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961.
We prove that for every fixed k, the number of occurrences of the transitive tournament Trk of order k in a tournament on n vertices is asymptotically minimized when is random. In the opposite direction, we show that any sequence of tournaments achieving this minimum for any fixed is necessarily quasirandom. We present several other characterizations of quasirandom tournaments nicely complementing previously known results and relatively easily following from our proof techniques. 相似文献
962.
Summary The hyperbolic system of the field equations of the Extended Thermodynamics governing the non-equilibrium thermodynamical processes of gases is studied. First, the extreme cases of strongly degenerate Fermi and Bose gases are discussed so as to complete the previous analysis by Liu and Müller. The physical interpretation of these results appears to be in agreement with quantum and statistical mechanics. Then, the propagation of discontinuity waves and the critical time for classical gases will be dealt with.
Supported by C.N.R., M.P.I. fondi ricerche 40% and 60% and INFN(sez. di Bologna). 相似文献
Sommario Si studia il sistema iperbolico delle equazioni di campo della Termodinamica Estesa che governa i processi termodinamici di non equilibrio nei gas. Nella prima parte si discutono i casi limite dei gas di Fermi e Bose fortemente degeneri completando la precedente analisi di Liu e Müller. L'interpretazione fisica di questi risultati appare in accordo con la meccanica quantistica e statistica. Nella seconda parte si studia la propagazione di onde di discontinuitá e il tempo critico per i gas classici.
Supported by C.N.R., M.P.I. fondi ricerche 40% and 60% and INFN(sez. di Bologna). 相似文献
963.
An Electrochemical Sensor for Reducing Sugars Based on a Glassy Carbon Electrode Modified with Electropolymerized Molecularly Imprinted Poly‐o‐phenylenediamine Film
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Qian Wang Leonardo Lataro Paim Xiuhua Zhang Shengfu Wang Nelson Ramos Stradiotto 《Electroanalysis》2014,26(7):1612-1622
An electrochemical sensor based on electropolymerizing o‐phenylenediamine (o‐PD) on a glassy carbon electrode (GCE) was developed for determination of reducing sugars. The molecular imprinted sensor was tested by differential pulse voltammetry (DPV) to verify the changes in peak currents of hexacyanoferrate. Under the optimum analytical conditions, the current change was linear to the logarithm of glucose and fructose concentration from 0.25 to 25 µM. The detection limit of glucose and fructose were 0.185 µM and 0.173 µM, respectively. Besides, the applicability of the sensitive sensor has been successfully evaluated by determining reducing sugars in the samples from sugarcane industries. 相似文献
964.
Dr. Anne B. Neef Dr. Lucile Pernot Verena N. Schreier Prof. Dr. Leonardo Scapozza Prof. Dr. Nathan W. Luedtke 《Angewandte Chemie (International ed. in English)》2015,54(27):7911-7914
Pathogen‐selective labeling was achieved by using the novel gemcitabine metabolite analogue 2′‐deoxy‐2′,2′‐difluoro‐5‐ethynyluridine (dF‐EdU) and click chemistry. Cells infected with Herpes Simplex Virus‐1 (HSV‐1), but not uninfected cells, exhibit nuclear staining upon the addition of dF‐EdU and a fluorescent azide. The incorporation of the dF‐EdU into DNA depends on its phosphorylation by a herpes virus thymidine kinase (TK). Crystallographic analyses revealed how dF‐EdU is well accommodated in the active site of HSV‐1 TK, but steric clashes prevent dF‐EdU from binding human TK. These results provide the first example of pathogen‐enzyme‐dependent incorporation and labeling of bioorthogonal functional groups in human cells. 相似文献
965.
966.
Nadia Marino Donatella Armentano Emilio Pardo Julia Vallejo Francesco Neve Leonardo Di Donna Giovanni De Munno 《Chemical science》2015,6(7):4300-4305
The different natures of the weakly coordinating anions – triflate or perchlorate – in the Cu2+-mediated self-assembly of cytidine monophosphate nucleotide play a fundamental role in the homochiral resolution process, yielding one-dimensional copper(ii) coordination polymers of opposite helicity that can be easily inverted, in a reversible way, by changing the nature of the anion as revealed by circular dichroism experiments both in solution and in the solid state. 相似文献
967.
