Composition of metal in type III carbonaceous chondrites and its relevance to the source-assignment of lunar metal     

Louis H. Fuchs  Edward Olsen 《Earth and Planetary Science Letters》1973,18(3):379-384

The metal in seven Type III carbonaceous chondrites has been measured for concentrations of Ni, Co and Cr. Cobalt in kamacite is 3.2 to 5.5 times greater than in taenite on composite grains containing both phases. No correlation was found between the metal compositions and sub-type classification. Ni and Co contents of kamacite from several of the Type III's studied fall outside of the range for these elements in bulk meteoritic metal and are relevant to the assignment of a meteoritic vs a non-meteoritic origin for lunar metal particles in the fines and breccias.  相似文献   

Aircraft icing in visual meterological conditions below low stratus clouds     

W. Fuchs  K. -P. Schickel 《Atmospheric Research》1995,36(3-4)

There are many reports about icing slightly below stratus clouds in visual meteorological conditions (VMC), which obviously occurs very often but not only in polar regions and over the sea. Calculations of the ice shape at the leading edge of aircraft wings and the main rotor blades of helicopters by computers of GMGO (German Military Geophysical Office) and DLR (Deutsche Forschungsanstalt für Luft- and Raumfahrt) show, that this specific ice accretion, which often accumulates to severe icing, depends mostly on two meteorological parameters: liquid water content (LWC) and air temperature, but does not depend on the size of the drizzle droplets in the case of helicopters.  相似文献   

Chronostratigraphy of a sediment record from the Hajar mountain range in north Oman: Implications for optical dating of insufficiently bleached sediments     

M. Fuchs  C. Woda  A. Bürkert 《Quaternary Geochronology》2007,2(1-4):202-207

In this study we report on optical stimulated luminescence (OSL) ages of quartz extracted from a sedimentary record in the N-Oman mountain range. Equivalent dose (D_E) distributions derived from single aliquot measurements (SAR) of small aliquots (ca. 200 grains) were investigated to test whether the skewness and broadness of the dose distribution can be used as criteria for the identification of insufficient bleaching. Furthermore, the methods proposed by Lepper and McKeever [2002 An objective methodology for dose distribution analysis. Radiation Protection Dosimetry 101 (1–4), 349-352]. Singhvi [Juyal, N., Chamyal, L.S., Bhandari, S., Bushan, R., Singhvi, A.K., in press. Continental record of the southwest monsoon during the last 130 ka: evidence from the southern margin of the Thar Desert, India. Quaternary Science Review] and Fuchs and Lang [2001 Fuchs, M., Lang, A., 2001. OSL dating of coarse-grain fluvial quartz using single-aliquot protocols on sediments from NE Peloponnese, Greece. Quaternary Science Review 20, 783–787.] to derive D_E's from insufficiently bleached sediments were compared. At first, the investigations were carried out on artificially bleached, irradiated and mixed quartz material from the Oman study area to simulate insufficiently bleached sediments. Then, the various statistical methods for identifying insufficient bleaching and D_E derivation were applied to the natural samples from the study area, where 18 samples were measured. For the identification of insufficient bleaching the preferential parameter is the broadness of a distribution. For D_E calculation, both the Singhvi method and the Fuchs and Lang method produce similar results, which are consistent with the stratigraphic order. A drawback of both methods is their sensitivity to low outliers. The Lepper and McKeever method was not applied to the natural samples, due to limitations in its application to a small number of aliquots and due to the ambiguous identification of the rising limb of the dose distributions.  相似文献   

Measuring streambank erosion due to ground water seepage: correlation to bank pore water pressure,precipitation and stream stage   总被引：1，自引：0，他引：1  

Garey A. Fox  Glenn V. Wilson  Andrew Simon  Eddy J. Langendoen  Onur Akay  John W. Fuchs 《地球表面变化过程与地形》2007,32(10):1558-1573

