Vertical mixing in the Baltic Sea and consequences for eutrophication - A review   总被引：1，自引：0，他引：1  

Jan Hinrich Reissmann  Hans Burchard  Rainer Feistel  Eberhard Hagen  Hans Ulrich Lass  Volker Mohrholz  Günther Nausch  Lars Umlauf  Gunda Wieczorek 《Progress in Oceanography》2009,82(1):47-80

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Altitudinal variation in soil organic carbon stock in coniferous subtropical and broadleaf temperate forests in Garhwal Himalaya     

Mehraj A Sheikh  Munesh Kumar  Rainer W Bussmann 《Carbon balance and management》2009,4(1):6-6

Background  

The Himalayan zones, with dense forest vegetation, cover a fifth part of India and store a third part of the country reserves of soil organic carbon (SOC). However, the details of altitudinal distribution of these carbon stocks, which are vulnerable to forest management and climate change impacts, are not well known.  相似文献   

Dynamics of dimensions in factor-space cosmology     

U. Bleyer  M. Rainer  M. Mohazzab 《Astronomische Nachrichten》1996,317(1):3-13

For multi-dimensional cosmological models we investigate the dynamics of both, scales and dimensions. The classical equation of motions and the corresponding Wheeler-de Witt equation are set up generally and the qualitative behaviour of the system is discussed for some specific model with 2 factor spaces: A space M₁ with dynamical dimension, and a compact internal space M₂ of constant dimension. With a natural choice of some contraint, there exist a solution where M₁ expands as usual space while M₂ is shrinking down to unobservable scales.  相似文献   

Effects of aqueous alteration on primordial noble gases and presolar SiC in the carbonaceous chondrite Tagish Lake     

M. E. I. Riebe  H. Busemann  C. M. O'D. Alexander  L. R. Nittler  C. D. K. Herd  C. Maden  J. Wang  R. Wieler 《Meteoritics & planetary science》2020,55(6):1257-1280

Effects of aqueous alteration on primordial noble gas carriers were investigated by analyzing noble gases and determining presolar SiC abundances in insoluble organic matter (IOM) from four Tagish Lake meteorite (C2‐ung.) samples that experienced different degrees of aqueous alteration. The samples contained a mixture of primordial noble gases from phase Q and presolar nanodiamonds (HL, P3), SiC (Ne‐E[H]), and graphite (Ne‐E[L]). The second most altered sample (11i) had a ~2–3 times higher Ne‐E concentration than the other samples. The presolar SiC abundances in the samples were determined from NanoSIMS ion images and 11i had a SiC abundance twice that of the other samples. The heterogeneous distribution of SiC grains could be inherited from heterogeneous accretion or parent body alteration could have redistributed SiC grains. Closed system step etching (CSSE) was used to study noble gases in HNO₃‐susceptible phases in the most and least altered samples. All Ne‐E carried by presolar SiC grains in the most altered sample was released during CSSE, while only a fraction of the Ne‐E was released from the least altered sample. This increased susceptibility to HNO₃ likely represents a step toward degassing. Presolar graphite appears to have been partially degassed during aqueous alteration. Differences in the ⁴He/³⁶Ar and ²⁰Ne/³⁶Ar ratios in gases released during CSSE could be due to gas release from presolar nanodiamonds, with more He and Ne being released in the more aqueously altered sample. Aqueous alteration changes the properties of presolar grains so that they react similar to phase Q in the laboratory, thereby altering the perceived composition of Q.  相似文献   

Fine structure of the magnetic field in M31     

Rainer Beck 《地球物理与天体物理流体动力学》2013,107(1-3):39-42

Abstract

The detailed magnetic field structure of M31, as deduced from radio polarization measurements, is analyzed. The field closely follows a dust lane parallel to the most conspicuous optical spiral arm, but also exhibits three-dimensional arc-like deviations from the otherwise axisymmetric configuration.  相似文献   

Lateglacial to Holocene rapid crater infilling of a MIS 2 maar volcano (West‐Eifel Volcanic Field,Germany): environmental history and geomorphological feedback mechanisms     

Peter Houben  Norbert Kühl  Rainer Dambeck  Jan Overath 《Boreas: An International Journal of Quaternary Research》2013,42(4):947-958

