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1.
Magnetic properties of the profiles of polluted and non-polluted soils. A case study from Ukraine 总被引：7，自引：0，他引：7
2.
S. N. Kravchenko 《Studia Geophysica et Geodaetica》2005,49(2):177-190
Palaeomagnetic data are presented from the southern Volodarsk-Volynsky Massif (VVM) of the Korosten Pluton, the Ukrainian Shield. Laboratory experiments (AF and thermal demagnetization, IRM acquisition, thermal separation), field tests (consistency and secular variation methods) and optical observations indicate that single domain and nearly single domain magnetite is the dominant carrier of a primary TRM in the anorthosites. Palaeomagnetic poles from the three sampling sites (Golovino and Turchinka quarries) are indistinguishable at the 95% confidence level and have been combined to yield a mean pole at Plat = 30 °N, Plon = 178 °E, a95 = 3.4 °.In the large slow cooling Korosten Pluton the U-Pb zircon/baddeleyite (Uzb) technique gives an age for the anorthosites, which are not equivalent to the time of magnetic blocking. Based on integrated analysis of geochronologic information and blocking-temperature data for magnetic minerals proposed by Briden et al. (1993), a first attempt has been undertaken to estimate the palaeomagnetic pole age from the Mesoproterozoic anorthosites. The Korosten Pluton has cooled from 850 °C (the closure temperature of U-Pb systematics in zircon/baddeleyite) to 350 °C (the closure temperature of K-Ar systematics in biotite) during 150 Ma after the emplacement of the anorthosites. Assuming a uniform cooling of the intrusion yields a rate of 3.3 °C/Ma. The cooling rate for the granites is 3.1 °C/Ma. The mafic and acid rocks have an average rate of 3.2 °C/Ma. Using the cooling gradient for the VVM (3.2 °C/Ma) and the mean natural blocking temperature of magnetite (520 °C) can be determined a remanence age. The estimate for TRM acquisition is 1656 ± 10.0 Ma.The magnetic pole for the VVM is in good agreement with the mean pole from the Baltic quartz porphyry dykes with an age of 1630 – 1648 Ma. The VVM pole is best dated and requires a revision of the latest paleogeographic reconstructions for the Fennoscandian and Ukrainian Shields at 1770 and 1650 Ma. (Pesonen et al., 2003). 相似文献
3.
Yu. G. Safonov G. I. Gorbunov A. A. Pek A. V. Volkov T. M. Zlobina G. G. Kravchenko E. P. Malinovsky 《Geology of Ore Deposits》2007,49(5):343-371
The current status of investigations of the structure of ore fields and deposits in Russia is considered. The importance of traditional lines of research in this field and the great body of information acquired is emphasized. The changes in ideas of geodynamic and tectonic crustal evolution have made it necessary to alter concepts of the geological and structural position of ore fields and deposits. New challenges are caused by these changes and progress in the knowledge of ore deposits and the depth of their formation, as well as geodynamic, tectonophysical, and hydrodynamic processes in ore-bearing crustal blocks. The results of hydrodynamic modeling of deposit formation controlled by deeply penetrating fault zones are discussed. Various relationships between hydrodynamic and structural factors in ore formation are considered. 相似文献
4.
We investigate the formation of interannual variability in minimum winter discharge for a number of rivers in the upper part of the Lena basin depending on the eventual factors that are responsible for this variability. The study revealed the most important variables which can be used as predictors of the discharge parameters under consideration. We have constructed the regression models for predicting the parameters of minimum winter discharge with a 1-4-month predictability. 相似文献
5.
