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This paper presents the results of an experimental study of the turbulent structure of the flow of two parallel jets from long round tubes in the near field of the flow. Measurements were performed for distances between the axes of the tubes s/d = 1.2, 1.8, and 2.4 and for Reynolds numbers Re =5.5x103 and 1.1x104. It is shown that in the near field of the closely spaced twin jets, the longitudinal velocity component on their axis decreases more slowly than in single jets. In this case, the distance between the jets s/d has practically no effect on the transverse scale of the jet and turbulent fluctuations of the longitudinal velocity component. Turbulence anisotropy is practically absent throughout the flow field, except in the outer regions of the jets.

A partially invariant solution of a three-dimensional problem with a free boundary for the Navier-Stokes equations is studied. The flow domain under consideration is a horizontal layer bounded by a solid plane from below and by a flat free surface from above. The vertical velocity and pressure are independent of the x and y coordinates. Three flow modes can be formed for different initial velocities of the flow: stabilization to the quiescent state with time, solution blow up within a finite time, and self-similar regime in which the layer thickness unboundedly increases with time.

Model buoyancy frequency distribution and the Wentzel-Kramers-Brillouin method are used to obtain an asymptotic solution to a problem of constructing solutions that describe internal gravity waves in a stratified medium with a background shear flow slowly varying in depth. Dispersion relation asymptotics are expressed in terms of the Airy functions. Asymptotics for various model distributions of background shear flows are used to obtain analytical representations of dispersion relations and eigenfunctions. Exact and asymptotic results are compared for various distributions of background shear flows and generation regimes typical of a real ocean.

The turbulent mixing on interfaces of three-layer gas systems after shock-wave passage has been studied. The influence of the initial roughness of interfaces on the development of instability and mixing of gases with different density has been investigated. The development of Richtmyer-Meshkov instability has been simulated using the implicit large eddy method and the MIMOZA code. The results of the study have been compared with available experimental data. It has been shown that the width of the mixing region and the enstrophy and mass of mixed gases depend significantly on the degree of interface roughness.

The physical grounds of droplet breakdown in a flow behind a transient shock wave in accordance with one of possible sheet stripping mechanisms (shedding of a liquid boundary layer) are considered. The analysis is performed on the basis of data of high-speed shadowgraphy of the droplet behavior behind the shock wave in the range of the Weber numbers We = 200-2200, measurements of the breakdown induction period, and registration of the ablation character. The condition of instability of the liquid surface by the sheet stripping mechanism and the criterion of interface breakdown are formulated with the use of parameters of an adjoint boundary layer in the fluid. On this basis and with due allowance for previous investigations, a dependence of the delay of droplet breakdown by this mechanism on the fluid characteristics and flow parameters is derived.

Results of optical and gas-dynamic investigations of the microwave discharge plasma under conditions of gas-jet synthesis of diamond are reported. The data are analyzed for determining the temperature and composition of the mixture in the discharge chamber for the purpose of further optimization of the method. The influence of the flow rate of the injected gas mixture on the macroparameters of the gas mixture flow at the exit of the discharge chamber is studied. The temperature and pressure measured in the discharge chamber are used for the numerical analysis of the mixture composition depending on the injected gas flow rate. It is demonstrated that the mixture composition at the exit of the discharge chamber correlates with the rate of diamond synthesis.

The structure of reproductive function in 4 species and many geographic ecotypes of stone pines was studied on natural and experimental (clone archive and test progenies) objects. In Siberian stone pine in the south of the forest zone in Western Siberia, the dynamics of cone production is determined by weather conditions in the year of pollination. Seed productivity is declining due to late spring frosts and higher temperatures in September. Over the past 30 years, the directional change of these factors has determined a significant decline in cone production. The productivity and stability of the species and geographic ecotypes of stone pines is determined by the correspondence of their need for warmth to the climate of the test site. Under the conditions of climate change, the local ecotype in terms of growth and cone production is often inferior to more thermophilic species and ecotypes.

