Home – Home – Jornals – Contemporary Problems of Ecology 2011 number 3

We have studied for the first time the organic geochemistry of the Vendian thick section stripped by the parametric well Vostok-3 in the depth range 5002-3870 m in southeastern West Siberia. The results point to the aquagene-plankton-derived and bacterial nature of the buried organic matter (OM). At some depth levels, the deposits are enriched in OM (up to 0.7-9.6%). The study of kerogens has shown that the OM is transformed to the apocatagenesis stage. The composition of biomarker hydrocarbons in bitumens has been studied, and the geochemical criteria for the petroleum presence prediction are considered.

The Oxfordian-Lower Hauterivian section of the Nordvik Peninsula (northern Central Siberia) is a reference for developing zonal scales for various fossil groups and improving the Boreal zonal standard. In the middle 1950s-late 1980s, it was studied extensively by geologists, stratigraphers, lithologists, and experts on various fossil groups. These studies yielded rich fossil and microfossil collections and a set of parallel zonal scales for various faunal groups. Recently, a new detailed ammonite zoning of the Oxfordian and Kimmeridgian units of this section has been proposed. These results contradict the previous biostratigraphic data on ammonites, foraminifers, and palynomorphs. In the present paper, all the biostratigraphic data on the Oxfordian and Kimmeridgian units of the Nordvik Peninsula (Cape Urdyuk-Khaya) and northern Central Siberia undergo a comprehensive analysis and comparison with those on the Boreal Realm. The ammonite-constrained stratigraphic position of the lower Upper Jurassic in the Cape Urdyuk-Khaya section is interpreted as Upper Oxfordian or Middle Oxfordian. In our view, this difference in the understanding is due to the misidentification of some Oxfordian ammonite forms. The zones based on other fossil groups (foraminifers, dinocysts) which were distinguished in the Upper Oxfordian and Kimmeridgian sections of the Nordvik Peninsula are well traceable circumarctically. Their stratigraphic position in various regions of the Northern Hemisphere is constrained by ammonites and bivalves. However, if we use the last alternative ammonite zoning of this part of the section, hardly explicable contradictions will appear in interregional foraminifer and dinocyst correlations.

The structure of the Lower-Middle Ordovician Tuloi and Karasinka Formations, which occur widely in northeastern Gornyi Altai, has been studied. A bed-by-bed description of a new section of the boundary sediments between these stratigraphic units has been given. The graptolite, trilobite, and brachiopod assemblages typical of the Tuloi and Karasinka Formations have been analyzed. Graptolite zones and subzones have been recognized, which permit correlating the stratotype and key sections of these local stratigraphic units with the stages of the International Stratigraphic Chart (ISC). The Karasa Formation occupies a considerably larger stratigraphic volume than presumed: It spans the late Arenig and the entire Llanvirn (including the Llandeilo) of the British standard, which is used in Russia (= Upper Dapingian-Darriwilian of the new Ordovician standard in the ISC). Finally, the paper discusses the suggested changes in the names of regional units (horizons) in the Ordovician stratigraphic chart of the western Altai-Sayan fold belt.

Based on the new petrological and thermochronological data, analysis of the metamorphism conditions and tectonic evolution of the Bodonchin zonal complex in Mongolian Altay was performed. Using mineral geothermometers and geobarometers, the parameters of the thermal state of the Mongolian Altay crust site during the collision of terranes were estimated, and the paleogeotherm at the peak of syncollisional metamorphism was reconstructed. The thermal state of the crust was characterized by either a high content of radioactive heat sources or a high mantle heat flow. The estimated metamorphism temperatures and pressures of rocks in two zones (staurolite-kyanite schists and migmatites) of the Bodonchin complex correspond to the paleogeotherms with average temperature gradients δT/δz = 25.5 and 27.2?C/km. The results of isotope dating of zircons and metamorphic minerals were used to construct a thermochronological model for the regressive stage of evolution of the polymetamorphic complex. The rates of the ascent of metamorphic rocks to the surface as a result of thrusts in the Bulgan Fault zone were estimated at 0.3-1 mm/year.

