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51.
The limit behavior of the conditional probability of error of linear and quadratic discriminant analyses is studied under wide assumptions on the class conditional distributions. Results obtained may help to explain analytically the behavior in applications of linear and quadratic discrimination techniques. 相似文献
52.
Simona Lai Emanuela Locci Giuseppe Saba Ivan Husu Giancarlo Masci Vittorio Crescenzi Adolfo Lai 《Journal of polymer science. Part A, Polymer chemistry》2003,41(20):3123-3131
Dry and hydrated poly(vinyl alcohol) (PVA) gels with 55% (a‐PVA) and 61% (s‐PVA) syndiotacticity and related PVA/lactyl chitosan (LC) blends have been investigated with 129Xe and cross‐polarization/magic‐angle‐spinning 13C NMR techniques. Although the dry gels exhibit two broad 129Xe resonances in the slow‐to‐intermediate exchange limit, both hydrated gels show three resonances. The corresponding dry blends exhibit two signals, the chemical shifts and line widths of which change with respect to those of pure PVA, whereas one (a‐PVA/LC) or two (s‐PVA/LC) signals appear in the spectra of the hydrated blends. A comparative analysis of the data demonstrates that LC rearranges the domains of the polymeric matrix in both the dry and hydrated blends according to the syndiotacticity of the PVA chains. Information on the molecular motions of the amorphous and swollen polymeric domains in the kilohertz range has been obtained from an analysis of the spin‐lattice relaxation times. These data indicate that the dynamics and arrangement of the PVA chains in the gels are strongly affected by their tacticity and the addition of the copolymer LC. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3123–3131, 2003 相似文献
53.
Adolfo R. Gutiérrez 《Chemical physics letters》1980,74(2):293-297
A doubling of the origin is observed in the low-temperature electronic absorption spectrum of the complex carbonyl(pyridine)-phthalocyaninatoruthenium(II) in glassy matrices. The effect is studied by optical hole burning and results suggest a non-degenerate singlet ground state of near C2v symmetry to be invoked. 相似文献
54.
Adolfo Gili 《Annali dell'Universita di Ferrara》1962,11(1):115-118
Riassunto Ammesso il connettivoaut sull’insieme degli eventi, si mostra come risultano definiti i connettivivel edet. Si deducono quindi i teoremi delle probabilità totali e delle probabilità composte.
Résumé Admis le connectifaut sur l’ensemble des événements, on montre comme résultent définis les connectifvel etet. On déduit de là les théorèmes des probabilités totales et des probabilités composées.相似文献
55.
56.
Aitzol Garcia-Etxarri Javier Aizpurua Jon Molina-Aldareguia Rebeca Marcilla Jose Adolfo Pomposo David Mecerreyes 《Frontiers of Physics in China》2010,5(3):330-336
We report the synthesis, characterization and modellization of optical anion sensors based on gold nanoparticles (Au NPs)
stabilized by amino-functional imidazolium ionic liquids (AFIL). The addition of different salts results in anion exchange
of the imidazolium ionic liquid stabilizer leading to a change in the optical response of the original nanoparticle aqueous
solution. In all cases except with dodecylbenzenesulfonic acid sodium salt, a sufficient amount of salt concentration (5 times
larger than equimolar) leads to the appearance of an absorption band between 600 and 700 nm in the ultravioletvisible (UV-vis)
spectrum. The presence of the salt produces aggregation of the particles that localise the optical response and produce a
large spectral red shift. Transmission electron microscopy images demonstrated that this optical change was due to the aggregation
of the nanoparticles. We simulate the optical response of both situations, before and after salt addition, and interpret the
experimental observations in terms of the different response of metallic single nanoparticles and nanoparticle aggregates.
Theoretical calculations for single nanoparticle and single nanoparticle dimers demonstrate that the colour change is not
due to the enlargement or structural changes of the Au NPs, but due to the formation of NP aggregation. These results show
the potential of nanoparticle plasmonics to perform effective chemical sensing. 相似文献
57.
Banchio AJ Gapinski J Patkowski A Häussler W Fluerasu A Sacanna S Holmqvist P Meier G Lettinga MP Nägele G 《Physical review letters》2006,96(13):138303
In this joint experimental-theoretical work we study hydrodynamic interaction effects in dense suspensions of charged colloidal spheres. Using x-ray photon correlation spectroscopy we have determined the hydrodynamic function H(q), for a varying range of electrosteric repulsion. We show that H(q) can be quantitatively described by means of a novel Stokesian dynamics simulation method for charged Brownian spheres, and by a modification of a many-body theory developed originally by Beenakker and Mazur. Very importantly, we can explain the behavior of H(q) for strongly correlated particles without resorting to the controversial concept of hydrodynamic screening, as was attempted in earlier work by Riese [Phys. Rev. Lett. 85, 5460 (2000)]. 相似文献
58.
Aleksey Tyazhev Georgi Marchev Valeriy Badikov Adolfo Esteban‐Martin Dmitrii Badikov Vladimir Panyutin Galina Shevyrdyaeva Svetlana Sheina Anna Fintisova Valentin Petrov 《Laser \u0026amp; Photonics Reviews》2013,7(4):L21-L24
The defect chalcopyrite crystal HgGa2S4 has been employed in a 1064‐nm pumped optical parametric oscillator operating at 100 Hz, to generate ∼5 ns long idler pulses near 4 µm with energies as high as 6.1 mJ and average power of 610 mW. At crystal dimensions comparable to those available for the commercial AgGaS2 crystal, operation of the 1064‐nm pumped HgGa2S4 OPO is characterized by much lower pump threshold and higher conversion efficiency, with the most important consequence that such a device might become practical at pump levels sufficiently lower than the optical damage threshold. 相似文献
59.
Abstract We investigate the accuracy of a Gaussian approach (GA) developed to estimate the performance of a direct-detection optical receiver with arbitrary optical and electrical filtering and in the presence of partially polarized noise due to polarization-dependent loss (PDL). The accuracy is assessed by comparison of the performance estimates obtained from the GA with the estimates obtained from a rigorous method (RM) based on the calculation of the moment-generating function of the current at the optical receiver output. We show that the GA has a good accuracy when considering the variation of the optical filter bandwidth, extinction ratio, degree of polarization of the noise (DOP), and angle between signal and noise polarizations. However, it fails to predict the receiver sensitivity within 2 dB of the RM when DOP is greater than 0.7 and signal and noise polarizations are orthogonal in the Jones space. Nevertheless, it is shown that the GA provides receiver sensitivity estimates with good accuracy in most cases of long-haul optical communication systems influenced by PDL, where the typical average DOP is below 0.15. Due to its simplicity, shorter computation time, and good accuracy, the GA is a good tool to assess the performance of such optical systems. 相似文献
60.
Abstract The performance assessment of orthogonal frequency division multiplexing signals in direct-detection transmission systems by using the error vector magnitude and several bit error ratio approaches is analyzed and compared through numerical simulation. It is shown that excellent accuracy of the bit error ratio estimates is obtained by a semi-analytical Gaussian approach for all the orthogonal frequency division multiplexing system configurations analyzed and that the error vector magnitude only provides reliable estimates of the system performance when the system is dominantly impaired by noise. Additionally, a novel Q-factor approach for orthogonal frequency division multiplexing optical signals showing improved bit error ratio estimates is also presented. 相似文献