Nitratbestimmung im Trinkwasser nach dem flow-stream-Prinzip mittels einer ionensensitiven Meßzelle     

U. Tietz  U. Grünke  I. Krause 《洁净——土壤、空气、水》1980,8(4):291-298

Beschrieben wird eine automatisierte Methode zur Bestimmung des Nitrats in Trinkwässern mittels einer ionensensitiven Meßzelle. Mit dem vorgestellten Verfahren können 80 Proben pro Stunde auf ihren Nitratgehalt im Konzentrationsbereich von 1,5 · 10^–5 bis 1,0 · 10^–3 Mol/l analysiert werden. Der Aufbau der Automateneinheit, der Durchflußmeßzelle, sowie das Meßprinzip weiden erläutert.  相似文献   

The effect of groundwater forcing on hyporheic exchange: Reply to comment on ‘Munz M,Krause S,Tecklenburg C,Binley A. Reducing monitoring gaps at the aquifer‐river interface by modelling groundwater‐surfacewater exchange flow patterns. Hydrological Processes. DOI: 10.1002/hyp.8080’     

S. Krause  M. Munz  C. Tecklenburg  A. Binley 《水文研究》2012,26(10):1589-1592

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On the air‐sea interaction in areas of thermal marine fronts in the Greenland Sea     

Timo Vihma  Jouko Launiainen  Gunther Krause 《大气与海洋》2013,51(3):596-610

Abstract

The effects of marine fronts on the local atmospheric surface layer and air‐sea interaction were studied. Several mesoscale fronts were crossed by a research vessel in the Greenland Sea. Air temperature, humidity and stability conditions, and the fluxes of momentum, as well as sensible and latent heat, were investigated. For relatively calm conditions, close air‐sea coupling was observed in the temperature whereas for stronger winds, the air temperature of the surface layer was not markedly modified by the front below. Changes in the moisture content in the frontal area were observed and, in one case, evaporation was observed on the warm water side and condensation on the cold water side of the front. Frontal differences in heating from the sea were assumed to affect the surface‐layer wind field.  相似文献   

Pressure effects on martian crustal magnetization near large impact basins     

Gunther KLETETSCHKA  John E. P. CONNERNEY  Norman F. NESS  Mario H. ACU A 《Meteoritics & planetary science》2004,39(11):1839-1848

Abstract— Martian crust endured several large meteoroid impacts subsequent to the demise of an early global magnetic field. Shock pressures associated with these impacts demagnetized parts of the crust, to an extent determined by shock resistance of magnetic materials in the crust. Impacts that form large basins generate pressures in excess of 1 GPa within a few crater radii of their impact sites. Crustal materials near the surface experience significantly reduced impact pressure, which varies with depth and distance from the impact point. We present new demagnetization experiments on magnetite (Fe₃O₄), hematite (α‐Fe₂O₃), and titanohematite (Fe_2‐xTi_xO₃ where x <0.2). Our measurements show that pressures of ?1 GPa are sufficient to partially demagnetize all of these minerals. The efficiency of demagnetization by impact pressure is proportional to the logarithm of the minerals' magnetic coercivity. The impact pressure magnetic response from exsolved titanohematite samples is consistent with the magnetization decay near Prometheus impact basin and may point to an oxidized igneous rock in Terra Sirenum region at the time of acquisition of magnetic remanence. The remaining magnetic anomalies near large impact basins suggest moderate crustal coercivity. These anomalies point to titanomagnetite as a magnetic carrier and more reduced condition during crustal formation.  相似文献   

Die Struktur eines Raseneisenerzes     

Alfons Krause  Anzelm Lewandowski 《Mineralogy and Petrology》1963,8(3):439-443

Ohne Zusammenfassung  相似文献   

Climate change and human activities: a case study in Xinjiang, China   总被引：4，自引：0，他引：4  

Zhuoting Wu  Hongjun Zhang  Crystal M. Krause  Neil S. Cobb 《Climatic change》2010,99(3-4):457-472

