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。
The recently discovered superconductor MgB2, with a transition temperature of 39K, has significant potential for future electronics. An essential step is the achievement of Josephson circuits, of which the superconducting quantum interference device (SQUID) is the most important. Here, we report Josephson quantum inte…
A constitutive model is derived for the time-dependent response of particle-reinforced elastomers at finite strains. An amorphous rubbery polymer is treated as a network of long chains linked by permanent junctions (chemical crosslinks, entanglements and filler particles). A strand between two neighboring junctions is…
This study investigates structural similarities in polyfluorosilicone (PFSi) gels made by different cross-linking procedures, using small-angle neutron scattering (SANS). The scattering properties of gels prepared from long and short precursor chains and of the un-cross-linked polymer solutions are reported. The gel s…
Phenol mineralization in the aqueous phase was studied employing oxygen as the oxidant. The reaction was carried out at intermediate oxygen pressures (3.2−16 bar) and temperatures (127−180 °C) employing a commercial catalyst supplied by Engelhard (Cu-203T). Two experimental setups were used: a basket stirred-tank reac…
We examined the epitaxial growth of ZnO films on a sapphire (0001) substrate by an atmospheric pressure atomic layer epitaxy technique using ZnCl 2 and O 2 sources. The films were deposited epitaxially in a substrate temperature range of 450−550 °C with a constant growth rate of 0.26 nm/cycle. It is noteworthy that th…
The surface segregation of a fluorochemical additive from a polyolefin host matrix has been investigated by X-ray photoelectron spectroscopy, optical microscopy, tapping mode atomic force microscopy, imaging time-of-flight secondary ion mass spectrometry, and contact angle analysis. The level of surface enrichment has…
The molecular mechanics and dynamics calculations, kinetics, and laser-excited luminescence studies were carried out for trivalent lanthanide (Ln(3+)) complexes of macrocyclic polyaminopolycarboxylate ligands TETA and DOTA (where TETA is 1,4,8,11-tetraazacyclotetradecane-1,4,8,11-tetraacetic acid and DOTA is 1,4,7,10-…
The synthesis and structural characterization of the first examples of microporous europium(III) and terbium(III) silicates (Na(4)K(2)X(2)Si(16)O(38) x 10H(2)O, X = Eu, Tb) are reported. The structure of these solids was solved by powder X-ray diffraction ab initio (direct) methods and further characterized by chemica…
Certain emerging fields of nanotechnology depend on self-assembly processes that lead to molecular structures which are organized and ordered or disorganized and disordered. Many such processes can be understood as combinations of nucleation, reversible growth, and reversible aggregation. We develop a descriptive theo…
Dual-mode electron paramagnetic resonance (EPR), in which an oscillating magnetic field is alternately applied parallel or perpendicular to the static magnetic field, is a valuable technique for studying both half-integer and integer electron spin systems and is particularly useful for studying transition metals invol…
The ferroelectricity of BaTiO 3 is investigated with the plane-wave pseudopotential method and the LCAO quantum chemical approach in the framework of density functional theory (DFT). Potential energy surfaces of various atomic displacements and the influence of lattice strain and lattice volume on the surfaces are exa…
Magnetodynamics in epitaxial Fe1-xCox films on GaAs (100) are studied using time-resolved ferromagnetic resonance, in which the free precession of the magnetization after an impulsive excitation is measured using the polar Kerr effect. The sample is rotated with respect to the static and pulsed field directions, provi…
Reproducible high-yield purification process of singlewalled carbon nanotubes was developed by combining two-step processes of thermal annealing in air and acid treatment. The process involves the thermal annealing in air with the powders rotated at temperatures of 470 °C for 50 min, which burns out the carbonaceous p…
We report the estimation of diffusion constants for oxygen vacancies in MgO based on optical absorption spectra. MgO single crystals were annealed in a reducing atmosphere (H 2 + Ar) to create oxygen vacancies and the samples were annealed in an oxidizing atmosphere (O 2 + Ar) to annihilate them. Fe 3+ impurities in t…
Abstract The homopolyester of 4‐hydroxyphenylacetic acid (HPAA) was synthesized by one‐pot, slurry‐melt, and acidolysis melt polymerization techniques and was characterized by its inherent viscosity and IR and NMR spectra. Differential scanning calorimetry (DSC), polarizing light microscopy (PLM), and wide‐angle X‐ray…
We investigated the temperature-dependent infrared properties of the compound θ-(BEDT-TTF) 2 RbZn(SCN) 4 . At temperatures above the metal-insulator transition, the optical conductivity remains finite in the low-energy region, but shows no conventional Drude feature typical of metals. Below the metal-insulator transit…
We imaged at single-particle resolution the birth, life and death of a sub-critical nucleus containing ~10 3 particles in a crystallizing hard-sphere colloidal fluid at volume fraction ϕ = 0.51. This gives a lower bound to the critical nuclear size for hard-sphere crystallization at this volume fraction.
The crystal structure of m-nitroaniline has been examined at several temperatures over the 90-350 K range. Thermal evolution of the lattice parameters reveals a weak anomaly at 110 K and an important one at 300 K. The thermal expansion coefficients have been calculated at several temperatures and the principal axes cr…
The crystal structure of the commensurate phase of Ca(2)CoSi(2)O(7), dicalcium cobalt disilicate, has been derived from the modulated structure described in (3 + 2)-dimensional space. The structure is orthorhombic P2(1)2(1)2; a = 23.510 (4), b = 23.510 (4), c = 5.025 (1) A (at 170 K), Z = 18. Since the crystal is twin…
The anchoring of the nematic liquid crystal N-(p-methoxybenzylidene)-p-butylaniline (MBBA) on Langmuir-Blodgett monolayers of fatty acids (COOHC(n)H(2n+1)) was studied as a function of the length of the fatty acid alkyl chain n (n=15,17,19,21). The monolayers were deposited onto glass plates coated with indium tin oxi…