A Survey of Charge-Balance Errors on Published Analyses of Potable Ground and Surface Waters   总被引：2，自引：0，他引：2  

Steven J. Fritz 《Ground water》1994,32(4):539-546

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Theoretical studies of the parameterization of the non-neutral surface boundary layer     

Walter-Georg Panhans  Fritz Herbert 《Boundary-Layer Meteorology》1979,16(2):155-167

The parameterization of the non-neutral atmospheric surface layer has been reexamined using the basic principles of small-scale energetics and thermodynamics. On the basis of this more complete treatment, theK-parameterization has been reformulated. It is found that the linear regression laws between fluxes and driving gradient forces of the turbulent heat and humidity exchanges in the surface layer can be derived in a much more comprehensive manner than by using the commonly used K-theory. With respect to stationary conditions and in the context of similarity concepts, a system of algebraic equations has been formulated which provides reasonable estimates of the distributions of the dimension less rates of viscous energy dissipation as well as turbulent kinetic and thermal-diffusive energy transport as functions of the variablez/L. Quantitative calculations have been performed using the scaling height formulations of Takeuchi and Yokoyama, Prandtl, and von Karman as closure conditions of the equations.  相似文献   

Photobleaching of humic rich dissolved organic matter   总被引：7，自引：0，他引：7  

Thomas?Brinkmann  Daniel?Sartorius  Fritz?H.?FrimmelEmail author 《Aquatic Sciences - Research Across Boundaries》2003,65(4):415-424

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Coupling of a Column System with ICP‐MS for the Characterisation of Colloid‐mediated Metal(loid) Transport in Porous Media     

George Metreveli  Eva‐Maria Kaulisch  Fritz H. Frimmel 《洁净——土壤、空气、水》2005,33(4):337-345

In this work a coupling method for the characterisation of colloid‐mediated transport of the metal(loid) species in porous media was developed. For this transport experiments quartz sand was used as column packing material and the synthetic three‐layer clay mineral laponite as model colloid. The determination of colloids was conducted by means of UV detection. The quantification of the metal(loid) ions was carried out in two different ways: (1) The fractions collected at the column outlet were analysed with an inductively coupled plasma mass spectrometer (ICP‐MS) (offline measurements); (2) the column system was directly coupled with ICP‐MS (online measurements). In the column experiments the influence of laponite colloids on the transport of Cu, Pb, Zn, Pt and As species was investigated. In the offline experiments as a consequence of dilution during sample preparation no metal(loid) species at the column outlet could be found. Unlike this the breakthrough of all metal(loid)s could be detected under the same experimental column conditions in the coupling experiments. This coupling technique offers the online detection of the metal species and colloidal particles with high resolution even at low concentrations and without any time‐consuming preparation. The coupling experiments have shown that the laponite particles accelerate the transport of the cationic metals. For anionic metal(loid) species no influence of laponite on their transport behaviour was found.  相似文献   

Preface     

Theodore A. Fritz  Shing F. Fung 《Surveys in Geophysics》2005,26(1-3):1-3

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Vegetation and climate change on the Bolivian Altiplano between 108,000 and 18,000 yr ago   总被引：1，自引：0，他引：1  

Alex Chepstow-Lusty  Mark B. Bush  Paul A. Baker  Sherilyn C. Fritz  James Aronson 《Quaternary Research》2005,63(1):90-98

A 90,000-yr record of environmental change before 18,000 cal yr B.P. has been constructed using pollen analyses from a sediment core obtained from Salar de Uyuni (3653 m above sea level) on the Bolivian Altiplano. The sequence consists of alternating mud and salt, which reflect shifts between wet and dry periods. Low abundances of aquatic species between 108,000 and 50,000 yr ago (such as Myriophyllum and Isoëtes) and marked fluctuations in Pediastrum suggest generally dry conditions dominated by saltpans. Between 50,000 yr ago and 36,000 cal yr B.P., lacustrine sediments become increasingly dominant. The transition to the formation of paleolake “Minchin” begins with marked rises in Isoëtes and Myriophyllum, suggesting a lake of moderate depth. Similarly, between 36,000 and 26,000 cal yr B.P., the transition to paleolake Tauca is also initiated by rises in Isoëtes and Myriophyllum; the sustained presence of Isoëtes indicates the development of flooded littoral communities associated with a lake maintained at a higher water level. Polylepis tarapacana-dominated communities were probably an important component of the Altiplano terrestrial vegetation during much of the Last Glacial Maximum (LGM) and previous wet phases.  相似文献   

