Benchmarks for multicomponent reactive transport across a cement/clay interface     

Nicolas C. M. Marty  Olivier Bildstein  Philippe Blanc  Francis Claret  Benoit Cochepin  Eric C. Gaucher  Diederik Jacques  Jean-Eric Lartigue  Sanheng Liu  K. Ulrich Mayer  Johannes C. L. Meeussen  Isabelle Munier  Ingmar Pointeau  Danyang Su  Carl I. Steefel 《Computational Geosciences》2015,19(3):635-653

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A Multi-Observatory Inter-Comparison of Line-of-Sight Synoptic Solar Magnetograms     

P. Riley  M. Ben-Nun  J. A. Linker  Z. Mikic  L. Svalgaard  J. Harvey  L. Bertello  T. Hoeksema  Y. Liu  R. Ulrich 《Solar physics》2014,289(3):769-792

The observed photospheric magnetic field is a crucial parameter for understanding a range of fundamental solar and heliospheric phenomena. Synoptic maps, in particular, which are derived from the observed line-of-sight photospheric magnetic field and built up over a period of 27 days, are the main driver for global numerical models of the solar corona and inner heliosphere. Yet, in spite of 60 years of measurements, quantitative estimates remain elusive. In this study, we compare maps from seven solar observatories (Stanford/WSO, NSO/KPVT, NSO/SOLIS, NSO/GONG, SOHO/MDI, UCLA/MWO, and SDO /HMI) to identify consistencies and differences among them. We find that while there is a general qualitative consensus, there are also some significant differences. We compute conversion factors that relate measurements made by one observatory to another using both synoptic map pixel-by-pixel and histogram-equating techniques, and we also estimate the correlation between datasets. For example, Wilcox Solar Observatory (WSO) synoptic maps must be multiplied by a factor of 3?–?4 to match Mount Wilson Observatory (MWO) estimates. Additionally, we find no evidence that the MWO saturation correction factor should be applied to WSO data, as has been done in previous studies. Finally, we explore the relationship between these datasets over more than a solar cycle, demonstrating that, with a few notable exceptions, the conversion factors remain relatively constant. While our study was able to quantitatively describe the relationship between the datasets, it did not uncover any obvious “ground truth.” We offer several suggestions for how this may be addressed in the future.  相似文献   

Publisher’s Erratum to: The Herschel PACS photometer calibration     

Markus Nielbock  Thomas Müller  Ulrich Klaas  Bruno Altieri  Zoltán Balog  Nicolas Billot  Hendrik Linz  Koryo Okumura  Miguel Sánchez-Portal  Marc Sauvage 《Experimental Astronomy》2014,37(2):127-127

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Structural characteristics of the Sudbury impact structure,Canada: Impact‐induced versus orogenic deformation—A review     

Ulrich Riller 《Meteoritics & planetary science》2005,40(11):1723-1740

Abstract— Orogenic deformation, both preceding and following the impact event at Sudbury, strongly hinders a straightforward assessment of impact‐induced geological processes that generated the Sudbury impact structure. Central to understanding these processes is the state of strain of the Sudbury Igneous Complex, the solidified impact melt sheet, its underlying target rocks, overlying impact breccias and post‐impact sedimentary rocks. This review addresses (1) major structural, metamorphic and magmatic characteristics of the impact melt sheet and associated dikes, (2) attempts that have been made to constrain the primary geometry of the igneous complex, (3) modes of impact‐induced deformation as well as (4) mechanisms of pre‐ and post‐impact orogenic deformation. The latter have important consequences for estimating parameters such as magnitude of structural uplift, tilting of pre‐impact (Huronian) strata and displacement on major discontinuities which, collectively, have not yet been considered in impact models. In this regard, a mechanism for the emplacement of Offset Dikes is suggested, that accounts for the geometry of the dikes and magmatic characteristics, as well as the occurrence of sulfides in the dikes. Moreover, re‐interpretation of published paleomagnetic data suggests that orogenic folding of the solidified melt sheet commenced shortly after the impact. Uncertainties still exist as to whether the Sudbury impact structure was a peak‐ring or a multi‐ring basin and the deformation mechanisms of rock flow during transient cavity formation and crater modification.  相似文献   

