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81.
Janina Szaran 《Chemical Geology》1998,150(3-4):331-337
Fractionation of the stable carbon isotopes between dissolved and gaseous carbon dioxide has been measured at temperature 25°C by two methods. In the first method the open system conditions and different methods of CO2 sampling were arranged. In the second method—the closed system conditions and CO2 gas extraction were used. The results obtained by these methods are very consistent. Gaseous CO2 is enriched in heavy isotope
by 1.03±0.02 permil in comparison to dissolved carbon dioxide. 相似文献
82.
Stanislaw Halas Janina Szaran Maciej Czarnacki Ahmad Tanweer 《Geostandards and Geoanalytical Research》2007,31(1):61-68
Refinements have been made to achieve over 99% yield in the conversion of CO to CO2 in order to improve the reproducibility and accuracy of δ18 O measurements in sulfates. BaSO4 (10-15 mg) was mixed with an identical amount of spectrographic-grade graphite and loaded into a Pt boat. The mixture was gradually heated to 1100 °C to reduce sulfate to CO and CO2 ; the former gas was simultaneously converted to CO2 by a glow discharge between Pt electrodes immersed in a magnetic field (produced by a pair of external neodymium magnets). A small memory effect was noticed during the analysis (less than 0.3‰ per 10‰ difference in δ18 O between two subsequently analysed samples). The memory effect, however, was suppressed by repetitive preparation of the same specimen. CO2 produced in this way from sulfate reference samples was analysed on a dual inlet and triple collector mass spectrometer along with CO2 equilibrated with VSMOW, GISP and SLAP water reference samples. To avoid large departures of measured isotope ratios from 18 O/16 O of the working calibrator we used CO2 gas prepared from ocean water sulfate for this purpose. The calibrated δ18 O values (in ‰) obtained in this way for NBS-127, IAEA SO-5 and IAEA SO-6 reference materials were 8.73 ± 0.05, 12.20 ± 0.07 and -10.43 ± 0.12, respectively. 相似文献
83.
F. W. Baier 《Astronomische Nachrichten》1984,305(4):175-185
The investigation of the distributions of number densities and radial velocities in the Coma cluster led us to the conclusion that this cluster possesses substructures. This result is in agreement with corresponding results for the Hydra I cluster and the Perseus cluster and with former conclusions by different authors that substructures are a typical phenomenon for a high percentage of all clusters of galaxies. 相似文献
84.
Frank W. Baier 《Astronomische Nachrichten》1985,306(4):261-261
85.
This catalogue is a compilation of references of publications with photometric data in and around Abell clusters of galaxies. Die Arbeit enthält eine Zusammenstellung der Publikationen mit photometrischen Daten für Abell-Haufen und ihre Umgebung. 相似文献
86.
We compiled informations with respect to optical structures, X-ray structures, cooling flow properties, and X-ray luminosities, respectively, for 342 nearby northern Abell clusters with central dominant galaxies. 相似文献
87.
Pál Sümegi Sándor Gulyás Dávid Molnár Gábor Bozsó István Fekete László Makó Péter Cseh Mihály Molnár Balázs P. Sümegi Peter Almond Christian Zeeden Tünde Törőcsik Janina J. Nett András Markó Frank Lehmkuhl 《第四纪科学杂志》2021,36(8):1364-1381
The 10 m thick Madaras loess–palaeosol profile is one of the Hungarian outcrops that yielded Upper Palaeolithic artefacts in 1966. To clarify the nature of the deposits and establish a reliable litho- and chronostratigraphy, a profile was opened and sampled at 25 cm intervals on the northern side of the brickyard in 1975. Analyses focused on grain size, carbonate content and the mollusc fauna. The chronology was based on the mollusc composition and a single date from the archaeological layer at the depth of ca 7 m below the surface. The 1975 profile was destroyed by mining but the reposited samples allowed an extended analysis of this important Marine Isotope Stage 2 record to which archaeological features were directly assigned. A new absolute chronology was built based on 11 14C dates. Environmental magnetic, geochemical and palaeoecological investigations allowed a refined view of site evolution with reliable chronology for the Last Glacial Maximum. Our results corroborated those of previous investigations done on other coeval loess–palaeosol sequences of the Southern Carpathian Basin. This also allowed for a temporal correlation to another local record with the published high-resolution chronology of the same brickyard and enabled modelling of local-scale heterogeneity of the environment in the long run. 相似文献
88.
Micronuclei (MN), nuclear buds (NB) and fragmented-apoptotic cells (FA) were analyzed in mature peripheral blood and immature cephalic kidney erythrocytes of flounder (Platichthys flesus), dab (Limanda limanda) and cod (Gadus morhua) from 12 offshore sites in the Baltic Sea (479 specimens) and 11 sites in the North Sea (291 specimens), which were collected during three research vessel cruises in December 2002, 2003 and in September 2004. The highest levels of environmental genotoxicity (frequencies of MN up to 0.5‰, NB – up to 0.75‰) and cytotoxicity (FA – up to 0.53‰) were observed in flatfishes from areas close to oil and gas platforms in the North Sea and in zones related to the extensive shipping and potentially influenced by contamination from large European Rivers (Elbe, Vistula, Oder). In dab from the offshore zones of the North Sea, the levels of nuclear abnormalities were higher as compared to those in dab from the Baltic Sea. Responses in immature kidney erythrocytes were higher than in mature erythrocytes from peripheral blood. MN frequency lower than 0.05‰ (the Baltic Sea) and lower than 0.1‰ (the North Sea) could be suspected as a reference level in the peripheral blood erythrocytes of flatfish. 相似文献
89.
The origin of the stratiform tin deposits in the schist belt of the Stara Kamienica Chain, southwestern Poland, is re-examined based upon new data which has become available. It is the author's opinion that no genetic implications should be attached to the stratiform character of the deposits. Hydrothermal metasomatism associated with acid intrusives of the Variscan Karkonosze massif introduced mineralizing fluids along tectonic lineaments. 相似文献
90.
Six complete samples of radio sources have been analysed by the Spearman rank and the Spearman partial-rank correlation coefficients. The relations between the radio luminosities and linear sizes as well as between linear sizes and redshift indicate that the observed angular diameter-redshift diagram may be explained by the changes of linear sizes with radio luminosity of radio sources. 相似文献