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This paper demontstrates the possibility of developing a high-voltage waveguide photodetector comprised of Schottky diodes and based on a Au/Ge - Si structure with Ge quantum dots pseudomorphic to a silicon matrix, which ensures an increase in the external quantum yield and open-circuit voltage. It is shown on this photodetector that there is a great increase and broadening in sensitivity up to λ = 2.1 μm, which coincides with the main radiation range of a black (gray) body at the emitter temperatures from 1200 to 1700 ºC, practically used in thermal photogenerators. This state of the ensemble of Ge quantum dots by means of molecular beam epitaxy can be obtained only under the condition of low growth temperature (250-300 ^oC). It is established that, below the Si absorption edge, photoresponse on the photodetectors under consideration is determined by two main mechanisms: absorption on the ensemble of Ge quantum dots and Fowler emission. It is shown by the analysis of the Raman scattering spectra on the optical photons of Ge - Si structures that the quantum efficiency of photodetectors based on them in the first case is due to the degree of nonuniform stress relaxation in the array of Ge quantum dots. The photoresponse directly associated with the Ge quantum dots is manifested on Schottky diodes with a hyperfine intermediate oxide layer SiO2, which eliminates the second mechanism. In further development, the proposed photodetector architecture with pseudomorphic Ge quantum dots can be used both for portable thermal photogenerators and fiber-optic data transmission systems at wavelengths corresponding to basic telecommunication standards (λ = 0.85, 1.3, and 1.55 μm) on the basis of silicon technologies.

This paper describes the stochastic models of electron-hole recombination in inhomogeneous semiconductors in two-dimensional and three-dimensional cases, which were developed on the basis of discrete (cellular automation) and continuous (Monte Carlo method) approaches. The kinetics of the particle recombination in pure diffusion and diffusion with tunneling is studied. Certain difference between the behavior of electron-hole spatial correlations calculated by discrete and continuous models and the nature of segregation formation in three-dimensional semiconductors associated with that behavior is revealed. The comparative analysis of the simulation characteristics determined via cellular automatic and continuous recombination models is carried out.

Estimations of CO₂ emission and net ecosystem exchange (NEE) between atmosphere and bog surface were made in south taiga of European Russia for summer seasons of 2013-2015. Flux measurements were carried out by static chamber method every 7-10 days on 3 homogeneous in soil moisture and vegetation type experimental sites. Statistically significant distinctions of NEE and CO₂ fluxes were found between different experimental sites. It has been established that bog significance in CO₂ balance to atmosphere should be assessed with regard to the spatial heterogeneity of bogs.

The results of long-term evaluation of carbon stock and current carbon sequestration based on the example of pine-dwarf shrub-sphagnum biogeocoenoses on Vasyugan mire are given. In different climatic conditions (different years) NРP varies from 206 to 337 g C m^-2 x year^-1. An increase in intensity of carbon emissions was revealed in drier vegetation periods. Most of the carbon losses are determined by emission of carbon dioxide (the average is 61.3 g C m^-2 x year^-1, or 23.5 % of NPP). Progression of peat formation may be stated. The removal of the carbon by mire waters calculated by the mathematical model is 3.0 % of NРР with an average value of the removal of 7.9 g C m^-2 x years^-1. On the basis of the model of vertical growth of mires was calculated present-day rate of carbon accumulation from 10.3 g C m^-2 x years^-1 in polygonal mires to 51.7 g C m^-2 x years^-1 in grassy mires.

Based on the example of Krivoye Lake (North Karelia) dependence of productivity of lake ecosystems on geographical, climatic conditions, and drainage terrestrial production is described in the form of dynamic mass-balance model. A model algorithm is presented. It has been concluded that at natural interannual fluctuations of nutrient loads and owing to absence of anthropogenic influence Krivoye Lake has been keeping the status of oligotrophic waterbody over more than 40 years.

The results of study of the ratio of hydrothermal (temperature and precipitation) conditions and ecological spectrum of the flora of vascular plants of the Tom river basin are presented. On the basis of the calculated coefficients of linear correlation between average monthly temperature data and sediments and environmental groups of model basins, it was found that the influence of the main parameters of hydrothermal regime (temperature and precipitation) on the plains and in the mountains, in varying degrees, affected the ecological spectrum of the flora. Hydrothermal conditions of the cold period of the annual cycle have the greatest impact on environmental features.

Historical changes in distribution of animals in European Russia are of permanent interest to specialists. To this end information contained in the Economic Notes to the General Land Survey of the Russian Empire (XVIII-XIX centuries) is of particular importance. The article presents the first results of the data analysis of mammalian fauna in the boreal forests of European Russia. The data are contained in a systematic sampling arranged on the basis of the Economic Notes and cover 7 provinces, 32 counties, and 377 specific dachas. There are 1774 animals mentioned (21 names of animals (species), 10 families and 5 orders). A comparison of distribution of certain species the most characteristic and significant for boreal forests in XVIII-XIX centuries and at the present time has been made.

The site of open shallows of the Volga Reach in the Rybinsk Reservoir (Volga) subjected to impact of common heron colonies was studied in 2009-2011. Some changes in phytoplankton community composition typical of water trophic level rise were noticed. Floristic wealth reduction along with increase in biomass due to phytophlagellates - cryptophytes, euglenales, dinophytes and chrysophytes, as well as flagellar forms of green algae were registered at the heronries. Changes in phytoplankton communities were temporary and connected with herons nesting period, which allows to treat the studied site as “traumatic” ecotone.

Traphic relationships were examined for macroinvertebrates and fish inhabiting St. Petersburg methane seep (Central part of lake Baikal, ~1400 m depth). The analyses of the values of carbon and nitrogen stable isotopes showed that all animals associated with the seep were heterotrophs with different feeding strategies, symbiotrophs were absent. Seep enimals consumed combined food with different portion of methane derived carbon ranged from 2.7 to 89 %. The average values of the δ¹³С varied from -26.2 ‰ (in benthopelagic amphipods) to -64.5 ‰ (in gastropods). The trophic food web of the methane seep consisted of filter feeders (pelagic amphipods TP 1.9), detritophages (gastropods TP 2.2 and burrowing amphipods TP 2.1), polyphages (nectobenthic and bentho-pelagic amphipods TP 2.8-3.2), and predators (flat worms TP 3.6-4.2 and cottoid fish TP 3.0-3.8). Animals occupying the similar trophic positions differed significantly in the δ¹³С values and utilized partly overlapping different food components.

The aim of the current study was to assess synergistic effect of thermal stress, pollution and parasitic infestation on the activity of antioxidant enzymes (peroxidase, catalase, and glutathione-S-transferase) in different populations of the wide-spread species of pulmonate mollusk Lymnаea stagnаlis distributed in the Belarus Republic water bodies. It has been shown that the combined influence of anthropogenic effect and parasitic infestation on the one hand and experimental hyperthermia coupled with the parasitic invasion on the other hand affect the activity of peroxidase. The combined impact of parasitic infestation and contamination of the reservoir leads to the change of the catalase activity. No significant correlations between the studied factors and the activity of glutathione-S-transferase were found. The simultaneous exposure to elevated temperature, pollution and infectiousness of mollusks does not affect the activity of the studied enzymes.