ROSAT observations of recent supernovae     

H. -U. Zimmermann 《Astrophysics and Space Science》1995,228(1-2):331-347

Results from ROSAT observations of recent supernova events are discussed in the light of a model, where the soft X-rays originate in the shock interaction of the expanding supernova ejecta with the circumstellar material, left from heavy mass loss of the progenitor object. Special attention is given to the observations of SN1993J in M81, where lightcurves and spectral measurements allow a more detailed analysis and comparison to numerical model calculations.  相似文献   

Late Early Miocene lake deposits near Mauensee, central Switzerland: Fish fauna (otoliths, teeth), accompanying biota and palaeoecology     

Jürg Jost  Daniel K?lin  Tanja Schulz-Mirbach  Bettina Reichenbacher 《Eclogae Geologicae Helvetiae》2006,99(3):309-326

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Labour markets in transition. The experiences of women in two border regions of East Germany     

Bettina van Hoven  Carmella Pfaffenbach 《GeoJournal》2002,56(4):261-269

The political turning point in the former GDR and the transformation processes that have been observed since then have significantly affected economic and social structures in the new Federal States. Gender roles, however, were subjected to even more dramatic changes. Whilst many women experienced the employment policies of the GDR era as beneficial, social researchers often designate them as the losers of unification nowadays. This is largely because the abundance of State support measures for employed women and mothers has been drastically reduced and women as a group have been hit hardest by the crisis on the East German labour market. Using two cases (Mecklenburg-Westpommerania and Thuringia), this paper aims to illustrate the impact of the transformation process on the everyday (working) lives of women. We are particularly concerned with a comparative analysis of how women experience and deal with regional disparities in East Germany. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Provenance analysis and tectonic setting of the Ordovician clastic deposits in the southern Puna Basin, NW Argentina   总被引：9，自引：0，他引：9  

Udo Zimmermann  Heinrich Bahlburg† 《Sedimentology》2003,50(6):1079-1104

Provenance studies on Early to Middle Ordovician clastic formations of the southern Puna basin in north-western Argentina indicate that the sedimentary detritus is generally composed of reworked crustal material. Tremadoc quartz-rich turbidites (Tolar Chico Formation, mean composition Q_t89 F7 L4) are followed by volcaniclastic rocks and greywackes (Tolillar Formation, mean Q_t33 F42 L25). These are in turn overlain by volcaniclastic deposits (mean Q_t24 F30 L46) of the Diablo Formation (late Arenig–early Llanvirn) that are intercalated by lava flows. All units were deformed in the Oclóyic Orogeny during the Middle and Late Ordovician. Sandstones of the Tolar Chico Formation are characterized by Th/Sc ratios > 1, La/Sc ratios ≈ 10, whereas associated fine-grained wackes show slightly lower values for both ratios. LREE (light rare earth elements) enrichment of the arenites is ≈ 50× chondrite, Eu/Eu* values are between 0·72 and 0·92, and flat HREE (heavy rare earth elements) patterns indicate a derivation from mostly felsic rocks of typical upper crustal composition. The ε_{Nd(t = sed)} values scatter around −11 to −9. The calculated Nd-T_DM residence ages vary between 1·8 and 2·0 Ga indicating contribution by a Palaeoproterozoic crustal component. The Th/Sc and La/Sc ratios of the Tolillar Formation are lower than those of the Tolar Chico Formation. Normalized REE (rare earth elements) patterns display a similar shape to PAAS (post-Archaean average Australian shale) but with higher abundances of HREEs. Eu/Eu* values range between 0·44 and 1·17, where the higher values reflect the abundance of plagioclase and feldspar-bearing volcanic lithoclasts. Average ε_{Nd(t = sed)} values are less negative at −5·1, and Nd-T_DM are lower at 1·6 Ga. This is consistent with characteristics of regional rocks of upper continental crust composition, which most probably represent the sources of the studied detritus. The rocks of the Diablo Formation have the lowest Th/Sc and La/Sc ratios, lower LREE abundances than the average continental crust and are slightly enriched in HREEs. Eu/Eu* values are between 0·63 and 1·17. The Nd isotopes (ε_{Nd(t = sed)} = −3 to −1; T_DM = 1·2 Ga) indicate that one source component was less fractionated than both the underlying Early Ordovician and the overlying Middle Ordovician units. Synsedimentary vulcanites in the Diablo Formation show the same isotopic composition. Our data indicate that the sedimentary detritus is generally composed of reworked crustal material, but that the Diablo Formation appears to contain ≈ 80% of a less fractionated component, derived from a contemporaneous continental volcanic arc. There are no data indicating an exotic detrital source or the accretion of an exotic block at this part of the Gondwana margin during the Ordovician.  相似文献   

