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1.
We have studied the approach of the Abelian sand pile model towards the stationary, self-organized criticality state. The uncorrelated limit is shown both numerically and by a simple analysis to follow the log-normal distribution. We introduce and evaluate several correlation fuctions to study the correlated region. 相似文献
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Friedel-Crafts reaction of benzylic or tertiary nitro compounds with benzene gave normal alkylation products. Similarly, 2-nitropropane (2-NP) gave cumene (1) which underwent further transformation affording a mixture whose behaviour with time was investigated : results were consistent with oxidative formation of the cumyl carbonium ion (7'). 相似文献
5.
The cyclic voltammetric behavior of carbon paste electrodes modified by direct admixing with the products of the reactions between ethanedial (glyoxal) and 5-amino-1,10-phenanthroline at 100°C and that of their iron(II) complexes is reported. The ligand(s) produced in absence of iron(II) are able to complex iron(II) and copper(II) ions reversibly, but other ions such as nickel(II), cobalt(II), cadmium(II) and manganese(II), if complexed, show no electrochemical activity. Admixing with the products of the reaction in the presence of excess of iron(II) ion, because of high insolubility and fast electron exchange, produces surfaces useful for amperometric detection in continuous-flow systems. The voltammetric and amperometric behavior in the presence of HSO?3 ions is reported in order to illustrate this application. 相似文献
6.
Chemical species obtained by reaction of 5-amino-1, 10-phenanthroline with ethanedial (glyoxal) are reported with regard to their preparation, chemical composition and spectrometric characterization (UV-visible, infrared and liquid secondary ion mass spectrometry). Products of the reaction are postulated to be a mixture of species with molecular weights of 339, 371,480 and 524 u. Chemical reactions leading to these products and possible structural formulas for each of these species are presented. The iron complexes of these ligands, because of their extremely low solubility in most solvents, find application as redox mediators when incorporated in carbon paste electrodes, particularly for sensing in continuous-flow systems. 相似文献
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Rosa Ortiz Joaquín Borrás Lourdes Perelló Horacio Jimenez 《Monatshefte für Chemie / Chemical Monthly》1986,117(4):443-451
The formation constants of the binary complexes Cu(CM)2+ and Cu(CM)
2
2+
as well as those of the ternary complexes Cu(CM)L
+ and Cu(CM)2
L
+ (CM=Cimetidine=N-Cyano-N-methyl-N[(5-methyl-1H-imidazol-4-yl)methyltioethyl]-guanidine; HL=Phenobarbital=5-ethyl-5-phenyl-barbituric acid) have been determined in 0.1 and 1.0 mol dm–3 NaClO4 methanol solutions at 25±0.2°C. The values of logX, log stat.., and logK confirm the stability of the ternary complexes.
Ternäre Komplexe von Cimetidin und Phenobarbital mit Cu(II) in methanolischer Lösung
Zusammenfassung Die Stabilitätskonstanten der binären Komplexe Cu(CM)2+ und Cu(CM) 2 2+ sowie die der ternären Komplexe Cu(CM)L + und Cu(CM)2 L + (CM=Cimetidin=N-Cyan-N-methyl-N-[(5-methyl-1H-imidazol-4-yl)methylthioethyl]-guanidin; HL=Phenobarbitalum=5-Ethyl-5-phenyl-barbitursäure) wurden in 0.1 und 1.0M Lösungen von NaClO4 in Methanol bei 25±0.2°C bestimmt. Die Werte von logX, log stat. und logK bestätigen die Stabilität der ternären Komplexe.相似文献
9.
Josué M. Heinrich Ignacio Niizawa Fausto A. Botta Alejandro R. Trombert Horacio A. Irazoqui 《Photochemistry and photobiology》2013,89(5):1127-1134
Light availability is a main issue in autotrophic growth of photosynthetic microorganisms. The change of the suspended cells concentration and that of their chlorophylls content during microalgal growth alters the optical properties of the aqueous suspension. This brings about changes in the properties of the radiation field inside the reactor. In this work, we have computed the evolution in time of the local volumetric rate of absorption of photons inside a photobioreactor by means of a Monte Carlo simulation algorithm previously developed. From this study, we have computed two operational variables that are useful tools for the analysis, performance comparison, optimization and scaling up of photobioreactors: the average rate of photon absorption and the volumetric distribution function of photons absorption rates. Based on these two variables, it is possible to systematically quantify the degree of stratification of the culture medium, which is a decisive aspect that hampers the reactor efficiency regarding the energy usage for biomass production. 相似文献
10.
Fernanda D. de Melo Hernández César A. Hernández Melo Horacio Tapia-Recillas 《代数通讯》2020,48(9):4013-4026
AbstractIn the present work, a procedure for determining idempotents of a commutative ring having a sequence of ideals with certain properties is presented. As an application of this procedure, idempotent elements of various commutative rings are determined. Several examples are included illustrating the main results. 相似文献