Einsteins' gravity with massive gravitons     

Attila Mészáros 《Astrophysics and Space Science》1985,111(2):399-405

Graviton may, in principle, have a small non-zero mass. In this paper the relevant theory of the massive graviton with six polarisations is developed. The drastic impact of a non-zero mass of the graviton on cosmology is also illustrated.  相似文献   

Interpretation of subhorizontal crustal reflections by metamorphic and rheologic effects in the eastern part of the Pannonian Basin     

Károly Posgay  Tamás Bodoky  Zoltán Hajnal  Tivadar M. Tóth  Tamás Fancsik  Endre Heged&#;s  Attila Cs. Kovács  Ern&#; Takács 《Geophysical Journal International》2006,167(1):187-203

The geologic origin of subhorizontal reflections, often observed in crustal seismic sections, was investigated by establishing metamorphic facies and strength of rocks in depth, and correlating these properties to seismic reflection sections from eastern Hungary. Estimation of the depths of metamorphic mineral stability zones utilized the principles developed by Fyfe et al. and known geothermal data of the area. The strength versus depth profile was derived by relating local seismic P -wave interval velocities to Meissner et al. 's activation energy. The results show that the series of subhorizontal reflections, observed in the Pannonian Basin, are a consequence of combined metamorphic and rheologic changes in depths. The synthesis of the integrated data set suggests that the retrograde alteration of the pre-Tertiary basement above the percolation threshold was made possible by the softening effect of shear zones and their water-conducting capacity. The subhorizontal reflections of highest energy, of the consolidated crust below the percolation threshold, originate in the depths of greenschist, amphibolite and granulite metamorphic mineral facies, which were formed in geothermal and pressure conditions similar to those existing today. These results imply the overprint of earlier (Variscan) metamorphic sequences of the crust by more recent retrograde metamorphic processes.  相似文献   

The Distribution of Redox Sensitive Elements (U, As, Sb, V and Mo) along a River-Wetland-Lake System (Balaton Region, Hungary)     

Françoise Elbaz-Poulicheet  Attila Nagy  Tibor Cserny 《Aquatic Geochemistry》1997,3(3):267-282

The distribution of redox sensitive elements (U, As,Sb, Mo and V) has been investigated in Lake Balatonand two man-made reservoirs (Lake Kis-Balaton-1 andKis-Balaton-2) built along the River Zala, the mainriver discharging into it. These elements underwentremoval in Lake Kis Balaton-2 (KB-2) during anoxicconditions (May and September).Similarities were found between the distributions ofdissolved As and Sb. Both elements had elevateddissolved concentrations in Lake Kis-Balaton-1 (KB-1)and in Lake Balaton in September. This increasedmobility could be due to a change of speciation (viareduction and the formation of methylated species).Such changes in speciation are well documented in theliterature and are generally enhanced during periodsof warmth and high primary productivity.Dissolved V and Mo distributions also showedsimilarities with higher concentrations in LakeBalaton than in other parts of the system.Although removal is not clearly detected from thedissolved concentrations, U, As, Sb and Mo aresignificantly enriched in the organic-rich sedimentsof Lake KB-1, while V is mainly associated with thealumino-silicate fraction. In Lake KB-1, theconcentrations of all elements in SPM (suspendedparticulate matter) are lower than in the depositedsediments (except for As) suggesting that enrichmentprocesses are occuring in the deposited sediments.Additionnally the cycling of As and Mo can be alsopartly controlled by uptake and scavenging processesin the water column, as suggested by the elevated Asand Mo concentrations observed in SPM seasonnally forAs in Lake KB-1 and at Z.mouth-1 station and for Mo atZ.mouth-1 station and Lake Balaton.  相似文献   

Low-frequency 3-D seismic survey of upper crustal magmatic intrusions in the northeastern Pannonian basin of Hungary     

Zoltn Hajnal  Endre Heged&#x;s  G. Randy Keller  Tams Fancsik  Attila Cs. Kovcs  Rbert Csabafi 《Tectonophysics》2004,388(1-4):239

