Organisch-chemische Untersuchungen an Kohlen-Maceralen mit der Ionensonde (IMS-3F)     

Monika Wolf 《Organic Geochemistry》1980,2(3-4)

Secondary ion mass spectra of coal macerals were recorded using the new Cameca ionprobe IMS-3F. The sporinite shows the most significant mass spectrum, the fusinite spectrum is poor in fragmentation masses that characterizes its aromacity (see Table 1). This unexpected results is believed to be influenced by the limited recording of masses (<250). Nevertheless, progress is to be expected in the field of organic geochemistry using the SIMS method.  相似文献   

New interpretations of the facies of the rhenish brown coal of West Germany     

Hans W. Hagemann  Monika Wolf 《International Journal of Coal Geology》1987,7(4)

New ideas concerning the understanding of the facies of the Rhenish brown coal of West Germany are discussed. These new interpretations are based on a significantly larger number of samples and refined procedures for analysis within the field of paleobotany, palynology, coal petrology and organic geochemistry than were available to P. W. Thomson and M. Teichmüller. The light and dark bands in the coal are mainly the result of different degrees of plant decomposition. The influence of the peat-forming plant communities plays a subordinate role in the petrographical composition of these particular strata of the Rhenish brown coal.  相似文献   

Quality assessment of OpenStreetMap data using trajectory mining   总被引：1，自引：0，他引：1  

Anahid Basiri  Mike Jackson  Pouria Amirian  Amir Pourabdollah  Monika Sester  Adam Winstanley 《地球空间信息科学学报》2016,19(1):56-68

OpenStreetMap (OSM) data are widely used but their reliability is still variable. Many contributors to OSM have not been trained in geography or surveying and consequently their contributions, including geometry and attribute data inserts, deletions, and updates, can be inaccurate, incomplete, inconsistent, or vague. There are some mechanisms and applications dedicated to discovering bugs and errors in OSM data. Such systems can remove errors through user-checks and applying predefined rules but they need an extra control process to check the real-world validity of suspected errors and bugs. This paper focuses on finding bugs and errors based on patterns and rules extracted from the tracking data of users. The underlying idea is that certain characteristics of user trajectories are directly linked to the type of feature. Using such rules, some sets of potential bugs and errors can be identified and stored for further investigations.  相似文献   

Measurements of Volatile Organic Compounds (VOC) During POPCORN 1994: Applying a New On-Line GC–MS-Technique     

Arno Wedel  Klaus-Peter Müller  Monika Ratte  Jochen Rudolph 《Journal of Atmospheric Chemistry》1998,31(1-2):73-103

Atmospheric concentrations of ca. 250 C6–C15 hydrocarb on and C4–C12 oxygenated volatile organic compounds (VOC) including alkanes, benzene and alkyl benzenes, monoterpenes and aldehydes were measured in August 1994 during the POPCORN campaign (POPCORN = Photo-Oxidant formation by Plant emitted Compounds and OH Radicals in North-Eastern Germany). About 80 substances together contributed 90% of the atmospheric carbon in this range of molecular weight. During this field campaign VOC-emissions from several crop and tree species and the ambient concentrations of CO, C2–C7 non-methane hydrocarbons (NMHC), C1 and C2 aldehydes, nitrogen oxides, ozone and hydroxyl-radicals (OH) were also measured. These data were used to interpret the VOC measurements presented here. The on-line GC–MS used for the VOC measurements combines adsorptive sampling with thermal desorption and GC–MS analysis in an automated system. Internal standards were used to quantify the measurements. Ozone was destroyed prior to the sample preconcentration through the gas phase reaction with NO. Aromatic compounds like benzene, toluene and xylenes were the most abundant compound class among the measured substances, -pinene and 3-carene, most probably originating from pineforests ca. 1 km away from the measuring site, were the most abundant monoterpenes. The highest mixing ratios of most compounds were measured in nights with strong inversion situations. The toluene mixing ratios then reached 630 pptv; -pinene mixing ratios went up to 430 pptv. The median of all toluene and -pinene measurements during the campaign was 125 pptv or 22 pptv, respectively. These values are on the lower end of ambient measurements reported for continental sites. In most samples also n-pentanal, n-hexananl, n-nonanal and n-undecanal were present. Median mixing ratios were 9, 16, 14 and 8 pptv, respectively. Emission studies indicate that these highly reactive compounds are most probably emitted from maize. It is shown by a simple first order approach that the potential for ozone formation during the POPCORN campaign was roughly equal for anthropogenic and biogenic VOC. From measured concentrations of ozone, OH-radicals, methane, CO, C2–C15 nonmethane hydrocarbons (NMHC) and C5–C11 aldehydes a photochemical production of ozone in the order of 3.5 ppb/h can be estimated. Apart from formaldehyde and acetaldehyde, which are at least partly products of VOC oxidation, the substance group with the largest contribution to the VOC turnover are the monoterpenes. They contribute ca. 30%. However, the mechanism of terpene oxidation is very complex and presently only partly understood. Thus the actual contribution of monoterpenes to ozone formation is very uncertain. Other measured compound classes such as light alkenes, alkanes, aromatics, and C5–C11 aldehydes contribute each between 10% and 15% to ozone formation. The measuring site was not influenced directly from strong biogenic or anthropogenic sources, and the results obtained during the POPCORN campaign can be regarded as a typical picture of a remote rural central European environment.  相似文献   

