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Imre Toth 《Planetary and Space Science》1997,45(12):1625-1637
Photoelectric observations of the minor planet 127 Johanna were made in the UBV (RI)c photometric system during its apparition in 1991 at the Piszkéstetõ mountain-station of Konkoly Observatory from August to December, when it showed a brightness variation with an amplitude of about 0.2 magnitude. The derived H, G values in the two-parameter magnitude system in V are 8.459 ± 0.013 and 0.114 ± 0.020, respectively. The determined V linear phase coefficient is of 0.036 ± 0.001 (mag/deg). The value of G and the observed values of color indices (U-B), (B-V) confirm that this asteroid belongs to the C taxonomic class as it was previously classified. The estimated effective diameter is between 96 and 118 km if the assumed V geometric albedo is of 0.06 and 0.04, respectively. The available data suggest a pure principal axis rotation mode. The mean synodic rotational period of the asteroid 127 Johanna is 6.94 ± 0.29 h. The uncertainty is due to the changing of aspect geometry. This value of the synodic rotation period means that this asteroid has an intermediate rotation period. The sense of rotation is prograde as indicated by the temporal evolution of the time derivative of the ecliptic longitude of the phase angle bisector as well as with the increasing synodic period of rotation during the same interval (October/November and December in 1991). The composite lightcurves created for short arc time data reveal structures with breakings and linear portions in V; this fact and the Fourier coefficients indicate a probably irregularly shaped body. There are slight indications that the B-V is redder close to the brightness minimum and the V-Rc is redder at the brightness maximum, and the periodic behavior cannot be proved in V-Ic. The less full rotational phase coverage of the observational data is insufficient to construct a shape model. The accurate pole orientation obviously cannot be determined using one opposition lightcurve data only. Further observations are required to get a more accurate knowledge of the physical parameters of this asteroid. For this purpose, a good opportunity to perform observations arose in December 1996, when this asteroid was in opposition at the northernmost declination. 相似文献
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Bálint Érdi Emese Forgács-Dajka Imre Nagy Renáta Rajnai 《Celestial Mechanics and Dynamical Astronomy》2009,104(1-2):145-158
The size of the stable region around the Lagrangian point L 4 in the elliptic restricted three-body problem is determined by numerical integration as a function of the mass parameter and eccentricity of the primaries. The size distribution of the stable regions in the mass parameter-eccentricity plane shows minima at certain places that are identified with resonances between the librational frequencies of motions around L 4. These are computed from an approximate analytical equation of Rabe relating the frequency, mass parameter and eccentricity. Solutions of this equation are determined numerically and the global behaviour of the frequencies depending on the mass parameter and eccentricity is shown and discussed. The minimum sizes of the stable regions around L 4 change along the resonances and the relative strength of the resonances is analysed. Applications to possible Trojan exoplanets are indicated. Escape from L 4 is also investigated. 相似文献
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The present study was carried out as part of a complex survey of urban groundwater quality and quantity in Szeged, southeast Hungary. The concentrations of 12 inorganic contaminants in 28 shallow groundwater monitoring wells were determined over a 2-year period (2010–2012). The evaluation of concentrations indicates remarkable contamination all over the city. Discriminant analysis (DA) was used to evaluate the spatial changes of groundwater quality. The groundwater levels were measured over a 14-year period (2000–2013). The fractal properties of water level fluctuations time series characterizing the groundwater system and Tisza River were investigated using rescaled range (R/S) analysis. The resulting Hurst exponents clearly showed the persistency and thus long memory effects of both the groundwater and the river flow. Comparison of the results of DA with the results of R/S analysis thus implies that the geological conditions and the changing groundwater quantities are not related to groundwater quality.
