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71.
We discuss Arp's hypothesis that the HII regions are more numerous and more conspicuous on the side of a galaxy facing its companion. Arp's hypothesis seems not to be true if we add to Hodge's sets of galaxies only the most probably tidally-interacting cases. 相似文献
72.
It is shown that the non-keplerian character of the rotation of the ring of gas particles in a close binary system gives too large an amplitude of the radial velocity curve if this amplitude is determined from the positions of the emission lines of the ring. 相似文献
73.
In this paper we consider the buying/selling prices of carbon dioxide (CO2) emission permits in trading models with uncertainty. Permission prices, although usually omitted from standard models, may significantly influence the trading market. We thus undertook to construct a more realistic trade model and to compare it with the standard one. To do this, we introduced several important changes to the standard model, namely, (1) a new optimized quality function; and (2) transactions with price negotiations between regions. We also enhanced the model using methods described in the literature to allow it to deal with reported emissions uncertainty. Additionally, we used an original method of simulating this kind of market based on a specialized evolutionary algorithm (EA). 相似文献
74.
Application of electron paramagnetic resonance spectroscopy to examination of carbonized coal blends
B. Pilawa S. Pusz M. Krzesiska A. Koszorek B. Kwieciska 《International Journal of Coal Geology》2009,77(3-4):372-376
Paramagnetic centers in two- and three-component coal blends carbonized at 1000 °C were studied by X-band (9.3 GHz) electron paramagnetic resonance (EPR) technique. The blends were prepared from three different Polish coals with carbon contents [wt.%]: 88.66, 86.21, and 82.67, respectively. The aim of this work was to compare EPR parameters and concentrations of paramagnetic centers in the initial and carbonized coal samples. Furthermore the spin–spin and spin–lattice interactions were characterized.EPR spectra were measured with magnetic modulation 100 kHz and microwave power 0.7 mW. Amplitudes and linewidths of EPR spectra were obtained. g-Factors were calculated from resonance condition. Concentrations of paramagnetic centers in the samples were determined. Influence of microwave power in the range 0.7–70 mW on EPR spectra was analyzed.All the studied samples revealed paramagnetism. Unpaired electrons are localized in the same atoms, because similar g-values in the range 2.0035–2.0038 were obtained for all the original samples. The EPR parameters of coal blends were additive in comparison with the parent coals. EPR spectra strongly changed after carbonization of the coal samples. Narrower EPR lines were measured for the original coal samples than for carbonized ones. We detected lower concentrations of paramagnetic centers in carbonized three-component coal blends than in two-component carbonized blends. EPR lines of the studied carbonized blends were not saturated at the microwave power used, which suggests fast spin–lattice relaxation processes in the samples. EPR examination proved chemical interactions between coal constituents during carbonization of coal blends. 相似文献
75.
Zofia Majewska Grażyna Ceglarska-Stefańska Stanisław Majewski Jerzy Ziętek 《International Journal of Coal Geology》2009,77(1-2):90-102
There is still no clear understanding of the specific interactions between coal and gas molecules. In this context sorption–desorption studies of methane and carbon dioxide, both in a single gas environment and gas mixtures, are of fundamental interest. This paper presents the results of unique simultaneous measurements of sorption kinetics, volumetric strain and acoustic emission (AE) on three tetragonal coal samples subjected to sorption of carbon dioxide and methane mixtures. The coal was a high volatile bituminous C coal taken from the Budryk mine in the Upper Silesia Basin, Poland. Three different gas mixtures were used in the sorption tests, with dominant CO2, with dominant CH4 and a 50/50 mixture.The experimental set-up was designed specially for this study. It consisted of three individual units working together: (i) a unit for gas sorption experiments using a volumetric method, (ii) an AE apparatus for detecting, recording and analysing AE, and (iii) a strain meter for measuring strains induced in the coal sample by gas sorption/desorption. All measurements were computer aided.The experiments indicated that the coal tested showed preferential sorption of CH4 at 2.6 MPa pressure and exhibited comparable affinities for CH4 and CO2 at higher pressures (4.0 MPa). The results of chromatographic analysis of the gas released on desorption suggested that the desorption of methane from the coal was favoured. The relationship between the volumetric strain and the amount of sorbed gas was found to be non-linear. These results were contrary to common opinions on the coal behaviour. Furthermore, it appeared that the swelling/shrinkage of coal was clearly influenced by the network of fractures. Besides, the AE and strain characteristics suggested common sources of sorption induced AE and strain.The present results may have implications for the sequestration of carbon dioxide in coal seams and enhanced coalbed methane recovery (ECBM). 相似文献
76.