Limited information exists on one of the mechanisms governing sediment input to streams: streambank erosion by ground water seepage. The objective of this research was to demonstrate the importance of streambank composition and stratigraphy in controlling seepage flow and to quantify correlation of seepage flow/erosion with precipitation, stream stage and soil pore water pressure. The streambank site was located in Northern Mississippi in the Goodwin Creek watershed. Soil samples from layers on the streambank face suggested less than an order of magnitude difference in vertical hydraulic conductivity (K_s) with depth, but differences between lateral K_s of a concretion layer and the vertical K_s of the underlying layers contributed to the propensity for lateral flow. Goodwin Creek seeps were not similar to other seeps reported in the literature, in that eroded sediment originated from layers underneath the primary seepage layer. Subsurface flow and sediment load, quantified using 50 cm wide collection pans, were dependent on the type of seep: intermittent low‐flow (LF) seeps (flow rates typically less than 0·05 L min^?1), persistent high‐flow (HF) seeps (average flow rate of 0·39 L min^?1) and buried seeps, which eroded unconsolidated bank material from previous bank failures. The timing of LF seeps correlated to river stage and precipitation. The HF seeps at Goodwin Creek began after rainfall events resulted in the adjacent streambank reaching near saturation (i.e. soil pore water pressures greater than ?5 kPa). Seep discharge from HF seeps reached a maximum of 1·0 L min^?1 and sediment concentrations commonly approached 100 g L^?1. Buried seeps were intermittent but exhibited the most significant erosion rates (738 g min^?1) and sediment concentrations (989 g L^?1). In cases where perched water table conditions exist and persistent HF seeps occur, seepage erosion and bank collapse of streambank sediment may be significant. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

GROSSULAR IN THE ALLENDE (TYPE III CARBONACEOUS) METEORITE*     

Louis H. Fuchs 《Meteoritics & planetary science》1974,9(1):11-18

Grossular garnet has been observed in several white inclusions in the Allende meteorite. Compositions range from Gro_9sPy₅ to Gro₈₈Py₁₂ in five inclusions. Its mottled appearance indicates that it crystallized from a glass of near-grossular composition and not by a solid state reaction between wollastonite, anorthite and melilite. These grossular-bearing inclusions either condensed directly as metastable liquids from the solar nebula or if initial solid condensates were liquefied by some subsequent heating process. In either case, a prolonged residence time in a thermal blanket appears necessary to effect crystallization of the grossular.  相似文献   

E. W. MIELKE: Geometrodynamics of Gauge Fields. On the Geometry of Yang-Mills and Gravitational Gauge Theories. Physical Research Vol. 3. Akademie-Verlag Berlin, 1987. Preis: DM 45     

H. Fuchs 《Astronomische Nachrichten》1988,309(3):196-196

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A. van der Merwe (ed.): Old and New Questions in Physics,Cosmology, Philosophy,and Theoretical Biology. Essays in Honour of Wolfgang Yourgrau. Plenum Press,New York and London, 1983. XV + 920 Seiten. Preis US $95.–. ISBN 0-306-40962-3     

H. Fuchs 《Astronomische Nachrichten》1984,305(5):279-280

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Faint Stars and the Structure of the Galaxy     

S. Phleps  K. Meisenheimer  C. Wolf  B. Fuchs  H. Jahreiss 《Astrophysics and Space Science》1999,265(1-4):231-232

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Polteilchen in der TREDERSchen Tetradentheorie     

H. Fuchs 《Astronomische Nachrichten》1977,298(1):27-32

In the framework of TREDERS ' tetrad theory of gravitation the interaction of pole-particles is considered in post-NEWTON ian approximation. The perihelion shift for the two-body problem is calculated for different matter-field-couplings. In general it depends not only from the sum of the masses but also from the reduced mass. The additional term is connected with the absorption of gravitation.  相似文献   

Exploring the method of optical dating and comparison of optical and 14C ages of Late Weichselian coversands in the southern Netherlands     

D. Vandenberghe  C. Kasse  S. M. Hossain  F. De Corte  P. Van Den Haute  M. Fuchs  A. S. Murray 《第四纪科学杂志》2004,19(1):73-86

A study was made of the applicability of three different techniques for equivalent dose (D_e) determination in the optical dating of quartz: the single‐aliquot regenerative‐dose technique (SAR), the single‐aliquot additive‐dose technique (SAAD) and the multiple‐aliquot additive‐dose technique (MAAD). For this purpose, quartz grains were extracted from a sequence of Upper Pleniglacial to Late‐glacial coversands exposed at the locality of Ossendrecht in the southwestern Netherlands, a site for which both radiocarbon and earlier luminescence dates are available, providing independent age control. Upon testing the different assumptions underlying each of the three OSL techniques investigated, the SAR protocol was found to be the technique of choice. The optical ages obtained with this protocol were in good agreement with the chronostratigraphical position of the sediments investigated and with the available chronostratigraphical information on the same and equivalent deposits. This confirms the suitability of the SAR technique for dating coversands. Furthermore, a small laboratory intercomparison of SAR‐based D_e determinations yielded results that were in fair overall agreement. Copyright © 2004 John Wiley & Sons, Ltd.  相似文献