In the region of Polygraphus proximus invasion, we studied the patterns of stem dendrophages consortia (simple structural systems in biocenosis that combine autotrophic and heterotrophic organisms based on topical and trophic relations), the core of which is host tree - Abies sibirica Ledeb. The analysis was carried out on 4835 trees from 46 plots in the dark coniferous fir forests of the Tomsk region according to the following indicators: the vital state of trees and stands; taxonomic composition of insects, their occurrence, abundance and ecological characteristics; participation in the formation of xylophages communities at different host tree weakening stages. On the fir trees together with P. proximus , 21 species of stem dendrophages were identified. In all studied stands, the four eyed fir bark beetle was absolutely dominant. Monochamus urussovi Fisch was a permanent inhabitant of the stands damaged by the alien bark beetle. A direct dependence of the species coincidence degree with the disturbance of forest stands and their taxation indicators was revealed ( r _s = 0.61). The species richness of the population consortia of fir is in an average dependence on the forest density and capacity ( r _s = 0.4). For the first time, the ability of mass species of stem dendrophages to selectively colonize fir trees at different stage of resistance decline and to reveal the features of pre- and post-invasive consortia was determined. In a multispecies group, P. proximus acts as an initiator of the succession of stem inhabitants, determining the composition of individual consortia, the sequence of colonization of the plant by species of dendrophages in accordance with the degree of weakening of the host tree and the ability of insects to use the forage substrate. It was found that the number of the main aboriginal physiological pests of fir is at a low level, and they populate weakened trees following the attacks of an alien bark beetle or drying out for other reasons. The transformation of the indigenous stem dendrophages complex as a result of the invasion of four eyed fir bark beetle is an example of a rapid consortiogenesis leading to ecological and evolutionary changes in ecosystems.

Generally accepted that F. moschata is a common element of the nemoral flora. Its area occupies the territory from western bourders of Europe and reaches the Ural Mountains on the East. From the last part of the XX century, data of detections of musk strawberries in plant communities in Western and Eastern Siberia, including the southern part of the Krasnoyarsk region, have been appeared. Locations of such cenopopulations of musk strawberry described for small-leaved forests (mainly) and fir forests of the Yenisei Sayan Mountains. The article aims to describe the phytocenotic confinement of growth in the Yenisei Sayan Mountains of two populations of F. moschata (samples No. 17-16 and No. 18-28), verified by cytogenetic tests and PCR diagnostics. We have shown that samples No. 17-16 and No. 18-28, in hybridization with experimental samples of F. moschata of European origin, form full-fledged achenes with germination characteristics of the species. To establish the species affiliation of the samples, we used a molecular marker - the alcohol dehydrogenase ( adh 1) gene. Comparing the DNA amplification result for samples No. 17-16 and No. 18-28 with primers specific for the adh 1 gene sequence showed the lengths of amplified fragments identity set for investigated samples to the F. moschata of European origin PCR profile. Comparison of the floristic similarity of these two plant communities, where the studied samples of F. moschata grow, showed little correspondence of these communities in species composition ( K_J = 0.2). This fact indicates the ability of F. moschata to develop not only ecological niches of small-leaved forests close to its needs (sample no. 17-16) but also fir forests (sample no. 18-28) in the Yenisey Sayan Mountains. The article discussed the origin (allochthonous or autochthonous type) of F . moschata population in the natural plant communities of the Yenisey Sayan Mountains on previous herbarium collections and our samples.

The world experience of applying of medicinal plants shows the prospect for development preparations based on the plant raw materials, including wild ones. In this regard it is necessary the field study for assessment current state of medicinal plants’ populations for rational use and preservation of biological diversity. For the populations of Althaea officinalis , we evaluated the botanical features, ontogenetic spectrum and morphological indicators of plants. So, structural indicators of four populations of А . officinalis in valleys of the rivers Altolkyn, Uter, Sergek and Koneu (Kurmangazysky rayon of Atyrau region) were investigated. It was determined that species composition of communities had 54 species from 50 genera and 26 families. The leading families by number of species were Poaceae , Asteraceae и Fabaceae . The most common species (category I) included 37 taxa; category II included 10 taxa; category III included 4 species; and category IV-V included 2 species. Mesophytes, mesoxerophytes and xeromesophytes dominated among ecological groups; herbaceous perennial, annual and biennial plants dominated among life forms. The maximum morphometric indicators of А . officinalis were noted for populations in the valley of the rive Aktolkyn; the minimum - floodplain of the river Sergek. Analysis of age spectrum made possible to determine, that population in the valet of the river Altolkym was characterized as stable, medium-age; in the floodplain of the river Sergek was stable and young; in the floodplain of the river Uter was non-stable, aging; in the valley of the river Koneu was young. As the results of field investigations, it is possible to recommend implementing action for collection of medicinal raw material of А . officinalis in the populations of the valleys of the rivers Altolkyn, Koneu and Sergek. It is not possible to collect raw material in the valley of the river Uter; actions for reconstruction of its structure are needed.