Jan Lewiński 《International Journal of Earth Sciences》1932,23(5):258-276
Zusammenfassung Die geologische Geschichte Nordwest-Polens zur Zeit der unteren Kreide kann in allgemeinen Zügen folgenderma\en dargestellt werden:Gegen Ende des Jura, ungefähr zur Zeit des Münder Mergels, sind hier Bewegungen eingetreten, die das Land teilweise trockengelegt und der Denudation preisgegeben haben. In den durch die Bewegungen gebildeten Senken blieben Lagunen erhalten, deren einige brackisches Wasser führten, während in anderen durch Eindampfung Gipslager abgesetzt wurden. Der Serpulit brachte eine positive Meeresbewegung mit, die sich im Infravalanginian derart verstärkte, da\ sich seine Ablagerungen nicht nur in den alten Senken kontinuierlich auf dem Serpulit abgesetzt, sondern auch auf denudierte, früher gehobene Schollen transgressiv ausgebreitet haben. Die Infravalanginian-See war brackisch und hat in NW-Polen typische Wealdenablagerungen abgesetzt, bei Tomaszów aber, etwas südlicher, ist das Infravalangian zwar litoral, aber rein marin ausgebildet, wobei es viele ähnlichkeit mit dem Infravalangian der Teschener Karpathen aufweist. Die Wealdensee und das karpathische Meer waren durch einen Sund verbunden, der sich über Tomaszów längs dem Polnischen Mittelgebirge gegen die Karpathen hinzog. Im Valanginian erreicht die neokome Transgression ihren Höhepunkt, es werden dunkle Tone mit reicher Hilsfauna abgesetzt; wahrscheinlich hat sich diese Transgression von Ru\land über die Polesje-Schwelle und über das westliche Polen nach Deutschland und weiter bis nach Ost-England erstreckt. Das polnische Becken stand in direkter Verbindung mit dem nordwestdeutschen; es war ebenfalls, obwohl dürftiger, mit dem karpathischen Meere verbunden; gerade hier ist der Weg zu suchen, den die Migrationen der nördlichen Elemente ins alpine Becken eingeschlagen haben. Im oberen Valanginian fängt eine Regression an, die in Zentral-Ru\land einsetzt und zu dessen Trockenlegung und zum Abschlu\ der Verbindung des polnischen Beckens mit dem Osten führt. Mit dem Anfang des Hauterivians macht sich die Regression auch in Polen fühlbar und verursacht die Verflachung des Meeres in Polen sowie den Abbruch der Verbindung mit dem karpathischen Meere, in welchem von nun ab keine nordischen eingewanderten Faunenelemente mehr erscheinen. Im oberen Hauterivian zieht sich das Meer von Polen und NO-Deutschland zurück. Auf dem neuen Lande herrscht mächtige Denudation, deren gröbere Produkte sich als sehr mächtige Flu\- und Seesande anhäufen. Das Landstadium dauert während des ganzen BarrÊme, Apt und eines Teiles des Albians an, bis zum Anfang der gro\en Gault-Transgression, die wieder in die Senken vordringt. 相似文献
77.
