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991.
Francesco Rosalbino Daniele Macciò Adriana Saccone Emma Angelini Stefano Delfino 《Journal of Solid State Electrochemistry》2010,14(8):1451-1455
The characteristics of oxide films on Zr and Zr–Nb alloys (with Nb content of 2.5, 5, and 10 at.%) galvanostatically formed (at a current density of 100 μA cm?2) in 0.5 M H2SO4 solution were investigated by means of electrochemical impedance spectroscopy. Electrochemical impedance spectroscopy spectra were interpreted in terms of an “equivalent circuit” with the circuit elements representing the electrochemical properties of a single layer oxide. The resistance of the oxide films was found to increase with increased Nb content in the alloy while the capacitance showed an opposite trend. The stability of the anodic oxide films grown in the sulfuric acid solution on Zr and Zr–Nb alloys was investigated by simultaneously measuring the electrode capacitance and resistance at a working frequency of 1 kHz as a function of exposure time to naturally aerated 3 M NaOH solution. Analyses of the electrode capacitance and resistance values indicated a decrease in chemical dissolution rate of the oxide films with the increase of Nb content in the alloy. 相似文献
992.
993.
Glycerol hydrogenolysis to propylene glycol 总被引:1,自引:0,他引:1
Adriana Marinoiu Gheorghe Ionita Costinela-Laura Gáspár Claudia Cobzaru Spiridon Oprea 《Reaction Kinetics and Catalysis Letters》2009,97(2):315-320
A nickel catalyst showed a considerable selectivity to propylene glycol (up to 98%) at 30% glycerol conversion, under moderate
hydrogenation conditions: 200 °C reaction temperature, 20–25 bar hydrogen pressure, 5 wt% catalyst and unprecedented low reaction
time of 8 h. 相似文献
994.
Adriana T. de Sousa Karl E. Bessler Prof. Dr. Sebastia˜o S. Lemos Javier Ellena Claudia C. Gatto 《无机化学与普通化学杂志》2009,635(1):106-111
Five novel organotin complexes with the anthraquinone dyes alizarin (1,2‐dihydroxyanthraquinone) and purpurin (1,2,4‐trihydroxyanthraquinone) were synthesized and characterized by elemental analyses, FTIR and NMR spectroscopy (1H, 13C and 119Sn). The crystal and molecular structures of four complexes were determined by X‐ray diffraction on single crystals: [Bu2Sn(aliz)(H2O)]·C2H5OH ( A1 ·EtOH), [Bu2Sn(aliz)(dmso)]2 ( A3 ), [(Bu2Sn)3O(Hpurp)2] ( P1 ) and [Bu2Sn(Hpurp)(dmso)]2 ( P2 ), where H2aliz = alizarin and H3purp = purpurin. The coordination mode of the ligands is identical to that found in their Al/Ca complexes, where they act as dianionic tridentate ligands forming five and six‐membered fused chelate rings. The coordination to the tin atoms occurs exclusively via the 1,2‐ phenolate oxygen and the adjacent quinoid oxygen atoms. The complexes A1 , A3 and P1 are dimers with hepta‐coordinated tin atoms in form of a slightly distorted pentagonal bipyramid. The trinuclear complex P2 contains two pentacoordinated and one heptacoordinated tin atoms. 相似文献
995.
Reactions of 2-(1H-benzimidazol-2-yl)phenol (1) and SnPh3Cl, SnPh2Cl2 and SnCl4 were investigated. One tetracoordinated triphenyltin(IV) compound: triphenyltin-2-(1H-benzimidazol-2-yl)phenolate] (3) and its adducts: [O → Sn] dimethylsulfoxide triphenyltin-[2-(1H-benzimidazol-2-yl)phenolate] (4), [O → Sn] aqua triphenyltin-[2-(1H-benzimidazol-2-yl)phenolate] (5) [O → Sn] ethanol triphenyltin-[2-(1H-benzimidazol-2-yl)phenolate] (6), [N → Sn] pyridine triphenyltin-[2-(1H-benzimidazol-2-yl)phenolate] (7), where 1 acts as a monodentate ligand bound through the phenol oxygen, were obtained. In the pentacoordinated compounds 4-7, the tin atom has tbp geometry. The three phenyl groups are in equatorial positions, whereas the benzimidazole and the Lewis base are in apical positions. Two hexacoordinated tin compounds: diphenyltin-bis[2-(1H-benzimidazol-2-yl-κN)phenolate-κO] (8), dichlorotin-bis[2-(1H-benzimidazol-2-yl-κN)phenolate-κO] (9) bearing two bidentate ligands are reported. The coplanar ligands in 8 and 9 form six membered rings by oxygen and nitrogen coordination. The tin geometry is all-trans octahedral. In 8 the two phenyl groups, and in 9 the two chlorine atoms are perpendicular to the plane of the ligands. Compounds were identified in solution mainly by 1H, 13C and 119Sn NMR and in the solid state by X-ray diffraction analysis. 相似文献
996.
