Pore Narrowing and Formation of Ultrathin Yttria-Stabilized Zirconia Layers in Ceramic Membranes by Chemical Vapor Deposition/Electrochemical Vapor Deposition

Chemical vapor deposition (CVD) and electrochemical vapor deposition (EVD) have been applied to deposit yttria-stabilized-zirconia (YSZ) on porous ceramic media. The experimental results indicate that the location of YSZ deposition can be varied from the surface of the substrates to the inside of the substrates by changing the CVD/EVD experimental conditions, i.e., the concentration ratio of the reactant vapors. The deposition width is strongly dependent on the deposition temperature used. The deposition of YSZ inside the pores resulted in pore narrowing and eventually pore closure, which was measured by using permpor-ometry. However, deposition of YSZ on top of porous ceramic substrates (outside the pores) did not result in a reduction of the average pore size. Ultrathin, dense YSZ layers on porous ceramic substrates can be obtained by suppressing the EVD layer growth process after pore closure

Experimental Observation of Classical Sub-Wavelength Interference with Thermal-Like Light

We show the experimental observation of the classical sub-wavelength double-slit interference with a pseudo-thermal light source. The experimental results are in agreement with the recent theoretical prediction shown in quant-ph/0404078 (to be appeared in Phys. Rev. A).Comment: 4 pages, 6 figure

Molecular characters and recombinant expression of the carboxylesterase gene of the meadow moth Loxostege sticticalis L. (Lepidoptera: Pyralidae)

Insect carboxylesterases are enzymes that catalyze the hydrolysis of ester and amide moieties, which play important roles in insecticide resistance, specifically allelochemical tolerance and developmental regulation. We obtained the cDNA encoding carboxylesterase gene of Loxostege sticticalis (LstiCarE) by a cDNA library screen. The full cDNA of LstiCarE is 1,980 bp in length, containing an open reading frame (ORF) of 1,875 bp, which encodes a preprotein of 625 amino acid residues. The LstiCarE contains the catalytic triad (Ser-His-Glu), the pentapeptide GxSxG motif and GxxHxxD/E motif, which are typical characteristic of esterases. The GxSxG and GxxHxxD/E motifs of LstiCarE are modified as GCSAG and GxxHxxQ, respectively. The 3-D model structure of LstiCarE showed that Ser197, His440 and Glu321 are aggregated together, which form the catalytic triad. The recombinant LstiCarE were successfully expressed in BL21 cells using recombinant plasmid DNA, and showed high carboxylesterase activity. However, the biochemical and physiological functions of carboxylesterase gene in L. sticticalis requires further investigation.Key words: Carboxylesterase gene, Loxostege sticticalis, recombinant expression

Bis(2,2′-bipyridyl-κ2 N,N′)(sulfato-κ2 O,O′)cobalt(II) ethane-1,2-diol monosolvate

The title compound, [Co(SO4)(C10H8N2)2]·C2H6O2, has the Co2+ ion in a distorted octa­hedral CoN4O2 coordination geometry. A twofold rotation axis passes through the Co and S atoms, and through the mid-point of the C—C bond of the ethane­diol mol­ecule. In the crystal, the [CoSO4(C10H8N2)2] and C2H6O2 units are held together by a pair of O—H⋯O hydrogen bonds

Symmetry guaranteed Dirac-line semimetals in two-dimensions against strong spin-orbit coupling

Several intriguing electronic phenomena and electric properties were discovered in three-dimensional Dirac nodal line semimetals (3D-DNLSM), which are, however, easy to be perturbed under strong spin-orbit coupling (SOC). While two-dimensional (2D) layers are an emerging material category with many advantages, 2D-DNLSM against SOC is yet to be uncovered. Here, we report a 2D-DNLSM in odd-atomic-layer Bi (the brick phase, another Bi allotrope), whose robustness against SOC is protected by the little co-group C_2v \times Z^T_2, the unique protecting symmetry we found in 2D.Specially, (4n+2) valence electrons fill the electronic bands in the brick phase, so that the Dirac nodal line with fourfold degeneracy locates across the Fermi level. There are almost no other low energy states close to the Fermi level; this allows to feasibly observe the neat DNLSM-induced phenomena in transport measurements without being affected by other bands. In contrast, Other VA-group elements also form the brick phases, but their DNL states are mixed with the extra states around the Fermi level. This unprecedented category of layered materials allows for exploring nearly isolated 2DDNL states in 2D.Comment: Totally 25 pages including main text, methods and supporting information, 4 figures, 8 SI figure

Intramolecular π Stacking in Cationic Iridium(III) Complexes with Phenyl-Functionalized Cyclometalated Ligands: Synthesis, Structure, Photophysical Properties, and Theoretical Studies