G. G. Valyavin V. D. Bychkov M. V. Yushkin G. A. Galazutdinov S. V. Drabek V. S. Shergin A. N. Sarkisyan E. A. Semenko T. E. Burlakova V. M. Kravchenko D. O. Kudryavtsev A. M. Pritychenko P. G. Kryukov S. L. Semjonov F. A. Musaev S. N. Fabrika 《Astrophysical Bulletin》2014,69(2):224-239
We propose a project of a high-resolution (R = 100 000) fiber-fed spectrograph for comprehensive studies of stellar atmospheres, exoplanet searches, asteroseismological studies, studies of stellar magnetism, active nuclei of bright galaxies, interstellar medium, etc. We present the optical scheme of the instrument. The operating wavelength region spans from 4000 to 7500 Å. We also present the optical scheme of the pre-fiber optic unit of the spectrograph. The unit supports four main modes of spectroscopic observations: the mode of traditional spectroscopy with the spectrum of the studied object taken along with the background spectrum in the immediate vicinity of the object; the mode of the simultaneous recording of the spectrum of the object and that of the wavelength standard; the mode of high-precision spectroscopy with an iodine cell, and the mode of spectropolarimetric observations with the measurement of all the Stokes parameters. 相似文献
6.
L. M. Sorokovikova G. I. Popovskaya I. V. Tomberg V. N. Sinyukovich O. S. Kravchenko I. I. Marinaite N. V. Bashenkhaeva T. V. Khodzher 《Russian Meteorology and Hydrology》2013,38(2):126-133
Based on the comprehensive hydrochemical and hydrobiological studies of the Selenga River near the Naushki settlement carried out in 2010, the quality of water flowing from the territory of Mongolia is assessed. The comparison with the results of the previous years indicates that the water quality deteriorated due to the intensification of economic activity in the river basin and unfavorable climatic factors. 相似文献
7.
Yu. A. Kugaenko N. M. Kravchenko V. A. Saltykov 《Journal of Volcanology and Seismology》2009,3(3):168-178
We report extensive anomalies identified in seismicity parameters at different energy levels which were observed during the precursory process of the Karymskii seismovolcanic crisis of January 1–2, 1996. The seismicity of different energies includes earthquakes contained in the Kamchatka regional catalog and seismic noise (amplitudes of 10?9–10?12 m, frequencies of a few tens of hertz), which is a manifestation of the seismic process in the lowest energy range. The parameters of background seismicity are considered in retrospect using techniques for analyzing the dynamics of the seismic process: RTL and the Z function. Microseismicity is examined using these authors’ own method based on monitoring the response of high frequency seismic noise to tidal excitation 相似文献
8.
Effect of salinity on abundance dynamics and cell size of microalga Corethron hystrix Hensen (Bacillariophyta) were studied. C. hystrix can normally grow within a rather narrow salinity range between 32 and 28‰. The viable cells of this microalga change their morphological characters at a salinity of 24‰. This salinity level probably marks the beginning of cell division restriction, because the general number of cells by the end of the experiment was lower than in the control. The decrease of salinity to 16‰ caused pronounced irreversible morphological changes: cell height increased, chloroplasts compressed, protoplasm became granular, cytoplasm retracted, and spines shortened. 相似文献
9.
Policy discourse and biography: scripting adulthood into housing policies in comparative perspective
Zhanna Kravchenko 《GeoJournal》2014,79(4):513-525
This article compares current Russian and Swedish policy discourses on state commitment to facilitating young adults’ access to housing by analyzing national, regional and municipal strategic documents. Both countries previously embraced the idea of housing as a commodified yet universal entitlement and exercised strong public regulation of housing redistribution, but are now establishing selective policies that support young people who comply with prescribed life-course norms. Thus, a life-course trajectory becomes integrated into the policy discourse, and a stable residential autonomy is considered a ‘crowning biographical event’, following a successful employment record and the establishment of a family unit. Notwithstanding important differences in policy formulation and realization, housing policies in Russia and Sweden are aimed to integrate emerging adults into market relations by increasing housing ownership through credit loans and stimulating individual responsibility for welfare provision. 相似文献
10.
Mollisols properties and changes in Ukraine and China 总被引：4，自引：2，他引：2
Soils are the foundation of civilizations and the basis for human food production.Mollisols in Ukraine and Northeast China are two out of the four major Mollisol regions in the world.The natural areas from which Mollisols developed are the prairies and steppes that experience temperate and freezing conditions.This review paper introduces the general climate,vegetation,and topography of Mollisols regions in Ukraine and Northeast China,analyzes their properties,including soil texture,soil organic matter content,soil bulk density,pH,cation exchange capacity and other chemical properties,and compares the property changes and management practices of Mollisols in relation to sustainable grain production. 相似文献