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891.
Helama S Schöne BR Kirchhefer AJ Nielsen JK Rodland DL Janssen R 《Marine environmental research》2007,63(3):185-199
Annual growth increments were examined from shells of the ocean quahog (Arctica islandica L.) from northwest Norway and from tree-ring samples of the Scots pine (Pinus sylvestris L.) from nearby coastal areas. The reconstructed annual growth increments were used to compare growth variability in marine and terrestrial ecosystems. Spatiotemporal comparison of the growth records showed statistically significant correlation during the 19th century A.D., indicative of ecosystem-independent response to pre-anthropogenic climate variations. Geographical correlation between marine and terrestrial records was only observed at the local scale. Years with particularly low winter or high summer North Atlantic Oscillation (NAO) indices showed the best synchronization of marine and terrestrial growth. Despite strong correlation during historical time, our palaeoecological evidence suggests that marine and terrestrial ecosystems may show dissimilar growth reaction to recently observed positive winter-NAO phases. 相似文献
892.
Daniel Häberle 《International Journal of Earth Sciences》1915,6(4-6):264-285
Ohne Zusammenfassung 相似文献
893.
Dr. H. M. E. Schürmann 《International Journal of Earth Sciences》1924,14(3):239-252
Ohne Zusammenfassung 相似文献
894.
895.
Conventional numerical predictions of deep excavations normally neglect the construction process of the retaining structure and choose the earth pressure at rest as initial condition at the beginning of the simulation. The presented results of simulation and measurements during the construction process of the Taipei National Enterprise Center show, that such an assumption leads to an underestimation of the horizontal wall deflection, the surface ground settlements as well as the loading of the struts in case of normally to slightly over‐consolidated clayey soil deposits. The stepwise installation process of the individual diaphragm wall panels results in a substantial modification of the lateral effective stresses in the adjacent ground. Especially the pouring process of the panel and the fresh concrete pressure causes a partial mobilization of the passive earth pressure and a distinct stress level increase in the upper half of the wall. As a consequence of the increased stresses prior to the pit excavation, up to 15% greater ground and wall movements are predicted. Moreover, the increased stress level due to the installation process of the diaphragm wall leads to substantial higher strut loadings during the excavation of the pit. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
896.
M. de Val-Borro R. G. Edgar P. Artymowicz P. Ciecielag P. Cresswell G. D'Angelo E. J. Delgado-Donate G. Dirksen S. Fromang A. Gawryszczak H. Klahr W. Kley W. Lyra F. Masset G. Mellema R. P. Nelson S.-J. Paardekooper A. Peplinski A. Pierens T. Plewa K. Rice C. Schäfer R. Speith 《Monthly notices of the Royal Astronomical Society》2006,370(2):529-558
897.
Jochen Heidt Immo Appenzeller Armin Gabasch Klaus Jäger Stella Seitz The FDF-Team 《Astrophysics and Space Science》2003,284(2):385-388
The FORS Deep Field project is a multi-colour, multi-object spectroscopical investigation of a ∼ 7′ × ′' region near the south
galactic pole based mostly on observations carried out with the FORS instruments attached to the VLT telescopes. It includes
the QSO Q 0103-260 (z = 3.36). The goal of this study is to improve our understanding of the formation and evolution of galaxies
in the young Universe. In this contribution, the photometric observations are presented. In particular, a combined B and I
selected UBgRIJKs photometric catalog of 8753 objects in the FDF is presented and its content is briefly described. The formal
50% completeness limits for point sources, derived from the coadded images, are 25.64, 27.69, 26.86, 26.68, 26.37, 23.60 and
21.57in U, B, g, R, I, J and Ks, respectively.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
898.
Yiannis Tsapras Rachel A. Street Keith Horne Alan Penny Fraser Clarke Hans Deeg Francisco Garzon Simon Kemp Maria Rosa Zapatero Osorio Alejandro Oscoz Abad Santiago Madruga Sanchez Carlos Eiroa Alcione Mora Antxon Alberdi rew Cameron John K. Davies Roger Ferlet Carol Grady Allan W. Harris Javier Palacios reas Quirrenbach Heike Rauer Jean Schneider Dolf de Winter Bruno Merin Enrique Solano 《Monthly notices of the Royal Astronomical Society》2001,325(3):1205-1212
In 1998 the EXPORT team monitored microlensing event light curves using a charge-coupled device (CCD) camera on the IAC 0.8-m telescope on Tenerife to evaluate the prospect of using northern telescopes to find microlens anomalies that reveal planets orbiting the lens stars. The high airmass and more limited time available for observations of Galactic bulge sources make a northern site less favourable for microlensing planet searches. However, there are potentially a large number of northern 1-m class telescopes that could devote a few hours per night to monitor ongoing microlensing events. Our IAC observations indicate that accuracies sufficient to detect planets can be achieved despite the higher airmass. 相似文献
899.
Santiago Torres Enrique García-Berro reas Burkert Jordi Isern 《Monthly notices of the Royal Astronomical Society》2001,328(2):492-500
In this paper we analyse the consequences in the white dwarf population of a hypothetical merger episode in our Galactic disc. We have studied several different merging scenarios with our Monte Carlo simulator. For each one of these scenarios we have derived the main characteristics of the resulting white dwarf population and we have compared them with the available observational data, namely the white dwarf luminosity function and the kinematic properties of the white dwarf population. Our results indicate that very recent (less than ∼6 Gyr ago) and massive (∼16 per cent of the mass of our Galaxy) merger episodes are quite unlikely in view of the available kinematical properties of the disc white dwarf population. Smaller merger episodes (of the order of ∼4 per cent of the mass of our Galaxy) are, however, compatible with our current knowledge of those kinematical properties. Finally, we prove that the white dwarf luminosity function is quite insensitive to such a merger episode. 相似文献
900.