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Constantino Tsallis 《Milan Journal of Mathematics》2005,73(1):145-176
We briefly review Boltzmann-Gibbs and nonextensive statistical mechanics as well as their connections with Fokker-Planck equations
and with existing central limit theorems. We then provide some hints that might pave the road to the proof of a new central
limit theorem, which would play a fundamental role in the foundations and ubiquity of nonextensive statistical mechanics.
The basic novelty introduced within this conjectural theorem is the generalization of the hypothesis of independence of the N random variables being summed. In addition to this, we also advance some nonlinear dynamical (possibly exact) relations which
generalize the concepts of Lyapunov exponents, entropy production per unit time, and their interconnection as first proved
by Pesin for chaotic systems.
The article is available online on SpringerLink (www.springerlink.com) using colors instead of greyscales in Figure 4.1.
Lecture held in the Seminario Matematico e Fisico on May 21, 2004 Received: December 2004 相似文献
4.
Gaffo L Constantino CJ Moreira WC Aroca RF Oliveira ON 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(1-2):321-327
Rhodium phthalocyanine (RhPc) was synthesized and ultra thin Langmuir-Blodgett (LB) films of RhPc were successfully fabricated. The LB film characterization was carried out using both UV-vis absorption spectra and Raman scattering. The Raman spectroscopy was carried out using 633 and 780 nm laser lines. LB films were deposited onto Ag nanoparticles to achieve the surface-enhanced pre-resonance Raman scattering (pre-SERRS) and surface-enhanced Raman scattering (SERS) for both laser lines, respectively, which allowed the characterization of the RhPc ultra thin films. The morphology of the LB RhPc neat film is extracted from micro-Raman imaging. 相似文献
5.
Patrícia M. Dias Dalva L. A. De Faria Vera R. L. Constantino 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):251-266
In the present work, the interaction between5,10,15,20-tetrakis(1-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) and its metallated form(CoTMPyP) with three cationic clays was investigatedby X-ray diffraction (XRD), UV-VIS and resonance Ramanspectroscopies. Sodium montmorillonites K10 and KSFand a synthetic fluorohectorite (FHT) containingdifferent macrocycle loadings, were prepared by an ionexchange reaction. In nonsaturated KSF and FHT, theCoTMPyP molecule assumes a flat orientation, relativeto the host layers, giving rise to at least twoabsorption bands in the Soret region (ca. 445 and 465 nm)assigned to adsorbed and intercalated CoTMPyP,respectively. For the delaminated K10 sample, a broadband centered around 456 nm, indicates a majorcontribution from the metalloporphyrin on the clayexternal surfaces. The electronic spectra of FHTsamples containing increasing amounts of CoTMPyPshow bands red shifted even when a small amount ofporphyrin is used, suggesting that the electroniclevels of the macrocycle are more affected by theinteraction with the clay than by the metalloporphyrindistortion inside the galleries. The resonance Ramanspectra obtained for all CoTMPyP samples presentedonly minor shifts in peak positions and band width,with the exception of the FHT saturated sample, wherethe bands are clearly broader when compared to otherloadings, suggesting that porphyrin aggregation isoccurring. In the case of TMPyP, the bands at ca. 430and 468 nm were assigned to nonprotonated andprotonated molecules, respectively. This assignment issupported by resonance Raman spectroscopy, which alsoshowed the 2 mode (ca. 1550 cm-1) to bethe most sensitive peak to protonation. 相似文献
6.
Quintanar L Yoon J Aznar CP Palmer AE Andersson KK Britt RD Solomon EI 《Journal of the American Chemical Society》2005,127(40):13832-13845
7.
A correction of a recent work on the dependence of the DC conductivity of diluted colloidal suspensions on the size, zeta potential, and state of motion of dispersed particles (C. Grosse, S. Pedrosa, V.N. Shilov, J. Colloid Interface Sci. 251 (2002) 304) is presented. It is shown that the procedure used in that work to calculate the contribution of the particles to the conductivity of the suspension leads to a result that includes the variation of the conductivity of the dispersion medium. Revised analytical and numerical calculations are presented, which strongly reinforce the conclusions reached in the original work: The expression for the conductivity increment based on the value of the dipolar coefficient of the suspended particles (calculated taking into account their electrophoretic motion) appears to be valid over the whole range of particle sizes. 相似文献
8.
Constantino E Rodríguez-Santiago L Sodupe M Tortajada J 《The journal of physical chemistry. A》2005,109(1):224-230
Cobalt cations are open shell systems with several possible electronic states arising from the different occupations of the 3d and 4s orbitals. The influence of these occupations on the relative stability of the coordination modes of the metal cation to glycine has been studied by means of theoretical methods. The structure and vibrational frequencies have been determined using the B3LYP method. Single-point calculations have also been carried out at the CCSD(T) level. The most stable structure of Co(+)-glycine is bidentate, with the Co(+) cation interacting with the amino group and the carbonyl oxygen of neutral glycine, and the ground electronic state being (3)A. For Co(2+)-glycine, the lowest energy structure corresponds to the interaction of the metal cation with the carboxylate group of the zwitterionic glycine, the ground electronic state being (4)A'. 相似文献
9.
Magno Aparecido G. Trindade Glaucia Maria da Silva Valdir Souza Ferreira 《Microchemical Journal》2005,81(2):209-216
This work presents an electroanalytical methodology developed for square-wave voltammetry based in the electrochemical reduction in hanging mercury drop electrode (HMDE), which is simple, fast, reliable and sensitive for determination of moxifloxacin (MOXI) in tablets and spiked urine human samples. The support electrolyte that provided a more defined and intense peak current for MOXI determination was the phosphate buffer 0.04 mol l− 1 pH 8.0. In the best-optimized conditions the drug presented an only peak of reduction at − 1.38 V vs. Ag/AgCl, using an Eacc. of − 0.30 V. An LOD of 0.44 and 3.20 ng ml− 1 and an LOQ of 1.46 and 10.60 ng ml− 1 were found for the pure standard of moxifloxacin and in the presence of matrix, respectively. A good recovery was obtained for assay spiked urine samples and a good quantification of MOXI was achieved in a commercial formulation. The methodology proposed was more sensitive than the spectrofluorimetric and spectrophotometric method with precision and accuracy equivalent. 相似文献
10.
Vera R. L. Constantino Luiz F. C. de Oliveira Paulo S. Santos Henrique E. Toma 《Transition Metal Chemistry》1994,19(1):103-107
Summary The synthesis, spectra and electrochemistry of [Ru(bipy)2-(picOH)]+ and -picO-[Ru(bipy)2]2
2+ (bipy = 2,2-bipyridine and picOH = 3-hydroxypicolinate ion) are described. The spectroscopic properties in the visible region are dominated by the intense Ru bipy chargetransfer transitions. In the binuclear complex, the two [Ru(bipy)2L]2+ moieties are nonequivalent, exhibiting E
1/2 = 0.69 and 1.20 V versus s.h.e. The partially oxidized species exhibits a weak intervalence transfer band at 1085 nm, and is consistent with a Robin-Day class II mixed valence complex. 相似文献