The northern Tien Shan is the northern front of the Himalayan mountain belt, which resulted fr om the collision between the Indian and Eurasian Plates. This region encompasses the most active seismic zones of the orogen, which generated the strongest ( M > 8) earthquakes. Since there are scarcely any written accounts, the only way to trace back strong earthquakes is the paleoseismological method. Since 1984 we have been studying the northwestern Issyk Kul' basin, wh ere there are differently directed anticlines, which constitute the Kungei megaanticline. Here, several active tectonic structures (faults, folds) are located, whose development was accompanied by strong earthquakes. Our field studies in 2008 in the Iiri-Taldybulak River valley, along the adyrs (foothills) of the Kungei-Ala-Too Range, revealed two unknown historical earthquakes. The first one, which occurred along the southern rupture in the late 7th century, gave rise to a seismic scarp; the latter broke through the river floodplain and a tash-koro (ancient settlement). The second one, which occurred along the northern rupture in the late 9th century, increased the height of the seismic scarp existing on the Early Holocene and older terraces. Note that this region already records a strong seismic event at ~500 A.D. Archeologic data have revealed one more strong earthquake, which took place in the 14th century. Note that the above-mentioned strong seismic events are coeval with the decline of the nomadic civilizatious (Wusun, Turkic, Mogul) in the northern Tien Shan and Zhetysu (Semirech'e).

Deep seismic investigation carried out in Russia in long-range profiles with peaceful nuclear explosions allowed clarifying in detail the structure of the upper mantle and the transition zone down to a depth of 700 km within the vast area of old and young platforms in Northern Eurasia. The variability of horizontal heterogeneity of the upper mantle with depth serves for the qualitative estimation of its rheologic properties. The upper part of the mantle (down to a depth of 80-100 km) is characterized by a block structure with significant velocity steps of seismic waves at the blocks often divided by deep faults. This is the most rigid part of lithosphere. Below 100 km, horizontal heterogeneity is insignificant, i.e., at these depths the substance is more plastic and not capable to retain block structure. On the lithosphere bottom at a depth of 200-250 km, a plasticity increase is observed as well but the zone of the lower velocities that might have been related to the area of partial melting (asthenosphere) has not been found. These three layers with different rheologic properties are divided by seismic boundaries presented by thin layering zones with alternating higher and lower velocities. At the specified depths, no phase boundaries have been distinguished.  These thin layering zones are assumed to form owing to high concentrations of mantle fluids at some depths where the mechanical properties and permeability of substance change. A minor quantity of fluids might result in streaks with partial or film melting at relatively low temperature, i.e., the appearance of weakened zones where subhorizontal shifts are possible. According to seismic data, seismic boundaries are observed at a depth of about 100 and 200 km in many world regions; they can be globally spread. There are signs that areas of xenolith formation and earthquake concentration, i.e., zones of high deformations, are confined to these depths.

The dielectric properties of the bentonite-oil-salt solution mixtures with different water and oil saturation were experimentally studied in the frequency range of 10 kHz to 4 GHz at 25-60?C. It has been established that besides the region of the Debye water relaxation, there are two more relaxation regions resulting from the interfacial interaction of the mixture components in this frequency range. To describe the dielectric permittivity and equivalent conductivity of the mixture, a spectroscopic model taking into account the multifrequency relaxation is proposed. The dependence of the model parameters on the water saturation and temperatures of the samples has been determined. The experimental data are compared with the modeling results, and the error of prediction for the dielectric permittivity and conductivity of mixture is estimated using the proposed model.

A spectral method for modeling high-frequency electromagnetic waves in axisymmetric geometry is proposed.The method is based on the expansion of the solutions of Maxwell's equations in Laguerre functions in the time region.
The spectral method is used to solve Maxwell's equations for both 2D media and stratified media. In the case of stratified media, a Fourier-Bessel expansion in the radial variable is used. The effectiveness of the spectral and finite-difference methods is compared. Harmonic solutions and solitary solutions by the Laguerre method are considered, and the dynamics of monochromatic and broadband electromagnetic pulses are examined.

