Electronic States in Two-Dimensional Triangular Cobalt Oxides: Role of Electronic Correlation

We obtain the electronic states and structures of two-dimensional cobalt oxides, Na$_{x}$CoO$_{2}$ (x=0, 0.35, 0.5 and 0.75) by utilizing the full-potential linear muffin-tin orbitals (FP-LMTO) methods, from which some essential electronic interaction parameters are estimated: the bare on-site Coulomb interaction of cobalt U$_{dd}$=7.5 eV renormalizes to 5 eV for x=0.35, the $pd$ hybridizations t$_{pd\sigma}$ and t$_{pd\pi}$ are -1.40 and 0.70 eV, respectively. The density of states at E$_{F}$ decreases from 6-7 states/eV in the local density approximation (LDA) to about 1.0 states/eV in the LDA+U scheme. The role of the intercalation of water molecules and the microscopic mechanism of the superconductivity in Na$_{0.35}$CoO$_{2}$$\cdot$mH$_{2}$O is discussed.Comment: minor errors correcte

The K\"ahler-Ricci flow on surfaces of positive Kodaira dimension

The existence of K\"ahler-Einstein metrics on a compact K\"ahler manifold has been the subject of intensive study over the last few decades, following Yau's solution to Calabi's conjecture. The Ricci flow, introduced by Richard Hamilton has become one of the most powerful tools in geometric analysis. We study the K\"ahler-Ricci flow on minimal surfaces of Kodaira dimension one and show that the flow collapses and converges to a unique canonical metric on its canonical model. Such a canonical is a generalized K\"ahler-Einstein metric. Combining the results of Cao, Tsuji, Tian and Zhang, we give a metric classification for K\"aher surfaces with a numerical effective canonical line bundle by the K\"ahler-Ricci flow. In general, we propose a program of finding canonical metrics on canonical models of projective varieties of positive Kodaira dimension

The mitochondrial genome of the thermal dimorphic fungus Penicillium marneffei is more closely related to those of molds than yeasts

AbstractWe report the complete sequence of the mitochondrial genome of Penicillium marneffei, the first complete mitochondrial DNA sequence of a thermal dimorphic fungus. This 35 kb mitochondrial genome contains the genes encoding ATP synthase subunits 6, 8, and 9 (atp6, atp8, and atp9), cytochrome oxidase subunits I, II, and III (cox1, cox2, and cox3), apocytochrome b (cob), reduced nicotinamide adenine dinucleotide ubiquinone oxireductase subunits (nad1, nad2, nad3, nad4, nad4L, nad5, and nad6), ribosomal protein of the small ribosomal subunit (rps), 28 tRNAs, and small and large ribosomal RNAs. Analysis of gene contents, gene orders, and gene sequences revealed that the mitochondrial genome of P. marneffei is more closely related to those of molds than yeasts

Modified f(G) gravity models with curvature-matter coupling

A modified f(G) gravity model with coupling between matter and geometry is proposed, which is described by the product of the Lagrange density of the matter and an arbitrary function of the Gauss-Bonnet term. The field equations and the equations of motion corresponding to this model show the non-conservation of the energy-momentum tensor, the presence of an extra-force acting on test particles and the non-geodesic motion. Moreover, the energy conditions and the stability criterion at de Sitter point in the modified f(G) gravity models with curvature-matter coupling are derived, which can degenerate to the well-known energy conditions in general relativity. Furthermore, in order to get some insight on the meaning of these energy conditions, we apply them to the specific models of f(G) gravity and the corresponding constraints on the models are given. In addition, the conditions and the candidate for late-time cosmic accelerated expansion in the modified f(G) gravity are studied by means of conditions of power-law expansion and the equation of state of matter less than -1/ 3 .Comment: 13 pages, 4 figure

Growth Mechanism and Structural Correlations of Hydroxyapatites on Surface Functionalized Carbon Fibers

In this study, hydroxyapatites were deposited on surface modified carbon fibers using a simulated body fluid; different amounts of COOH functional group were formed on the fiber surfaces by different degrees of KOH pretreatment. The effect of the surface functional group on the growth features of the hydroxyapatite crystals was analyzed, and the detailed stacking and structural correlations of the grown crystals to the substrate carbon fibers were examined to realize the mineralization mechanism. It was observed that hydroxyapatite nanocrystallites longitudinally constructed a crystal chain along [211] direction; several aligned crystal chains were then bundled to form a spindle structure which ultimately composed differently featured coatings. A mild KOH pretreatment created a small amount of functional group that activated few sites for hydroxyapatite nucleation compliant to the COOH bond structure, yielding a horizontally oriented olive structure under an orientation correlation HAP [112] or [211]//C [100]. A severer treatment induced more nucleation sites; attributed to the repulsion between the close COO(-) ligands, the bond structure was bent, leading to the radially aligned and ball-featured growth of hydroxyapatites with a different correlation HAP [112] or [211] //C [002]. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.064201jes

Histopathological Changes in Gills, Liver, and Kidney Tissues of Bighead Carp (Aristichthys nobilis) Due to the Effects of Acute High-Temperature Stress

Histopathological evaluation of fish tissues is a reliable method for detecting exposure to toxins and other environmental perturbations that cause stress or even death. This study aimed to evaluate the histopathological changes that might occur in the internal organs of Bighead carp (Aristichthys nobilis) following acute high-temperature stress. By examining tissues sampled at various timepoints after heat shock (3, 6, 12, and 24 hours), we observed severe anatomical alterations in three vital organs. In the gills, epithelial lifting and edema, blood congestion, primary lamellae thickening, and secondary lamellae curling, shortening, and fusion were evident. In the liver, karyolysis, necrosis, hyperemia, dilation of sinusoids, nuclear hypertrophy, and congestion of the central vein were observed. Kidneys displayed dilation of the Bowman's space, an increase in the diameter of the renal tubules, hyperemia, shrinkage and congestion of the glomeruli, and tubular necrosis. Cumultaively, this analysis indicates that Bighead carp are highly susceptible to changes in environmental temperature, and rapid intervention is required in response to temperature disruptions during aquaculture. This study will therefore encourage aquaculturists to closely monitor culture temperatures for this economically important species of fish

Composition and non-volatile taste components of Hypsizigus marmoreus

Two strains of Hypsizigus marmoreus (Peck.) Bigelow (Tricholomataceae) are successfully cultivated and commercially available in Taiwan, and their composition and non-volatile taste components of fruit bodies and mycelia were studied. Both fruit bodies were higher than mycelia in contents of carbohydrate, ash and fiber but lower in contents of fat and protein. Total sugar and polyol contents were 45.47-91.50 mg/g and total free amino acid contents were in the descending order of white strain fruit bodies (122.97) > normal strain fruit bodies (95.94) > white strain mycelia (53.20) > normal strain mycelia (46.87 mg/g). Monosodium glutamate-like components of both fruit bodies were 3-4-fold higher than those of both mycelia. Total 5'-nucleotides contents were 6.43-11.02 mg/g with white strain fruit bodies being the highest. Equivalent umami concentrations of both fruit bodies were higher than those of mycelia, Overall, H. marmoreus fruit bodies possessed highly intense umami taste. (C) 2008 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved