126,878 research outputs found
A class of Petrov-Galerkin finite element methods for the numerical solution of the stationary convection-diffusion equation.
No full textA class of Petrov-Galerkin finite element methods is proposed for the numerical solution of the n dimensional stationary convection-diffusion equation. After an initial review of the literature we describe this class of methods and present both asymptotic and nonasymptotic error analyses. Links are made with the classical Galerkin finite element method and the cell vertex finite volume method. We then present numerical results obtained for a selection of these methods applied to some standard test problems. We also describe extensions of these methods which enable us to solve accurately for derivative values of the solution
Melanesicus caledoniae Beaver & Petrov & Sittichaya 2021, comb. n.
No full textMelanesicus caledoniae (Beaver & Liu) comb. n. Xyleborus caledoniae Beaver & Liu 2016: 26. Taxonomy. The senior author has examined the holotype (MNHN) and paratypes (QMB, RAB). A. Petrov has examined a further specimen from New Caledonia. The species is distinguished from other species of Melanesicus primarily by its elytral sculpture (see key above, and Beaver & Liu 2016). Distribution. The species is endemic to New Caledonia. New record: NEW CALEDONIA: S-Prov. Refuge de Plano, 2 km NNE Farino, 21°38’55’’S 165°46’53’’E, ca. 270 m, at light, 28.-30.XI.2009, Schuh (1) (APP). Biology. Unknown. Remarks. Photographs of female and male are included in Beaver & Liu (2016, Figs 5‒8).Published as part of Beaver, R. A., Petrov, A. V. & Sittichaya, W., 2021, A new genus of ambrosia beetle from Melanesia (Coleoptera: Curculionidae Scolytinae: Xyleborini), pp. 163-172 in Zootaxa 4949 (1) on page 169, DOI: 10.11646/zootaxa.4949.1.9, http://zenodo.org/record/463608
Melanesicus tishechkini Beaver & Petrov & Sittichaya 2021, sp. n.
No full textMelanesicus tishechkini Petrov sp. n. (Figs 1‒4)Published as part of Beaver, R. A., Petrov, A. V. & Sittichaya, W., 2021, A new genus of ambrosia beetle from Melanesia (Coleoptera: Curculionidae Scolytinae: Xyleborini), pp. 163-172 in Zootaxa 4949 (1) on page 165, DOI: 10.11646/zootaxa.4949.1.9, http://zenodo.org/record/463608
On an inequality for concentration functions
No full textThe abstracts (in two languages) can be found in the pdf file of the article.
Original author name(s) and title in Russian and Lithuanian:
В. В. Петров. Об одном неравенстве для функций концентрации
V. Petrov. Vienos nelygybės koncentracijos funkcijom
Premnobius perezdelacrucei Petrov & Atkinson
No full textPremnobius perezdelacrucei Petrov & Atkinson Fig. 4 C, D Premnobius perezdelacrucei Petrov & Atkinson, 2018: 42. Gnathotrupes megapunctatus Bright, 2019: 410. New synonymy. Similar species. Among the American species this most closely resembles P. assiduus. Diagnosis. Length 2.45 mm, 4 as long as wide (Petrov & Atkinson 2018: 42). Very slender, with proportionately elongate pronotum. Frons shining, weakly reticulate, with sparse setae. Pronotum elongate, 80% as long as elytra; anterior margin rounded, weakly elevated with small asperities; summit located about 25% of length from anterior margin. Disc smooth, shining, with shallow, sparse punctures; vestiture a mixture of taller and shorter erect setae. Elytral striae not impressed, interstriae 2 width of striae; vestiture of erect setae, length greater than width of interstriae, mostly uniseriate, about twice as long at base of declivity. Declivity occupying posterior 33% of elytral length. A raised posterolateral crest present from interstria 4 to apex, transition gradual above. Declivity with a small, sharp tooth near base on interstria 3, displaced mesally from declivital margin; a laterally flattened, apically rounded projection on crest about 2/3 of the distance to apex, its basal length greater than its height. New Records. Brazil: Bahia, Una, Fazenda Vera Cruz, 1518′24″ S 3909′30″W, 24-II-2013, ethanol-baited, cocoa cabruca agroforestry system, S. Novais (MEFEIS, 1); Minas Gerais, Capinópolis, Fazenda Grama, 1846′7.32″S 4928′38.65″W, 16-III-2020, 30-III-2020, ethanol-baited FIT, Khaya grandifoliola stand planted IX-2015, C.F. Faria (MEFEIS, 2); same general locality, 1846′6.18″S 4928′51.59″W, 10-III-2020, ethanol-baited, Khaya grandifoliola stand planted IX-2014, C.F. Faria (MEFEIS, 1); French Guiana: Paracou (Res. Station?), XI-1996, canopy window trap, P.G. Hammond (NHMUK, 1). Distribution. Widely distributed from southeastern Mexico and the Dominican Republic to southern Brazil (Fig. 12C).Published as part of Atkinson, Thomas H., Flechtmann, Carlos A. H. & Petrov, Alexander V., 2023, Synopsis of the Neotropical Premnobiina (Coleoptera: Curculonidae: Scolytinae Ipini) with descriptions of new species, new synonymy and keys to species, pp. 69-91 in Zootaxa 5249 (1) on page 77, DOI: 10.11646/zootaxa.5249.1.4, http://zenodo.org/record/768531
Melanesicus nukuruanus Beaver & Petrov & Sittichaya 2021, sp. n.
No full textMelanesicus nukuruanus Beaver sp. n. (Figs 5‒8)Published as part of Beaver, R. A., Petrov, A. V. & Sittichaya, W., 2021, A new genus of ambrosia beetle from Melanesia (Coleoptera: Curculionidae Scolytinae: Xyleborini), pp. 163-172 in Zootaxa 4949 (1) on page 167, DOI: 10.11646/zootaxa.4949.1.9, http://zenodo.org/record/463608
Petrov V. V. — La population de l'Inde. Esquisse démographique
No full textG. G. Petrov V. V. — La population de l'Inde. Esquisse démographique. In: Population, 21ᵉ année, n°3, 1966. pp. 583-584
Petrov V. V. — La population de l'Inde. Esquisse démographique
No full textG. G. Petrov V. V. — La population de l'Inde. Esquisse démographique. In: Population, 21ᵉ année, n°3, 1966. pp. 583-584
(Table 8-7) Strontium90 measurements and salinity from Boris Petrov cruise BP99
No full text(Table 8-7) Strontium90 measurements and salinity from Boris Petrov cruise BP9
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