Disordered environment

The important paper of Abrahams et a/. (1979) first made clear that the conductivity degenerate electron gas at zero temperature in a disordered environment must tend continuously to zero as the Fermi energy EF tends to Ec. Abrahams et al defined a dimensionless conductivity... 

In the case of the denatured PYP, the chromophore is surrounded by completely disordered environment of the water. The relaxations due to the interactions between the excited chromophore with a large dipole moment and surrounding disordered water environment produce a large extent dynamic Stokes shift of the fluorescence. Nevertheless, it is much slower compared with that taking place in the disordered PNS of the ferulic acid analogue as demonstrated in the analysis of the previous section (3.3). 

For the P40B15Na45 sample calcinated at 200 °C, two peaks are observed at 2.5 and — 4.6 ppm (see Figure 38). These peaks are broader than the peaks for samples calcinated at higher temperatures, which indicates a more disordered environment around two phosphorus sites. In addition to the sharp peaks due to the crystalline phases, all P40B10Na50 show more resonances in range 8/11 ppm... 

Fig. 4.12. (a) 2D quasi-equilibrium proton-driven spin-diffusion spectrum at 295 K of amorphous, atactic polystyrene C-enriched at the aromatic carbon Ci. The mixing time was set to 10 s. Within this time frame, a completely disordered environment is sampled (see Fig. 4.8(c)). (b) Rate-constants for r.f.-driven spin-diffusion obtained from mixing times smaller than 4 ms from the same compound, (c) Structure of a microstructure, constructed by Rapold et al. [71] to describe amorphous atactic polystyrene. The rate constants in (b) can be well explained by a set of such microstructures. From the microstructures, in turn, the weighted distributions p( 8)/sin /3 can be extracted. The result is given in (d). (Figure adapted from Refs. [30, 70]). 

Sullivan, K. M. (2008). The interaction of agricultural pesticides and marginal iodine nutrition status as a cause of autism spectrum disorders. Environ. Health Perspect. n6 Ai55. 

Silbergeld, E. K. and Goldberg, A. M. (1974a) H yperactivity A lead induced behavior disorder. Environ. Hlth. Persp. 7, 227-232. 

Coming from NaOH addition, Na ions have been detected in samples with the lowest Ca contents, so that (Ca + Na)/Ce atomic ratio is always lower than 0.10. It can be thus considered a first step that alkaline and alkaline-earth cations are substituted for cations. In a recent a NMR study, which will be published later, on such Ce-based compounds adopting fluorite-type structure, the recorded spectra present characteristic features of electric-field gradient and isotropic chemical distributions (asymmetry of the central line and broadening of the spinning side bands). This is in agreement with the occurrence of Na+ disordered environments with various numbers of 0 and F anions at different distances surrounding Na" " cations. 

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