Seasonal isotopic shifts in fish of the Pantanal wetland,Brazil   总被引：1，自引：0，他引：1  

Karl M. Wantzen  Francisco de Arruda Machado  Maren Voss  Hinnerk Boriss  Wolfgang J. Junk 《Aquatic Sciences - Research Across Boundaries》2002,64(3):239-251

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Advances in radiative transfer     

Rainer Wehrse  Wolfgang Kalkofen 《Astronomy and Astrophysics Review》2006,13(1-2):3-29

This review describes advances in radiative transfer theory since about 1985. We stress fundamental aspects and emphasize modern methods for the numerical solution of the transfer equation for spatially multidimensional problems, for both unpolarized and polarized radiation. We restrict the discussion to two-level atoms with noninverted populations for given temperature, density and velocity fields. Unfortunately this article was originally published with typesetter's errors: The correct publication date was 25 February 2006, not 3 January 2006. The content was not in the final form. The publishers wish to apologize for this mistake. The online version of the original version can be found at /10.1007/s00159-005-0025-8.  相似文献   

Is there a black hole among the black-hole candidates?     

Wolfgang Kundt  Daniel Fischer 《Journal of Astrophysics and Astronomy》1989,10(1):119-138

None of the tentative black-hole identifications has remained without serious difficulties. As a class, the black-hole candidates differ in no obvious property from neutron-star binaries other than in their estimated high mass. We favour an interpretation of the black-hole candidates as binary neutron stars surrounded by a more or less massive accretion disc  相似文献   

Announcement     

Wolfgang Cramer  Uta Fritsch  Rik Leemans  Sabine Lütkemeier  Dagmar Schr?ter  et al. 《Journal of Paleolimnology》1989,2(4):319-320

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The XVIIIth General Assembly of the International Union of Geodesy and Geophysics (IUGG) at Humburg,FR Germany, 1983     

Franz Goerlich  Torge Wolfgang 《GeoJournal》1984,8(4):299-300

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Gas infall in the nuclei of Seyfert galaxies observed?     

Wolfgang Kundt 《Astrophysics and Space Science》1988,149(1):175-180

Cross-correlations between line intensities, their blue and red wings and the continuum in Seyfert galaxies have been recently interpreted as evidences for gas infall onto a supermassive AGN (Gaskell, 1987, 1988). The same data can be re-interpreted in terms of outflow when radiative transfer delays of the line photons are allowed for. This re-interpretation assigns a smaller mass to the central engine and a (somewhat) smaller size to its broad-line region.  相似文献   

A new approach to Gaussian beams on a sphere: theory and application to long-period surface wave propagation     

Wolfgang Friederich 《Geophysical Journal International》1989,99(2):259-271

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Electron acceleration in solar flares     

Wolfgang Dröge  Peter Meyer  Paul Evenson  Dan Moses 《Solar physics》1989,121(1-2):95-103

For the period September 1978 to December 1982 we have identified 55 solar flare particle events for which our instruments on board the ISEE-3 (ICE) spacecraft detected electrons above 10 MeV. Combining our data with those from the ULEWAT spectrometer (MPI Garching and University of Maryland) electron spectra in the range from 0.1 to 100 MeV were obtained. The observed spectral shapes can be divided into two classes. The spectra of the one class can be fit by a single power law in rigidity over the entire observed range. The spectra of the other class deviate from a power law, instead exhibiting a steepening at low rigidities and a flattening at high rigidities. Events with power-law spectra are associated with impulsive (<1 hr duration) soft X-ray emission, whereas events with hardening spectra are associated with long-duration (<1 hr) soft X-ray emission. The characteristics of long-duration events are consistent with diffusive shock acceleration taking place high in the corona. Electron spectra of short-duration flares are well reproduced by the distribution functions derived from a model assuming simultaneous second-order Fermi acceleration and Coulomb losses operating in closed flare loops.  相似文献   

Orbital-scale record of the late Cenomanian–Turonian oceanic anoxic event (OAE-2) in the Tarfaya Basin (Morocco)     

Wolfgang Kuhnt  Florian Luderer  Sandra Nederbragt  Jürgen Thurow  Thomas Wagner 《International Journal of Earth Sciences》2005,94(1):147-159

High sedimentation rates (up to 12 cm/kyear) of laminated organic carbon-rich biogenic limestones in the Tarfaya Basin provide an unusually high (millennial) resolution record of the late Cenomanian oceanic anoxic event (OAE-2). The global positive carbon-isotope excursion across the Cenomanian–Turonian corresponds to 11 light/dark sedimentary cycles. We interpret these cycles as a response to orbital obliquity variation and estimate the duration of the complete excursion as 440 kyear or one long eccentricity cycle. On this timescale, the main increase in ¹³C values occurred over a short time interval of less than 20 kyear in the late Cenomanian and reached a first maximum approximately 15 kyear prior to the bulk (mainly coccoliths) ¹⁸O-derived sea surface maximum temperature that occurs coeval to the extinction of Rotalipora cushmani. Organic carbon-accumulation rates follow obliquity cycles, reaching a maximum approximately 10 kyear after the last occurrence of R. cushmani, then slowly decreasing during the early Turonian. Thus, the maximum temperature and the maximum organic carbon accumulation in the Tarfaya Basin lagged by at least 15 kyear behind the global carbon-isotope shift and a proposed reduction of atmospheric CO₂ content. The climate change across the Cenomanian/Turonian boundary probably occurred independent of CO₂ levels and may have been controlled by different greenhouse gases (water vapour and methane) and changes in ocean circulation (i.e., opening of the Equatorial Atlantic gateway)  相似文献   

U-Pb zircon ages for the Luzhenguan Complex in northern part of the eastern Dabie orogen   总被引：4，自引：0，他引：4  

Wolfgang Siebe 《中国科学D辑(英文版)》2005,48(9):1357-1367

The Dabie Mountain is the collisional orogenic belt between the North China Block and the Yangtze Block. As the eastern segment of the central-China orogenic belt, its tectonic framework is corresponding to the Qinling orogenic belt as a whole[1]. The NHB in northern part of Dabie Orogen is regarded as the joint belt between the Yangtze Block and the North China Block, and roughly corresponds to the north Qinling belt of the Qinling orogenic belt, which separated the Tongbai-Dabie hig…  相似文献