Region I

In a.p. ZV(a) and ZV(i) samples, broad bands arising from hydrated vanadates were detected in the 800-1100 cm-i region. Metavanadate-like species (band at 920 cm i) prevailed on ZV samples with V-content < 1.5 atoms nm 2 and decavanadates (bands at 850-880 cm i and 960-990 cm- ) in the range 1.5-3 atoms nm 2. A.p. ZV(acac) samples showed bands from CH3 and C=0, suggesting the adsorption of VO(acac)2 as such (spectra not reported). 

In those cases where i. (region A in Eig. 6.6), the real current density i essentially coincides with the kinetic current density i 4, and the electrode reaction is controlled kinetically. When 4 ik (region C), we practically have i 4, and the reaction is diffusion controiled. When 4 and 4 have comparable values, the electrode operates under mixed control (region B). The relative valnes of these current densities depend on the kinetic parameters and on the potential. 

Although the ROA spectra of typical /1-sheet proteins share some of the features observed in /3-sheet poly-L-lysine, there are also some differences, especially in the amide I region. This is because the /1-sheet in proteins tends to be twisted and irregular, whereas that in polypeptides tends to be extended, multistranded and relatively flat. 

The gas component, which is the most important form in which matter is found in outer space (up to 98-99%), is dominated by the element hydrogen, which makes up 70% of the mass and 90% of the particles. In ionized form (the H-II regions) the gas can be recognized by its recombination and fluorescence light emission. The hydrogen is mainly present in neutral form (H-I regions), at a mean density of 2x 107 particles per cubic metre and a mean temperature of about 80 K. 

Radioastronomers first learned of 3He in 1955 at the fourth I.A.U. Symposium in Jodrell Bank, when the frequency of the hyperfine 3He+ line at 8.666 GHz (3.46 cm) was included by Charles Townes in a list of radio-frequency lines of interest to astronomy (Townes 1957). The line was (probably) detected for the first time only twenty years later, by Rood, Wilson Steigman (1979) in W51, opening the way to the determination of the 3He abundance in the interstellar gas of our Galaxy via direct (although technically challenging) radioastronomical observations. In the last two decades, a considerable collection of 3He+ abundance determinations has been assembled in Hi I regions and planetary nebulae. The relevance of these results will be discussed in Sect. 4 and 5 respectively. 

Weinberger, D. R., Berman, K. F. and Zee, R. F. Physiologic dysfunction of dorsolateral prefrontal cortex in schizophrenia. I. Regional cerebral blood flow evidence. Arch. Gen. Psychiatry 43 114-124,1986. 

The corresponding lanthanide allyl, Sm(C5H5)2(allyl), has recently been reported and preliminary indications, based upon the absence of infrared absorptions in 1610—1640 cm i region, are consistent with a jr-bonded structure 149). Since the jr-bonded structure would be formally eight coordinate and the a-bonded structure only six coordinate, this would be the predicted ground state. 

Table II lists the IR characteristics of the alkaloids. The IR spectra are of little use in structural identification apart from noting the absence of a carbonyl peak in the flavans and the bands for phenolic and aromatic bonds in the 3200 and 1590 cm i regions, respectively.

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