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71.
Marcio Vidotti Vinícius R. Gonçales Vinicius S. Quartero Barbara Danc Susana I. Córdoba de Torresi 《Journal of Solid State Electrochemistry》2010,14(4):675-679
The present work describes the synthesis of platinum nanoparticles followed by their electrophoretic deposition onto transparent
fluorine-doped tin oxide electrodes. The nano-Pt-modified electrodes were characterized by voltammetric studies in acidic
solutions showing a great electrocatalytic behavior towards H+ reduction being very interesting for fuel cell applications. Morphological characterization was performed by atomic force
microscopy on different modified electrodes showing a very rough surface which can be tuned by means of time of deposition.
Also, nickel hydroxide thin films were galvanostatically grown onto these electrodes showing an interesting electrochemical
behavior as sharper peaks, indicating a faster ionic exchange from the electrolyte to the film. 相似文献
72.
73.
Pedro R. Aranda Susana Moyano Luis D. Martinez Irma E. De Vito 《Analytical and bioanalytical chemistry》2010,398(2):1043-1048
A new, simple, and selective method for preconcentration and determination of Cr(VI) in aqueous samples. After adsorption
in “batch mode” on Aliquat 336-AC, determinations were made directly on the solid by X-ray fluorescence spectrometry, which
had the advantage of not requiring the step of elution of the chromium retained. The enrichment factor was calculated considering
that the tablets obtained from 10 mL solution of Cr(VI) (1000 μg L-1) had a final thickness of 0.64 mm and a diameter of 16.7 mm; the volume deposited on the pellet was 0.14 cm3. The preconcentration factor obtained was 71-fold, which was highly satisfactory for chromium trace analysis by XRF. Finally,
the method was successfully applied to the determination of Cr(VI) in drinking water samples. 相似文献
74.
Classification of wines from five Spanish origin denominations by aromatic compound analysis 总被引:1,自引:0,他引:1
Wine is a complex matrix in which aroma compounds play an important role in the characterization of the flavor pattern of a given wine. Twelve volatile compounds were determined in 244 samples of Spanish red wines from different denominations of origin: Rioja, Navarra, Valdepe?as, La Mancha, and Cari?ena. The samples were analyzed by GC using headspace solid-phase microextraction. The concentration (mg/mL) intervals obtained were 3-methyl-butyl acetate (3.9 to 116), 3-methyl-1-butanol (93 to 724), ethyl hexanoate (0.8 to 39), 1-hexanol (0.3 to 6.7), ethyl octanoate (1.4 to 41), diethyl succinate (0.2 to 13), 2-phenyl ethyl acetate (0 to 5.3), hexanoic acid (0 to 8.3), geraniol (0 to 3.0), 2-phenylethanol (1.5 to 56), octanoic acid (0 to 20), and decanoic acid (0 to 3.3). Wines were classified by multivariate statistical methods: principal component analysis, and lineal discriminant analysis. A correct differentiation among wines according to their origin was obtained by lineal discriminant analysis. 相似文献
75.
Mata S Cortijo V Caminati W Alonso JL Sanz ME López JC Blanco S 《The journal of physical chemistry. A》2010,114(43):11393-11398
The Fourier transform microwave spectra of the hydrated forms of the tautomeric pair 2-pyridinone/2-hydroxypyridine (2PO/2HP) have been investigated in a supersonic expansion. Three hydrated species, 2PO-H?O, 2HP-H?O, and 2PO-(H?O)?, have been observed in the rotational spectrum. Each molecular complex was confidently identified by the features of the 1?N quadrupole hyperfine structure of the rotational transitions. The presence of water affects the tautomeric equilibrium -N═C(OH)- ? -NH-C(═O)-, which is shifted to the enol form for the bare molecules 2PO/2HP but to the keto tautomer for the hydrated forms. 相似文献
76.
A problem of decision making under uncertainty in which the choice must be made between two sets of alternatives instead of two single ones is considered. A number of choice rules are proposed and their main properties are investigated, focusing particularly on the generalizations of stochastic dominance and statistical preference. The particular cases where imprecision is present in the utilities or in the beliefs associated to two alternatives are considered. 相似文献
77.
78.
Monica Dal Maso Isabel A. Perillo Celia B. Schapira Susana Gorzalczany María C. Acevedo Susana M. Sicardi 《Journal of heterocyclic chemistry》1999,36(3):803-811
A series of 4-hydroxy-2H-1,2-benzothiazme-3-carboxamide 1,1-dioxides substituted on the sulfonamide nitrogen with ethoxycarbonylalkyl, cyanoalkyl and dialkylaminoalkyl groups was synthesized. Spectroscopic properties of the obtained products were analyzed. Findings from the pharmacological study of some of the compounds as antiinflammatory and analgesic agents are reported. 相似文献
79.
80.