The transition from people''s property to private property: Consequences of the restitution principle for urban development and urban renewal in East Berlin''s inner-city residential areas     

Bettina Reimann 《Applied geography (Sevenoaks, England)》1997,17(4):301-313

The constitutional decision to return to their original owners all real-estate property in East Germany that had either been expropriated or placed under state administration (the restitution principle) has had significant consequences for urban development and urban renewal. Experiences from East Berlin's innercity residential areas illustrate the effects on the state of repair of housing, the character of residential neighbourhoods, the tenants living in the areas affected, and the future structure of real-estate ownership. The case studies reveal a picture of a contradictory development of residential neighbourhoods, including shifting power relations and new polarizations, especially between tenants and landlords.  相似文献   

Respiratory adaptations to oxygen lack in three species of Glossiphoniidae (Hirudinea) in Lake Esrom, Denmark     

Bettina Pohle  Kirsten Hamburger   《Limnologica》2005,35(1-2):78-89

The weight-specific respiration rate (μl O₂ mg⁻¹ AFDW h⁻¹) of three species of leech from Lake Esrom, Denmark, Glossiphonia concolor, G. complanata and Helobdella stagnalis was measured in a closed stirred chamber with a micro electrode. At declining oxygen concentration (mg O₂ l⁻¹) all three species expressed moderate ability to regulate respiration, in G. concolor and G. complanata down to 2 mg O₂ l⁻¹, in H. stagnalis down to 0.75 mg O₂ l⁻¹. Survival in anoxia was measured in closed bottles. The time to 50% survival (LD₅₀) was 30 days in G. concolor at 20 °C and 30 and 4 days in H. stagnalis at 10 and 20 °C, respectively. The results were discussed in relation to habitat and spatial distribution of the three species in the lake.  相似文献   

Viscosity of peridotite liquid up to 13 GPa: Implications for magma ocean viscosities     

Christian Liebske  Bettina Schmickler  Hidenori Terasaki  Brent T. Poe  Akio Suzuki  Ken-ichi Funakoshi  Ryota Ando  David C. Rubie 《Earth and Planetary Science Letters》2005,240(3-4):589-604

The viscosity of synthetic peridotite liquid has been investigated at high pressures using in-situ falling sphere viscometry by combining a multi-anvil technique with synchrotron radiation. We used a newly designed capsule containing a small recessed reservoir outside of the hot spot of the heater, in which a viscosity marker sphere is embedded in a forsterite + enstatite mixture having a higher solidus temperature than the peridotite. This experimental setup prevents spheres from falling before a stable temperature above the liquidus is established and thus avoids difficulties in evaluating viscosities from velocities of spheres falling through a partially molten sample.

Experiments have been performed between 2.8 and 13 GPa at temperatures ranging from 2043 to 2523 K. Measured viscosities range from 0.019 (± 0.004) to 0.13 (± 0.02) Pa s. At constant temperature, viscosity increases with increasing pressure up to  8.5 GPa but then decreases between  8.5 and 13 GPa. The change in the pressure dependence of viscosity is likely associated with structural changes of the liquid that occur upon compression. By combining our results with recently published 0.1 MPa peridotite liquid viscosities [D.B. Dingwell, C. Courtial, D. Giordano, A. Nichols, Viscosity of peridotite liquid, Earth Planet. Sci. Lett. 226 (2004) 127–138.], the experimental data can be described by a non-Arrhenian, empirical Vogel-Fulcher-Tamman equation, which has been modified by adding a term to account for the observed pressure dependence of viscosity. This equation reproduces measured viscosities to within 0.08 log₁₀-units on average. We use this model to calculate viscosities of a peridotitic magma ocean along a liquid adiabat to a depth of  400 km and discuss possible effects on viscosity at greater pressures and temperatures than experimentally investigated.  相似文献   

