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A problem of expansion of heterogeneous detonation in a suspension of aluminum particles in gaseous oxygen from a circular tube and its propagation in a semi-bounded or unbounded space is studied by numerical methods. The effects of the particle diameter in monodisperse suspensions and of the composition of bidisperse suspensions on detonation propagation regimes are studied. The calculated results are compared with data on heterogeneous detonation of gas suspensions in a plane channel and on gas detonation. The critical values of the channel width and the tube diameter are found to differ by a factor of 2-2.5, as it is also observed in gas detonation. However, the ratio of the critical diameter to the detonation cell size in the case of heterogeneous detonation can be smaller than that in gas mixtures by an order of magnitude.

It is shown that detonation can be transmitted from a reacting bubble medium into an explosive gas volume located above the interface. Experiments were performed in which bubble detonation was initiated by wire explosion in a gas-liquid medium. The dynamics of the boundary of the gas-liquid medium after the arrival of the bubble detonation wave at it was studied. The distance between the wire and the boundary of the bubble medium was decreased to 1 cm, at which the gas volume was initiated by the hot products from the wire explosion and the discharge plasma. The probability of detonation transmission from the bubble medium to the volume of the gas mixture depending on the depth of immersion of the wire is determined, and the mechanisms of ignition of the explosive gas volume are described.

Numerical modeling of PETN ignition by a copper oxide film absorbing laser radiation has been performed. The calculation results showed the presence of a minimum in the curve of the dynamic delay of PETN ignition by a rectangular laser pulse versus thickness of the absorbing film. This effect is due to the fact that when the film thickness is commensurate with the reciprocal of the absorption coefficient, the amount of heat generated in the thin film due to the multiple reflection of the light flux is proportional to its thickness. Therefore, the smaller the film thickness, the more time is required to heat it to the ignition temperature of PETN. In the case of a thick film, additional energy and time are required to heat its cold part to the ignition temperature of PETN.

This paper compares two methods of near-threshold initiation of a loose-packed PETN charge: by impact of a plate and by injection of an intense flow of hot gases into the powder. Synchrotron diagnostics of material density was used. Both methods lead to the development of detonation in about 10  s, but the nature of initiation differs sharply. Initiation by an impermeable piston involves the formation of a dense plug of compressed material. After some delay, a wave is formed at the front of this plug which initiates chemical reaction and accelerates to normal detonation. For high-enthalpy initiation by a hot gas flow, the compression of the powder is low and the process develops in the gas-permeable material, starting from the stage of rapid convective combustion followed by transition to detonation.

This paper describes the experimental results in the study of detonation transfer in thin layers of a PVV-12M plastic-bonded explosive (90% of RDX and 10% of bond) through solid and perforated partitions. The critical thicknesses of steel or Plexiglas partitions, exceeding which makes detonation transfer impossible, are determined for the explosive layers with a thickness of 2-12 mm. It is shown that shock waves in the plates, which bound the explosive charge, can stay ahead of the initiating shock wave in the passive part of the explosive charge and load the explosive charge from the lateral surface. Thus, the peripheral desensitized layers of the explosives are formed, which reduce the layer thickness of the detonable explosive and complicate the detonation transfer. Detonation transfer through the partitions whose thickness is greater than the critical thickness can be carried out with the use of holes in the partition, closed by thin plates. The plate thicknesses at which detonation propagates through the hole either in forward and reverse directions or in the forward direction only, are determined.

The electrical resistance of copper foil under shock compression is measured. The electrical resistance and electrical conductivity are plotted as functions of the shock pressure in the interval up to 20 GPa. These dependences are monotonic and have no visible inflections or singularities. A qualitative dependence of the electrical resistance of the metal on the shock impedance of the material of the block containing the sample is found. A comparison of the data obtained in this study with results of other authors shows that it is important to take into account the block material, the shape and thickness of the sample, and the procedure of determining the state of the sample.

Explosion characteristics of PMMA particles with three different diameters (100 nm, 800 nm, and 30 μm) are studied experimentally. The explosion severity including the maximum explosion pressure and the pressure rise rate of 100-nm PMMA particles significantly exceed those of 800-nm and 30-μm PMMA particles at low concentrations due to a greater specific surface area. However, the explosion severity of 100-nm PMMA particles gradually decreases below that of 800-nm PMMA particles once the dust concentration reaches 250 g/m³ and above because 100-nm PMMA particles are prone to agglomerate, but it is still higher than that of 30-μm PMMA particles. In addition, the maximum explosion pressures increase with increasing concentrations of PMMA particles of all sizes, peaking at 250 g/m³, while they do not change significantly as the concentrations go beyond 500 g/m³. According to the explosion classification based on the deflagration index, nano-PMMA particles indicate a higher explosion risk and more serious explosion severity than those of micro-particles.