The syntheses of two new heteroleptic cationic iridium complexes containing 2,6-diphenylpyridine (Hdppy) and 2,4,6-triphenylpyridine (Htppy) as the cyclometalated ligands, namely, [Ir(dppy)2phen]PF6 (1, phen = 1,10-phenanthroline) and [Ir(tppy)2phen]PF6 (2), are described. The X-ray crystal structure of 2 reveals a distorted octahedral geometry around the Ir center and close intramolecular face-to-face π–π stacking interactions between the pendant phenyl rings at the 2-position of the cyclometalated ligands and the NN ancillary ligand. This represents a new π–π stacking mode in charged Ir complexes. Complexes 1 and 2 are green photoemitters: their photophysical and electrochemical properties are interpreted with the assistance of density functional theory (DFT) calculations. These calculations also establish that the observed intramolecular interactions cannot effectively prevent the lengthening of the Ir–N bonds of the complexes in their metal-centered (3MC) states. Complexes 1 and 2 do not emit light in light-emitting electrochemical cells (LECs) under conditions in which the model compound [Ir(ppy)2phen]PF6 (3) emits strongly. This is explained by degradation reactions of the 3MC state of 1 and 2 under the applied bias during LEC operation facilitated by the enhanced distortions in the geometry of the complexes. These observations have important implications for the future design of complexes for LEC applications

Modular co-evolution of metabolic networks

The architecture of biological networks has been reported to exhibit high level of modularity, and to some extent, topological modules of networks overlap with known functional modules. However, how the modular topology of the molecular network affects the evolution of its member proteins remains unclear. In this work, the functional and evolutionary modularity of Homo sapiens (H. sapiens) metabolic network were investigated from a topological point of view. Network decomposition shows that the metabolic network is organized in a highly modular core-periphery way, in which the core modules are tightly linked together and perform basic metabolism functions, whereas the periphery modules only interact with few modules and accomplish relatively independent and specialized functions. Moreover, over half of the modules exhibit co-evolutionary feature and belong to specific evolutionary ages. Peripheral modules tend to evolve more cohesively and faster than core modules do. The correlation between functional, evolutionary and topological modularity suggests that the evolutionary history and functional requirements of metabolic systems have been imprinted in the architecture of metabolic networks. Such systems level analysis could demonstrate how the evolution of genes may be placed in a genome-scale network context, giving a novel perspective on molecular evolution.Comment: 26 pages, 7 figure

Thermal behaviour of multilayer and functionally-graded YSZ/Gd2Zr2O7 coatings

[EN] Zirconates with pyrochlore structure, such as Gd2Zr2O7, are new promising thermal barrier coatings because of their very low thermal conductivity and good chemical resistance against molten salts. However, their coefficient of thermal expansion is low, therefore their thermal fatigue resistance is compromised. As a solution, the combination of yttria-stabilised zirconia (YSZ) and Gd2Zr2O7 can reduce the thermal contraction mismatch between the thermal barrier coating parts. In the present study, two possible designs have been performed to combine YSZ/Gd2Zr2O7. On the one hand, a multilayer coating was obtained where YSZ layer was deposited between a Gd2Zr2O7 layer and a bond coat. On the other hand, a functionally-graded coating was designed where different layers with variable ratios of YSZ/Gd2Zr2O7 were deposited such that the composition gradually changed along the coating thickness. Multilayer and functionally-graded coatings underwent isothermal and thermally-cycled treatments in order to evaluate the oxidation, sintering effects and thermal fatigue resistance of the coatings. The YSZ/Gd2Zr2O7 multilayer coating displayed better thermal behaviour than the Gd2Zr2O7 monolayer coating but quite less thermal fatigue resistance compared to the conventional YSZ coating. However, the functionally-graded coating displays a good thermal fatigue resistance. Hence, it can be concluded that this kind of design is ideal to optimise the behaviour of thermal barrier coatings.This work has been supported by the Spanish Ministry of Economy and Competitiveness (project MAT2015-67586-C3-R). A. Borrell acknowledges the Spanish Ministry of Economy and Competitiveness for her Juan de la Cierva-Incorporacion contract (IJCI-2014-49839) and the Program to Support Research and Development (PAID-00-15) of the Universitat Politecnica de Valencia. P. Carpio acknowledges the Valencia Government for his post-doc contract (APOSTD/2016/040).Carpio-Cobo, P.; Salvador Moya, MD.; Borrell Tomás, MA.; Sanchez, E. (2017). Thermal behaviour of multilayer and functionally-graded YSZ/Gd2Zr2O7 coatings. Ceramics International. 43(5):4048-4054. https://doi.org/10.1016/j.ceramint.2016.11.178S4048405443