Energetic region

Typical adsorption and desorption isotherms for a porous soHd are indicated in Fig. 1.13. Following the adsorption branch, the steep initial rise (A) is caused by adsorption in the most energetic regions of the soHd (single layer adsorption). Thereafter, in the flat region (B), gas molecules adsorb on sites already occupied by other molecules (multilayer adsorption). 

The absence of radiation at the lower, more energetic region of the UV spectrum of the ID65 SPD is readily evident. Because more bonds are capable of interacting with incident photons at these lower wavelengths, this difference can lead to actual differences in the results obtained. 

One of these assumption was that the continuum / extends from —oo to oo. This is often a good approximation to the situation where the edge(s) ofthe continuum is(are) far from the energetic region of interest, in this case the energy Ei. In the solid state physics literature this is sometunes referred to as the wide band approximation. 

The energetic region has rarely been studied for two reasons one experimental and the other theoretical. Experimentally, accurate measurements of G t) or G u>) over the energetic region require an extremely stiff transducer, which, due to lack of enough sensitivity, is in general not suitable for the commonly studied entropic region. For this reason, the experimental G t) and G u>) results studied in Chapters 10 and 11 are confined to the... 

The applicability of the SVGA in the energetic region of interest here (which for cold collisions is near the threshold) depends on variation of the continuum spectmm in this region over the pump pulse bandwidth. In most cases studied, the SVGA provides a reasonably good description of the PA process. 

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