Krzysztof Pleskot Rik Tjallingii Mirosław Makohonienko Norbert Nowaczyk Witold Szczuciński 《Journal of Paleolimnology》2018,59(4):443-459
Western Poland is located in the central European climatic transition zone, which separates the mild and humid Atlantic climate of Western Europe and the East European continental climate. This region is sensitive to lateral shifts of the European climate zones and is particularly suitable for reconstructing Holocene climate variability. This paper presents detailed analyses of the sedimentary record from Lake Strzeszyńskie since the Late Pleistocene. These include smear-slide and thin-section observations, X-ray fluorescence core scanning, magnetic susceptibility measurements, pollen analyses, and radiocarbon dating. The sediment record reveals three distinct sedimentary units consisting of: (1) an alternation of sand layers and laminated silt and clay deposits accumulated prior to 14,600 cal yr BP; (2) faintly laminated calcareous sediments intercalated with organic matter-rich layers deposited between 14,600 and 10,200 cal yr BP; and (3) massive calcareous mud deposited after 10,200 cal yr BP. The Holocene period is marked by nine phases of organic-rich sedimentation and enhanced Fe deposition, which occurred at ca. 10.1, 9.3, 6.4–6.1, 5.5–5.1, 4.7–4.5, 2.7–2.4, 1.3–1.2, 0.8–0.6, 0.4–0.2 kyr cal BP. These phases are associated with high lake levels and correspond with wet periods recognized in several other records from Poland and central Europe. These phases partly coincide with North Atlantic cold periods, which may suggest that high lake levels are triggered by an ocean-continent linking mechanism. 相似文献
78.
79.
Fortuniak Krzysztof Przybylak Rajmund Araźny Andrzej Pawlak Włodzimierz Wyszyński Przemysław 《Theoretical and Applied Climatology》2017,130(3-4):959-970
Maize is grown by millions of smallholder farmers in South Asia (SA) under diverse environments. The crop is grown in different seasons in a year with varying exposure to weather extremes, including high temperatures at critical growth stages which are expected to increase with climate change. This study assesses the impact of current and future heat stress on maize and the benefit of heat-tolerant varieties in SA. Annual mean maximum temperatures may increase by 1.4–1.8 °C in 2030 and 2.1–2.6 °C in 2050, with large monthly, seasonal, and spatial variations across SA. The extent of heat stressed areas in SA could increase by up to 12 % in 2030 and 21 % in 2050 relative to the baseline. The impact of heat stress and the benefit from heat-tolerant varieties vary with the level of temperature increase and planting season. At a regional scale, climate change would reduce rainfed maize yield by an average of 3.3–6.4 % in 2030 and 5.2–12.2 % in 2050 and irrigated yield by 3–8 % in 2030 and 5–14 % in 2050 if current varieties were grown under the future climate. Under projected climate, heat-tolerant varieties could minimize yield loss (relative to current maize varieties) by up to 36 and 93 % in 2030 and 33 and 86 % in 2050 under rainfed and irrigated conditions, respectively. Heat-tolerant maize varieties, therefore, have the potential to shield maize farmers from severe yield loss due to heat stress and help them adapt to climate change impacts. 相似文献
80.
A. Róaska 《Monthly notices of the Royal Astronomical Society》1999,308(3):751-762
We study the vertical structure of the transition layer between an accretion disc and a corona in the context of the existence of a two-phase medium in thermally unstable regions. The disc is illuminated by hard X-ray radiation, and satisfies the condition of hydrostatic equilibrium. We take into account the energy exchange between the hot, Compton-heated corona (∼108 K) and cool disc (∼104 K) arising from both radiative processes and thermal conduction. In the case including thermal conduction, we perform a local stability analysis, and conclude that thermal conduction does not suppress thermal instability. In spite of the continuous temperature profile T ( τ ) there are regions of strong temperature gradient, in which spontaneous perturbations can lead to cloud condensation in the transition layer. We determine the minimum size λ TC of such a perturbation. 相似文献