We examined both long-term climate variability and anthropogenic contributions to current climate change for Xinjiang province of northwest China. Xinjiang encompasses several mountain ranges and inter-mountain basins and is comprised of a northern semiarid region and a more arid southern region. Climate over the last three centuries was reconstructed from tree rings and temperature series were calculated for the past 50 years using weather station data. Three major conclusions from these analyses are: (1) Although temperature varied considerably in Xinjiang over the last 200 years, it was non-directional until the last 50 years when a substantial warming trend occurred; (2) The semiarid North Xinjiang was representative of the northern hemisphere climate, while the more arid South Xinjiang resembled the southern hemisphere climate, meanwhile, (3) The entire Xinjiang province captured the global-scale climate signal. We also compared human contributions to global change between North and South Xinjiang, including land cover/land use, population, and greenhouse gas production. For both regions, urban areas acted as heat islands; and large areas of grassland and forest were converted to barren land, especially in North Xinjiang. Additionally, North Xinjiang also showed larger increase in population and greenhouse gas emissions mainly associated with animal production than those in South Xinjiang. Although Xinjiang province is a geographically coupled mountain–basin system, the two regions have distinct climate patterns and anthropogenic activities related to land cover conversion and greenhouse gas production.  相似文献   

Magnetic zones of Mars: Deformation‐controlled origin of magnetic anomalies     

Gunther KLETETSCHKA  Robert J. LILLIS  Norman F. NESS  Mario H. ACUÑA  Jack E. P. CONNERNEY  Peter J. WASILEWSKI 《Meteoritics & planetary science》2009,44(1):131-140

Abstract— Intense magnetic anomalies over Martian surface suggest preservation of large volumes of very old crust (>3 Gyr) that formed in the presence of a global magnetic field. The global distribution of the magnetic intensities observed above the Martian crust suggests a division into three zones. Zone 1 is where the magnetic signature is negligible or of relatively low intensity at Mars Global Surveyor (MGS) satellite mapping altitude (400 km). Zone 2 is the region of intermediate crustal magnetic amplitudes and zone 3 is where the highest magnetic intensities are measured. Crater demagnetization near zone 3 reveals the presence of rocks with both high magnetic intensity and coercivity. Magnetic analyses of terrestrial rocks show that compositional banding in orogenic zones significantly enhances both magnetic coercivity and thermal remanent magnetization (TRM) efficiency. Such enhancement offers a novel explanation for the anomalously large intensities inferred of magnetic sources on Mars. We propose that both large magnetic coercivity and intensity near the South Pole is indicative of the presence of a large degree of deformation. Associated compositional zoning creates conditions for large scale magnetic anisotropy allowing magnetic minerals to acquire magnetization more efficiently, thereby causing the distinct magnetic signatures in zone 3, expressed by intense magnetic anomalies. We use a simple model to verify the magnetic enhancement. We hypothesize that magnetically enhanced zone would reside over the down welling plume at the time of magnetization acquisition.  相似文献   

BIFoR FACE: Water–soil–vegetation–atmosphere data from a temperate deciduous forest catchment,including under elevated CO2     

A. Rob MacKenzie  Stefan Krause  Kris M. Hart  Richard M. Thomas  Phillip J. Blaen  R. Liz Hamilton  Giulio Curioni  Susan E. Quick  Angeliki Kourmouli  David M. Hannah  Sophie A. Comer-Warner  Nicolai Brekenfeld  Sami Ullah  Malcolm C. Press 《水文研究》2021,35(3):e14096

The ecosystem services provided by forests modulate runoff generation processes, nutrient cycling and water and energy exchange between soils, vegetation and atmosphere. Increasing atmospheric CO₂ affects many linked aspects of forest and catchment function in ways we do not adequately understand. Global levels of atmospheric CO₂ will be around 40% higher in 2050 than current levels, yet estimates of how water and solute fluxes in forested catchments will respond to increased CO₂ are highly uncertain. The Free Air CO₂ Enrichment (FACE) facility of the University of Birmingham's Institute of Forest Research (BIFoR) is the only FACE in mature deciduous forest. The site specializes in fundamental studies of the response of whole ecosystem patches of mature, deciduous, temperate woodland to elevated CO₂ (eCO₂). Here, we describe a dataset of hydrological parameters – seven weather parameters at each of three heights and four locations, shallow soil moisture and temperature, stream hydrology and CO₂ enrichment – retrieved at high frequency from the BIFoR FACE catchment.  相似文献   

‘Box‐Profile’ Ion Implants as Geochemical Reference Materials for Electron Probe Microanalysis and Secondary Ion Mass Spectrometry     

