Artículos de revistas: Recent submissions
Now showing items 821-840 of 4968
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(Elsevier Ltd, 1998)We discuss the recent appearance of very broad (FWZI∼20000 km s-1) double-peaked Balmer emission lines in the nuclei of the galaxies NGC 1097, Pictor A and M 81. Such profiles are rare, and only found in about 10% of ...
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(1990)Three protease fractions were obtained by purification of a thistle extract with ammonium sulfate. The optimum pH and temperature on the proteolytic activity of the crude extract was found to be 5·7 and 37°C, respectively. ...
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(1992)During some biogeochemical processes mediated by bacteria, essential nutrients such as phosphate can become limiting for the microorganisms, affecting their biological activity. We have analyzed changes in total protein ...
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(1984)We consider systems of differential equations of the form (1) x’ = f(t,x), for t ∊ [a,∞), x in some domain D ⊂ IRn and f ∈ c1 ([a,∞) × D) (a a fixed real number). We assume that the solution x(t,to,xo) of (1) defined for ...
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(1995)In this paper I examine the extent to which contemporary ecological patterns in 42 harvester ant assemblages of three continents can be explained as a result of present-day environments or from differences in the history ...
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(1992)Relative reactivities of potassium persulfate (KPS) and ferrous ammonium sulfate-potassium persulfate (FAS-KPS) systems, in aqueous medium, as initiators for grafting of methyl methacrylate (MMA) onto chitin, were studied. ...
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(Elsevier, 2000)The infrared spectra of the azabipiridyl macrocycle complexes of Ni(II), Cu(II) and Zn(II) were registered between 4000 and 200 cm-1. The spectral assignment allowed to identify the complex formation and structural differences ...
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(1998)The infrared spectra of naphthalocyanine (H2Nc) and its copper(II) complex (CuNc) were registered in the region 4000-450 cm-1. These compounds were deposited onto a smooth copper surface and their specular infrared spectra ...
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(1995)Deuterium quadrupole splittings from the aromatic ring of a series of deuterium labeled n-alkylpyridinium ions with linear n-alkyl groups from Ci to Cie have been measured using 2H-NMR spectroscopy. These splittings were ...
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(1988)From Schizanthus pinnatus Ruiz et Pav. we have isolated seven new tropan-3α,6β-diol diesters, schizanthines F (1), G (2), H (3), I (4), K. (8), L (9), and M (10), together with tropine, (-) -6β-angeloyloxytropan-3α-ol (5), ...
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(1997)We have used a deep CO survey of the third galactic quadrant (May et al. 1993) to derive the physical properties of molecular clouds in the outer Galaxy. Within the range of this survey, from 194° to 270° in galactic ...
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(1999)In this paper we consider a class of nonlinear singularly perturbed elliptic problems of the form ε2 Δu - u + f(u) = 0 in Ω, for a superlinear, subcritical function f. Here Ω a smooth bounded domain, ε > 0 is a small ...
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(1996)A theoretical evaluation of inelastic transition amplitudes corresponding to collisions between low-energy electrons (up to 5 eV) and small metallic clusters is presented. The target is excited into a particle-hole state ...
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(1990)The negative ions of the alkaline-earth-metal atoms (Be to Ba) have been studied by means of a pseudopotential model together with configuration- interaction and multiconfiguration self-consistent-field techniques. Only ...
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(1980)Hydroxamic acid concentration in Gramineae, both natural and incorporated, correlates with resistance to the aphid Metopolophium dirhodum. 2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one, a hydroxamic acid isolated ...
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(Elsevier, 1999)The IR spectra of the M(mnt)(baba) where M = Ni and Pd, mnt = 1,2-maleonitrile and baba = biacetylbisanyline, were recorded in the high as well in the low energy region. A complete assignment of the observed bands was ...
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(Elsevier, 1999)The possibility of gaining insight into chemical bonding and reactivity through various local temperatures and associated entropy densities is explored. Comparisons of these quantities with other local reactivity descriptors ...
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(1985)The hydroxamic acid content of leaves of cereals correlates well with resistance to aphids. In maize these compounds were absent from xylem exudates and guttation drops. Lateral veins of leaves of 7-day-old maize plants ...
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(1985)The content of the simple indole alkaloid gramine in barley leaves decreased with age. Conversely, susceptibility to aphids increased in older plants. Population growth rate of the greenbug Schizaphis graminum correlated ...
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(1982)Toxicity of DIMBOA, the major cyclic hydroxamic acid in maize extracts, to the aphid Schizaphis graminum, was decreased by addition of cysteine to the insect diet. The ld50 for DIMBOA on aphids was, after 24 hr, 2.1 and ...