The purpose of this work is to study the potentialities in the phase-shifting real-time holographic interferometry using photorefractive crystals as the recording medium for wave-optics analysis in optical elements and non-linear optical materials. This technique was used for obtaining quantitative measurements from the phase distributions of the wave front of lens and lens systems along the propagation direction with in situ visualization, monitoring and analysis in real time. 相似文献
997.
Mar Creixell Adriana P. Herrera Magda Latorre-Esteves Madeline Torres-Lugo 《Journal of magnetism and magnetic materials》2010,322(15):2244-14393
Epidermal growth factor (EGF) was conjugated with carboxymethyldextran (CMDx) coated iron oxide magnetic nanoparticles using carbodiimide chemistry to obtain magnetic nanoparticles that target the epidermal growth factor receptor (EGFR). Epidermal growth factor modified magnetic nanoparticles were colloidally stable when suspended in biological buffers such as PBS and cell culture media. Both targeted and non-targeted nanoparticles were incubated with CaCo-2 cancer cells, known to overexpress EGFR. Nanoparticle localization within the cell was visualized by confocal laser scanning microscopy and light microscopy using Prussian blue stain. Results showed that targeted magnetic nanoparticles were rapidly accumulated in both flask-shaped small vesicles and large circular endocytic structures. Internalization patterns suggest that both clathrin-dependent and clathrin-independent receptors mediated endocytosis mechanisms are responsible for nanoparticle internalization. 相似文献
998.
We present an index that measures the nestedness pattern of bipartite networks, a problem that arises in theoretical ecology. Our measure is derived using the sum of distances of the occupied elements in the incidence matrix of the network. This index quantifies directly the deviation of a given matrix from the nested pattern. In the simplest case the distance of the matrix element ai,j is di,j=i+j, the Manhattan distance. A generic distance is obtained as di,j=(iχ+jχ)1/χ. The nestedness index is defined by ν=1−τ, where τ is the “temperature” of the matrix. We construct the temperature index using two benchmarks: the distance of the complete nested matrix that corresponds to zero temperature and the distance of the average random matrix where the temperature is defined as one. We discuss an important feature of the problem: matrix occupancy ρ. We address this question using a metric index χ that adjusts for matrix occupancy. 相似文献
999.
Adriana Mejía Castaño Susan Montgomery Sonia Natale Maria D. Vega Chelsea Walton 《Journal of Pure and Applied Algebra》2018,222(7):1643-1669
Let p and q be distinct prime numbers. We study the Galois objects and cocycle deformations of the noncommutative, noncocommutative, semisimple Hopf algebras of odd dimension and of dimension . We obtain that the non-isomorphic self-dual semisimple Hopf algebras of dimension classified by Masuoka have no non-trivial cocycle deformations, extending his previous results for the 8-dimensional Kac–Paljutkin Hopf algebra. This is done as a consequence of the classification of categorical Morita equivalence classes among semisimple Hopf algebras of odd dimension , established by the third-named author in an appendix. 相似文献
1000.
R.M. Lees Reba-Jean Murphy Adriana Predoi-Cross D.R.T. Appadoo R.R.J. Goulding 《Journal of Molecular Spectroscopy》2009,256(1):91-98
The high-resolution Fourier transform spectrum of the ν8 CO-stretching band of CH318OH between 900 and 1100 cm−1 has been recorded at the Canadian Light Source (CLS) synchrotron facility in Saskatoon, and the majority of the torsion-rotation structure has been analyzed. For the νt = 0 torsional ground state, subbands have been identified for K values from 0 to 11 for A and E torsional symmetries up to J values typically well over 30. For νt = 1, A and E subbands have been assigned up to K = 7, and several νt = 2 subbands have also been identified. Upper-state term values determined from the assigned transitions using the Ritz program have been fitted to J(J + 1) power-series expansions to obtain substate origins and sets of state-specific parameters giving a compact representation of the substate J-dependence. The νt = 0 subband origins have been fitted to effective molecular constants for the excited CO-stretching state and a torsional barrier of 377.49(32) cm−1 is found, representing a 0.89% increase over the ground-state value. The vibrational energy for the CO-stretch state was found to be 1007.49(7) cm−1. A number of subband-wide and J-localized perturbations have been seen in the spectrum, arising both from anharmonic and Coriolis interactions, and several of the interacting states have been identified. 相似文献