Diatom Paleolimnological Record of Holocene Climatic and Environmental Change in the Altai Mountains, Siberia     

Karlyn S. Westover  Sherilyn C. Fritz  Tatyana A. Blyakharchuk  Herbert E. Wright 《Journal of Paleolimnology》2006,35(3):519-541

The sedimentary diatom records of three shallow lakes in the Altai Mountains, southern Siberia, were examined to assess the nature and timing of Holocene environmental changes. Few paleoenvironmental records, especially reconstructions not based on pollen, have been reported from this region. The lakes differ in elevation, annual precipitation, and catchment vegetation. Diatom assemblages in all lakes were dominated for the entire period of record by small benthic species of Pseudostaurosira Williams & Round, Staurosira Ehrenberg, and Staurosirella Williams & Round. Planktonic taxa only occur in very low abundances (<5%). The most diverse diatom flora was found in Dzhangyskol, which is situated at the lowest elevation within a forested catchment. A lack of detailed information on the ecological preferences of the dominant taxa and the complexity of environmental drivers make direct interpretation of the diatom record difficult. However, other proxies suggest that dramatic shifts in dominance between Staurosira elliptica and Staurosirella pinnata in Grusha Ozero reflect millennial-scale variability in climate. Together, chironomids and diatoms provide evidence of a cooling possibly correlative to the Younger Dryas Stade and subsequent early-Holocene warming consistent with pollen evidence of afforestation, which also is likely linked to increased humidity. By ~6000 cal year BP, the transition to a cooler, more continental climate had begun. The diatom record of Akkol shows significantly less variation in diatom community composition, but biogenic silica accumulation rates, a proxy for diatom productivity, appear to reflect climatic variability driven by insolation trends over the past 8000 years. Long-term variability in Dzhangyskol is not clearly linked to climate.  相似文献   

A diatom-based reconstruction of drought intensity, duration, and frequency from Moon Lake, North Dakota: a sub-decadal record of the last 2300 years   总被引：2，自引：0，他引：2  

Kathleen R. Laird  Sherilyn C. Fritz  Brian F. Cumming 《Journal of Paleolimnology》1998,19(2):161-179

Diatom assemblages preserved in sediment cores from closed-basin lakes can provide high-resolution records of past hydrologic and climatic conditions, including long-term patterns in the intensity, duration, and frequency of droughts. At Moon Lake, a closed-basin lake in eastern North Dakota, a comparison of diatom-inferred salinity and the precipitation-based Bhalme-Mooley Drought Index (BMDI) over the last 100 years was highly significant, suggesting that the diatom record contains a sensitive archive of past climatic conditions. A sub-decadal record of inferred salinity for the past 2300 years indicates that extreme droughts of greater intensity than those during the 1930s 'Dust Bowl' were more frequent prior to A.D. 1200. This high frequency of extreme droughts persisted for centuries and was most pronounced from A.D. 200–370, A.D. 700–850 and A.D. 1000–1200. A pronounced shift to generally wetter conditions with less severe droughts of shorter duration occured at A.D. 1200. This abrupt change coincided with the end of the 'Medieval Warm Period' (A.D. 1000–1200) and the onset of the 'Little Ice Age' (A.D. 1300–1850).  相似文献   

Geodynamic and tectonic evolution of the southeastern Bohemian Massif: The Thaya section (Austria)     

