2,391 research outputs found
Preliminary results of measurements by automated probes Vega 1 and 2 or particle concentration in clouds of Venus at heights 47-63 KM
Results of the preliminary processing of the Vega 1 and 2 descender data on the cloud layer structure of the Venusian atmosphere are discussed. A photoelectric counter for aerosol particles is described together with its optical and pneumatic circuits and operation algorithm. Vertical profiles of concentrations of particles with a diameter of 0.4 microns agree quantitatively with the Pioneer-Venus and Venera 9 and 10 data. Concentrations of these particles are: in the B layer, up to 190/cu cm; in the C layer, up to 10/cu cm; and in the D layer, up to 130/cu cm. Layers have sharp boundaries with a significant vertical heterogeneity of the aerosol concentration field inside them
Application of introduced nano-diamonds for the study of carbon condensation during detonation of high explosives
This paper describes the experimental studies of the formation of
nano-diamonds during detonation of TNT/RDX 50/50 mixture with small-angle x-ray
scattering (SAXS) method at a synchrotron radiation beam on VEPP-3 accelerator.
A new experimental method with introduction of nano-diamonds into the
explosive has been applied. Inclusion of the diamonds obtained after detonation
into the TNT and RDX explosives allows modelling of the case of instant
creation of nano-diamonds during detonation.Comment: Latex, 4 pages, 2 figures (proc. of SR-2008
Detector for imaging of explosions: present status and future prospects with higher energy X-rays
The detector for imaging of explosions (DIMEX) is in operation at the
synchrotron radiation (SR) beam-line at VEPP-3 electron ring at Budker INP
since 2002. DIMEX is based on one-coordinate gas ionization chamber filled with
Xe-CO2(3:1) mixture at 7atm, and active Frisch-grid made of Gas Electron
Multiplier (GEM). The detector has spatial resolution of ~0.2mm and dynamic
range of ~100 that allows to realize the precision of signal measurement at a
percent level. The frame rate can be tuned up to 8 MHz (125 ns per image) and
up to 32 images can be stored in one shot. At present DIMEX is used with the
X-ray beam from 2T wiggler that has ~20 keV average energy. Future possibility
to install similar detector at the SR beam-line at VEPP-4 electron ring is
discussed.Comment: 14 pages, 15 figures. Submitted to JINS
Genetic Structure and Geographical Differentiation of Larix sibirica Ledeb. in the Urals
The Ural Mountains and the West Eurasian Taiga forests are one of the most important centers of genetic diversity for Larix sibirica Ledeb. Forest fragmentation negatively impacts forest ecosystems, especially due to the impact of their intensive use on the effects of climate change. For the preservation and rational use of forest genetic resources, it is necessary to carefully investigate the genetic diversity of the main forest-forming plant species. The Larix genus species are among the most widespread woody plants in the world. The Siberian larch (Larix sibirica, Pinaceae) is found in the forest, forest-tundra, tundra (Southern part), and forest-steppe zones of the North, Northeast, and partly East of the European part of Russia and in Western and Eastern Siberia; in the Urals, the Siberian larch is distributed fragmentarily. In this study, eight pairs of simple sequence repeat (SSR) primers were used to analyse the genetic diversity and population structure of 15 Siberian larch populations in the Urals. Natural populations in the Urals exhibit indicators of genetic diversity comparable to those of Siberia populations (expected heterozygosity, He = 0.623; expected number of alleles, Ne = 4017; observed heterozygosity, Ho = 0.461). Genetic structure analysis revealed that the examined populations are relatively highly differentiated (Fst = 0.089). Using various algorithms for determining the spatial genetic structure, the examined populations formed three groups according to geographical location. The data obtained are required for the development of species conservation and restoration programs, which are especially important in the Middle Urals, which is the region with strong forest fragmentation
Dynamic Linkages Between Kazakhstan and Its Major Trading PArtners' Stock Market
