177,596 research outputs found
Oedemera (Oedemera) jani Poloni 2023, n. sp.
No full textOedemera (Oedemera) jani n. sp. Figs 5-9, 14-15 Material examined Type Material. Holotypus, ♂: China: SICHUAN prov. // Wolong National Nature // Reserve, Namasi vill., // 2150 m, 23.VI.2014, // 31°01’28’’N 103°09’40’’E, /// shrubs in close stream valley // along stream bank, above // small water dam, side valley, // J. Hájek & J. Růžička leg. Paratypi: same locality, 1 ♂, 1 ♀ (all types at NMPC). Description of the male, holotype Coloration. (Fig. 5) Elytra, pronotum and head olivaceous green, metallic. Legs sienna, proximal side of fore tibiae terra-cotta. Tarsi and second antennomere terra-cotta. The whole surface covered with a sparse, short, recumbent white pubescence. External morphology. Body length: 6,6 mm. Head rostrate, eyes slightly protruding. Space between the scapes half of the interocular space. Apical and central part of head with shallow and dense punctures, space between punctures micro-shagreened. Posterior part of head wrinkled. Only the apical part of the head with long, erect, yellow setae. First maxillary palpomere 1.5× longer than the second, last antennomere twice as long as the second, slightly securiform. Antennae 11-segmented, the scape 3× longer than the second antennomere, the third 1.5× longer than the scape, the following progressively shortening. Last antennomere slightly emarginated at apex. Pronotum moderately cordiform and distinctly elongated anteriorly. Surface glabrous, wrinkled, except in the central part, characterized by an irregular punctuation and smoother ventrally. Disc with two antero-basal depressions. Sides slightly emarginated, smooth. Elytra with surface rugose and shagreened. Intermediate venation and elytral suture raised, first venation extended on 1/3 of elytral length. Claws simple. Thorax, in his ventral side smooth, with shallow and sparse punctures. Abdomen with sparse, shallow punctures. Pygidium rounded. Last ventrite simple, not emarginated at apex. Male genitalia: as in Figs 7-8, 14-15. Variation of paratypes Sexual dimorphism: The female differs from male by having hind femora not thickened and the pronotum not distinctly elongated anteriorly (Fig. 6). Length: 10,3 (holotype male); 9,4 (paratype male); 8,3 (paratype female). Comparative diagnosis This species belongs to the O. virescens species group as defined by Švihla (1999). It can be easily distinguished from the other members of this group by the shape of pronotum, cordiform and distinctly elongated anteriorly (especially in male, Fig. 9) and by the shape of male genitalia from the similar O. (Oedemera) virescens (Linnaeus, 1767). In the latter species the aedeagus has a wider base and more tapered apex, and larger and more tapered parameres. The ssp. chalybea Faldermann, 1837 is characterised by the shape of aedeagus, straight and not tapered (Fig. 17) and by longer and larger parameres (Fig. 16) (Švihla 1999), and is thus particularly similar to O. jani n. sp. The new species can be anyway distinguished by the shape of pronotum, by the aedeagus, thicker in the apical portion (Figs 8, 15), and by the more rounded and shorter parameres (Figs 7, 14). Etymology. The species is named after one of the two collectors, Jan Růžička.Published as part of Poloni, Riccardo, 2023, Two new species of the genus Oedemera from China (Coleoptera: Oedemeridae), pp. 57-60 in Fragmenta entomologica (Basel, Switzerland) (Basel, Switzerland) 55 (1) on pages 59-60, DOI: 10.13133/2284-4880/1463, http://zenodo.org/record/814838
Denominarsi e distinguersi nella montagna bergamasca. I cognomi di Castione della Presolana dal XIII al XVI secolo
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Una società fluida. L'economia di Firenze nel tardo medioevo
No full textIl saggio assume come punto di partenza la pubblicazione della traduzione in italiano del monumentale libro di R. Goldthwaite sull'economia fiorentina tra il 1300 e il 1600. Esso mira a stimolare una discussione su alcune delle idee più "provocatorie" del lavoro di Goldthwaite, e propone alcune riflessioni suggerite dalle sue ipotesi interpretative. Goldthwaite condivide la visione "ottimistica" della crisi del Trecento che oggi tende a prevalere tra gli storici dell'economia, e descrive la seconda metà del Trecento come una fase di grande espansione dell'economia fiorentina. L'analisi innovativa dello studioso americano è il punto di partenza per una riflessione sul tema complesso dell'integrazione come fattore di crescita economica, sulla base di alcuni rilievi critici sui modelli "regionalisti" ispirati soprattutto dalla "New Institutional Economics". Inoltre, l'articolo discute la stimolante ipotesi di Goldthwaite che nella seconda metà del XIV secolo Firenze avrebbe sperimentato la transizione da un sistema economico caratterizzato dall'egemonia di alcune grandi compagnie, tipico della prima metà del secolo, a una struttura assai più fluida, frammentata e acentrica. Partendo da questa prospettiva, sono proposte alcune considerazioni sulle trasformazioni sociali ed economiche del tardo medioevo
Factoring block Fiedler Companion Matrices
No full textWhen Fiedler published his “A note on Companion matrices” in 2003 on Linear Algebra and its Applications, he could not have foreseen the significance of this elegant factorization of a companion matrix into essentially two-by-two Gaussian transformations, which we will name (scalar) elementary Fiedler factors. Since then, researchers extended these results and studied the various resulting linearizations, the stability of Fiedler companion matrices, factorizations of block companion matrices, Fiedler pencils, and even looked at extensions to non-monomial bases. In this chapter, we introduce a new way to factor block Fiedler companion matrices into the product of scalar elementary Fiedler factors. We use this theory to prove that, e.g. a block (Fiedler) companion matrix can always be written as the product of several scalar (Fiedler) companion matrices. We demonstrate that this factorization in terms of elementary Fiedler factors can be used to construct new linearizations. Some linearizations have notable properties, such as low bandwidth, or allow for factoring the coefficient matrices into unitary-plus-low-rank matrices. Moreover, we will provide bounds on the low-rank parts of the resulting unitary-plus-low-rank decomposition. To present these results in an easy-to-understand manner, we rely on the flow-graph representation for Fiedler matrices recently proposed by Del Corso and Poloni in Linear Algebra and its Applications, 2017
Caratterizzazione energetica dei forni combinati ad uso professionale: parte 2: controllo del processo di preparazione dei cibi
No full textObiettivo del presente lavoro è l’analisi del consumo energetico dei forni professionali per la cottura di alimenti, allo scopo di individuare nuove soluzioni per il risparmio energetico e la riduzione dei costi di esercizio. Quindi viene presentato e validato un modello concettuale del processo di cottura basato sull’analisi dei flussi energetici coinvolti durante un generico processo di cottura, considerando il sistema forno + cibo. L’evoluzione energetica del sistema viene descritta suddividendo il processo di cottura in tre fasi ed introducendo il concetto dei livelli energetici di cottura, funzione del tipo di forno e del tipo di ricetta. Tale modello viene poi applicato definendo una strategia di ordinamento ottimale delle cotture per la riduzione dei consumi globali d’esercizio
Xanthochroina Ganglbauer, 1881, a new genus of Oedemeridae for the Italian fauna (Coleoptera)
No full textIn this paper is reported for the first time with certainty the presence in Italy of the genus Xanthochroina, exhibiting a Holarctic discontinuous distribution. The Mediterranean species X. auberti is recorded from western Liguria and information on the range of the species is updated
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