A specially designed 700-km² grid survey, deploying 1000 regularly distributed low-frequency seismic recording systems, successfully investigated one of the most complex geologic environments of the Pannonian basin. The wide-angle signals penetrated through over 1000 m of multi-phase igneous lithology and recognized, for the first time, the underlying enigmatic Permian to Early Triassic basement rocks. Tomographic inversion of the first arrival grid data resulted in determination of an accurate three-dimensional (3-D) velocity field, to a depth of 4 km. The anomalous changes of the spatial velocity data outline the regional extent of the Late Miocene magmatic intrusions, which are covered by over 2000 m of Mid-Miocene to Pleistocene clastics. Complex relationship was found between the surface potential data and the intrusive bodies. This multi-faceted geophysical data analysis established a functional technique for mapping a subsurface with intricate acoustic and structural complexity.  相似文献   

Partial melting of crustal rocks     

Attila Kilinc 《Engineering Geology》1989,27(1-4):279-299

Shales and graywackes were first metamorphosed at 650°C and then partially melted at 700 and 750°C at 2, 4, 6, and 8 kilobars in the presence of 0.75m NaCl−0.45m KCl and 0.225m CaCl₂−0.750m NaCl solutions. In experiments with shales,KK+Na ratio in the decreases with increasing pressure at 650 and 700°C; however, at 750°C this ratio is equal to 0.5 at all pressures investigated. This suggests that melts at 700°C and at 2 to 8 kilobars pressure may be affected metasomatically whereas melts at 700°C and in the same pressure range will not. Melt composition produced in the shale-KClNaCl experiments is granite at 2, 4 and 6 kilobars pressure, whereas the melt compositions in the shale-CaCl₂NaCl experiments range from quartz monzonite (2–5 kilobars) to granodiorite (above 5 kilobars). Experiments with graywacke-KClNaCl produced melts of trondhjemite composition at 2, 2.5, 4, 6, and 7.5 kilobars.

These results indicate that partial melting of crustal rocks such as metamorphosed shales and graywackes in the deeper parts of the crust can produce large volumes of granitic magmas ranging in composition from true granite to trondhjemite to quartz monzonite and granodiorite.  相似文献   

Assessment of the sensitivity of the landscape in a sample area in Hungary for climatic variability     

Attila Kernyi  Peter Csorba 《地球表面变化过程与地形》1991,16(7):663-673

In the northeastern part of Hungary near the township of Tokaj a landscape research project has been performed in a 9 km² area. The aim of this study is to examine the possibilities of expressing the climatic sensitivity of the given small landscape unit by analysing the capabilities of such a small sample area and synthésizing the data obtained. The landscape analysis consisted of field and laboratory measurements, theoretical calculations, analyses of maps, as well as the construction of thematic maps (on the scale of 1:10000) and cartograms. In view of climatic sensitivity four of the landscape factors were regarded as crucial: (1) the water budget of the soils, (2) the thickness of the soils and loose sediments, (3) insolation, and (4) land use. By synthesis of these factors a five-grade climatic sensitivity map was produced. On the basis of the areal proportion of the different classes of sensitivity it was established that the study area is moderately sensitive to climate. Examination of the moisture content of soil clearly indicated different responses of the areas from the different sensitivity classes to changes in temperature and precipitation. The four main landscape factors selected proved to be useful in the rough delineation of the classes on the climatic sensitivity map. However, the use of the other landscape factors improved its accuracy.  相似文献   

How is the sun working?     

