Die Altersfolge der primär ausgeschiedenen sulfidischen Mineralien in den oberschlesischen Zink- und Bleierzlagerstätten und die Bedeutung der Altersfolge der primär ausgeschiedenen Mineralien der Erzlagerstätten überhaupt     

Bergrat Dr. phil. Eugen Schulz 《International Journal of Earth Sciences》1913,4(2):126-136

Ohne Zusammenfassung  相似文献   

Large-Scale and Mesoscale Distribution of Plankton Biomass and Metabolic Activity in the Northeastern Central Atlantic     

Santiago Hernández-León  Lutz Postel  Javier Arístegui  May Gómez  María Fernanda Montero  Santiago Torres  Carlos Almeida  Eugen Kühner  Ullrich Brenning  Eberhard Hagen 《Journal of Oceanography》1999,55(4):471-482

Plankton biomass and indices of metabolism and growth [electron transport system (ETS), glutamate dehydrogenase (GDH) and aspartate transcarbamylase (ATC) activities] were studied over a 2,800 km east-west section of the tropical North Atlantic Ocean (21°N) in <200, 200–500 and >;500 µm size classes. On the large-scale, zooplankton (>;200 µm) enzymatic activities increased westward in the study section, where large cyanobacteria chains (Trichodesmium spp.) were observed. Parallel to it, an increase in medium calanoids (1–2 mm length) was observed towards the western part of the transect, whereas small calanoids (<1 mm) were dominant throughout the boundary area of the subtropical gyre. Microplankton ETS and mesoplankton ETS and ATC activities seemed to match the wave length of low frequency waves. Our results suggest that such waves are related to the observed enhancement of metabolic activity of micro- and mesoplankton. The large-scale and mesoscale variability observed give evidence of the inadequacy of assuming a steady-state picture of the euphotic zone of tropical and subtropical waters.  相似文献   

On the breakdown of zircon upon “dry” thermal annealing     

Tamás Váczi  Lutz Nasdala  Richard Wirth  Mathias Mehofer  Eugen Libowitzky  Tobias Häger 《Mineralogy and Petrology》2009,97(1-2):129-138

Zircon samples without and with secondary chemical alteration from diverse sources were subjected to heat treatment at 1400 °C for 96 h. Resulting new phases and textures suggest that decomposition of zircon into component oxides occurred in all experiments to various degrees. The crucible material was found to have a strong influence on the extent of breakdown, especially in the case of altered starting materials. In this study the progressive stages of the breakdown of zircon grains are described. The factors that may govern the decomposition are discussed, including radiation damage, secondary alteration and external reaction conditions (sample container, atmosphere). Alumina crucibles should generally be avoided in dry annealing of zircon, to minimise uncontrolled breakdown into oxides.  相似文献   

Short-term Tests of Potassium dIdD Vector Magnetometer     

Eugen Vujić 《Acta Geophysica》2015,63(5):1276-1295

  相似文献   

On Data Interpolation at Three Croatian Repeat Stations by Using the Spherical Elementary Currents Systems Method     

Eugen Vujić 《Acta Geophysica》2016,64(2):320-335

A general mathematical tool for expanding vector systems on a sphere into basis functions, spherical elementary current system (SECS) method, was applied for separation of the geomagnetic field variations into external and internal parts, over a limited region of central and southeastern Europe. The registered variations at three Croatian repeat stations were compared to the variations estimated by the SECS method using the variations from the different sets of observatories. The results of the SECS method were also compared to a simple assumption that the variations at repeat station are equal to those at particular observatory. The relevance of this comparison was to get an insight about the possibility of using the SECS method for estimating the geomagnetic field variations over Croatia. The guidelines for the application of the SECS method for the purpose of reducing repeat station data were also given.  相似文献   

Buffon (1707–1788) als geologischer Pionier     

Eugen Seibold  Ilse Seibold 《International Journal of Earth Sciences》2009,98(8):2023-2029

  相似文献   

Estimation of the normal geomagnetic field and geological interpretation of the normal field anomalies over middle-northern Croatia     

Eugen Vujić  Giuliana Verbanac  Stanislav Francisković-Bilinski  Vladis Vujnović  Antun Marki 《Studia Geophysica et Geodaetica》2011,55(1):175-190

