O core

Cunciii ralin . for u o core Current rating for J-. J.5-,, 4-( [Pg.537]

The most frequent structures of organo-alumoxanes are hexameric cage structures (41-45) [67] (Figure 3.5-11) (Table 3.5-3). The Al O core can be described as a drum-like hexagonal prism with alternating A1 and O atoms. The AI3O3 hexago-... 

Let us now consider the effect of a spectator vacancy on the Auger rate of the C, N, and O core hole in CH4, NH3, and H20 molecules, respectively. These molecules are isoelectronic with Ne however, the degeneracy of the outer valence orbitals is preserved only in the tetrahedral CH4. The Fano-ADC Auger widths of the singly core-ionized molecules [44] are presented in Table 6.4 alongside the available literature data. The calculated total Auger... 

A significantportion of 6lNi is also made as itselfby the s process (see Glossary), as it occurs in the thermonuclear shells of presupernova stars. The weak s process occurs during helium burning that makes the large (C, O) core of the presupernova... 

Carboxylate complexes of the lanthanides differ from those of many trivalent transition metals in that they do not adopt oxo-centered structures with M3 O cores. The hydrated acetates have a long history, with the first examples reported by Cleve in 1874 they can be synthesized by dissolving the oxides in acetic acid and the anhydrous compounds obtained by azeotropic distillation. 

Fig. 28. The Ba(OC6H3-3.5-r-Bii2)2(18-crown-6) core (r-Bu groups have been omitted for clarity) of BafOCjHj-S.S-r-BuniitlS-crown-b) 2(ArOH) (l8-crown-6). The coordination geometry can be described as hexagonal bipyramidal with the oxygen atoms of the BaO O, core defining the vertices of the polyhedron. (Redrawn from Ref, 130.)...

Fig. 12 OK edge XAS 2nd derivative spectra for Ti02 (a) conduction and valence band edge defects, (b) virtual bound resonance states defect states and shallow Ti and O core states...

The shape and geometric parameters of the Nb—O core for this compound are similar to those of the earlier values reported for [Nb(OMe)5]2 (224). The... 

Slowly add 50 mL of concentrated NH OH 56% (=28% NHj), meanwhile rapidly stirring the solution with a corrosion resistant mechanical paddle. The Fe O cores produced in this way are not stabilized and sink as a heavy, black precipitate. 

The analysis of nucleosynthesis in hypernovae suggests a possible classification scheme of supernova explosions [111]. In this scheme, core collapse in stars with initial main sequence masses Mms < 25 — 30M leads to the formation of neutron stars, while more massive stars end up with the formation of black holes. Whether or not the collapse of such massive stars is associated with powerful hypernovae ( Hypernova branch ) or faint supernovae ( Faint SN branch ) can depend on additional ( hidden ) physical parameters, such as the presupernova rotation, magnetic fields. [39], or the GRB progenitor being a massive binary system component [145, 117]. The need for other parameters determining the outcome of the core collapse also follows from the continuous distribution of C+O cores of massive stars before the collapse, as inferred from observations, and strong discontinuity between masses of compact remnants (the mass gap between neutron stars and black holes) [28]2. 

The amount of leO produced by a massive star depends strongly on a) the mass of the C/O-core at the time of iron core collapse and b) the C/O-ratio established in the C/O-core at core-He exhaustion. Both factors can be influenced in various ways. While the C/O-core mass is a strong function of the He-core mass and of the convection model, the C/O-ratio of core-He burning is sensitive to the 12C(a, y)160 nuclear reaction rate and — again — the employed convection model. While we postpone the discussion of the dependence of the 16 O yield on stellar wind mass loss to later, let us in the following compare the results of models where mass loss is unimportant. 

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