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351.
Ronaldo Dias Clécio S. Ferreira Nancy L. Garcia 《Statistical Inference for Stochastic Processes》2008,11(1):11-34
Let be an unknown 2 times differentiable function and consider M to be an α- homogeneous Poisson process on Graf(f). The goal is to estimate f having a sample of the inhomogeneous Poisson process N constructed by dislocating each point of M perpendicularly to Graf(f) by a normal random variable with zero mean and constant variance σ2. The exact formulas for the mean measure and the intensity function of N are obtained. Then, the function f is estimated directly using a hybrid spline approach to penalized maximum likelihood. Simulation results indicate the procedure
to be consistent as and .
相似文献
352.
Marlon Nunes da Silva Celso V. Santilli Sandra H. Pulcinelli 《Journal of Sol-Gel Science and Technology》2012,63(2):230-234
The hydrophilic characteristics of zinc oxide combined with the electronic properties of this width band gap semi-conductor were used to produce transparent, anti fog and photocatalytic porous films by using a simple sol?Cgel dip-coating process. The observed values of contact angles (near to 10°) and calculated spreading coefficients (close to zero) indicate that sol?Cgel dip-coated ZnO porous films show excellent wettability. The photocatalytic behavior of these films measured from methylene blue degradation is dependent on the film thickness in agreement with wettability results; as the film thickness increases from 0.1?±?0.05 to 0.5?±?0.05 the photocatalytic reaction rate constant increases from 0.9?×?10?3 to 5.5?×?10?3 min?1. 相似文献
353.
Mauro Francisco Pinheiro da Silva Heloisa Cristina de Jesus Fraga da Costa Eduardo Rezende Triboni Mário José Politi Paulo Celso Isolani 《Journal of Thermal Analysis and Calorimetry》2012,107(1):257-263
The synthesis and characterization of graphite oxide (GO), graphene (GS), and the composites: GS–CeO2 and GO–CeO2 are reported. This synthesis was carried out by mixing aqueous solutions of CeCl3·7H2O and GO, which yields the oxidized composite GO–CeO2. GO–CeO2 was hydrothermally reduced with ethylene glycol, at 120 °C, yielding the reduced composite GS–CeO2. GO, GS ,and the composites with CeO2 were characterized by CHN, TG/DTG, BET, XRD, SEM microscopy, FTIR, and Raman spectroscopy. The estimation of crystallite
size of CeO2 anchored on GO and on GS by Raman, XRD, and SEM agreed very well showing diameters about 5 nm. The role of particles of CeO2 coating carbon sheets of GO and GS was discussed. 相似文献
354.
Freire KR Lins AC Dórea MC Santos FA Camara CA Silva TM 《Molecules (Basel, Switzerland)》2012,17(2):1652-1664
The aim of this study was to determine the palynological origin, phenolic and flavonoid content, and antioxidant properties of twenty-five samples of bee pollen harvested during a nine-month period (February-November) from the Canavieiras municipality (northeastern Brazil). Of the 25 samples analyzed, only two (February 01 and 02) were heterofloral. The predominant pollens in the samples analyzed during that month were: Cecropia, Eucalyptus, Elaeis, Mimosa pudica, Eupatorium, and Scoparia. Ethyl acetate fractions were analyzed by HPLC-DAD. The flavonoids isoquercetin, myricetin, tricetin, quercetin, luteolin, selagin, kaempferol, and isorhamnetin were detected. The flavonoid present in all 22 samples was isolated and identified as isorhamnetin 3-O-b-neohesperidoside. The total phenolic contents determined using the Folin-Ciocalteu reagent ranged from 41.5 to 213.2 mg GAE/g. Antioxidant activities based on the 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis 3-ethylbenzothiozoline-6-sulfonic acid (ABTS), and Fe2+ ion chelating activity assays were observed for all extracts, and correlated with the total phenolic content. 相似文献
355.
356.
Andrade CA Santos-Magalhães NS de Melo CP 《Journal of colloid and interface science》2006,298(1):145-153
The investigation of the characteristics of mixed floating monolayers of phospholipids and usnic acid (UA), an active metabolite from lichens, can provide valuable information on how to prepare stable liposomes that could serve as carriers of UA for therapeutic proposes. The present paper is concerned with the thermodynamic analysis of the behavior of Langmuir monolayers formed by mixing different phospholipids (dibehenoylphosphatidylcholine, DBPC, dipalmitoylphosphatidylcholine, DPPC, and dioleoylphosphatidylcholine, DOPC) and UA at varied molar fractions. Relevant thermodynamic parameters such as excess areas, excess free energies and free energy of mixing were derived from the surface pressure data obtained from compression measurements performed in a Langmuir trough. For the largest lateral pressure examined (25 mN/m), negative values of the excess free energy were found only for the DOPC/UA monolayer, which should be the most stable of them. Based on the calculated values of the free energy of mixing, we note that the DBPC/UA and DPPC/UA systems present the best mixed character at low pressures and when the molar fraction of the UA is 0.5; at that relative concentration and at low values of the external pressure, the UA molecules can better mix and interact with the phospholipid molecules. The compression isotherms for mixed monolayers show no visible transitions, exhibiting a more organized phase that corresponds to a negative free energy of mixing. We have established that the most stable monolayers were those corresponding to DOPC/UA mixtures with a UA molar fraction of 0.75. 相似文献
357.
358.
Alvarenga Gabriel M. Palombarini Julio Gonçalves Rosana A. Berengue Olivia M. Nunes Ronaldo S. Santos Sydney F. Villullas Hebe M. Ciapina Eduardo G. 《Journal of Solid State Electrochemistry》2023,27(9):2465-2477
Journal of Solid State Electrochemistry - The aim of this work was to study the effect of a RuO2 support on the activity of Pd nanoparticles for formic acid oxidation, comparing the results with... 相似文献
359.