Haosheng Wu  Roman Bttger  Frdric Couffignal  Jens Gutzmer  Joachim Krause  Frans Munnik  Axel D. Renno  Ren Hübner  Michael Wiedenbeck  Ren Ziegenrücker 《Geostandards and Geoanalytical Research》2019,43(4):531-541

Although electron probe microanalysis and secondary ion mass spectrometry are widely used analytical techniques for geochemical and mineralogical applications, metrologically rigorous quantification remains a major challenge for these methods. Secondary ion mass spectrometry (SIMS) in particular is a matrix‐sensitive method, and the use of matrix‐matched reference materials (RMs) is essential to avoid significant analytical bias. A major problem is that the number of available RMs for SIMS is extremely small compared with the needs of analysts. One approach for the production of matrix‐specific RMs is the use of high‐energy ion implantation that introduces a known amount of a selected isotope into a material. We chose the more elaborate way of implanting a so‐called ‘box‐profile’ to generate a quasi‐homogeneous concentration of the implanted isotope in three dimensions, which allows RMs not only to be used for ion beam analysis but also makes them suitable for EPMA. For proof of concept, we used the thoroughly studied mineralogically and chemically ‘simple’ SiO₂ system. We implanted either ⁴⁷Ti or ⁴⁸Ti into synthetic, ultra‐high‐purity silica glass. Several ‘box‐profiles’ with mass fractions between 10 and 1000 μg g^?1 Ti and maximum depths of homogeneous Ti distribution between 200 nm and 3 μm were produced at the Institute of Ion Beam Physics and Materials Research of Helmholtz‐Zentrum Dresden‐Rossendorf. Multiple implantation steps using varying ion energies and ion doses were simulated with Stopping and Range of Ions in Matter (SRIM) software, optimising for the target concentrations, implantation depths and technical limits of the implanter. We characterised several implant test samples having different concentrations and maximum implantation depths by means of SIMS and other analytical techniques. The results show that the implant samples are suitable for use as reference materials for SIMS measurements. The multi‐energy ion implantation technique also appears to be a promising procedure for the production of EPMA‐suitable reference materials.  相似文献   

Understanding the hydrological system dynamics of a glaciated alpine catchment in the Himalayan region using the J2000 hydrological model          下载免费PDF全文

S. Nepal  P. Krause  W.‐A. Flügel  M. Fink  C. Fischer 《水文研究》2014,28(3):1329-1344

This paper provides the results of hydrological modelling in a mesoscale glaciated alpine catchment of the Himalayan region. In the context of global climate change, the hydrological regime of an alpine mountain is likely to be affected, which might produce serious implications for downstream water availability. The main objective of this study was to understand the hydrological system dynamics of a glaciated catchment, the Dudh Kosi River basin, in Nepal, using the J2000 hydrological model and thereby understand how the rise in air temperature will affect the hydrological processes. The model is able to reproduce the overall hydrological dynamics quite well with an efficiency result of Nash–Sutcliffe (0.85), logarithm Nash–Sutcliffe (0.93) and coefficient of determination (0.85) for the study period. The average contribution from glacier areas to total streamflow is estimated to be 17%, and snowmelt (other than from glacier areas) accounts for another 17%. This indicates the significance of the snow and glacier runoff in the Himalayan region. The hypothetical rise in temperature scenarios at a rate of +2 and +4 °C indicated that the snowmelt process might be largely affected. An increase in snowmelt volume is noted during the premonsoon period, whereas the contribution during the monsoon season is significantly decreased. This occurs mainly because the rise in temperature will shift the snowline up to areas of higher altitude and thereby reduce the snow storage capacity of the basin. This indicates that the region is particularly vulnerable to global climate change and the associated risk of decreasing water availability to downstream areas. Under the assumed warming scenarios, it is likely that in the future, the river might shift from a ‘melt‐dominated river’ to a ‘rain‐dominated river’. The J2000 model should be considered a promising tool to better understand the hydrological dynamics in alpine mountain catchments of the Himalayan region. This understanding will be quite useful for further analysis of ‘what‐if scenarios’ in the context of global climate and land‐use changes and ultimately for sustainable Integrated Water Resources Management in the Himalayan region. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献