The precision blackbody sources developed at the All-Russian Institute for Optical and Physical Measurements (Moscow, Russia) and their characteristics are analyzed. The precision high-temperature graphite blackbody BB22p, large-area high-temperature pyrolytic graphite blackbody BB3200pg, middle-temperature graphite blackbody BB2000, low-temperature blackbody BB300, and gallium fixed-point blackbody BB29gl and their characteristics are described.

No abstract

No abstract

A rather direct way of studying a high-density exciton system is outlined to take full account of the non-boson behaviour of excitons. Many-exciton systems are shown to be always non-ideal and thus they can only be characterised by their total energy and total number. The single-exciton energy and distribution function can be understood simply in the framework of the mean-field approximation and they both depend upon the exciton density. It is shown that our approach could be applied to both Frenkel and Wannier-Mott excitons in materials of bulk and low-dimensional structures as well as under the action of an external field.

No abstract