Over extended periods issues of forest management intensification are important in all aspects of Russian forest sector development. Sufficient research has been done in silviculture, forest planning and forest economics to address forest management intensification targets. Systems of our national territory forest management and forest economics zoning due to specifics of timber processing and forest area infrastructure have been developed. Despite sufficient available experience in sustainable forest management so far intensification issues were addressed due to development of new woodlands without proper consideration of forest regeneration and sustainable forest management operations. It resulted in forest resource depletion and unfavorable substitution of coniferous forests with less valuable softwood ones in considerable territories (especially accessible for transport). The situation is complicated since degree of forest ecosystem changes is higher in territories with high potential productivity. Ongoing changes combined with the present effective forest management system resulted in a situation where development of new woodlands is impossible without heavy investments in road construction; meanwhile road construction is unfeasible due to distances to timber processing facilities. In the meantime, changes in forest legislation, availability of forest lease holding, and promising post-logging forest regeneration technologies generate new opportunities to increase timber volumes due to application of other procedures practically excluding development of virgin woodlands. With regard to above, the Russian territory was zoned on a basis of key factors that define forest management and forest use intensification based on forest ecosystem potential productivity and area transport accessibility. Based on available data with GIS analysis approach (taking into consideration value of various factors) the Russian Federation forest resources have been zoned due to forest management and forest use intensity.

We provide information on distribution, ecosystems occurrence and density of local populations of 7 rare and endangered species of Orchidaceae family (Orchidaceae Juss.). The species were investigated on representative for the Sountern Evenkia area of state natural reserve ‘Tungussky’. Four of these species (Calypso bulbosa (L.) Oakes, Cypripedium calceolus L., C. macranthon Sw., C. ventricosum Sw) are included to the Red Book of the Russian Federation (2008) and three (Cypripedium guttatum Sw., Dactylorhiza cruenta (O. F. Muell.) Soo, Epipactis helleborine (L.) Grantz) to the Red Book of the Krasnoyarsky Krai (2012). Six of rare and endangered orchid species (except for Cypripedium guttatum) found in the reserve are near the north boundary of their range. Six of the species (except for Dactylorhiza cruenta ) are typical forest plants and occur mostly in herb-shrub story of rare Larix and Pinus-Larix forests with shrub-green moss or low-herb-green moss cover, on warm southern and western slopes. The habitats of Dactylorhiza cruenta are very different from other species. Local populations of the species are located on the narrow coast of the Hushma river, covered with shrub-leguminous meadows and shrub thickets. The density of populations of Calypso bulbosa varies from very low (1 specimen/sq.m.) to dense (19 specimen/sq.m.). The density of Cypripedium calceolus and C. macranthon varies similarly from 1.2 to 6.3 specimen/sq.m. The density of local populations of C. ventricosum is low. It is about 2.5 specimen/sq.m. Long-root species C. guttatum has population density from 11.15 to 78.18 partial scions/sq.m. Epipactis helleborine occurrence is very rare. This species occurs only as singular specimen. The density of populations of Dactylorhiza cruenta is from 4.3 to 9.2 species/sq.m. Despite that most of the rare and endangered Orchid species exist on the boundary of their range, all species found in the reserve are stable, blossom and produce harvest each year and reproduce themselves by seed and/or by vegetative reproduction.

The study of embryogenic potential of Larix sibirica was conducted using zygotic embryos of trees resistant to larch bud midge as explants. Immature isolated zygotic embryos and megagamethophytes of Larix sibirica were experimentally cultured on AI medium (Tretyakova, 2012). As a result of experiments, 15 proliferative cell lines (Cl) of L. sibirica were obtained from embryo culture. Cls differed in somatic embryo production, more specifically, in embryo quantity, size, and capability to mature, to germinate, and to form viable plantlets. The number of somatic embryos ranged from 2040 to 11103 per 1 gram of fresh weight of embryogenic callus (EC) in young (age up to one year) Cls. The proliferate activity of Cls are maintained during two-six years. Morphogenesis and maturation of somatic embryos are observed 45 days on the medium AI added by ABA. The number of mature somatic embryos ranged from 12 to 1220 per 1 gram of EC. Small somatic embryos of hybrid Cl5 did not mature on AI medium. Different anomalies are observed in the morphogenesis of somatic embryos: destruction of embryo domain development and cytokinesis. The minimum embryo anomalies were observed in Cl4. In this Cl viable embryos are 83.31±3.00 %. The germination of somatic embryo occurred on medium AI hormones and due to elongation of hypocotyls and roots. Somatic seedlings were transferred to soil substrate at the condition of growth-chamber and then to soil at the greenhouse of V. N. Sukachev Institute of Forest SB RAS in 2013. Thus, the collection of embryogenic cell lines of L. sibirica was created. This collection will be used in a plantation forest growing larch in Siberia.