Materials Literature
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Finite-field many-body perturbation theory and coupled cluster calculations are reported for the static second dipole hyperpolarizability γαβγδ of trans-butadiene. A very large basis set of [9s6p4d1f/6s3p1d] size (336 contracted Gaussian-type functions) should lead to self-consistent field (SCF) values of near-Hartree…
The synthesis of mesoporous silica materials has been achieved with d -glucose as a nonsurfactant pore-forming agent in the sol−gel reactions of tetraethyl orthosilicate under basic or near neutral (pH 6) conditions. Regardless of the pH values of the medium, transparent and monolithic glucose-containing silica gels c…
Numerical studies of amorphous silicon show that the lowest 4% of vibrational modes are plane-wave like ("propagons") and the highest 3% of modes are localized ("locons"). The rest are neither plane-wave like nor localized. We call them "diffusons." Since diffusons are by far the most numerous, we try to characterize…
A sharp distinction between magnetoresistance (MR) behavior for the magnetic fields applied perpendicular (H_{perp}) and parallel (H_{par}) to the film plane is found in colossal-magnetoresistance film La_{1-x}Ca_{x}MnO_{3} (x \approx 3). At increasing of H_{perp} the MR is first negative (at H_{perp} < 4 kOe), then p…
The effect of disorder on the perpendicular magnetoresistance of magnetic multilayers is investigated theoretically. Various kinds of disorder are considered: (i) interface substitutional disorder and (ii) bulk disorder in the various layers and in the leads. The calculations are based upon the non-equilibrium Green's…
Poly(acrylic acid) (PAAc) and poly(vinyl chloride) (PVC) were treated with an argon plasma to create unsaturated bonds at the surface. By use of X-ray photoelectron spectroscopy and Fourier transform infrared measurements, it was shown that the pendant groups of these polymers are removed by the argon plasma treatment…
Poly(vinylpyrrolidone) (PVP)-stabilized Pt clusters (1.4 nm average particle size) were embedded in an amorphous microporous titania−silica mixed oxide (AMM- Me Si 30 Ti) by means of a modified sol−gel procedure. The Pt particles were shown by transmission electron microscopy to retain their approximate original avera…
V 2 O 5 aerogel (ARG) has been studied as an insertion host for lithium ions and for several polyvalent cations. The stability, reversibility, and capacity for ion insertion and release processes make the amorphous ARG an interesting material for battery applications. The local structural modifications resulting from…
The reversibility of the adsorption isotherms of various gases has been studied on MCM-41 materials of various diameters, and their mixtures have been prepared by mechanical mixing in 1:1 weight ratio. As expected the results of the latter indicated a pore size distribution having two peaks. The isotherms were complet…
Boron nitride (BN) nanotubes have been produced from elemental boron powder using a new low-temperature process, which involves ball milling of boron powder in ammonia gas at room temperature, and followed by annealing at temperatures up to 1300°C in nitrogen gas. Ball milling induces nitriding reactions between the b…
The propriety of the theory presented in the authors' previous paper [Tosaka et al. Macromolecules 1997, 30, 6592], which predicted that monoclinic crystallites are the majority in the β‘-modification of syndiotactic polystyrene, was assessed by examining the structure of the modification. The electron diffraction pat…
Model polyisoprene−polylactide (PI−PLA) diblock copolymers were synthesized by a combination of living anionic polymerization and controlled coordination-insertion polymerization. Living anionic polymerization of isoprene followed by end-capping with ethylene oxide yielded hydroxyl-terminated polyisoprenes (PI−OH) wit…
We report here a simple and low-temperature method to induce the patterning of monolayers of semiconductor nanocrystals with dual color emission. We have used the patterned self-assembled monolayers (SAMs) of alkanethiolates on gold as a template to assemble two specific size CdSe nanocrystals into regular two-dimensi…
Catalytic dendrophanes 9 and 10 were prepared as functional mimics of the thiamine-diphosphate-dependent enzyme pyruvate oxidase, and studied as catalysts in the oxidation of naphthalene-2-carbaldehyde (4) to methyl naphthalene-2-carboxylate (8) (Scheme 1). They are composed of a thiazolio-cyclophane initiator core wi…
The structure of silk fibroin fiber from a wild silkworm, Samia cynthia ricini, whose amino acid sequence is similar to the spider (major ampullate) silk, was determined with solid-state NMR. The 15 N and 13 C labelings for the dominant amino acids, alanine and glycine, residues of S.c.ricini silk fibers, were perform…
Amorphous, atactic polypropylene structures, consisting of 125, 729, and 2197 monomer repeat units folded into periodic cells, were generated to study the effects of simulation size on the transport of small molecules in simulations of amorphous polymers. The diffusion coefficients and solubilities of three particles…
To characterize the possible magnetic structures created on magnetic multilayers a model has been formulated and studied. The interlayer inhomogeneous structures found indicate either (i) a regular periodic, (ii) a quasiperiodic change in the magnetization or (iii) spatially chaotic glass states. The magnetic structur…
The valence level photoemission spectra in the Anderson impurity model for Ce compounds at zero temperature are studied as a function of the photon energy $ω$. Most of former studies on Ce compounds are based on the sudden approximation, which is valid in high energy region. For the photoemission in the adiabatic limi…
This paper first describes the effect of neutron irradiation on the thermomechanical behavior of stress-relieved Zircaloy-4 fuel tubes that have been analyzed after exposure to five different fluences ranging from nonirradiated material to high burnup. In the second part, a viscoplastic model is proposed to simulate,…
The dipolar-random field Ising model (DRFIM) recently introduced displays a behaviour that can be connected to the magnetization of bidimensional magnetic media. Epitaxial magnetic garnet films seem to be the ideal test material for such a model. In this work the results of the measurements performed on garnet samples…