Dr. H. Fritz 《Mineralogy and Petrology》1996,58(3-4):253-278

Summary The tectonostratigraphy within eastern sections of the Bohemian Massif includes two different terranes. A Proterozoic terrane is composed of the Moravo-Silesian parautochthon, the Moravian nappe complex and the Moldanubian Variegated and Monotonous complexes. A Paleozoic terrane includes the Gföhl Gneiss and the granulite klippen. Both terranes are separated by an oceanic suture zone which is represented by the Letovice ophiolite complex (Czech Republic) and the Raabs complex in Austria. The Raabs structural unit is interpreted to represent a tectonic melange of a dismembered ophiolite complex and metaandesites.The tectonic evolution of the southeastern Bohemian Massif includes: (1) Paleozoic extension predating late Variscan nappe stacking; (2) Variscan (c. 350-320 Ma) NE-directed nappe assembly by foreward propagation of thick-skinned nappes, whereas individual thrusts initiated within different crustal levels; (3) post-stacking Variscan W-E extension which was responsible for penetrative nappe internal deformations; and, (4) dispersion of units by a system of dextral strike-slip faults and genetically related thrust- and normal faults. The kinematic history during Variscan convergence is explained to have been related to oblique (dextral) transpression of Proterozoic against Paleozoic terranes.

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Geodynamische und tektonische Entwicklung der südöstlichen Böhmischen Masse: Das Thaya Profil (Österreich)

Zusammenfassung Eine Gliederung der südöstlichen Böhmischen Masse umfaßt zwei kontinentale Blöcke (Terranes). Das proterozoische Terrane besteht aus dem Moravo-Silesischen Parautochton, den Moravischen Decken und basalen Anteilen des Moldanubikums (Bunte Serie und Monotone Serie). Das paläozoische Terrane umfaßt den Moldanubischen Gföhler Gneis und die Granulitklippen. Beide Krustenblöcke werden durch eine ozeanische Sutur getrennt, die durch den Letovice-Ophiolith (Tschechien) und die Raabser Einheit (Österreich) repräsentiert ist. Die Raabser Einheit wird als eine tektonische Melange, bestehend aus einem Ophiolith und einer kalkalkalischen, andesitischen Suite gedeutet. Die tektonische Entwicklung läßt folgende Entwicklungsstufen erkennen: (1) Paläozoische Krustenextension vor der spätvariszischen Deckenstapelung; (2) Spätvariszische (ca. 350-320 Ma) nordostgerichtete Deckenstapelung, wobei jüngere Decken in Richtung des Vorlandes progradierten. Dabei wurden einzelne Deckenbahnen in unterschiedlichen Krustenniveaus betätigt; (3) Generelle West-Ost Extension und Entwicklung des penetrativen Gefüges nach der Deckenstapelung; (4) Verteilung der Einheiten durch gleichzeitige Aktivität von steilen nordost-streichenden Scherzonen und flachen Auf- und Abschiebungen. Die kinematische Entwicklung während der variszischen Gebirgsbildung ist auf schräge (dextrale) Plattenkonvergenz zwischen dem proterozoischen und dem paläozoischen Terrane zurückzuführen.

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With 10 Figures  相似文献   

Medium-scale maps after survey from space—The “Metric-Camera”—Experiment     

Fezer Fritz Prof. Dr.  Reichenbach Bernhard  Witschel Christian MA  Hell Günter Prof. Dr.-Ing.  Duster Manfred Dipl.-Ing  Heidrich Brigitte 《GeoJournal》1987,14(4):467-478

Airphotos have been used for topographic survey since the Twenties. The “European Space Agency” (ESA), the “Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt” (DFVLR) and “Carl Zeiss” have modified this successful technique for spacecraft and recently have tested the system over four continents. Each of these satellite photos covers a region of 189×189 km to the scale of 1∶800000 and may be enlarged to 1∶250000 or 1∶100000. Between the altitudes of 200 and 300 km, mapmaking or-revision seems to be economic in zones or in countries, where existing maps are of minor quality or outdated. In this paper, examples from deserts and semideserts in the Sudan are presented.  相似文献