M. S. Longair,high energy astrophysics,vol. 1,particles photons and their detection,Cambridge University Press,Cambridge, 1992     

Ulrich R. M. E. Geppert 《Astrophysics and Space Science》1993,201(1):153-154

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Phase boundaries in finite amplitude mantle convection     

Ulrich Christensen 《Geophysical Journal International》1982,68(2):487-497

Summary. Phase boundaries are included in dynamical finite element models of mantle convection. They are represented by point chains which act as additional sources of buoyancy forces when distorted, and as additional source or sink of heat. The influence of the exothermic olivine-spinel transition is studied in both shallow and deep convection models. The flow is only slightly enhanced by the transition. The increase of temperature due to latent heat release is step-like in the deep model, in the case of shallow convection it is more diffuse. Other quantities like ocean-floor topography, gravity anomalies, and stress distribution are no more than moderately affected. In a further investigation the effect of spinel post-spinel transition, whether endothermic or exothermic, on deep convection is examined. The effect on the flow is negligibly small in both cases.  相似文献   

Toxic effects of Zn2+, Cu2+, Cd2+ and NH3 on Chinese prawn     

Zang Weiling  Xu Xuancheng  Dai Xilin  Zhu Zhengguo  Xu Guirong  Xu Renguo 《中国海洋湖沼学报》1993,11(3):254-259

This study deals with the toxic effects of Zn²⁺, Cu²⁺, Cd²⁺ and NH₃ on Chinese prawn (Penaeus orientalis). The median lethal concentrations of the toxic matters on Chinese prawn were determined. Cd²⁺>Cu²⁺>Zn²⁺>NH₃-Nm is the toxic order of these chemicals to Chinese prawn. The toxic order of concentrated Zn²⁺ and Cd²⁺ in tissues and organs of Chinese prawn is in the order. gill>shell+appendage>viscera>muscle.  相似文献   

Can coronal loop transients be driven magnetically?     

Ulrich Anzer 《Solar physics》1978,57(1):111-118

In this note we investigate the possibility of magnetic driving of loop transients. The action of local magnetic forces to balance gravity in a coasting loop and to confine the loop has been proposed by Mouschovias and Poland (1977). In this paper we use similar configurations but deal with the global field structure and present models which show both the initial phase of large acceleration and the later phase of almost constant velocity. We use very simple one-dimensional models consisting of a ring current which is subjected to gravitational attraction. The velocity curves calculated for these models are in good agreement with the observations. Therefore we conclude that if such ring currents can be produced fast enough in the solar corona, they are capable of driving the loop transients observed in the ATM white light coronagraph.On leave from Max-Planck Institut für Physik und Astrophysik, Föhringer Ring 6, 8 München 40, F.R.G.The National Center for Atmospheric Research is sponsored by the National Science Foundation.  相似文献   

Convective energy transport in stellar atmospheres     

Roger K. Ulrich 《Astrophysics and Space Science》1970,7(2):183-200

The motion of convective cells in an environment which changes rapidly with depth is examined. In such an environment a cell may move through regions with different levels of ionization and with associated differences in heat capacity. The energy equation is cast in a manner which is independent of the history of these cells. The convective flux at a given level of the atmosphere is written as an average over an ensemble of cells originating at a range of other levels. A procedure for correcting the temperature gradient for these non-local effects is described and results for a model solar atmosphere are given. The principal results are: (1) The rms velocity varies smoothly and is non-zero well into the photosphere (e.g.,v _rsm=1.4 km/sec at =0.2); (2) Convective overshoot reduces the radiative flux to 60% and 90% of the total at =2.5 and 0.2 respectively; and (3) The interior adiabat of the convective envelope is less sensitive to the assumed value of the average cell size than in the usual treatment of convection.Supported in part by the National Science Foundation [GP-9433, GP-9114], the Office of Naval Research [Nonr-220(47)], and Air Force Grant AG-AFOSR-171-67.  相似文献   

Über einige Auswirkungen der Eutrophierung des Bodensee-Obersees auf seine planktisch lebenden Copepodenpopulationen     

Dr. Ulrich Einsle 《Aquatic Sciences - Research Across Boundaries》1967,29(2):305-310

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