Materials Literature
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RATIONALE AND OBJECTIVES: To evaluate the physical and pharmacological profiles of SH U555A, a suspension of magnetic iron oxide particles that is designed to enhance the visualization of liver tumors and metastases. MATERIAL AND METHODS: Chemical and physical methods were used to characterize the size and structure o…
This paper presents a review on Latosols (oxisols) genesis, classification and use in tropical Brazil.Chemical, physical and mineralogical aspects are throughly discussed, as well as their relationship withsoil use and management. Some problems of definition are considered for all types of Latosols recognizedin the Br…
Results of an investigation into the influence of hydrosol pH on the optical properties of gold colloidal particles capped with a novel aromatic bifunctional molecule, 4-carboxythiophenol (4-CTP), are presented. Changes in the optical properties of the carboxylic acid derivatized clusters have been interpreted as aris…
Compositional zoning in hundreds of almandine‐rich garnets in amphibolite by facies micaceous quartzites from the Picuris Range, north‐central New Mexico USA, indicates that although Mn, Mg and Fe achieve chemical equilibrium at hand‐sample scale during garnet growth, Ca does not. Instead, Ca concentrations at the sur…
Cancer chemotherapy is not always effective. Difficulties in drug delivery to the tumor, drug toxicity to normal tissues, and drug stability in the body contribute to this problem. Polymeric materials provide an alternate means for delivering chemotherapeutic agents. When anticancer drugs are encapsulated in polymers,…
The EXAFS Debye-Waller factor depends on the correlation of atomic motion and can yield original information on the vibrational dynamics of crystalline solids. In this paper an introductory treatment of thermal disorder in EXAFS, based on thc cumulant approach, is given. Thc general relation between mean-square relati…
We have studied transport properties (resistivity, Hall effect, thermopower, and thermal conductivity) of Bi 2 S 3 and two new ternary bismuth sulfides, KBi 6.33 S 10 and K 2 Bi 8 S 13, to explore their potential for thermoelectric applications. While both Bi 2 S 3 and K 2 Bi 8 S 13 display an essentially metallic con…
Abstract In this research, the effects of the materials and the processing conditions on the cell morphology of foamed PVC/wood‐fiber composites were studied with a view to establishing their process‐structure relationships. Each step of microcellular PVC/wood‐fiber composites processing is addressed, including the su…
A new formulation of the coupled-wave method for two-dimensional gratings is proposed. It is based on mathematical and physical results recently obtained for one-dimensional gratings. Numerical evidence obtained for many different diffraction problems, including dielectric, metallic, volume, and surface-relief grating…
Ferrous dodecyl sulfate, Fe(DS) 2, micellar solution was used to make nanosized magnetic particles whose size is controlled by the surfactant concentration and by temperature. The average particle size varies from 3.7 to 11.6 nm, with a standard deviation ranging from 0.22 to 0.34. In contrast to what is obtained in h…
The magnetic properties of oxo-bridged oxo-(carboxylato)-bridged and oxo-bis(carboxylato)-bridged iron(III) dimers are found to depend on the iron−(μ-O) distance as well as on the iron−(μ-O)−iron angle. With an angular and radial overlap model we account for both these dependencies. The use of an angular overlap model…
The specialized‐performance polymers poly(arylene‐1,3‐oxadiazole)s —see Figure for an example—have high‐value end uses based on their electronic, optical, and thermal properties. The syntheses, solid‐state structure, properties, and applications of poly(arylene‐1,3,4‐oxadiazole)s are reviewed. magnified image
Polymer-protected Pd−Pt bimetallic colloids in the size range 1.5−5.5 nm with controllable core/shell structures have been successfully prepared by a so-called hydrogen-sacrificial protective strategy. The obtained bimetallic colloids were characterized by transmission electron microscopy and infrared carbon monoxide…
New semiconductors and host materials are expected to be found among newly synthesized boron/carbon/nitrogen (B/C/N) materials based on the graphite network. The synthesis, structure, and properties of such materials, including solid solutions, more‐ordered B/C/N hybrids, and compounds (e.g., BC 3 , C 5 N, BC 2 N, BC…
Starting from a single precursor, bis(3-methoxysalicylaldehydato)copper (II), which contains an O(4)Cu chromophore, three routes to discrete dinuclear Cu(II)/Ln(III) complexes (Ln = Pr, Eu, Gd, Yb) are described. The pairs of chromophores occurring in the resulting complexes are either O(4)Cu/O(4)Ln or O(2)N(2)Cu/O(4)…
New reflection and transmission optical filters based on guided-mode resonances in multilayer waveguide gratings are characterized and compared with homogeneous thin-film filters. These guided-mode resonance filters are implemented by integration of diffraction gratings into classical thin-film multilayers to produce…
The crystal structure of the emptied clathrate form (δ e form) of syndiotactic polystyrene, obtained by removing the guest molecules from different clathrate δ forms, is presented. Chains in s(2/1)2 helical conformation are packed in the monoclinic unit cell with axes a = 17.4 Å, b = 11.85 Å, c = 7.70 Å, and γ = 117°…
Abstract Donor–acceptor polyenes of various lengths, and that combine aromatic electron‐donating moieties with powerful heterocyclic electron‐withdrawing terminal groups, have been synthesized and characterized as efficient nonlinear optical (NLO) chromophores. Their linear and nonlinear optical properties have been i…
The linear and nonlinear optical properties of donor−acceptor π-electron chromophores having conjugated bridges varying in aromaticity and electron excessivity are investigated using the INDO/1 semiempirical Hamiltonian. NLO response properties of such chromophores are more sensitive to the electron excessivity of the…
The first detection and characterization of oxomanganese(V) porphyrin complexes under ambient catalytic conditions is described. The reaction of (tetra-( N -methylpyridyl)porphyrinato)manganese(III) [Mn(III)TMPyP] with a variety of oxidants such as m -chloroperoxybenzoic acid ( m -CPBA), HSO 5 -, and ClO - has been sh…