Evidences for and the models of self-similar skeletal structures in fusion devices, severe weather phenomena and space

The paper briefly reviews (i) the evidences for self-similar structures of a skeletal form (namely, tubules and cartwheels, and their simplest combinations), called the Universal Skeletal Structures (USS), observed in the range 10-5 cm - 1023 cm. in the high-current electric discharges in various fusion devices, severe weather phenomena, and space, (ii) the models for interpreting the phenomenon of skeletal structures, including the hypothesis for a fractal condensed matter (FCM), assembled from nanotubular dust, and (iii) probable role of FCM, which might be responsible for the USS phenomenon, in tornado, ball lightning, and waterspout.Comment: 17 pages, 6 figures, reported at the 6-th Symposium "Current Trends in International Fusion Research: A Review", Washington, D.C., USA, 200

Magneto-optical evidence of the percolation nature of the metal-insulator transition in the 2D electron system

We compare the results of the transport and time-resolved magneto-luminescence measurements in disordered 2D electron systems in GaAs-AlGaAs heterostructures in the extreme quantum limit, in particular, in the vicinity of the metal-insulator transition (MIT). At filling factors $\nu <1$, the optical signal has two components: the single-rate exponentially decaying part attributed to a uniform liquid and a power-law long-living tail specific to a microscopically inhomogeneous state of electrons. We interprete this result as a separation of the 2D electron system into a liquid and localized phases, especially because the MIT occurs strikingly close to those filling factors where the liquid occupies ${1\over 2}$ of the sample area (the percollation threshold condition in two-component media).Comment: 5 pages RevTex + 4 fig., to appear in PRB, Rapid Com