Based on the ground survey of total-field magnetic data at 53 sites, which recorded a time-series over the interval 2003–2005, the core field + long wavelength lithospheric field over the middle-northern Croatia region was calculated. The area of the survey was 18900 km², an average distance between the neighbouring sites being 12 km. The results were reduced to 2004.5 epoch. This “normal” total-field was estimated using the firstorder Taylor polynomial as a function of geographic coordinates, and the polynomial coefficients were calculated with three methods of adjustment: simple and weighted least squares fits and adjustment according to the most frequent value. The stability of the normal field was tested using the Monte Carlo-type test, by decreasing the input data set in each adjustment (up to 90%). All obtained field residuals (measured-“normal”) were mutually compared, as well as fit coefficients of the Taylor polynomials. The residual values indicate the presence of shorter-wavelength anomalies, specifically three major residual anomalies were found (−106 nT, 74 nT and 57 nT). The geostatistical analysis of the ground survey data and the normal field residuals (respectively), using the median absolute deviation method, was further conducted in order to evaluate the calculated anomalies. The geological situation around the anomalies derived by the median absolute deviation method, and around the normal field residual anomalies, is given. The correlation was found between higher value anomalies of the normal field residuals, and shallow volcanic rocks and oil field, respectively.  相似文献   

Book review     

E. F. Stumpfl 《Mineralium Deposita》1990,25(2):162-162

  相似文献   

Spectroscopic and bond-topological investigation of interstitial volatiles in beryl from Slovakia   总被引：1，自引：0，他引：1  

Jana Fridrichová  Peter Bačík  Valéria Bizovská  Eugen Libowitzky  Radek Škoda  Pavel Uher  Daniel Ozdín  Martin Števko 《Physics and Chemistry of Minerals》2016,43(6):419-437

Nine beryl samples from Western Carpathians, Slovakia, were investigated by infrared and Raman spectroscopy and differential thermal analysis. Two types of water H₂O I and H₂O II were detected. Infrared spectroscopy proved the presence of water type I and II in the presence of alkali cations with several bands: (1) symmetric stretching vibration—ν₁; (2) antisymmetric stretching mode—ν₃; (3) bending vibration—ν₂. The presence of singly and doubly coordinated type II water (IIs and IId) was confirmed by single-crystal IR spectroscopy. From Raman spectra a band at 3606 cm^?1 was assigned to ν₁ of water type I and the range of 3597–3600 cm^?1 to water type II. The presence of doubly coordinating water indicates a relatively highly hydrated environment with the presence of alkali ions including Na as the dominant cation coordinated by H₂O II. CO₂ bands were detected only by single-crystal IR spectroscopy. Thermal analysis proved total water loss in the range of 1.4–2.0 wt% and three main dehydration events. Based on the study of bond-topological arrangements two molecules of H₂O IId are each bound with two H···O1 bonds and one Na–O_W bond with an angular distortion, and by releasing one H₂O molecule more stable H₂O IIs is produced. The H₂O I molecule is bound only by two equivalent hydrogen bonds. The H₂O IIs molecule with a Na–O_W bond strength of 0.28 vu and two H···O1 bonds of 0.14 vu without any forced angular distortion is the most stable of all.  相似文献   

The OH site in topaz: an IR spectroscopic investigation     

Anke Watenphul  Eugen Libowitzky  Bernd Wunder  Matthias Gottschalk 《Physics and Chemistry of Minerals》2010,37(9):653-664

The OH site in topaz is investigated by IR spectroscopy depending on the OH concentration and temperature. The two OH bands that can be distinguished are due to the local ordering of F and OH in opposite sites of the crystal structure. The first typical sharp band stems from OH groups with fluorine in the opposite (=acceptor) site. The second band occurs as a shoulder on the low-energy wing and is related to two opposite OH groups. The degree of local OH–OH ordering depends on the OH concentration and, due to statistical F/OH distribution, can be predicted by probability calculations. The substitution of OH for F has a non-linear effect on the increase of the lattice parameters. An autocorrelation analysis of the IR spectra revealed two temperature-induced phase transitions. At −135°C, the local symmetry changes from P1 to Pbn2₁, although this change involves only the H atoms. The transition from Pbn2₁ to Pbnm at 160°C is caused by changes of the local F/OH ordering in the crystal structure.  相似文献