Materials Literature
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Summary Lime, mined gypsum and some gypsum‐like by‐products have been frequently applied to soil to counter acidity. We have examined the changes in the chemical and mineralogical properties of three acid soils resulting from the application of three industrial by‐products (phosphogypsum, red gypsum and sugar foam). W…
Band calculations show that a stripe-like anti-ferromagnetic spin wave is enforced by a 'half-breathing' phonon distortion within the CuO plane of HgBa_2CuO_4. This spin-phonon coupling is increased further by shear distortion and by increased distance between Cu and apical oxygens. The effects from spin-phonon coupli…
A review is given for the recent progress of research in the field of oxide-based diluted magnetic semiconductor (DMS), which was triggered by combinatorial discovery of transparent ferromagnet. The possible advantages of oxide semiconductor as a host of DMS are described in comparison with conventional compound semic…
A semiempirical formalism is presented for deriving interatomic potentials for materials such as caesium or cerium which exhibit volume collapse phase transitions. It is based on the Finnis-Sinclair second-moment tight-binding approach, but incorporates two independent bands on each atom. The potential is cast in a fo…
We use Langer's approach to calculate the reaction rate of a system of two (classical) spins interacting via the exchange coupling $J$ in a magnetic field $H$, with uniaxial anisotropy of constant $K$. We find a particular value of the exchange coupling, that is $j\equiv J/K = j_c\equiv 1-h^2$, where $h\equiv H/2K$, w…
We study linear guided waves propagating in a slab waveguide made up of a negative-refractive-index material, the so-called left-handed waveguide. We reveal that the guided waves in left-handed waveguides possess a number of peculiar properties such as the absence of the fundamental modes, mode double degeneracy, and…
BACKGROUND: One of the features of high-risk atherosclerotic plaques is a preponderance of macrophages. Experimental studies with hyperlipidemic rabbits have shown that ultrasmall superparamagnetic particles of iron oxide (USPIOs) accumulate in plaques with a high macrophage content and that this induces magnetic reso…
Summary The organic carbon content of soil is positively related to the specific surface area (SSA), but large amounts of organic matter in soil result in reduced SSA as determined by applying the Brunauer–Emmett–Teller (BET) equation to the adsorption of N 2 . To elucidate some of the controlling mechanisms of this r…
Magnetotransport properties of the compound Ca4Mn3O10 are interpreted in terms of activated hopping of small magnetic polarons in the non-adiabatic regime. Polarons are most likely formed around Mn3+ sites created by oxygen substoichiometry. The application of an external field reduces the size of the magnetic contrib…
We present a full formalism for the calculation of the linear and second-order optical response for semiconductors and insulators. The expressions for the optical susceptibilities are derived within perturbation theory. As a starting point a brief background of the single and many particle Hamiltonians and operators i…
Wave propagation inside generalized gyrotropic media is considered in the present Letter. It is shown that in this type of materials, the left- and right- handed circularly polarized light can be coupled to each other, which may possess some potential applications to quantum information.
Poly(vinylpyrrolidone)−water solutions of 60−80 wt % PVP apparently do not freeze when cooled far below the expected freezing point. Such solutions remain highly viscous liquids and ultimately become glasses. It has been reported before that when small-angle X-ray scattering from these solutions is measured, occasiona…
For the purpose of providing a route to multifunctionalized dendrimers, new types of 1 → (2 + 1) C -branched monomers, possessing either ester and protected hydroxy groups or mixed esters, were designed and synthesized. Thus, di- tert -butyl 4-(3-[X]oxypropyl)-4-aminoheptanedioate (X = MeCO, 4; X = CH 2 CH 2 CN, 6; X…
By altering solvent/nonsolvent ratio and temperature, a comprehensive study is carried out to understand the molecular aggregation of poly[(1,3-phenyleneethynylene)- alt -oligo(2,5-dialkoxy-1,4-phenyleneethynylene)]s 1 and 2 in solution, which possess different lengths of linear phenyleneethynylene (PE) fragments. Alt…
Strontium titanate precursor thin films were directly deposited on different self-assembled monolayers (SAM) in an aqueous solution at 40−60 °C. We have investigated the film growth rate, mechanism, and kinetics. The film microstructure and thickness can be controlled by appropriate SAM surfaces and solution condition…
An Au/SiO 2 system with most of the metal particles less than 2.0 nm in size were prepared by deposition on silica of preformed gold sols derived from Au(PPh 3 ) 3 Cl. In this form, it was inactive in the CO + O 2 reaction at ca. 333 K, because of the presence of phosphine ligands on the surface of metal particles. Th…
We characterize the dynamic growth rate behavior of a carbon nanotube (CNT) forest grown by means of optical interference phenomena. The CNT growth rate increased with an increase in CNT length at the initial stage and became stabilized after the CNT length was about 2 μm. Then the growth rate started to decelerate, p…
A series of binary (HgSe) and ternary (HgSe 1 - x S x ) mercury chalcogenide clusters are synthesized utilizing a colloidal technique involving the phase separation of metal and chalcogen precursors in the presence of strong Hg(II) coordinating ligands. The clusters vary in size between 2 and 3 nm and possess the cubi…
A three-dimensional networked osmium nanomaterial (N-Os) was prepared by a thermal decomposition of Os3(CO)12 within mesopores of MCM-48. The novel N-Os species shows high catalytic activity and excellent reusability in the oxidation reactions of unsaturated compounds under mild conditions.
gamma-Al(2)O(3)-supported Ir(4) and Ir(6) were prepared by decarbonylation of tetra- and hexanuclear iridium carbonyls, respectively, and compared as catalysts for ethene hydrogenation at atmospheric pressure and temperatures in the range 273-300 K. Rates of the reaction were determined along with extended X-ray absor…