This paper reviews the experimental work conducted at the physicochemical workstation of the Novosibirsk free electron laser (FEL) since 2005 on developing methods for studying the fractional composition of nanoobjects of different nature. It has been found that the submillimeter radiation of the FEL leads to soft ablation of biological macromolecules. Furthermore, the molecules are transferred to the aerosol phase separately, each type of molecules forms its own fraction of aerosol nanoparticles without destruction and denaturation, and their sizes correlate with molecular weight. It is suggested that submillimeter laser ablation can be used to determine the sizes of nanoobjects of different origin. The paper discusses the results of experiments with mineral clusters, nanopowders, synthetic and biological polymers carried out using traditional methods of investigation of the fractional composition of nanoscale materials (atomic force microscopy, scanning electron microscopy, dynamic light scattering, and x-ray diffractometry) and using the new method-the analysis of the aerosol products of submillimeter laser ablation. It is shown that submillimeter laser ablation with the subsequent registration of aerosol products by modern equipment is a versatile, simple, fast, and accurate method which can complement the above-mentioned methods.

Characteristics of a system of polarization-optical detection of a pulsed terahertz spectrometer in nonlinear crystals of zinc telluride (ZnTe) are considered. The influence of the ZnTe crystal thickness (0.5, 1, and 2 mm) on the detection system sensitivity is studied experimentally; a comparison with model calculations is performed. The effect of the time step and the interval of scanning of the terahertz pulse on the spectral resolution and range of the spectrometer is demonstrated experimentally and theoretically. Terahertz transmission spectra of typical container materials are measured.

Pulsed generation of terahertz radiation in GaAs, InAs, and InSb semiconductors under the action of femtosecond laser radiation at the wavelength of 775 nm is studied. The generation efficiency is shown to increase by a factor of 2.7 if InAs is placed into a magnetic field of 0.8 T. An increase in the generation efficiency by the mechanism of optical rectification in InAs samples with the 〈111〉 orientation is demonstrated.

The rate of data transfer through an optical communication channel with a photon counter based on an avalanche photodiode being used as a detector in this channel is studied. The rate of data transfer through the optical channel is found as a function of the reverse bias voltage of the photodiode, the optical signal power, and the threshold level of detection.

This paper considers the results of using a two-mirror multiple-beam reflection interferometer (RI) which has a response function in reflection similar to the response function of a Fabry-Perot interferometer in transmission. The two-mirror cavity of the RI included two flat mirrors, one of which was highly reflective, and the other had an asymmetric coefficient of reflection from different sides. The light reflected from the RI was brought to an optical fiber through a collimator lens. The optical fiber, collimator, and RI constituted an integrated fiber RI, which was first used for continuous tuning of the wavelength of an erbium ring fiber laser with a continuous generation in the spectral range 1520-1566 nm.

This paper analyzes the effect of changes in the key parameters of an algorithm for identifying cracks in images of rolls of continuous casting machines. The effects of the background threshold of binary conversion and the filter kernel size on the total error of calculations of geometric characteristics of cracks are considered. The range of crack lengths for which the developed algorithm is suitable is calculated based on experimental data.

New nonparametric statistics and a criterion (test) based on them are proposed to check the hypothesis of homogeneity of three and two samples, where one sample contains an even number of elements and, hence, can be divided into two samples, against an alternative hypothesis, which implies that random values of one sample are stochastically greater than random values of two other samples. The test is mainly sensitive to shifts of distributions and is more powerful than the Wilcoxon-Mann-Whitney and Whitney tests, at least for problems with samples from exponential and uniform distributions.

An effective algorithm of predicting the trend (deterministic basis) m(t) of a steady (in a wide sense) random process X(t) is proposed. The initial information about the random process X(t) is limited to the assumption that its mean value (mathematical expectation) is equal to zero. The interval [0, T] of observation of the trend sum m(t) and the sample x(t) of the random process X(t) is assumed to be finite. Construction of a prediction estimate μ(T + τ), where τ is the prediction interval, ensures automatic allowance for statistical characteristics of the random process X(t).

Based on an analysis of asymptotic properties of a family of nonparametric decision functions in the pattern recognition problem, a method for synthesizing the structure of this family is proposed.

This paper considers the problem of reducing the computation time in the formation of a single image based on its individual fragments using the sliding window method. A payoff function is obtained. Numerical simulation helped demonstrating the effect of the measurement error and the window size on the accuracy of determination of the shift coordinates of the fragments. The choice of the form of the functional and the window size is substantiated.

