Investigation of X-Ray Flares with Long Rising Phases     

Urszula Bąk-Stęślicka  Jerzy Jakimiec 《Solar physics》2005,231(1-2):95-115

We have used Yohkoh and GOES X-ray observations to investigate flares with a long rising phase. We have found that a characteristic feature of such flares is a long time interval, Δ t ≥ 20 min, between the temperature maximum and the maximum of the emission measure. We have carried out detailed analysis for 10 limb flares of this type. Time variation of the heating function, E_H(t), has been determined for their loop-top X-ray kernels. The time variation of E_H(t), together with the temperature–density diagnostic diagrams, have been used to explain the large value of the time interval, Δ t. The main point is that for these flares the heating function E_H(t) decreases so slowly after the temperature maximum, that for the long time, Δ t, the energy flux reaching flare foot points is sufficient to maintain significant chromospheric evaporation. Investigation of the flare evolution in the temperature–density diagnostic diagrams allowed us to work out a new method of determination of the density for flare kernels. This method can be applied to all the kernels for which their altitudes can be estimated. The advantage of this method is that for the density determination it is not necessary to assume what is the extension of the emitting plasma along the line of sight.  相似文献   

On the origin of the bimodal duration distribution of gamma-ray bursts and the subjet model     

A. Janiuk  B. Czerny  R. Moderski  D. B. Cline  C. Matthey  S. Otwinowski 《Monthly notices of the Royal Astronomical Society》2006,365(3):874-884

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Extremely Low Frequency Electromagnetic Investigation on Mars     

Joanna Kozakiewicz  Andrzej Kulak  Jerzy Kubisz  Krzysztof Zietara 《Earth, Moon, and Planets》2016,118(2-3):103-115

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On the effect of coronal outflow on spectra formation in galactic black hole systems     

A. Janiuk  B. Czerny  P. T. &#;ycki 《Monthly notices of the Royal Astronomical Society》2000,318(1):180-186

We present the results of both analytical and numerical calculations of the amplitude of the reflection component in X-ray spectra of galactic black hole systems. We take into account the anisotropy of Compton scattering and the systematic relativistic bulk motion of the hot plasma. In the case of the single scattering approximation, the reflection from the disc surface is significantly enhanced owing to the anisotropy of Compton scattering. On the other hand, the calculations of multiple scattering obtained using the Monte Carlo method show that the anisotropy effect is much weaker in that case. Therefore, the enhanced back-scattered flux may affect the observed spectra only if the disc surface is highly ionized, which reduces the absorption in the energy band corresponding to the first Compton scattering.  相似文献   

Effects of heated water discharge on the evaporation from a river surface     

Jerzy Jaworski 《Journal of Hydrology》1973,19(2):145-155

The investigations concerned the effects of thermal waters on the river evaporation process and the development of formulae, based on standard hydrological and meteorological data, for determination of evaporation from the Vistula river.  相似文献   

Ionic surfactants adsorption on heterogeneous surfacesAdsorption de tensioactifs ioniques sur les surfaces hétérogènes     

Jean-Maurice Cases  Jerzy Mielczarski  Ella Mielczarska  Laurent J. Michot  Frédéric Villiéras  Fabien Thomas 《Comptes Rendus Geoscience》2002,334(9):675-688

The adsorption of surfactants from aqueous solution is a phenomenon of major importance in applications ranging from ore flotation and paint technology to enhanced oil recovery. As this paper will illustrate, the process is very complex and of high scientific interest; its results can be extended to the retention of organic compounds (humic and fulvic acids, pollutants...) on solids in the biosphere. For a good understanding of the mechanisms involved in surfactants adsorption at the hydrophilic solid–aqueous solution interface, thermodynamic models have to take into account: (i) the physical chemistry of the surfactant in aqueous solution for choosing the appropriate reference phase, (ii) the surface heterogeneity of the adsorbing solid, (iii) the intensity of normal adsorbate–adsorbent bonds responsible for adsorption, (iv) the intensity of lateral bonds that favour the formation of surface aggregates through cooperative process and finally, (v) suitable theoretical models to describe adsorption phenomena. Once this has been achieved, two systems can be discussed: systems characterised by strong normal adsorbate–adsorbent bonds, currently used in ore flotation, which lead, in the case of heterogeneous surfaces, to the formation of lamellar aggregates at monolayer concentration and bilayer formation for higher concentrations. Systems characterised by weak normal adsorbate–adsorbent bonds, currently used in enhanced oil recovery and hydrocarbon (bio)remediation, which correspond to: (i) formation of globular micelles at the solid surface near the CMC when the temperature is higher than the Krafft point, (ii) formation of bilayered lamellar aggregates in the opposite case, (iii) three-dimensional condensation on substrate (T<T_Krafft) if the ionic surfactant interacts with cations in the bulk. To cite this article: J.-M. Cases et al., C. R. Geoscience 334 (2002) 675–688.  相似文献   

