Correction to: Estimating rockfall release frequency from blocks deposited in protection barriers,growth disturbances in trees,and trajectory simulations     

Farvacque  Manon  Corona  Christophe  Lopez-Saez  Jerome  Mainieri  Robin  Stoffel  Markus  Bourrier  Franck  Eckert  Nicolas  Toe  David 《Landslides》2022,19(1):263-264

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Transcurrent nature of the Teisseyre–Tornquist Zone in Central Europe: results of the POLCRUST-01 deep reflection seismic profile     

M. Narkiewicz  A. Maksym  M. Malinowski  M. Grad  A. Guterch  Z. Petecki  J. Probulski  T. Janik  M. Majdański  P. Środa  W. Czuba  E. Gaczyński  L. Jankowski 《International Journal of Earth Sciences》2015,104(3):775-796

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Detecting subtle hydrochemical anomalies with multivariate statistics: an example from ‘homogeneous’ groundwaters in the Great Artesian Basin,Australia     

Bethany O'Shea  Jerzy Jankowski 《水文研究》2006,20(20):4317-4333

The major ion composition of Great Artesian Basin groundwater in the lower Namoi River valley is relatively homogeneous in chemical composition. Traditional graphical techniques have been combined with multivariate statistical methods to determine whether subtle differences in the chemical composition of these waters can be delineated. Hierarchical cluster analysis and principal components analysis were successful in delineating minor variations within the groundwaters of the study area that were not visually identified in the graphical techniques applied. Hydrochemical interpretation allowed geochemical processes to be identified in each statistically defined water type and illustrated how these groundwaters differ from one another. Three main geochemical processes were identified in the groundwaters: ion exchange, precipitation, and mixing between waters from different sources. Both statistical methods delineated an anomalous sample suspected of being influenced by magmatic CO₂ input. The use of statistical methods to complement traditional graphical techniques for waters appearing homogeneous is emphasized for all investigations of this type. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Observations of the birth of a small coronal hole     

Solodyna  Craig V.  Krieger  Allen S.  Nolte  Jerome T. 《Solar physics》1977,54(1):123-134

Using soft X-ray data from the S-054 X-ray spectrographic telescope aboard Skylab, we observed temporal changes in the emission structure of the X-ray corona associated with the birth of a small coronal hole. Designated as CH6, this coronal hole was born near the equator in a time interval less than 9 1/2 hr. By constructing a light curve for a point near the center of CH6, we observed a sudden 40% decrease in X-ray emission associated with the birth of this coronal hole. On a time scale of hours, the growth of CH6 in area proceeded faster than the average rate predicted by the diffusion of solar fields. The short term decay of CH6 followed the diffusive rate to within experimental uncertainty, On a time scale of one rotation, the subsequent development of CH6 was not consistent with steady growth at the average rate predicted by diffusion.Skylab Solar Workshop Post-Doctoral Appointee, 1975–1977. The Skylab Solar Workshops are sponsored by NASA and NSF and managed by the High Altitude Observatory, National Center for Atmospheric Research.  相似文献   

Methane on Triton: Physical state and distribution     

Dale P. Cruikshank  Jerome Apt 《Icarus》1984,58(2):306-311

Infrared spectrophotometric measurements of Neptune's satellite Triton obtained between 1980 and 1982 in the spectral range 0.8–2.5 μm show six individual absorption bands attributable to methane. An additional band in the Triton data is not methane. The Triton spectral data conform more closely to a laboratory spectrum of frozen methane than to a synthetic spectrum of methane gas computed for conditions of low temperature expected at the satellite. Additionally, the strength of the bands vary with Triton's orbital position. The data thus suggest that methane in the ice phase is mostly responsible for the bands in Triton's spectrum, and that the ice is distributed nonuniformly around the satellite's surface.  相似文献   

The Monitor project: rotation of low-mass stars in the open cluster NGC 2547     

Jonathan Irwin  Simon Hodgkin  Suzanne Aigrain  Jerome Bouvier  Leslie Hebb  Estelle Moraux 《Monthly notices of the Royal Astronomical Society》2008,383(4):1588-1602

We report on the results of an I -band time-series photometric survey of NGC 2547 using the MPG/ESO 2.2-m telescope with Wide Field Imager, achieving better than 1 per cent photometric precision per data point over  14 ≲ I ≲ 18  . Candidate cluster members were selected from a V versus V − I colour–magnitude diagram over  12.5 < V < 24  (covering masses from  0.9 M_⊙  down to below the brown dwarf limit), finding 800 candidates, of which we expect ∼330 to be real cluster members, taking into account contamination from the field (which is most severe at the extremes of our mass range). Searching for periodic variations in these gave 176 detections over the mass range  0.1 ≲ M /M_⊙≲ 0.9  . The rotation period distributions were found to show a clear mass-dependent morphology, qualitatively intermediate between the distributions obtained from similar surveys in NGC 2362 and 2516, as would be expected from the age of this cluster. Models of the rotational evolution were investigated, finding that the evolution from NGC 2362 to 2547 was qualitatively reproduced (given the uncertainty in the age of NGC 2547) by solid body and core-envelope decoupled models from our earlier NGC 2516 study without need for significant modification.  相似文献   

High‐resolution quantification of earthworm calcite granules from western European loess sequences reveals stadial–interstadial climatic variability during the Last Glacial     