Improved algorithms for calculating oil saturation based on the cross-plot method are considered. Oil saturation is determined by comparing analytical parameters obtained by well logging and the corresponding parameters of physical reservoir models that are specifically created at metrological centers. The application of cluster analysis to this problem are discussed. Testing was performed on real data.

This paper considers retrial queueing (RQ) systems with Poisson (elementary) and Markovmodulated Poisson processes. The study is performed by the method of asymptotic cumulants using the theory of vector characteristic functions and the matrix form of equations, which makes it possible to obtain asymptotic results for the whole class of models. The analysis of a single-line RQ system performed revealed the range of applicability of asymptotic results for prelimit situations.

A scanning tunneling microscope equipped with an attachment for high-resolution tunneling spectroscopy is described. The electronic unit of the microscope provides advance of the needle, scanning, and measurement of the tunneling current, and has means for coupling with a tunnel current spectrometer. The spectrometer uses a modulation procedure for measuring the second derivative of the volt-ampere characteristic of the tunneling gap and has a sensitivity of up to 0.25 pA for a modulating signal amplitude of 2 mV.

The data are presented concerning the amount of mobile compounds of chemical elements (ChE) in soils under various kinds of human impact (acetate-ammonium buffer at pH 4,8) and the plants of ripple-seed plantain (Plantago major L.) (extracting agents such as diluted 1:1 HCl, 10 % HCl, distilled H₂O). The content of total ash, mineral admixtures of soil origin, water-soluble forms of ChE, polysaccharides and chlorophyll were determined in plants. The data obtained were compared with those for other regions. The ecological state of Plantago major L. was estimated and a conclusion was drawn about its possible use as a medicinal raw material.

Changes in the composition of microbial complexes and their biochemical activity in soil in the vicinity of a strong source of HF emission HF were studied. A sharp decrease of the biomass, the number of asporous bacteria and actinomycetes, and a smaller decrease of the number of microscopic fungi was revealed, along with a decrease in the enzymatic and respiratory activity of polluted soil with the relative increase in the fraction of soporiferous bacteria. On the basis of the response of introduced population of Bacillus subtilis to different doses of HF, NaF, Na₂SO₃ microbiological norm-fixing for technogenic soil ecosystems was carried out.

Changes of plant communities in sand and sabulous pits during overgrowing for different time intervals in the northern taiga of West Siberia were studied during the recent 13 years. It was demonstrated that at the first stage of overgrowing the species composition of the communities depends on the physical properties of the ground. Either grass or woody species dominate at this stage. Later on, the change of phytocoenoses leads to the development of the forest community of the zonal or derived type. The time of the appearance of the forest phytocoenosis depends on chance factors.

The peculiarity of humus distribution in the structure of embryozems of the technogenic landscapes of the forest-steppe zone of the Kuznetsk Basin and zonal black soil allowed revealing the genetic distinctions which are essential. In turn, this is considered as the diagnostic parameter of the character, intensity and orientation of soil processes and the evolution of the landscapes.

The fractional composition and size distribution of the soil of man-made landscapes is considered. The dependence of the formation of a certain type of embryozems in the forest-steppe zone of Kuzbass on the granulometric composition of soil-forming rocks was revealed. The content of physical clay throughout the profile of embryozems was calculated.

¹³⁷Cs speciation and distribution in such components of biogeocoenosis of the Yenisei's floodplain as soils, rhizosphere, and plants were studied. Investigation was carried out near the zones affected by the Krasnoyarsk KMCPP. The change of the specific activity of radionuclides with an increase in the distance from the source of pollution was demonstrated, the ratio of the specific activities of radionuclides in soil and in the rhizosphere was followed, and their distribution in plant's body was revealed. The variety of forms of ¹³⁷Cs occurrence including mobile ones was revealed. On the basis of the results of laboratory experiments, the amount of ¹³⁷Cs carried out of plants during the flood was calculated.

It is demonstrated that an increase in grazing pressure on the soil of dry steppe in Southern Tyva causes an increase in the content of microbiomass and a decrease in the level of its specific activity, a decrease in the number and species diversity of oribatid mites. During the recovery of the pasture for three years, the content of the microbial biomass decreases, the level of its specific activity increases but the number and species diversity of the oribatid mites community do not recover.