Leonardo S. Barbosa William Marshall Larissa Albantakis Giulio Tononi 《Entropy (Basel, Switzerland)》2021,23(3)
The Integrated Information Theory (IIT) of consciousness starts from essential phenomenological properties, which are then translated into postulates that any physical system must satisfy in order to specify the physical substrate of consciousness. We recently introduced an information measure (Barbosa et al., 2020) that captures three postulates of IIT—existence, intrinsicality and information—and is unique. Here we show that the new measure also satisfies the remaining postulates of IIT—integration and exclusion—and create the framework that identifies maximally irreducible mechanisms. These mechanisms can then form maximally irreducible systems, which in turn will specify the physical substrate of conscious experience. 相似文献
968.
Leonardo Rydin Gorjo Dirk Witthaut Klaus Lehnertz Pedro G. Lind 《Entropy (Basel, Switzerland)》2021,23(5)
With the aim of improving the reconstruction of stochastic evolution equations from empirical time-series data, we derive a full representation of the generator of the Kramers–Moyal operator via a power-series expansion of the exponential operator. This expansion is necessary for deriving the different terms in a stochastic differential equation. With the full representation of this operator, we are able to separate finite-time corrections of the power-series expansion of arbitrary order into terms with and without derivatives of the Kramers–Moyal coefficients. We arrive at a closed-form solution expressed through conditional moments, which can be extracted directly from time-series data with a finite sampling intervals. We provide all finite-time correction terms for parametric and non-parametric estimation of the Kramers–Moyal coefficients for discontinuous processes which can be easily implemented—employing Bell polynomials—in time-series analyses of stochastic processes. With exemplary cases of insufficiently sampled diffusion and jump-diffusion processes, we demonstrate the advantages of our arbitrary-order finite-time corrections and their impact in distinguishing diffusion and jump-diffusion processes strictly from time-series data. 相似文献
969.
Cid B. de Araújo Glauco S. Maciel Leonardo de S. Menezes Nikifor Rakov Edilson L. Falco-Filho Vladimir A. Jerez Younes Messaddeq 《Comptes Rendus Chimie》2002,5(12)
We present recent results on frequency upconversion (UPC) obtained in fluoroindate glasses (FIG) doped with Ho3+, Tm3+ and Nd3+ ions and codoped with Pr3+/Nd3+ and Yb3+/Tb3+ ions. The results for the Ho3+-doped samples show strong evidence of energy transfer (ET) between Ho3+ ions resonantly excited at 640 nm. The origin of the blue-green upconverted fluorescence observed was identified and the dynamics of the signals revealed the pathways involved in the UPC process. In the case of Tm3+-doped FIG, the samples were resonantly excited at 650 nm and the main mechanism that contributes for the red-to-blue upconversion is excited-state absorption (ESA). The FIG samples codoped with Pr3+/Nd3+ were excited at 588 nm in resonance with transitions starting from the ground state of the Nd3+ and the Pr3+ ions. It was observed that the presence of Nd3+ ions enhanced the Pr3+ emission at 480 nm by two orders of magnitude. Multiphonon (MP)-assisted upconversion is also discussed for Nd3+-doped FIG pumped at 866 nm. Emission at 750 nm with a peculiar linear dependence with the laser intensity was observed and explained. A rate-equation model that includes MP absorption via thermally coupled electronic excited states of Nd3+ was developed and describes well the experimental results. The role played by effective phonon modes is clearly demonstrated. MP-assisted UPC process was also studied in Yb3+/Tb3+-codoped FIG samples excited at 1064 nm, which is off-resonance with electronic transitions starting from the ground state. It was determined that the mechanism leading to Tb3+ emission in the blue is due to ET from a pair of excited Yb3+ ions followed by ESA in the Tb3+ ions. 相似文献
970.
We apply our previously developed formalism of contexts of histories, suitable to deal with quantum properties at different times, to the measurement process. We explore the logical implications which are allowed by the quantum theory, about the realization of properties of the microscopic measured system, before and after the measurement process with a given pointer value. 相似文献