compounds were attempted to be synthesized from Ba(DPM) 2 and amines. Complexes obtained were evaluated based on decreases of their weight with increasing temperature by thermogravimetry. The simple vaporizing phenomenon, showing a one-step weight-reduction curve, wa…
Experimental results of studying the behaviour of dielectric constant under the phase transition into paraelectric state in 10/100-Y/Y PLLZT solid solutions are presented. The investigations are performed on the solid solutions located within the regions of uniphase FE or AFE state of the phase diagrams, as well as on…
Abstract The structure and dynamics of silica and acrylamide gels were studied using a probe diffusion technique of dynamic light scattering (DLS). Latex particles, diameter = 0.05 μm, embedded in the gel network serve as a probe through their diffusion behavior within the network. A quantitative analysis of the homog…
In situ FTIR spectroelectrochemical experiments have been carried out on Cu2+-ZSM-5 with 40 and 100 % ion exchange level with Nafion films coated on glassy carbon electrodes, and on the application of these electrodes to the interaction of NO with the electrogenerated species in aqueous solution. Voltammetric results…
Reaction between tetramethylammonium fluoride (CH 3 ) 4 NF and MoO 3 in 1:1 molar ratio in the minimum amount of dry acetonitrile gives tetramethylammonium trioxyfluoromolybdate (VI), (CH 3 ) 4 N[MoO 3 F] in very high yields. The compound has been characterized by elemental analyses and IR spectral studies. The advant…
Abstract We investigated detailed conditions for synthesizing the tubular form of MCM‐41 mesoporous aluminosilicate. The method is the delayed neutralization method in which the rate of neutralization is one of the controlling factors. Rapid neutralization results in the particulate form while gradual neutralization l…
Langbeinite is a soluble potassium‐magnesium sulfate mineral (K2SO42MgSO4) found as an evaporite in many regions of the world. Langbeinite was used as a reclaiming material in a fine textured (clay loam) saline sodic soil (Grabe Series). This amendment can be dissolved and directly into the irrigation water, displacin…
Recombinant Escherichia coli strains harboring heterologous polyhydroxyalkanoate (PHA) biosynthesis genes were shown to accumulate unusually large amounts of PHA. In the present study, integrated cellular responses of metabolically engineered E. coli to the accumulation of poly(3-hydroxybutyrate) (PHB) in the early st…
Isothermal calorimetry and X-ray diffraction analyses were used to investigate the hydration of tricalcium aluminate (3CaO·Al 2 O 3 ) in 0·5, 1·0 and 3·0 M magnesium sulphate solutions. Hydration was carried out isothermally at temperatures ranging from 30 to 80°C. Monosulphate (Ca 4 Al 2 (OH) 12 ·(SO 4 )·6H 2 O), ett…