In 28 basic floristic areas (BFA) of Siberia, relative abundance of endemic and hemiendemic species, and only endemic species, have been determined. Diagrams show the localities of intensive speciation, mostly mountains. Endemic species have been divided into zonal groups: (1) arctic, alpine, and arctic-alpine; (2) taiga-boreal, mountainous, and hyparctic; (3) steppe, forest-steppe, and nemoral. In these groups, the homogeneity of BFA`s was evaluated by the Preston`s index (1
As a result of her own investigations and a result of generalization of literary data, the author has established the level of lichen diversity of mountainous ecosystems which is represented at present by 1736 species from 290 genera and 87 families. For Altai-Sayan mountainous region, the lichen diversity of mountainous ecosystems consists of 1348 species from 283 genera and 81 families and for Altai
Materials of all-year-round censuses of birds carried out by the author in the Visim reserve territory and in its protected zone in six habitats from December 1983 to November 1984 have been analyzed. With the help of classification of ordered objects, 6 general seasonal periods have been distinguished: relative winter stabilization; pre-spring migrations and beginning of arrival; nesting on the background of local and remote migrations; post-nesting local migrations and beginning of departure; departure and autumn flight; end of flight and pre-winter migrations. A concise quantitative characterization of the periods is given. With the help of non-metrical gradations, 4 types of intra-annual time course of ornithological complexes have been distinguished. Comparison with the available literature data has demonstrated that in the Middle Urals, northern forest-steppe of the Circum-Ob region, the Central Altai and in the deserts of Turkmenistan, the intra-annual stability of the physiognomy of ortnithocomplexes decreases from settlements and forests towards half-open and open habitats, and the intra-annual similarity of forest ornithocomplexes decreases from southern taiga to desert tugais. In the Ural, the abundance of settled species is relatively high, and the change of population aspects is determined by nesting migratory species. In the forest-steppe and especially in tugais, the proportion of species staying during the non-nesting time (migratory, wintering) is considerably higher, which is just what determines the increase of interseasonal differences between the bird population variants. By the character of seasonal variability of bird populations, the ornithocomplexes of the south of boreal vegetation zones and of the desert zone differ in the time of change of periods. Besides, the ornithocomplexes of tugais is characterized by a strong intra-annual differentiation.
Phytocenotic attachment of species of the genus Allium L. in Eurasia has been elucidated. It has been established that the highest species diversity is characteristic of xerophyte types of biomes and of rocky and stony vegetation. Amplitude humidity estimates of ecological scales for 56 species have been analyzed, and ecological areal of 15 species growing in Siberia has been described. It is demonstrated that in species playing an important role in the phytocenosis, the humidity tolerance amplitude is wider than that in species whose abundance in the community is not high.
On the basis of results of long-term censuses, the basic trends in the change of physiognomy of communities of small mammals have been studied and their hierarchical classification has been made. Changes of populations of the North, North-East, Central, and the whole Russian Altai have been compared.
Transient free convection flow of a viscous fluid between two infinite vertical parallel plates is investigated. The temperature at one of the plates is assumed to be Td, at another plate the heat flux is assumed to be constant. The velocity and temperature distributions are found using the Laplace transform technique and are shown for small values of time t, because the initial stage of the unsteady process corresponding to the one-dimensional heat-transfer mechanism is under investigation.
Formation of temperature fields and radiation fluxes at melting and solidification of a semitransparent medium was simulated with consideration of optical properties of material dependency on radiation frequency. Two different models of rectangular bands for the absorption factor were considered.
V.P. Zamuraev, A.F. Latypov*
Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia *Novosibirsk State University, Russia
Pages: 301-310
The probes for pressure measurement are usually mounted at the butt end of a narrow duct adhering to the tested volume. A question of the agreement between the pressure measured in this way and the true pressure in the volume is considered. The problem is solved for short ducts within the framework of the Euler equations. The disturbance is created in the tested volume by an instant local release of energy. The MacCormack method is used for the solution together with a grid procedure, which enables us to introduce in some subregions a grid with the cell sizes less by an order. This technique does not produce oscillations and nonphysical waves. A considerable excess of the mean pressure near the narrow duct bottom over the mean pressure in the volume has been revealed, which is related to the effect of anomalous aerodynamic heating. The dispersion of gas density and temperature in the tested volume is very significant during a long time. The research results cast doubt on the possibility of using only one pressure measured with the aid of a probe in a narrow duct to determine the flow parameters in hot-shot wind tunnels and in the ducts of aggregates with rapid processes.
On the basis of the equations of magnetogasdynamics the characteristics of an open high-current arc in argon at atmospheric pressure were computed versus the interelectrode distance, current strength, and geometry of electrodes. The numerical results agree satisfactorily with experiment.