Attila Grandpierre 《Solar physics》1990,128(1):3-6

I assume that at the solar core finite amplitude flows are generated by some process for which a candidate can be the planetary tides. I assume also that there are some local magnetic flux bundles at the solar core with a strength larger than 10³ G. The aim of this paper is to show that these assumptions involve an electric field generation which then produces local thermonuclear runaways which shoot up convective cells to the outer layers. Within certain conditions these primal convective cells erupt in the subphotospheric layers which phenomenon can produce high-energy particle beams which when injected into magnetic flux tubes appear as flares. I suggest these processes for solving the neutrino problem, and also to interpret the spiky character of the solar neutrino flux and the correlation of the energy production of the Sun with its atmospheric activity.  相似文献   

The effects and characteristics of atmospheric dust during martian global dust storm 2001A     

Attila Elteto  Owen B. Toon 《Icarus》2010,210(2):589-611

We present retrieved trends in dust optical depth, dust effective radius and surface temperature from our analysis of Mars Global Surveyor Thermal Emission Spectrometer daytime data from global dust storm 2001A, and describe their significance for the martian dust cycle. The dust optical depth becomes correlated with surface pressure during southern spring and summer in years both with and without a global dust storm, indicating that global dust mixing processes are important at those seasons. The correlation is low at other times of the year. We found that the observed decay of optical depths at the later stages of the dust storm match, to first-order, theoretical values of clearing from Stokes–Cunningham fallout of the dust. Zonally averaged effective radius is constant within standard deviation of results (between 1.2 and 2.0 μm, with a global mean for all seasons of 1.7 μm), at all latitudes and seasons except at southern latitudes of 35° and higher around equinoxes in both martian years, where it is larger than average (2–3 μm). The emergence and disappearance of these larger particles correlates with observations of polar cap edge storms at those latitudes. Northern latitude observations under similar conditions did not yield a similar trend of larger average effective radii during the equinoxes. We also report on a linear correlation between daytime surface temperature drop and rise in optical depth during the global dust storm. Global dust storm 2001A produced a significant optical depth and surface temperature change.  相似文献   

Retrieval algorithm for atmospheric dust properties from Mars Global Surveyor Thermal Emission Spectrometer data during global dust storm 2001A     

Attila Elteto  Owen B. Toon 《Icarus》2010,210(2):566-588

We present a new parameter retrieval algorithm for Mars Global Surveyor Thermal Emission Spectrometer data. The algorithm uses Newtonian first-order sensitivity functions of the infrared spectrum in response to variations in physical parameters to fit a model spectrum to the data at 499, 1099, and 1301 cm⁻¹. The algorithm iteratively fits the model spectrum to data to simultaneously retrieve dust extinction optical depth, effective radius, and surface temperature. There are several sources of uncertainty in the results. The assumed dust vertical distribution can introduce errors in retrieved optical depth of a few tens of percent. The assumed dust optical constants can introduce errors in both optical depth and effective radius, although the systematic nature of these errors will not affect retrieval of trends in these parameters. The algorithm does not include the spectral signature of water ice, and hence data needs to be filtered against this parameter before the algorithm is applied. The algorithm also needs sufficient dust spectral signature, and hence surface-to-atmosphere temperature contrast, to successfully retrieve the parameters. After the application of data filters the algorithm is both relatively accurate and very fast, successfully retrieving parameters, as well as meaningful parameter variability and trends from tens of thousands of individual spectra on a global scale (Elteto, A., Toon, O.B. [2010]. Icarus, this issue). Our results for optical depth compare well with TES archive values when corrected by the single scattering albedo. Our results are on average 1–4 K higher in surface temperatures from the TES archive values, with greater differences at higher optical depths. Our retrieval of dust effective radii compare well with the retrievals of Wolff and Clancy (Wolff, M.J., Clancy, R.T. [2003]. J. Geophys. Res. 108 (E9), 5097) for the corresponding data selections from the same orbits.  相似文献   

The Dynamic Energy Source of the Sun and the Duplicity of the Stellar Energy Production     

Attila Grandpierre 《Astrophysics and Space Science》1997,258(1-2):177-184

Some possible ways of the energy production with fusion reactions in the Sun was explored theoretically in the first half of this century. Nowadays it is a standard view that the Sun produces its energy on a uniform level. I point out, that in the stellar and solar energy production a dynamic energy source is necessarily present behind the uniform one, and generates a direct connection between the core and the surface layers through tunnels. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献