EDITOR A. CastellarinASSOCIATE EDITOR A. Fiori 相似文献
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This paper presents a short theoretical summary of the series expansion-based 2.5D combined geoelectric weighted inversion (CGWI) method and highlights the advantageous way with which the number of unknowns can be decreased due to the simultaneous characteristic of this inversion. 2.5D CGWI is an approximate inversion method for the determination of 3D structures, which uses the joint 2D forward modeling of dip and strike direction data. In the inversion procedure, the Steiner’s most frequent value method is applied to the automatic separation of dip and strike direction data and outliers. The workflow of inversion and its practical application are presented in the study. For conventional vertical electrical sounding (VES) measurements, this method can determine the parameters of complex structures more accurately than the single inversion method. Field data show that the 2.5D CGWI which was developed can determine the optimal location for drilling an exploratory thermal water prospecting well. The novelty of this research is that the measured VES data in dip and strike direction are jointly inverted by the 2.5D CGWI method. 相似文献
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István Cziczer Imre Magyar Radovan Pipík Madelaine Böhme Stjepan Ćorić Koraljka Bakrač Mária Sütő-Szentai Miklós Lantos Edit Babinszki Pál Müller 《International Journal of Earth Sciences》2009,98(7):1741-1766
Life and depositional environments in the sublittoral zone of Lake Pannon, a large, brackish Paratethyan lake from the Late
Miocene, were reconstructed from fossils and facies of the Szák Formation. This formation is exposed in several, roughly coeval
(9.4–8.9 Ma) outcrops, located along strike of the paleo-shelf-break in northwestern Hungary. The silty argillaceous marl
of the formation was deposited below storm wave base, at 20–30 to 80–90 m water depth. The abundance of benthic organisms
indicates that the bottom water was usually well oxygenated. Interstitial dysoxia, however, may have occurred immediately
below the sediment–water interface, as evidenced by occasional preservation of trace fossils such as Diplocraterion. The fauna comprised endemic mollusks, including brackish cockles of the subfamily Lymnocardiinae, dreissenid mussels (Congeria), and highly adapted, uniquely large-sized deep-water pulmonate snails (planorbids and lymnaeids). Ostracods were dominated
by endemic species and, in some cases, endemic genera of candonids, leptocytherids, cypridids, and loxoconchids. Fish remnants
include a sciaenid otolith and the oldest skeletal occurrence of Perca in Europe. The phytoplankton comprised exclusively endemic coccolithophorids, mostly endemic dinoflagellates (prevailingly
Spiniferites), and cosmopolitan green algae. The Late Miocene fauna and flora of Lake Pannon were in many ways similar to the modern Caspian
biota, and in particular cases can be regarded as its precursor. 相似文献
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Ruslan I. Kostov Christo Protochristov Chavdar Stoyanov Lszl Csedreki Alíz Simon Zita Szikszai Imre Uzonyi Bisserka Gaydarska John Chapman 《Geoarchaeology》2012,27(5):457-469
Neolithic artifacts made of nephrite, □Ca2(Fe,Mg)5Si8O22(OH)2, are found at prehistoric settlements in Bulgaria. This study investigates these objects based on particle induced X‐ray emission using a scanning nuclear microprobe (micro‐PIXE technique). Seven nephrite artifacts from the Neolithic sites of Kovachevo, Bulgarchevo and Galabnik in southwest Bulgaria were analyzed to quantify their composition and to establish if a correlation exists between the distribution of major and trace elements, color, impurities, and texture. The nephrite artifacts are tremolite in composition, with a proposed ultrabasic origin. Based on the geochemical data obtained by micro‐PIXE, we divide the artifacts into Group 1 objects from the Kovachevo site and Group 2 objects from the Galabnik and Bulgarchevo sites. The analytical data and microprobe analyses are compared with geochemical data of nephrite from across the globe. The results are in a good agreement with previous electron microprobe and electron paramagnetic resonance (EPR) spectroscopy data. Our study provides a better understanding of the mineralogy and geochemistry of nephrite artifacts and helps to address questions regarding origin and the distribution of such materials in Bulgaria and other Balkan countries. 相似文献
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Heat wave risk assessment and mapping in urban areas: case study for a midsized Central European city,Novi Sad (Serbia) 总被引:1,自引:0,他引:1
Stevan Savić Vladimir Marković Ivan Šećerov Dragoslav Pavić Daniela Arsenović Dragan Milošević Dragan Dolinaj Imre Nagy Milana Pantelić 《Natural Hazards》2018,91(3):891-911
Risk assessment and mapping methodologies for heat waves as frequently occurring hazards in central and southeastern Europe were applied in this study, and the impact of heat waves on the mortality of urban populations was determined as part of the assessment. The methodology for conducting the heat wave risk assessment is based on European Commission’s Guidelines for Risk Assessment and Mapping. The Novi Sad (Serbia) urban area was studied during summer 2015, which was one of the hottest summers in the last few decades. In situ air temperature measurements from urban stations and mortality of urban populations were used. Nocturnal urban heat island (UHI) intensity values between the various built-up zones and natural surrounding areas were used for the hazard level calculation. Temperature data from 9 p.m. to 5 a.m. were used because during the night, the UHI intensity reached its maximum values. The average daily number of deaths by LCZs was used to define the impact level of the vulnerability index. Calculations for both hazard levels were completed during two intensive heat waves (in July and August 2015) when it was expected that there may be a high level of risk. The results and maps show that the urban area is complex, and the heat wave risk on the population is not uniform. The most densely built-up areas (LCZs 2, 5 and 6) have very high or high risk values that are influenced by a higher rate of mortality. The obtained results and maps can be used by local authorities to prevent and mitigate climate-related hazards, for medical institutions as well as urban planners and for ancillary local, regional or national services. According to these results, the local authorities could define hot spots where they can place medical and rescue teams and install points with water supplies, etc. 相似文献
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I. Fejes 《Journal of Geodesy》1983,57(1-4):365-373
A fast and simple method is proposed for Doppler receiver pair quality evaluation. By evaluating collocated raw Doppler data the noise characteristics of the receivers can be directly obtained. Test evaluations of JMR receivers are presented. 相似文献