Transport of South Atlantic water through the passages south of Guadeloupe and across 16°N, 2000–2004   总被引：1，自引：1，他引：1  

Monika Rhein  Kerstin Kirchner  Christian Mertens  Reiner Steinfeldt  Maren Walter  Ulrich Fleischmann-Wischnath 《Deep Sea Research Part I: Oceanographic Research Papers》2005,52(12):2234-2249

CTD, vessel-mounted ADCP and LADCP measurements in the Caribbean passages south of Guadeloupe (three repeats) and along 16°N (five repeats) were carried out between December 2000 and July 2004. The CTD data were used to calculate the contribution of South Atlantic water (SAW) in the upper 1200 m between the isopycnals σ_θ=24.5 and 27.6. Northern and southern source water masses are defined and an isopycnal mixing approach is applied. The SAW fractions are then combined with the ADCP flow field to calculate the transport of SAW into the Caribbean and across 16°N. The SAW inflow into the Caribbean through the passages south of Guadeloupe ranges from 7.6 to 11.6 Sv, which is 50–75% of the total inflow. The mean (9.1±2.2 Sv) is in the range of previous estimates. Ambiguities in the northern and southern source water masses of the salinity maximum water permitted us only to calculate the contribution of SAW from the eastern source in this water mass. We estimated the additional SAW transport by the western source to be of the order of 1.9±0.7 Sv. The calculation of the SAW transport across 16°N was hampered by the presence of several anticyclonic rings from the North Brazil Current (NBC) retroflection region, some of the rings were subsurface intensified. Provided that the rings observed at 16°N are typical rings and that all rings which are annually produced in the NBC retroflection area (6.5–8.5 per year) reach 16°N, the SAW ring transport across 16°N is calculated to 5.3±0.7 Sv. From the 5 repeats at 16°N, only two showed a net northward flow, suggesting that the mean northward SAW transport is dominated by ring advection. The joint SAW transports of the Caribbean inflow (9.1 Sv) and the flow across 16°N (5.3 Sv) sum up to 14.4 Sv. The transport increases to 16.3 Sv if the additional SAW transport from the western source of SMW (1.9±0.7 Sv) is included. These transport estimates and the following implications depend strongly on the assumption that the surface water in the Caribbean inflow is of South Atlantic origin. The transport estimates are, however, in the range of the inverse model calculations for the net cross-hemispheric flow. About 30–40% of this transport is intermediate water from the South Atlantic, presumably supporting studies which found the contributions of intermediate and upper warm water to be of a comparable magnitude. For the upper warm water (σ_θ<27.1), the Caribbean inflow seems to be the major path (7.9±1.6 Sv), the ring induced transport across 16°N is about 30% of that value. The intermediate water transport across 16°N was calculated to be 2.3–3.6 Sv, the inflow into the Caribbean is slightly smaller (1.5–2.4 Sv).  相似文献   

Preselection of a sorption model based on a column test: the algorithm and an example of its application     

Marciniak  Marek  Okońska  Monika  Kaczmarek  Mariusz 《Hydrogeology Journal》2021,29(4):1551-1567

  相似文献   

Disentangling late-Holocene climate and land use impacts on an Austrian alpine lake using seasonal temperature anomalies,ice-cover,sedimentology, and pollen tracers   总被引：1，自引：0，他引：1  

Roland Schmidt  Monika Roth  Richard Tessadri  Kaarina Weckström 《Journal of Paleolimnology》2008,40(1):453-469

