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11.
A. M. Zvyagintsev I. B. Belikov N. F. Elanskii I. N. Kuznetsova Ya. O. Romanyuk M. G. Sosonkin O. A. Tarasova 《Russian Meteorology and Hydrology》2010,35(12):806-812
The comparison is represented of the results of surface ozone concentration measurements in two megalopolises, Moscow and
Kiev. A temporal course of ozone concentration and temperature in both cities is close by the shape and is typical of medium-polluted
plain stations. In both megalopolises, two maxima are observed within the seasonal ozone concentration variability, in spring
and summer, and during the day, a usual ozone concentration maximum (approximately in 2–3 hours after the local noon) and
the night one being typical of big cities. An average ozone concentration and an average temperature in corresponding periods
are higher in Kiev than in Moscow. Evidently, the summer maximum is associated with photochemical ozone generation processes,
and the spring one, with dynamic processes of its transport in the atmosphere. In both megalopolises, the episodes are observed
in the warm period under meteorological conditions being unfavorable for the pollutant scattering in the atmosphere when the
ozone concentration exceeds the threshold limit value and is dangerous for health. The repeatability of such episodes is the
highest one in July-August. In Kiev, such episodes are more frequent than in Moscow. An effective statistical model is constructed
for both megalopolises in which the observed ozone concentration is represented in the form of regression function of temperature
and relative humidity. 相似文献
12.
Oksana A. Tarasova Sander Houweling Nikolai Elansky Carl A. M. Brenninkmeijer 《Journal of Atmospheric Chemistry》2009,63(1):49-71
Presented is a detailed comparison of CH4 and δ13C–CH4 measurements with simulations of the global transport model TM3. Experimental data were obtained during campaigns along the
Trans-Siberian railroad in the framework of the TROICA project. Two summer (1999 and 2001) and one spring (2003) expeditions
are evaluated. Model simulations include sensitivity tests to further investigate the isotopic composition of natural gas
and emissions from Siberian wetlands. Comparison of the average mixing ratio of methane and its isotopic composition (δ13C) has been performed for different geographic zones, including the European part of Russia, Western Siberia and Central Siberia.
Simulations are in reasonable agreement with the measurements for the European part of Russia and confirm a high contribution
of natural gas to the observed methane levels. An increase of emission from bogs shifts the simulated methane isotopic composition
closer to the observations. The relative importance of the Western Siberia emissions in current inventories is underestimated
in comparison with other wetland regions in the former USSR. Simulated average mixing ratios are in a good agreement with
the observations in Central Siberia, while 13C(CH4) values tend to be higher than measured in all considered scenarios. These results point to a bias in the modeled source
mixture over Russia, which could be repaired by shifting emissions from isotopically heavy methane sources (e.g. coal, oil
or biomass burning) to light sources (e.g. wetlands, ruminants, waste treatment). Alternatively, the average isotopic signature
of Siberian wetlands may be lighter than expected. 相似文献
13.
Oksana A. Tarasova Nicolai F. Elansky Gennady I. Kuznetsov Irina N. Kuznetsova Irina A. Senik 《Journal of Atmospheric Chemistry》2003,45(3):245-259
The impact of air transport on the surface ozone variations is analyzed at Kislovodsk High Mountain Station for the period 1989–1996 on the basis of 2D back trajectories. It was shown that the contribution of photochemical and dynamical processes is different for the different seasons. In summer months the surface ozone concentration is governed by photochemical ozone production in semi polluted air from the regions of Northern Caspian, Southern Ural and Volga region. Time of the seasonal ozone maximum appearance is defined by joint influence of the processes of photochemical production and destruction in the eastern sectors and advection from Ukraine and Central Europe. The value of the seasonal minimum is determined by the processes of ozone destruction in the air coming from northeastern direction in the stable frontal zone. Distribution of sectors of the air transport changes from year to year and it can partly explain strong negative trend of the surface ozone concentration at the site. 相似文献
14.
A. A. Tatarnikova A. M. Tatarnikov V. F. Esipov T. N. Tarasova V. I. Shenavrin E. A. Kolotilov A. E. Nadzhip 《Astronomy Reports》2011,55(10):896-910
We present the results of our analysis of the spectrophotometric and photometric data for the symbiotic nova PU Vul acquired
in 2001–2008. The continuum in the optical observed in 2006–2008 cannot be reconciled with a standard model including light
from the cool component, hot component, and nebula. The hot component’s temperature increased to 194 000 K by 2008, while
its luminosity decreased by a factor of ten compared to the plateau of 1979–1991. The evolution of the hot component as reflected
by the Hertzsprung-Russell diagram does not agree with a theoretical model describing the evolution of a thermonuclear outburst
in a white-dwarf envelope. We estimate the mass of the hot component to be 0.5M
⊙ based on the luminosity of the hot component during the plateau stage. Our spectroscopy reveals periodic continuum-flux variations
due to brightness variability of the cool component, with an amplitude of at least 2
m
at 7000 ?. The spectral type of the cool component in 2008 was M6.3. 相似文献
15.