Eocene-Pliocene time scale and stratigraphy of the Upper Rhine Graben (URG) and the Swiss Molasse Basin (SMB)     

Jean-Pierre Berger  Bettina Reichenbacher  Damien Becker  Matthias Grimm  Kirsten Grimm  Laurent Picot  Andrea Storni  Claudius Pirkenseer  Andreas Schaefer 《International Journal of Earth Sciences》2005,94(4):711-731

We present a general stratigraphic synthesis for the Upper Rhine Graben (URG) and the Swiss Molasse Basin (SMB) from Eocene to Pliocene times. The stratigraphic data were compiled both from literature and from research carried out by the authors during the past 6 years ; an index of the stratigraphically most important localitites is provided. We distinguish 14 geographical areas from the Helvetic domain in the South to the Hanau Basin in the North. For each geographical area, we give a synthesis of the biostratigraphy, lithofacies, and chronostratigraphic ranges. The relationships between this stratigraphic record and the global sea-level changes are generally disturbed by the geodynamic (e.g., subsidence) evolution of the basins. However, global sea-level changes probably affected the dynamic of transgression–regression in the URG (e.g., Middle Pechelbronn Beds and Serie Grise corresponding with sea-level rise between Ru1/Ru2 and Ru2/Ru3 sequences, respectively) as well as in the Molasse basin (regression of the UMM corresponding with the sea-level drop at the Ch1 sequence). The URGENT-project (Upper Rhine Graben evolution and neotectonics) provided an unique opportunity to carry out and present this synthesis. Discussions with scientists addressing sedimentology, tectonics, geophysics and geochemistry permitted the comparison of the sedimentary history and stratigraphy of the basin with processes controlling its geodynamic evolution. Data presented here back up the palaeogeographic reconstructions presented in a companion paper by the same authors (see Berger et al. in Int J Earth Sci 2005).  相似文献   

Segmentation and kinematics of the North America‐Caribbean plate boundary offshore Hispaniola          下载免费PDF全文

Sylvie Leroy  Nadine Ellouz‐Zimmermann  Jordane Corbeau  Frédérique Rolandone  Bernard Mercier de Lépinay  Bertrand Meyer  Roberte Momplaisir  José‐Luis Granja Bruña  Anne Battani  Céline Baurion  Evgueni Burov  Valérie Clouard  Rémy Deschamps  Christian Gorini  Youri Hamon  Manfred Lafosse  Jottin Leonel  Laetitia Le Pourhiet  Pilar Llanes Estrada  Nicolas Loget  Francis Lucazeau  Daniel Pillot  Jeffrey Poort  Kevin R. Tankoo  José‐Luis Cuevas  José‐Fernando Alcaide  Claude Jean Poix  Alfonso Muñoz‐Martin  Serge Mitton  Yamil Rodriguez  Julien Schmitz  Leonardo Seeber  Andres Carbo‐Gorosabel  Santiago Muñoz 《地学学报》2015,27(6):467-478

We explored the submarine portions of the Enriquillo–Plantain Garden Fault zone (EPGFZ) and the Septentrional–Oriente Fault zone (SOFZ) along the Northern Caribbean plate boundary using high‐resolution multibeam echo‐sounding and shallow seismic reflection. The bathymetric data shed light on poorly documented or previously unknown submarine fault zones running over 200 km between Haiti and Jamaica (EPGFZ) and 300 km between the Dominican Republic and Cuba (SOFZ). The primary plate‐boundary structures are a series of strike‐slip fault segments associated with pressure ridges, restraining bends, step overs and dogleg offsets indicating very active tectonics. Several distinct segments 50–100 km long cut across pre‐existing structures inherited from former tectonic regimes or bypass recent morphologies formed under the current strike‐slip regime. Along the most recent trace of the SOFZ, we measured a strike‐slip offset of 16.5 km, which indicates steady activity for the past ~1.8 Ma if its current GPS‐derived motion of 9.8 ± 2 mm a^?1 has remained stable during the entire Quaternary.  相似文献   

Global warming-related tree growth decline and mortality on the north-eastern Tibetan plateau   总被引：1，自引：0，他引：1  

Eryuan Liang  Christoph Leuschner  Choimaa Dulamsuren  Bettina Wagner  Markus Hauck 《Climatic change》2016,134(1-2):163-176

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