Ho systems

It is not uncommon to find the persistence of a spin adduct quantified in terms of half-life . This is a dangerous practice unless the experimental conditions are precisely defined, or it is known that the nitroxide decays by a unimolecular process. Decay may depend on reaction with a reducing agent present in the system, in which case the concentration of this species will influence the half-life. More commonly, decay will be second order (p. 5), in which case the time for disappearance of 50% of the spin adduct will show a profound dependence on its absolute concentration. The possibility of bimolecular association of nitroxides has been recognized for many years, but only very recently has it been suggested that this may be a complication under experimental conditions employed for spin trapping. Whilst the problem, which was encountered with the important [DMPO-HO ] system (Bullock et al., 1980), seems unlikely to be widespread, it is one which should always be borne in mind in quantitative studies. 

The FO type of treatment for the HOs implies that the weights of the s- and p-components of the HO system at each heavy atom are fixed as the interhybrid angles are fixed by the s-weights of HOs. This also means that the shapes of the hybridization tetrahedra remain fixed. Selection of the s-weights or equivalently of the ujb triples of angles can be done in a variety of ways, each potentially producing... 

In doing this wft-miJHt. Bo sure t.hnt dx is the differential o a function of the state of t.ho system fnr nnlv in that case is it proper to write a partial derivative like (Ax/thi).— Thus in particular we cannot TDroceed in fhi yray with nvpaomna fn- AW or.d JG tfrffllgh Sliperfieifl.llV t.hov look... 

The main Lewis acid employed industrially to synthesize ethylbenzene is formed of the AIO3/HO system. The general mechanism of its action in a Friedei/Crafts type reaction can be illustrated as follows ... 

FIGURE 5.12 The stratospheric HO family. The upper panel shows only the reactions affecting the inner dynamics of the HO system. The lower panel includes additional reactions that affect OH and H02 levels these reactions will be discussed subsequently. 

Confer, R. G., and R. C. Bainbridge, Voice control in the microsuigical suite, in Proc. of the Voice HO Systems Applications Conference 84, 1984, American Voice I/O Society, Arlington, Va. 

Fig. 2.8. The close-packed to bcc phase transformation and melting points vs. the atomic number for the lanthanide metals. The high temperature phase below the melting point has the bcc structure. In a study of the Dy-Ho system by Spedding et al. (1973) the hep to bcc transformation was found to coincide with the melting point at 75 at.% Ho-25 at.% Dy.

A more likely configuration for the holmium-yttrium phase dh ram is presented in fig. 112. Based on the investigation by Spedding et al. (1973) of phase equilibria in the Tb-Ho, Tb-Er, Dy-Ho, Dy-Er and Er-Y systems (see sections 2.54.1, 2.55.1, 2.60.1, 2.61.1 and 2.69.1, respectively), it would appear that no measurable gap would be found between the Uquidus and solidus Unes in the holmium-yttrium system when high purity metals are used. The shape of the soUdus-liquidus line can only be determined by using sensitive experimental techniques and high purity metals that is, it may be curved with a minimum (as found in the Er-Y system) or it may be linear (as found in the Dy-Ho system). Since holmium does not have the... 

Ferrimagnetic resonance studies (FMR) have been made on evaporated amorphous thin films of Ho-, Gd-, Tb- and DyFc2 by Lubitz et al. (1976) and on bulk sputtered Tb-, Gd-, and YFe2 by Bhagat and Paul (1976). The former study indicated broadened linewidths which were consistent with a Landau-Lifshitz relaxation parameter of order 10 /sec for the Gd and Ho alloys, comparable with that observed in crystalline transition metal systems. The Dy and Ho systems... 

The CdSe-R2Sc3 (R = La, Gd, Ho) systems are analogous to relative sulphide systems (Aliyev et al. 1984). The compounds CdPr2Sc4 and CdPr4Sc7 which melt. 

Returning to the subject of basis sets, we shall invariably employ basis functions written as products of radial and angular parts (6.3.13). For the radial part R r), we shall consider a variety of functional forms, all obtained by adapting in some way the simple analytical functions found in model systems - the hydrogenic atom and the three-dimensional HO system, for instance - to the... 

The degeneracy of the hydrogenic states of different angular momenta is peculiar to the Coulomb potential and is lilted in a many-electron system. The degeneracy of the one-electron isotropic HO system is also different from that of the hydrogenic system see Section 6.6.1. 

Use of the principal quantum number n for the HO system emphasizes the close relationship of the HO functions (6.6.3) with the Laguerre functions (6.5.17) but complicates the expression for the... 

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