Charlotte Prud'homme  Olivier Moine  Jerome Mathieu  Segolene Saulnier‐Copard  Pierre Antoine 《Boreas: An International Journal of Quaternary Research》2019,48(1):257-268

High concentrations of calcite fossil granules produced by earthworms (ECG) have been identified in most of the stratigraphical units along the loess‐palaeosol reference sequence of Nussloch (Germany). They are particularly abundant in interstadial brown soils and in tundra gley horizons, the latter reflecting short‐term phases of aggradation then degradation of permafrost. These granules are characterized by a radial crystalline structure produced in the earthworms by specific bio‐mineralization processes. In our study, we used this biological indicator combined with ¹⁴C and OSL dating, and sedimentological parameters to characterize millennial‐time scale climatic variations recorded in loess sequences. The approach is based on high‐resolution counts of ECG throughout a 17‐m‐thick loess sequence (332 samples). Strong increases in granule and mollusc concentrations suggest warmer climate conditions during palaeosol formation phases, associated with increasing biodiversity, biological activity and vegetation cover. Decreased granule concentrations occur within primary loess deposits, indicating a strong correlation with palaeoenvironmental conditions and demonstrating the reliability of ECG concentration variations as a new palaeoenvironmental proxy. Finally, this pattern is also recorded in loess sequences located about 600 km westward in northern France demonstrating the large‐scale validity of this new palaeoclimatic proxy.  相似文献   

Lead orthophosphates—IV Formation and stability in the environment     

Jerome O. Nriagu 《Geochimica et cosmochimica acta》1974,38(6):887-898

Experimental and predicted thermochemical constants are used to assess the formation and stability of lead phosphates in soil and sedimentary environments. For the chemical conditions likely to be encountered in oxidizing environments, the stability fields of pyromorphites [Pb₅(PO₄)₃X, X = OH^?, Cl^?, Br^? and F^?] and plumbogummite [PbAl₃(PO₄)₂(OH)₅-H₂O] predominate strongly over those of the other secondary lead minerals. The theoretical phase relationships together with several field observations are used as the basis for suggesting that the interaction of lead and phosphorus (to form pyromorphites and plumbogummite in particular) is an important buffer mechanism controlling the migration and fixation of lead in the environment. Calculations using the concentrations of lead and phosphate ions in serum indicate that the solubility of lead phosphates may be the limiting factor with regard to lead ion concentration in human body. The removal of lead from wastewater by precipitation as lead chloropyromorphite is considered a spin-off of possible industrial interest.  相似文献   

Reduction of pounding effects in elevated bridges during earthquakes     

Robert Jankowski  Krzysztof Wilde  Yozo Fujino 《地震工程与结构动力学》2000,29(2):195-212

Pounding of adjacent superstructure segments in elevated bridges during severe earthquakes can result in significant structural damage. The aim of this paper is to analyse several methods of reduction of the negative effects of collisions induced by the seismic wave propagation effect. The analysis is conducted on a detailed three‐dimensional structural component model of an isolated highway bridge. The results show that the influence of pounding on the structural response is significant in the longitudinal direction of the bridge and significantly depends on the gap size between superstructure segments. The smallest response can be obtained for very small gap sizes and for gap sizes large enough to prevent pounding. Further analysis indicates that the bridge behaviour can be effectively improved by placing hard rubber bumpers between segments and by stiff linking the segments one with another. The experimental results show that, for the practical application of such connectors, shock transmission units can be used. Copyright © 2000 John Wiley & Sons, Ltd.  相似文献   

Optical dating and soil micromorphology at MacCauley's Beach,New South Wales,Australia   总被引：1，自引：0，他引：1       下载免费PDF全文

Nathan R. Jankowski  Zenobia Jacobs  Paul Goldberg 《地球表面变化过程与地形》2015,40(2):229-242

The ability to position landscapes in a context of time and space is a particular goal of Quaternary science research. The lack of context for dating samples published previously for MacCauley's Beach, an important site for the reconstruction of Australian sea levels, warranted a re‐evaluation of both the site stratigraphy and chronology. In this study, we combined optically stimulated luminescence (OSL) dating of sedimentary quartz grains and soil micromorphology of the same samples to improve our understanding of the depositional history and chronology of the sediments. This combination allowed the contextualization of samples not only in time and space, but also in terms of their depositional histories. The latter is important in OSL dating, where pre‐, syn‐ and post‐depositional processes can all influence the accuracy and precision of the final age estimates. The sediment profile at MacCauley's Beach is made up of three major units. The basal mottled mud layer has undergone extensive pedogenesis since deposition, and only a minimum age of 14.7 ± 2.7 ka could be calculated. The overlying grey mud, with OSL ages from the bottom and top of the unit of 10.0 ± 0.7 and 7.7 ± 0.5 ka, respectively, shows evidence of soil structure collapse. This unit correspond to the onset of the mid‐Holocene sea‐level high stand for this region. The overlying sand layer was first deposited at 7.5 ± 0.4 ka, with deposition continuing beyond 6.6 ± 0.4 ka. Not only does the chronology presented constrain the timing of deposition (and the extent of post‐depositional processes) at MacCauley's Beach, but the methodological approach used here can be applied to any site to aid in the interpretation of formation processes and assess their influence on OSL age determination. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献