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31.
María Navarro-Cceres Marcelo Caetano Gilberto Bernardes Mercedes Snchez-Barba Javier Merchn Snchez-Jara 《Entropy (Basel, Switzerland)》2020,22(11)
In tonal music, musical tension is strongly associated with musical expression, particularly with expectations and emotions. Most listeners are able to perceive musical tension subjectively, yet musical tension is difficult to be measured objectively, as it is connected with musical parameters such as rhythm, dynamics, melody, harmony, and timbre. Musical tension specifically associated with melodic and harmonic motion is called tonal tension. In this article, we are interested in perceived changes of tonal tension over time for chord progressions, dubbed tonal tension profiles. We propose an objective measure capable of capturing tension profile according to different tonal music parameters, namely, tonal distance, dissonance, voice leading, and hierarchical tension. We performed two experiments to validate the proposed model of tonal tension profile and compared against Lerdahl’s model and MorpheuS across 12 chord progressions. Our results show that the considered four tonal parameters contribute differently to the perception of tonal tension. In our model, their relative importance adopts the following weights, summing to unity: dissonance (0.402), hierarchical tension (0.246), tonal distance (0.202), and voice leading (0.193). The assumption that listeners perceive global changes in tonal tension as prototypical profiles is strongly suggested in our results, which outperform the state-of-the-art models. 相似文献
32.
Francisco Radler de Aquino Neto Jari Nobrega Cardoso Alberto dos Santos Pereira Maria Conceiao Zupo Fernandes Carlos Alberto Caetano Andre Luiz de Castro Machado 《Journal of separation science》1994,17(4):259-263
HTHRGC was found essential for optimizing representative preparation of high molecular weight samples and enabling fingerprinting of heavy fractions of crude oils and associated paraffinic deposits in production pipelines. Laboratory experiments aimed at simulating the process of paraffin deposition could also be easily evaluated. A comparative investigation of the performance of cold on-column and SPI (PTV type) injectors, in conjunction with high temperature capillary columns, for analysis of high molecular weight fractions, was also conducted during the course of this work. 相似文献
33.
The question of whether or not DNA is intrinsically conducting is still a challenge. The ongoing debate on DNA molecules as an electronic material has so far underestimated a key distinction of the system: the role of base pairing in opposition to correlations along each chain. We show that a disordered base paired double chain presents truly or, at least, effectively delocalized states. This effect is irrespective to the sequencing along each chain. 相似文献
34.
We have investigated the excitation intensity dependence of the spatial distribution of the emission of photoluminescence from heavilly doped n-type GaAs.It was found that above a certain threshold of excitation, maximum emission originated from an anular zone surrounding the point of excitation rather than from that point.This new effect is explained in terms of the quasi Fermi level dependence of the rate of recombination through recombination centers. 相似文献
35.
R. A. Caetano F.A.B.F. de Moura M. L. Lyra 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,80(3):321-324
In this work, we investigate the competition of disorder, nonlinearity and non-adiabatic process on the wave packet dynamics
in 1D. We follow the time evolution of the second moment of the wave packet distribution to characterize its spreading behavior.
In order to describe the dynamical behavior of one-electron wave packets, we solve a discrete nonlinear Schr?dinger equation
which effectively takes into account a diagonal disorder and a nonlinear contribution. Going beyond the adiabatic regime,
we consider that the nonlinearity relaxes in time according to a Debye-like law. In the adiabatic regime, it has been recently
demonstrated that the interplay of disorder and nonlinearity leads to a sub-diffusive spread of the wave packet. Here, we
numerically demonstrate that no sub-diffusive spreading of the second moment of the wave packet distribution takes place when
the finite response time of the nonlinearity is taken into account. 相似文献
36.
In this paper we consider generalized Hardy spaces which include classical Hardy spaces and Hardy-Lorentz spaces as special
cases. We give real interpolation results for such spaces. As applications, we solve an interpolation problem for Besov spaces
of generalized smoothness and prove the boundedness of pseudodifferential operators acting both in these spaces and in the
local Hardy spaces. For the latter spaces, we also obtain wavelet decompositions. 相似文献
37.