We document the Lateglacial to Holocene sedimentation and vegetation history of a small, infilled crater landform in the West‐Eifel Volcanic Field (WEVF; western Germany). We analysed geomorphological landform change, sedimentological and geochronological data, pollen, and plant macrofossils of a 16‐m‐long sediment core from the Eichholz Maar (EHM). The EHM erupted between ～20 and 15 ka ago (MIS 2). Lacustrine siliclastic infilling was completed about 7500 years ago. Lateglacial rates of sedimentation are generally 2 to 5 times higher than in other maar lakes of the WEVF. Local factors, therefore, overprint the relative efficacy of the climate‐controlled variance of sedimentation rates at the Lateglacial/Holocene transition. The predominance of local factors relates to inherent geomorphological process–response mechanisms that were triggered by the EHM eruption. Rapid crater infilling and its completion by the mid‐Holocene are attributed to a combination of small storage capacity and geomorphological activity. A late Boreal interval of significant lake‐level fall can, however, be attributed to a period of continental‐scale climate change as recorded in other European lacustrine settings. Our findings highlight the importance of utilizing geomorphological information to reveal the relative significance of local controls as opposed to climate control when investigating small‐sized lake settings with active sediment supply systems.  相似文献   

Detailed Analysis of Solar Data Related to Historical Extreme Geomagnetic Storms: 1868 – 2010     

Laure Lefèvre  Susanne Vennerstrøm  Mateja Dumbović  Bojan Vršnak  Davor Sudar  Rainer Arlt  Frédéric Clette  Norma Crosby 《Solar physics》2016,291(5):1483-1531

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Cosmogenic nuclides in the Košice meteorite: Experimental investigations and Monte Carlo simulations          下载免费PDF全文

Pavel P. Povinec  Jozef Masarik  Ivan Sýkora  Andrej Kováčik  Juraj Beňo  Matthias M. M. Meier  Rainer Wieler  Matthias Laubenstein  Vladimir Porubčan 《Meteoritics & planetary science》2015,50(5):880-892

Results of nondestructive gamma‐ray analyses of cosmogenic radionuclides (⁷Be, ²²Na, ²⁶Al, ⁴⁶Sc, ⁴⁸V, ⁵⁴Mn, ⁵⁶Co, ⁵⁷Co, ⁵⁸Co, and ⁶⁰Co) in 19 fragments of the Ko?ice meteorite are presented and discussed. The activities varied mainly with position of fragments in the meteoroid body, and with fluxes of cosmic‐ray particles in the space affecting radionuclides with different half‐lives. Monte Carlo simulations of the production rates of ⁶⁰Co and ²⁶Al compared with experimental data indicate that the pre‐atmospheric radius of the meteoroid was 50 ± 5 cm. In two Ko?ice fragments, He, Ne, and Ar concentrations and isotopic compositions were also analyzed. The noble‐gas cosmic‐ray exposure age of the Ko?ice meteorite is 5–7 Myr, consistent with the conspicuous peak (or doublet peak) in the exposure age histogram of H chondrites. One sample likely contains traces of implanted solar wind Ne, suggesting that Ko?ice is a regolith breccia. The agreement between the simulated and observed ²⁶Al activities indicate that the meteoroid was mostly irradiated by a long‐term average flux of galactic cosmic rays of 4.8 particles cm^?2 s^?1, whereas the short‐lived radionuclide activities are more consistent with a flux of 7.0 protons cm^?2 s^?1 as a result of the low solar modulation of the galactic cosmic rays during the last few years before the meteorite fall.  相似文献   

Multirate time integration for coupled saturated/unsaturated porous medium and free flow systems     

Iryna Rybak  Jim Magiera  Rainer Helmig  Christian Rohde 《Computational Geosciences》2015,19(2):299-309

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Upper crustal emplacement and deformation of granitoids inside the Uppermost Unit of the Cretan nappe stack: constraints from U–Pb zircon dating,microfabrics and paleostress analyses     

Tilo Kneuker  Wolfgang Dörr  Rainer Petschick  Gernold Zulauf 《International Journal of Earth Sciences》2015,104(2):351-367

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