This paper examines the linkages among stock markets of six countries. Kazakhstan stock market was chosen as dependant variable. Other five stock markets represent trade partner countries’ markets, namely Russia, Ukraine, US, China, Turkey. Particular study implemented Johansen – Juselius (1990) technique to investigate the cointegration between variables and Granger causality test (1969) to determine the causal relationship among stock markets. Trace test within cointegration approach identified the two cointegrating equations among variables, which implies the existence of long run equilibrium relationship among six stock markets. Granger causality test determined the bilateral causal relationships between stock markets of Kazakhstan and Russia, Kazakhstan and Ukraine, Kazakhstan and US. There is unidirectional relationship between Chinese and Kazakhstan stock markets. Granger test did not find any causal relationship between stock markets of Kazakhstan and Turkey
Dipyrazolodioxadiazocines as Easily Storable and “Ready to Use” Precursors for in Situ Generation of Enolate-Iminium 1,4-Dipoles: an Atom-Economical Approach Topyrazolo[5,1-d][1,3,5]Dioxazines
The work was supported by Russian Science Foundation, project № 19-13-00290
Genetic Structure of Pinus Populations in the Urals
The sustainable use and conservation of forest resources must be carried out with a detailed study of the main forest-forming plant species. Coniferous forests form the basis of boreal forest ecosystems and are of great economic importance. Representatives of forest-forming boreal coniferous species are species of the genus Pinus, including Siberian pine (Pinus sibirica Du Tour) and Scots pine (Pinus sylvestris L.), which are valuable and widely used woody plant species. The purpose of this research was to conduct an extended study of genetic diversity, genetic structure, and differentiation of P. sibirica and P. sylvestris populations under the conditions of their habitat in the Middle and Northern Urals. We studied twelve populations of two Pinus species using the inter-simple sequence repeat (ISSR)-based DNA polymorphism detection PCR method. Populations are characterized by relatively high levels of genetic diversity (P. sylvestris: He = 0.163; ne = 1.270; I = 0.249; P. sibirica: He = 0.148; ne = 1.248; I = 0.225). Analysis of the intrapopulation genetic structure reveals that the studied populations are highly differentiated (P. sylvestris: GST = 0.362; P. sibirica: GST = 0.460). The interpopulation component comprised 36% and 46% of the total genetic diversity for P. sylvestris and P. sibirica, respectively. Using various algorithms to determine the spatial genetic structure, it was determined that P. sylvestris populations form two groups according to their location at a certain altitude above sea level. P. sibirica populations form two clusters, with an additional subdivision of the two populations into subclusters identified. The data obtained during the study may be useful for further research as well as for conservation management planning and related forestry practices aimed at preserving the genetic resources of valuable forest plant species
Genetic Structure of Pinus Populations in the Urals
The sustainable use and conservation of forest resources must be carried out with a detailed study of the main forest-forming plant species. Coniferous forests form the basis of boreal forest ecosystems and are of great economic importance. Representatives of forest-forming boreal coniferous species are species of the genus Pinus, including Siberian pine (Pinus sibirica Du Tour) and Scots pine (Pinus sylvestris L.), which are valuable and widely used woody plant species. The purpose of this research was to conduct an extended study of genetic diversity, genetic structure, and differentiation of P. sibirica and P. sylvestris populations under the conditions of their habitat in the Middle and Northern Urals. We studied twelve populations of two Pinus species using the inter-simple sequence repeat (ISSR)-based DNA polymorphism detection PCR method. Populations are characterized by relatively high levels of genetic diversity (P. sylvestris: He = 0.163; ne = 1.270; I = 0.249; P. sibirica: He = 0.148; ne = 1.248; I = 0.225). Analysis of the intrapopulation genetic structure reveals that the studied populations are highly differentiated (P. sylvestris: GST = 0.362; P. sibirica: GST = 0.460). The interpopulation component comprised 36% and 46% of the total genetic diversity for P. sylvestris and P. sibirica, respectively. Using various algorithms to determine the spatial genetic structure, it was determined that P. sylvestris populations form two groups according to their location at a certain altitude above sea level. P. sibirica populations form two clusters, with an additional subdivision of the two populations into subclusters identified. The data obtained during the study may be useful for further research as well as for conservation management planning and related forestry practices aimed at preserving the genetic resources of valuable forest plant species
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