Viable pool of microorganisms detected in the upper layer of technogenic soil formed on coal dumps, ash dumps and ore slurry are considered. The ecological-physiological features of oligotrophic bacteria are analyzed. The biofilms of prokaryotes and tiny colonial forms were revealed. The effect of recultivation and soil improvers on the major groups of microorganisms was demonstrated.

Basic trends of the transformation of meadow soil humus under the influence of long-term flood with surface waters having high mineralization were analyzed. Displacement of the balance between the forms of humic acids differing in binding with soil, forms the contraction of the ratio С_HA/С_FA and the level of humification of organic matter are considered.

Forms of zinc compounds in light-chestnut soil under pollution with zinc, copper, cadmium, lead introduced separately and jointly were studied. It was discovered that for any kinds of pollution the initial relations between the forms of an element change. With an increase in the level of pollution, for all its kinds, accumulation of the most mobile forms of zinc in the soil is observed. It was revealed that ion exchange has the highest significance in the fixation of zinc in polluted soil.

On the basis of the data on the air-dry mass of plant species - dominants and subdominants in five life forms (mosses, lichens; herbs; subshrubs; shrubs; trees), quotients of similarity for ecosystems were calculated over the types of formations in the map Vegetation of the West Siberian Plain. By means of the cluster analysis of thus obtained similarity matrix, two classifications were compiled (over apportionments and over groups of apportionments of the indicated map). The calculated self-descriptiveness of the proposed schemes, estimated by the value of included dispersion, is higher by 11-16 % in comparison with division of vegetation on the initial map.

Cluster anаlysis of ecosystems over the plant cover, mortmass and the underground part of the biota (including soil humus) showed that the effects of zonal heat supply and wetting (swamping) may be considered to be approximately equal to each other for the differentiation of vegetation, while the effect of swamping obviously dominates for the underground part of ecosystems. Intra-type differences of the underground block are determined by the zonal-subzonal inhomogeneity in heat and humidity supply, composition of vegetation and flood during high water. In this situation, there is no clear coincidence with the subzonal division. Integration has more likely group character (with respect to this index) for similar flood during high water and the composition of forest-forming species.

Conditions of the rise and development of fire events and evaluation of forest fire statistics are presented for the ribbon-like pineries of the south of Siberia - Tsacucheisky, Balgazynsky, Minusinsky and Shushensky. The consequences of the effect of fire events on vegetation, including the state of tree stands and reafforestation processes, are evaluated. It is demonstrated that a decrease in the area occupied by ribbon-like pineries in the south of Siberia as a result of the impact from crown fire brings about steppe formation processes at these territories

General and additional ecological niches of the first and second order of pathogenic micromycetes of berry plants of the Vaccinioideae subfamily are considered in the article.

The paper shows introduction prospects for many species of woody plants from the Far East in Komi Republic. About 65 % of 68 species and forms collected in the Botanical Garden are highly winter-resistant. Woody species from the Far East are similar in seasonal development cycles to local woody plants.

Three types of altitudinal belt columns were recognized on the southern macroslope of the Tannu-Ola ranges. The main vegetation communities of every belt were described, their classification scheme according to Braun-Blanquet approach was accomplished.

Results of long-term bryological investigations in the Great Vasyugan Swamp are summarized. Coenotical and moss diversity is described: 8 types of mire communities and 122 moss species inhibiting them. Ecological optimums and amplitudes in Ramensky scale are calculated for all the types of mire communities and common moss species.

Results of the anаlysis of reserve and the structure of the overground phytomass of the prevailing alpine associations of Eastern Sayan are presented for r. Kryzhin (Eastern Sayan) as an example.

Traumatic effect on plants under ground fire of different kinds is investigated. The classification of traumas of herbs, tree trunks and crowns, as well as other transformations caused by fire is given. Types of pyrogenic traumas are compared with the character of fire events and the degree of pyrogenic transformation of biocoenosis. The possibility to use them as indicators of the pyrogenic intensity, the state and trends of biocenosis transformations is determined.