A. V. Chugaev A. E. Budyak I. V. Chernyshev E. O. Dubinina B. I. Gareev K. N. Shatagin Yu. I. Tarasova N. A. Goryachev S. Yu. Skuzovatov 《Petrology》2018,26(3):213-245
This paper reports the results of a detailed isotopic (Sm–Nd, Pb–Pb, and δ34S) and geochemical studies of Neoproterozoic metasedimentary rocks from the Patom and Bodaibo domains of the Baikal–Patom belt (northern Transbaikalia). It was shown that the metasedimentary rocks of these domains are strongly variable in their geochemical and isotope geochemical characteristics. Regular variations in these characteristics were observed, and their correlation with the main stages of the evolution of the sedimentary paleobasin in the Neoproterozoic was established. 相似文献
16.
We present an analysis of spectrophotometric observations of the latest cycle of activity of the symbiotic binary Z And from
2006 to 2010. We estimate the temperature of the hot component of Z And to be ≈150 000−170 000 K at minimum brightness, decreasing
to ≈90 000 K at the brightness maximum. Our estimate of the electron density in the gaseous nebula is N
e
= 1010−1012 cm−3 in the region of formation of lines of neutral helium and N
e
= 106−107 cm−3 in the region of formation of the [OIII] and [NeIII] nebular lines. A trend for the gas density derived from helium lines
to increase and the gas density derived from [OIII] and [NeIII] lines to simultaneously decrease with increasing brightness
of the system was observed. Our estimates show that the ratios of the theoretical and observed fluxes in the [OIII] and [NeIII]
lines agree best when the O/Ne ratio is similar to its value for planetary nebulae. The model spectral energy distribution
showed that, in addition to a cool component and gaseous nebula, a relatively cool pseudophotosphere (5250–11 500 K) is present
in the system. The simultaneous presence of a relatively cool pseudophotosphere and high-ionization spectral lines is probably
related to a disk-like structure of the pseudophotosphere. The pseudophotosphere formed very rapidly—over several weeks—during
a period of increasing brightness of Z And. We infer that in 2009, as in 2006, the activity of the system was accompanied
by a collimated bipolar ejection of matter (jets). In contrast to the situation in 2006, the jets were detected even before
the system reached its maximum brightness. Moreover, components with velocities close to 1200 km/s disappeared at the maximum,
while those with velocities close to 1800 km/s appeared. 相似文献
17.
Polychlorinated biphenyls and organochlorine pesticides in bottom sediments of the Irkutsk Reservoir
The concentrations of organochlorine pesticides (HCCH, DDT, and HCB) and 34 congeners of polychlorinated biphenyls were studied in bottom sediments of the Irkutsk Reservoir, the first in the Angara Chain of Reservoirs. The degree of pollution of bottom sediments was evaluated in accordance with classifications of regional and international standards. A correlation was found to exist between the distribution of some organic compounds and organic carbon concentration. 相似文献
18.
Budyak A. E. Skuzovatov S. Yu. Tarasova Yu. I. Wang Kuo-Lung Goryachev N. A. 《Doklady Earth Sciences》2019,484(1):92-96
Doklady Earth Sciences - A comparison of the lithological–geochemical parameters for the deposits of the Dalnetaiga series of the Bodaibo synclinorium (the Buzhuikhta and Khomolkho... 相似文献
19.
A. E. Budyak A. V. Parshin A. M. Spiridonov V. N. Reutsky B. B. Damdinov M. G. Volkova Yu. I. Tarasova V. A. Abramova N. N. Bryukhanova O. V. Zarubina 《Geochemistry International》2017,55(2):184-194
This study provides geochemical, mineralogical, and isotope data for rocks and ores from Lower Proterozoic black shale formations of the Kodar–Udokan structural and formational zone, which host the Khadatkanda gold—uranium deposit. The results indicate that the uranium and gold mineralizations were formed at different times in relation to different geodynamic settings. The gold mineralization is associated with the inception of the Syulban fault and has a juvenile source. The later Th–U mineralization originated during tectonic rejuvenation of the Syulban fault zone, while the sources of radioactive elements were presumably the underlying sediments of the Kodar Group, which are widespread throughout the area of the Baikal mountain region (BMR). Based on the above results, the Au–U mineralization in the study area can be recognized as unconformity-type deposits, analogous to the well-known deposits of Australia and Canada. In this connection, the Baikal mountain region has a good potential for the discovery of Au—U deposits. 相似文献
20.
S. F. Vinokurov N. P. Tarasova A. N. Trunova V. A. Sychkova 《Doklady Earth Sciences》2017,475(1):771-774
Snow samples from the territory of the Setun River Valley Wildlife Sanctuary are analyzed for the content of rare-earth elements, heavy metals, and other hazardous elements by the inductively coupled plasma mass-spectrometry method. The changes in the concentrations of rare-earth elements, Pt, Pd, and indicator ratios of elements in the solid fractions of snow are revealed. A trend toward a decrease in the content of several elements northeastward of the Moscow Ring Road (MRR) is established. The level of seasonal atmospheric contamination of the area under study is assessed, and a possible source is identified. 相似文献