Newton L Dias Filho Devaney R do Carmo Laércio Caetano André H Rosa 《Analytical sciences》2005,21(11):1359-1363
A mercury-sensitive chemically modified graphite paste electrode was constructed by incorporating modified silica gel into a conventional graphite paste electrode. The functional group attached to the (3-chloropropyl) silica gel surface was 2-mercaptoimidazole, giving a new product denoted by 3-(2-thioimidazolyl)propyl silica gel, which is able to complex mercury ions. Mercury was chemically adsorbed on the modified graphite paste electrode containing 3-(2-thioimidazolyl)propyl silica (TIPSG GPE) by immersion in a Hg(II) solution, and the resultant surface was characterized by cyclic and differential pulse anodic stripping voltammetry. One cathodic peak at 0.1 V and other anodic peak at 0.34 V were observed on scanning the potential from -0.1 to 0.8 V (0.01 M KNO3; v = 2.0 mV s(-1) vs. Ag/AgCl). The anodic peak at 0.34 V show an excellent sensitivity for Hg(II) ions in the presence of several foreign ions. A calibration graph covering the concentration range from 0.02 to 2 mg L(-1) was obtained. The detection limit was estimated to be 5 microg L(-1). The precision for six determinations of 0.05 and 0.26 mg L(-1) Hg(II) was 3.0 and 2.5% (relative standard deviation), respectively. The method can be used to determine the concentration of mercury(II) in natural waters contaminated by this metal. 相似文献
38.
39.
Barbosa LR Itri R Caetano W Neto Dde S Tabak M 《The journal of physical chemistry. B》2008,112(14):4261-4269
Small-angle X-ray scattering (SAXS) and electron paramagnetic resonance (EPR) have been carried out to investigate the structure of the self-aggregates of two phenothiazine drugs, chlorpromazine (CPZ) and trifluoperazine (TFP), in aqueous solution. In the SAXS studies, drug solutions of 20 and 60 mM, at pH 4.0 and 7.0, were investigated and the best data fittings were achieved assuming several different particle form factors with a homogeneous electron density distribution in respect to the water environment. Because of the limitation of scattering intensity in the q range above 0.15 A(-1), precise determination of the aggregate shape was not possible and all of the tested models for ellipsoids, cylinders, or parallelepipeds fitted the experimental data equally well. The SAXS data allows inferring, however, that CPZ molecules might self-assemble in a basis set of an orthorhombic cell, remaining as nanocrystallites in solution. Such nanocrystals are composed of a small number of unit cells (up to 10, in c-direction), with CPZ aggregation numbers of 60-80. EPR spectra of 5- and 16-doxyl stearic acids bound to the aggregates were analyzed through simulation, and the dynamic and magnetic parameters were obtained. The phenothiazine concentration in EPR experiments was in the range of 5-60 mM. Critical aggregation concentration of TFP is lower than that for CPZ, consistent with a higher hydrophobicity of TFP. At acidic pH 4.0 a significant residual motion of the nitroxide relative to the aggregate is observed, and the EPR spectra and corresponding parameters are similar to those reported for aqueous surfactant micelles. However, at pH 6.5 a significant motional restriction is observed, and the nitroxide rotational correlation times correlate very well with those estimated for the whole aggregated particle from SAXS data. This implies that the aggregate is densely packed at this pH and that the nitroxide is tightly bound to it producing a strongly immobilized EPR spectrum. Besides that, at pH 6.5 the differences in motional restriction observed between 5- and 16-DSA are small, which is different from that observed for aqueous surfactant micelles. 相似文献
40.
A Simple and Rapid Estimation of Totals Polyphenols Based On Carbon Paste Electrode Modified with Ruthenium Oxo‐Complex
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Paulo A. Raymundo‐Pereira Marcos F. S. Teixeira Fábio R. Caetano Márcio F. Bergamini Luiz H. Marcolino‐Júnior 《Electroanalysis》2015,27(10):2371-2376
A simple and fast method based on electrochemical measurements was proposed for estimation of total polyphenols using a carbon paste modified electrode. The method was based on catalytic response exhibited by a ruthenium complex [(bpy)2(NH3)RuIII(µ‐O)RuIII(NH3)(bpy)2]4+ in presence of gallic acid (GA). Calibration plots using chronoamperometry (CA) showed a linear response for GA concentrations ranging from 6.6×10?6 to 1.9×10?4 mol L?1 with a detection limit of 4.9×10?7 mol L?1. Comparative studies using the official method revealed a good agreement between methods suggesting that the proposed method can be applied for polyphenol estimation without any sample treatment. 相似文献