Search results for "Rossi"
showing 10 items of 267 documents
Ultrafast decay of the excited singlet states of thioxanthone by internal conversion and intersystem crossing.
2010
The experimental ultrafast photophysics of thioxanthone in several aprotic organic solvents at room temperature is presented, measured using femtosecond transient absorption together with high-level ab initio CASPT2 calculations of the singlet- and triplet-state manifolds in the gas phase, including computed state minima and conical intersections, transition energies, oscillator strengths, and spin-orbit coupling terms. The initially populated singlet pi pi* state is shown to decay through internal conversion and intersystem crossing processes via intermediate n pi* singlet and triplet states, respectively. Two easily accessible conical intersections explain the favorable internal conversio…
Constantine X Doukas (1059–1067) versus Uzes – about the Nomads on Boats on the Danube in 1064
2021
The reign of the Doukas dynasty in 1059–1078 was a time when new threats to the Byzantine Empire emerge in Europe and Asia. One of them was the increased activity of Turkmen who were penetrating the lands belonging to the Byzantines. A manifestation of these threats was visible during the rule of Constantine X Doukas (1059–1067) in 1064. We have there an invasion of the tribe of Uzes, who crossed the Danube. They ventured so far, as the vicinity of Thessalonica and the province of Hellas, plundering everything in their path. Their actions surprised the defense of the Byzantines. This attack on the empire was related to their crossing of the Danube, about which Michael Attaliates and Skylitz…
La città contemporanea e il territorio agricolo. Una relazione in continuo divenire
2014
Does the balanced relationship between the city and the country, typical of the birth of the urban centers and still existing in the eighteenth century, hold on until today? Can the relationship between the two parts be still considered an equal relationship? And again, can the “limits” of the contemporary city, with their residue of agricultural land be considered key points for the renaissance of a contemporary ecologically-oriented city? These are some questions underlying the research of which this paper presents the results. In order to answer these questions, this research has reflected on the transformation, over the centuries, of the relationship between town and country, on the mai…
Three-state Landau-Zener model in the presence of dissipation
2019
A population transfer based on adiabatic evolutions in a three-state system undergoing an avoided crossing is considered. The efficiency of the process is analyzed in connection with the relevant parameters, bringing to light an important role of the phases of the coupling constants. The role of dissipation is also taken into account, focusing on external decays that can be described by effective non-Hermitian Hamiltonians. Though the population transfer turns out to be quite sensitive to the decay processes, for very large decay rates the occurrence of a Zeno-phenomenon allows for restoring a very high efficiency.
Mesomorphic Donor-Acceptor-substituted 1,4-Distyrylbenzenes
2009
Conjugated oligomers with terminal donor-acceptor substitution attract increasing attention in organic chemistry because of their outstanding and not seldom unexpected properties in materials science [1 – 4]. Although a variety of oligo(1,4-phenylene-vinylene)s with terminal donor-acceptor substitution (DAOPVs 1, Scheme 1) are known [5 – 22], the number of thermotropic liquid crystals among them is very low and is confined to monomers (n = 1), that means to certain push-pull substituted (E)-stilbenes [23 – 31]. The behavior of conjugatedmolecules, which are highly polar and form mesophases by self-organization, is very interesting for various applications of liquid crystals [3]. A big disad…
Polyphasic taxonomic characterization of Lactobacillus rossiae isolates from Belgian and Italian sourdoughs reveals intraspecific heterogeneity.
2009
Abstract (GTG) 5 -PCR fingerprinting and pheS sequence analysis of 18 Lactobacillus rossiae isolates, mainly originating from Belgian and Italian artisan sourdoughs, revealed intraspecies grouping as evidenced by the delineation of three and two subgroups, respectively. On the other hand, 16S rRNA and rpoA gene sequence analysis and DNA–DNA hybridizations supported the accommodation of all isolates in a single species. No correlation between genetic and phenotypic heterogeneity was observed. Collectively, these data do not warrant taxonomic division of L. rossiae . On the other hand, the considerable differences in intraspecies sequence variation of L. rossiae isolates displayed by the pheS…
Organotin(IV) derivatives with 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidine and their cytotoxic activities: The importance of being conformers
2014
Abstract The organotin(IV) compounds Me2SnCl2(dbtp)(1), Me2SnCl2(dbtp)2 (2), Et2SnCl2(dbtp) (3), Et2SnCl2(dbtp)2 (4), Et2SnCl2(dptp) (5), nBu2SnCl2(dbtp)2 (6), nBu2SnCl2(dptp) (7), Ph2SnCl2(dbtp) (8), Ph2SnCl2(EtOH)2(dptp)2 (9), where dbtp = 5,7-di-tert-butyl-1,2,4-triazolo[1,5-a]pyrimidine and dptp = 5,7-diphenyl-1,2,4-triazolo [1,5-a]pyrimidine, have been tested by MTT for their cytotoxic activity on three tumor cell lines, HepG2 (human hepatocellular carcinoma), HeLa (human cervix adenocarcinoma) and MCF-7 (human breast cancer). Except for 1 and 2, which were ineffective, all compounds significantly showed a dose-dependent anti-proliferative effect against the three cell lines. By calcul…
Lo spirito celato nel desiderio. Riflessioni per una fenomenologia ed un'ermeneutica metafisica della persona
2020
L’analitica esistenziale evidenzia come ogni persona che viene a questo mondo non sceglie l’essere e non sceglie la forma della sua esistenza; ogni persona è definita da un limite originario per la sua libertà, un’insuperabile finitezza. Inoltre - fatto massimamente ovvio, ma sorprendentemente suggestivo di senso - ogni persona che viene a questo mondo, nasce piccolo/piccola e il tempo dell’esistenza è un continuo, possibile, processo di crescita personale. Proprio dai mondi dell’educazione apprendiamo questa verità semplice: con evidenza emerge che la persona non è ma diviene se stessa; quasi debba colmare una mancanza costitutiva percepita come intollerabile, essa appare segnata da una te…
Eu3+ ternary and tetrakis complexes with carbazole and methyl group substituted dibenzoylmethane derivatives: Induction of aggregation enhanced emiss…
2019
Abstract Two dibenzoylmethane (DBM) derivatives with methyl (Me-DBM) or carbazole (CBZ-DBM) substituents at the para-position of the phenyl ring and their four novel ternary and tetrakis Eu3+ complexes with 1,10-phenanthroline (PHEN) as a secondary ligand or tetraethylamonium ion (N+(Et)4) as the counter-cation were synthesized and characterized. The investigation of the optical properties of the complexes revealed that Me-DBM based compounds exhibit aggregation enhanced emission (AEE), while in the case of CBZ-DBM this effect is not observed. At the same time, the introduction of a carbazole substituent reduces the emission quantum yield of the complexes. The decrease in luminescence effic…
(p, 2)-Equations with a Crossing Nonlinearity and Concave Terms
2018
We consider a parametric Dirichlet problem driven by the sum of a p-Laplacian ($$p>2$$) and a Laplacian (a (p, 2)-equation). The reaction consists of an asymmetric $$(p-1)$$-linear term which is resonant as $$x \rightarrow - \infty $$, plus a concave term. However, in this case the concave term enters with a negative sign. Using variational tools together with suitable truncation techniques and Morse theory (critical groups), we show that when the parameter is small the problem has at least three nontrivial smooth solutions.