R-Fe systems

The RB2 compounds are, in the R-Mn and R-Fe systems, the compounds with the highest R-content. This is probably due to the fact that without a total rearrangement of the 3d basis lattice two 3d atoms can be replaced by an R-atom. However, if R-richer compounds were to be formed, either the majority of the 3d atoms of an element must be replaced by R-atoms or in an R basis lattice few 3d atoms must be fitted in. This however would result in a deviation from the principal of close packed structures. The result would obviously be a large increase of the Gibbs free energy G. Therefore these structures and compounds are not stable compared to the neighbouring structures or neighbouring compounds. 

The R-Fe system (fig. 14.77) shows the anomalous Tc increase as the Fe concentration decreases even for the Y-Fe system. As we shall see in the following sections Fe tends to show more localized character than Ni and Co. The application of the Friedel model (subsection 3.1.6), with couplings between semi-localized 3d-moments within a band, could in principle account for the increased strength of exchange on diluting Fe with Y since the 3d polarization around an impurity centre oscillates in space. 

The excess chemiccil potential is thus determined from the average of exp[—lT (r )/fe In ensembles other than the canonical ensemble the expressions for the excess chem potential are slightly different. The ghost particle does not remain in the system and the system is unaffected by the procedure. To achieve statistically significant results m Widom insertion moves may be required. However, practical difficulties are encounte when applying the Widom insertion method to dense fluids and/or to systems contain molecules, because the proportion of insertions that give rise to low values of y f, dramatically. This is because it is difficult to find a hole of the appropriate size and sha... 

Cationic Fp (olefin) complexes [Fp = f/5-C5H5Fe(CO)2] undergo regio-specific addition of heteroatomic nucleophiles.32 Subsequent ligand transfer (carbonyl insertion) occurs with retention of configuration at the migrating center (R—Fe—CO -> RCOFe).33 A combination of these processes has provided a novel stereospecific azetidinone synthesis which can also be applied to condensed systems.34... 

Ik = r fe, r, , rj, so that a particle belongs to only one such unit, and the particles in all these sets equal N, the total number of particles in the system. Denoting the number of particles in a set /< by n, leads to Eq.(l). At this point, there is no restriction as to the number of sets chosen or the numbers of particles in each set. This seems to raise the danger of possibly mishandling the statistics of the system by treating some particles in a preferrential way. It will be shown below that, even though this is a real danger, it can be avoided. 

Boehler R. (1992) Melting of the Fe-FeO and the Fe-FeS systems at high pressure constraints on core temperatures. Earth Planet. Sci. Lett. Ill, 217—227. 

The Cyt f complex lying between PS II and PS I in the electron-transport system resembles the Cyt be complex of mitochondria and photosynthetic bacteria. These cytochrome complexes possess one Rieske iron-sulfur protein R-FeS (a [2Fe-2S] protein discovered by John Rieske) and a so-called subunit IV. The two fc-hemes of Cyt b(, and the subunit IV span the thylakoid membrane, while the R-FeS and Cyt/ are located near the lumen side. As previously noted, the placement of the i>-hemes across the thylakoid membrane helps form a redox chain across the membrane. The function of the Cyt complex in green-plant thylakoids is to oxidize the plastohydroquinone formed by PS II and to transfer these electrons to plastocyanin. Accordingly, the Cyt ig/ complex has therefore also been called the plastohydroquinone-plastocyanin-oxidoreductase. ... 

Kobetic, R., Triolo, R.J., and Marsolais, E.B., Muscle selection and walking performance of multichannel FES systems for ambulation in paraplegia, IEEE Trans. Rehabil. Eng. TRE-5 23-29, 1997. 

During 1983, R.D. (NEC) became aware of the possibilities of modifying and using the 22-channel cochlear implant technology (Cochlear Ltd., Lane Cove, N.S.W., AustraHa) as the basis for an implantable FES system for the restoration of multiple functions in SCI paraplegics. 

Davis, R., Houdayer, T., Andrews, B., BarriskiU, A., and Parker, S. Paraplegia implantable Praxis24-FES system and external sensors for multi-functional restoration. Proceedings of the 5th Annual Conference International Function Electrical Stimualtion Soc, Aalborg, Denmark, June 18-21,2000 pp. 35-38. 

The ternary R-Fe Co, Ni)-C phase diagrams Phase diagrams of the Ce-Fe-C, Gd-Fe-C, Sm-Co C and Y-Ni-C systems have been reported. The Ce-Fe-C and Gd-Fe-C systems are, respectively, representative of the light and heavy lanthanide systems (Park et al. 1982, Stadelmaier and Park 1981), forming two and six ternary compounds, respectively. 

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