Major and trace elements, minerals and grain-size were analysed from a sediment core covering the last 4,000 years of an Austrian Alpine lake (Oberer Landschitzsee, ObLAN, 2,076 m a.s.l.). These analyses were combined with autumn and spring temperature anomalies and ice-cover estimated from a diatom and chrysophyte cyst, thermistor-based regional calibration dataset and selected pollen markers published previously. Diatom-inferred pH (Di-pH) and DOC (Di-DOC) completed the multi-proxy approach, which, together with ordination techniques (PCA and RDA), helped (1) to confirm proposed climatic patterns and hypotheses, and (2) to disentangle the complex interactions between climatic and anthropogenic impacts. Shifts in chemical and physical weathering, erosion, production, lake stratification, redox potentials and air pollution were the major processes that have affected Oberer Landschitzsee in relation to climate, lake/catchment interactions, and human impact. Geochemistry supported the finding that the four waves of high-altitude land use (Early to Middle Bronze, ca. 1,800–1,300 B.C.; Late Bronze to Hallstatt, ca. 1,000–500 B.C.; Celtic to Roman, ca. 300 B.C.–400 A.D.; and Medieval, ca. 1,000–1,600 A.D.) were coupled mainly with warm periods. Increased production, onset of lake stratification, and the deterioration of hypolimnetic oxygen conditions were the major changes governing in-lake processes during climate warming. They resulted in specific element assemblages associated with organic matter accumulation (Br), oxygen depletion (As, Ga, Cu, S), and changes in redox (Fe/Mn). The Se/Di-DOC ratio was introduced to track shifts between in-lake production and allochthonous sources. Nutrient loading from pastures, coupled with climate warming, could explain that in-lake production was highest during Roman and Medieval land use. Lithogenic elements mainly originated from chemical weathering of silicate bedrock and they increased when intense land-use was coupled with climate deterioration and/or increased humidity. These perturbations were highest during a High Medieval climate fluctuation around 1,000 A.D. The association of sand with LOI and C/N and the decoupling of sand from quartz and feldspar separates erosion from physical weathering. Di-DOC, S, and C/N showed hybrid characters in relation to climate and human impact. The mineral proportions indicated gradients in relation to weathering, snow-cover and running waters, as well as vegetation. Air pollution by metallurgic industries, starting during the High Medieval and culminating during the Late Medieval, caused lead accumulation and could have contributed to As and S enrichment. Corresponding features in the distribution of selected elements and pollen tracers, as well as changes in mineral proportions, supported the hypotheses of shifts in seasonal climate and an overall trend towards more continental climate conditions since Medieval times.  相似文献   

Do cytotoxic chemotherapy drugs discharged into rivers pose a risk to the environment and human health? An overview and UK case study     

Andrew C. Johnson  Monika D. Jürgens  Richard J. Williams  Klaus Kümmerer  Andreas Kortenkamp  John P. Sumpter 《Journal of Hydrology》2008,348(1-2):167-175

  相似文献   

The Monitoring Network of the Vancouver 2010 Olympics   总被引：1，自引：0，他引：1  

Paul Joe  Bill Scott  Chris Doyle  George Isaac  Ismail Gultepe  Douglas Forsyth  Stewart Cober  Edwin Campos  Ivan Heckman  Norman Donaldson  David Hudak  Roy Rasmussen  Paul Kucera  Ron Stewart  Julie M. Thériault  Teresa Fisico  Kristen L. Rasmussen  Hannah Carmichael  Alex Laplante  Monika Bailey  Faisal Boudala 《Pure and Applied Geophysics》2014,171(1-2):25-58

  相似文献   

Lower Miocene structural evolution of the central Vienna Basin (Austria)     

Monika Hölzel  Kurt Decker  András Zámolyi  Philipp Strauss  Michael Wagreich 《Marine and Petroleum Geology》2010

The tectonic evolution of the Vienna Basin overlying the Alpine-Carpathian fold and thrust belt includes two stages of distinct basin subsidence and deformation. The earlier phase contemporaneous with thrusting of the Alpine-Carpathian floor thrust is related to the formation of a wedge-top basin (“piggy-back”), which was connected to the evolving foreland basin (Lower Miocene; c. 18.5–16 Ma). This stage is followed by the formation of a pull-apart basin (Middle to Upper Miocene; c. 16–8 Ma). Sediments of the latter unconformably overly wedge-top basin strata and protected them against erosion.  相似文献