Acoustic emission and sorptive deformation induced in coals of various rank by the sorption-desorption of gas   总被引：1，自引：0，他引：1  

Zofia Majewska  Jerzy Ziętek 《Acta Geophysica》2007,55(3):324-343

Simultaneous measurements of acoustic emission (AE) and expansion/contraction of coal samples subjected to gas sorption-desorption processes were conducted on high-and medium-rank coal. The aim of this study was to examine the influence of the coal rank and type of sorbate on measured AE and strain characteristics. The experimental equipment employed in this study consisted of a pressure vessel and associated pressurisation and monitoring units. The arrangement of pressure-vacuum valves permitted the coal sample to be pressurised and depressurised. Carbon-dioxide and methane were used as sorbats.  相似文献   

Seismic doublets and multiplets at Polish coal and copper mines     

Sławomir Jerzy Gibowicz 《Acta Geophysica》2006,54(2):142-157

The following criteria for selection of doublets at Polish coal mines were accepted: the difference in magnitude (based on seismic moment) of two events not larger than 0.15, the distance between their hypocenters not greater than 150 m, and the time interval between their occurrence not longer than 10 days. Similarly, the criteria for seismic events at copper mines are: the difference in magnitude not exceeding 0.15, the distance not greater than 200 m, and the time interval not longer than 20 days. Seismic events from the Wujek and Ziemowit coal mines that occurred between 1993 and 1995, and seismic events from the Polkowice copper mine that occurred between 1994 and 1996 and from the Rudna copper mine that occurred between 1994 and 2004 were considered. Their source parameters and focal mechanisms were known in most cases from previous studies. Altogether 108 seismic pairs from coal mines and 118 pairs from copper mines were found, forming doublets, triplets and quadruplets, within the magnitude range from 0.7 to 3.5. The distance and time intervals between two events forming pairs are not dependent on magnitude of these events. The focal mechanism of seismic events forming pairs is similar in over 60 percent of pairs at coal mines and in about one third of pairs at copper mines. Spatial distributions of doublets in particular sections of coal and copper mines display dominant linear trends, characteristic for a given area, which are often in conformity with the direction of nodal planes determined by fault plane solution of one or both the events forming a doublet. In such cases, the rupture plane can be discriminated among the nodal planes.  相似文献   

Induction vector estimates in the Polish-Czechoslovak part of the Carpathians     

Jerzy Jankowski  Václav Petr  Jana Pečová  Oldřich Praus  Reviewer A. Janáčková 《Studia Geophysica et Geodaetica》1979,23(1):89-93

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The action of neutral oleic acid in the flotation of hematite     

Claudio Gutiérrez  Jerzy Iskra 《International Journal of Mineral Processing》1977,4(2):163-171

Acidification of solutions of oleate salts forms emulsions of oleic acid. It was found that these emulsions produce a different adsorption behaviour on different size fractions of the same mineral. At low oleate concentrations, for the finer fractions, adsorption at acid pH was higher than chemisorption at pH = 7.5; adsorption was lower for the coarser, flotation-size fractions. Therefore, the conclusions obtained in acid solutions for the adsorption of oleate on fine minerals cannot be applied to flotation-size minerals.At low oleate concentrations there is a good correlation between oleate adsorption and hematite flotation. This does not hold for oleate concentrations > 5· 10^?5M, where there is poor flotability in the acid region, although the adsorption of oleic acid is very high. This is attributed to the disordered character of the layer of cooperatively adsorbed oleic acid.  相似文献