RESUMO
Broad-band (4-20 000 cm-1) spectra of real and imaginary conductance of a set of high-quality pristine and AuCl3-doped single-walled carbon nanotube (SWCNT) films with different transparency are systematically measured. It is shown that while the high-energy (≥1 eV) response is determined by well-known interband transitions, the lower-energy electrodynamic properties of the films are fully dominated by unbound charge carriers. Their main spectral effect is seen as the free-carrier Drude-type contribution. Partial localization of these carriers leads to a weak plasmon resonance around 100 cm-1. At the lowest frequencies, below 10 cm-1, a gap-like feature is detected whose origin is associated with the energy barrier experienced by the carriers at the intersections between SWCNTs. It is assumed that these three mechanisms are universal and determine the low-frequency terahertz-infrared electrodynamics of SWCNT wafer-scale films.
RESUMO
The article is a brief description of the current state of the Estonian Defense Forces medical service and is based on the study of the open access foreign sources. At the beginning, the general information about Estonia, its Defense Forces, and their medical service is presented. Then the medical service particular features are described with more detail, namely, the organization of the inpatient and outpatient treatment, medical supply, scientific research, combat medicine, medical staff education and training, medical service personnel income.