The present work continues the analysis of results of Dementjev et al. (2015) in order to identify the interlayer interactions of the pi-bands. Analysis of the N(E) C KVV Auger spectra of highly-ordered pyrographite showed the absence of the electron exchange between the pi-bands in 1-6 layers. Since the pi-bands are formed by the p(z) -> pi transitions, one can suggest that the pi-band occupation at each graphene layer is formed by the p(z)-electrons of this layer. Since the p(z), electrons belong to the sigma(p)-bands, the p(z) -> pi transitions in the sigma(p-)bands in each of 2-6 graphene layers result in formation of holes H, whose concentration is equal to the concentration of electrons in the pi-bands [H-i] [pi(i)]. This shows the origin of the ambipolar conductivity in graphene.The absence of the electronic interaction between the pi-bands allows a suggestion that the interaction between top six graphene layers is due to the van der Waals electrostatic attractive forces. These forces promote the p(z) -> pi transitions in each of the 2-6 graphene layers and depend on the number of graphene layers above. The N(E) C INV Auger spectra allow identification of number (1-6) of graphene layers and the pi-band occupation at each of the layer. For the first time a specification of the van der Waals forces in HOPG was done. (C) 2016 Elsevier B.V. All rights reserved.

N(E) C KVV Auger spectra (V= sigma(s)sigma(p)pi) were used for measurement of the pi-band electron occupation of five outer layers on freshly cleaved bulk HOPG. The pi-band electron occupation of the 1-5 graphene layers was measured relative to the electron concentration in the sigma(p)-band. In-depth pi-band profiles were obtained by means of variation of the Auger electron takeoff angle within the range of 15-90 degrees. Differences in the pi-band electron occupation of the 1-5 graphene layers were determined. The pi-band electron occupation varies from 0 at the top graphene layer to that of the pi-band electron occupation typical for bulk HOPG at the 5th graphene layer counted from the outer surface. These results are discussed on the basis of the pi-band formation under the interlayer interaction of the p(z)-electrons. (C) 2015 Elsevier B.V. All rights reserved.

SUMMARY: A brief consideration is given of the hydrological conditions assoc- iated with bogllake geological systems that result in a specific type of the natural landscape subject to excessive and unsteady moistening. Some water balance relations are presented that define the stability of central bog lakes and the structure of bog/lake systems as a function of water supply. relations are presented for steady states of Bog/lake and bog systems when the climatic factors and the morphological coefficient of natural or forced drain- age are changed. These relations define the limit of drainage or irrigation of the system without their degradation or decay. calculation of the steady-state region and location of real undrained bog/lake and bog systems. Predicted