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排序方式: 共有237条查询结果,搜索用时 15 毫秒
31.
Helio S. Migon Mariane Branco Alves André F. B. Menezes Eduardo G. Pinheiro 《商业与工业应用随机模型》2023,39(3):471-493
We briefly review the main developments of Bayesian dynamic models. The emphasis is on marketing applications. Typical examples in this area are discussed. The concepts of monitoring and intervention are carefully explained with illustrative examples and open source computational routines. We avoid algebraic developments and instead use graphical examples to illustrate theoretical aspects. Two real-world problems using Bayesian dynamic models are discussed. Finally, we describe recent developments and alternative proposals to formally address the dependence when dealing with the modeling of multiple time series. 相似文献
32.
Costa EV Pinheiro ML de Souza AD Barison A Campos FR Valdez RH Ueda-Nakamura T Filho BP Nakamura CV 《Molecules (Basel, Switzerland)》2011,16(11):9714-9720
Phytochemical investigation of the branches of Annona foetida Mart. led to isolation from the CH(2)Cl(2) extract of four alkaloids: Atherospermidine (1), described for the first time in this species, liriodenine (2), O-methylmoschatoline (3), and annomontine (4). Their chemical structures were established on the basis of spectroscopic data from IR, MS, NMR (1D and 2D), and comparison with the literature. Compounds 2-4 showed potent trypanocidal effect when evaluated against epimastigote and trypomastigote forms of Trypanosoma cruzi. 相似文献
33.
Lopez Kenneth Pinheiro Silvana Zamora William J. 《Journal of computer-aided molecular design》2021,35(8):923-931
Journal of Computer-Aided Molecular Design - A multiple linear regression model called MLR-3 is used for predicting the experimental n-octanol/water partition coefficient (log PN) of 22... 相似文献
34.
35.
P H Ptacek M L Pinheiro 《The Journal of the Acoustical Society of America》1971,49(2):Suppl 2:493-Suppl 2:498
36.
Alexandre A. Martins Mario J. Pinheiro 《International Journal of Theoretical Physics》2008,47(10):2706-2715
We address the problem of inertial property of matter through analysis of the motion of an extended charged particle. Our
approach is based on the continuity equation for momentum (Newton’s second law) taking due account of the vector potential
and its convective derivative. We obtain a development in terms of retarded potentials allowing an intuitive physical interpretation
of its main terms. The inertial property of matter is then discussed in terms of a kind of induction law related to the extended
charged particle’s own vector potential. Moreover, it is obtained a force term that represents a drag force acting on the
charged particle when in motion relatively to its own vector potential field lines. The time rate of variation of the particle’s
vector potential leads to the acceleration inertia reaction force, equivalent to the Schott term responsible for the source
of the radiation field. We also show that the velocity dependent term of the particle’s vector potential is connected with
the relativistic increase of mass with velocity and generates a longitudinal stress force that is the source of electric field
lines deformation. In the framework of classical electrodynamics, we have shown that the electron mass has possibly a complete
electromagnetic origin and the obtained covariant equation solves the “4/3 mass paradox” for a spherical charge distribution. 相似文献
37.
Rute F. Domingos Sara Carreira Josep Galceran Pascal Salaün José P. Pinheiro 《Analytica chimica acta》2016
The free metal ion concentration and the dynamic features of the metal species are recognized as key to predict metal bioavailability and toxicity to aquatic organisms. Quantification of the former is, however, still challenging. In this paper, it is shown for the first time that the concentration of free copper (Cu2+) can be quantified by applying AGNES (Absence of Gradients and Nernstian equilibrium stripping) at a solid gold electrode. It was found that: i) the amount of deposited Cu follows a Nernstian relationship with the applied deposition potential, and ii) the stripping signal is linearly related with the free metal ion concentration. The performance of AGNES at the vibrating gold microwire electrode (VGME) was assessed for two labile systems: Cu-malonic acid and Cu-iminodiacetic acid at ionic strength 0.01 M and a range of pH values from 4.0 to 6.0. The free Cu concentrations and conditional stability constants obtained by AGNES were in good agreement with stripping scanned voltammetry and thermodynamic theoretical predictions obtained by Visual MinteQ. This work highlights the suitability of gold electrodes for the quantification of free metal ion concentrations by AGNES. It also strongly suggests that other solid electrodes may be well appropriate for such task. This new application of AGNES is a first step towards a range of applications for a number of metals in speciation, toxicological and environmental studies for the direct determination of the key parameter that is the free metal ion concentration. 相似文献
38.
Particle Deposition in Porous Media: Analysis of Hydrodynamic and Weak Inertial Effects 总被引:1,自引:0,他引:1
We have studied the transport and capture of non-Brownian particles in porous media, when the particles are mainly submitted to hydrodynamic and weak inertial effects. Visualization experiments have been performed using several models of porous media which consist of transparent etched networks of interconnected channels. Typical particle deposits have been observed at the corners of the grains of the porous medium. Their shape and their orientation were dependent on flow rate and on the anisotropy of the flow field. A trajectory analysis model has been applied to a porous medium made of a doubly periodic array of rectangular grains very close to the experimental model. This numerical model has been used to localize particle deposits and to determine particle capture efficiency on the grains over a range of low Stokes numbers, grain aspect ratios and flow-field anisotropy ratios. The results have been interpreted in terms of shape of particle deposits and compared successfully to experimental observations. 相似文献
39.
Rodolfo Casana Manoel M. Ferreira A. R. Gomes Paulo R. D. Pinheiro 《The European Physical Journal C - Particles and Fields》2009,62(3):573-578
In this work, we focus on some properties of the parity-even sector of the CPT-even electrodynamics of the standard model
extension. We analyze how the six non-birefringent terms belonging to this sector modify the static and stationary classical
solutions of the usual Maxwell theory. We observe that the parity-even terms do not couple the electric and magnetic sectors
(at least in the stationary regime). The Green’s method is used to obtain solutions for the field strengths E and B at first order in the Lorentz-covariance-violating parameters. Explicit solutions are attained for point-like and spatially
extended sources, for which a dipolar expansion is achieved. Finally, an Earth-based experiment is presented that can lead
(in principle) to an upper bound on the anisotropic coefficients as stringent as
相似文献
40.
Sebastião V. Canevarolo Marcelo K. Bertolino Luís A. Pinheiro Vincenzo Palermo Stefano Piccarolo 《Macromolecular Symposia》2009,279(1):191-200
In this work it is presented three applications of real time analysis during extrusion process using an optical device developed by our research group, which applies the concepts of light extinction. Monitoring of polymer blends morphology takes place to infer data concerned to dispersed phase size and concentration. The detector also enables information about melting temperature of polymer during extrusion and the level of viscous heating, and the exfoliation step during processing of a polymer-clay nanocomposite. 相似文献