Materials Literature
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Nanostructured NdFeB films were prepared by magnetron sputtering followed by rapid thermal annealing at a ramp rate of 200 °C/s. Isotropically oriented Nd2Fe14B crystallites were formed in the films and coercivities up to 20 kOe and remanence ratios up to 0.8 were obtained. Transmission electron microscopy analysis sh…
Abstract The general concepts of x-ray and neutron reflectivity are outlined. Theoretical principles are discussed at the beginning where both, the optical treatment based on the solution of the Helmholtz equation and the kinematical scattering formalism are given. Afterwards experimental standard setups are presented…
This work describes the synthesis of new adamantane-based polyimides by reaction of 1,3-bis(4-aminophenyl)adamantane (4) with various aromatic tetracarboxylic dianhydrides (5). The films have low dielectric constants ranging from 2.76 to 2.92. The poly(amic-acid)s 6 have inherent viscosities of 0.98∼1.42 dL/g. The pol…
Ostwald solubility coefficients, as log L, for solutes in water and ethanol have been combined to give log P EtOH for partition between the two pure solvents. Sixty-four such values have been correlated through our solvation equation, the coefficients of which lead to the conclusion that ethanol and water solvents are…
We study the crossover from quasi-free electron to small polaron in the Holstein model for a single electron by means of both exact and self-consistent calculations in one dimension and on an infinite coordination lattice. We show that the crossover occurs when both strong coupling (λ > 1) and multiphonon (α 2 > 1) co…
All articles of this category Solid bases prepared by derivatisation of amorphous silica and hexagonal mesoporous silica with dimethylaminopropyl groups are good catalysts for Michael addition reactions. Of the prepared catalysts, those based on hexagonal mesoporous silica show particularly high activities. The sol-ge…
An analytical method is developed for the effective magnetostriction of magnetostrictive composites based on Green’s function technique. For an elastically isotropic composite of magnetostrictive and nonmagnetostrictive phases, the analytical results give explicit effective-medium approximate formulas for the effectiv…
Oxidation studies of hot‐pressed RE‐α‐sialons, RE x ‐Si 12‐4.5 x Al 4.5 x O 1.5 x N 16‐1.5 x (with x = 0.40 for RE = Nd, Sm, Yb; and x = 0.48 for RE = Y) were carried out in oxygen in a TG apparatus for ca. 20 h. Very good oxidation resistance was found for the Yb‐doped samples, with parabolic rate constants K p simil…
The reaction-induced phase separation in a blend of a commercial polysulfone (PSu) with diepoxide-cyclic anhydride monomers, was studied. The diepoxide was based on diglycidylether of bisphenol A (DGEBA) and the hardener was methyl tetrahydrophthalic anhydride (MTHPA), used in stoichiometric proportion. Benzyldimethyl…
Experiments using time-correlated photon counting and optical bandpass filters measure new features in the time and spectral dependences of single-bubble sonoluminescence (SBSL). The SBSL full width at half maximum (FWHM) varies with wavelength at 3 \ifmmode^\circ\else\textdegree\fi{}C, but not at 24 \ifmmode^\circ\el…
We present an optimization-based synthesis algorithm for the design of diffractive optical elements (DOE’s) that are finite in extent, have subwavelength features, and are aperiodic. The subwavelength nature of the DOE’s precludes the use of scalar diffraction theory, and their finite extent and aperiodic nature preve…
A new photoluminescent material has been synthesized by the interaction of (3-aminopropyl)triethoxysilane with acetic acid under oxygen-free conditions. The photophysical properties of this material in bulk form, colloidal solution, and thin films have been studied by absorption, excitation, steady-state fluorescence,…
Coulomb blockade (CB) was observed in Al/aluminum oxide/Ni nanowire single-junction arrays fabricated by electrochemical deposition of Ni into porous aluminum oxide nanotemplates. The bias dependence of the tunneling current and the temperature dependence of the zero-bias anomalies observed in the tunneling spectra ar…
The reduction of [N(octyl) 4 ] 2 [CuCl 2 Br 2 ] in organic solution (toluene) using Li[BEt 3 H] leads to colloidal Cu protected by cationic surfactants (NR 4 + ). According to HRTEM (high-resolution transmission electron microscopy) and UV/vis data, the organosol is composed of relatively large Cu particles with diame…
cis-Biphenyl-2,3-dihydrodiol-2,3-dehydrogenase (BphB) is involved in the aerobic biodegradation of polychlorinated biphenyls (PCBs). The crystal structure of the NAD+-enzyme complex was determined by molecular replacement and refined to an R-value of 17.9% at 2.0 A. As a member of the short-chain alcohol dehydrogenase…
A model of strength degradation for ceramics subject to damage from contact with hard spheres is developed. Primary attention is focused on tough ceramics with heterogeneous microstructures which deform in a quasi‐plastic mode. Brief consideration is also given to ideally brittle ceramics which form classical ring cra…
Several photosensitive polyimide (PSPI) precursors were synthesised by the acid/base complexations of conventional poly(amic acid) precursors with photochemically cross-linkable 2-(dimethylamino)ethyl methacrylate. PSPIs in films were prepared from the photosensitive precursors by thermal imidisation, whereas the corr…
The new compounds N -phenyl-4,4‘-bipyridinium (PhQ + ), N -(4-acetylphenyl)-4,4‘-bipyridinium (4-AcPhQ + ), and N -(2,4-dinitrophenyl)-4,4‘-bipyridinium (2,4-DNPhQ + ), together with the known ligand N -methyl-4,4‘-bipyridinium (MeQ + ), have been used to prepare a series of Ru(II) complex salts trans -[Ru(NH 3 ) 4 (L…
Single-crystal Ni2MnGa shows a nearly 0.2% strain under a magnetic field of 8 kOe at −8 °C. Polycrystalline samples have been prepared near stoichiometry to study the composition dependence of the magnetic and elastic properties. A narrow band of compositions has been found having a range of Curie and martensitic tran…
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