Добірка наукової літератури з теми "Analyse des isotope stables"

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Статті в журналах з теми "Analyse des isotope stables":

1

Fitzsimons, I. C. W., B. Harte, and R. M. Clark. "SIMS stable isotope measurement: counting statistics and analytical precision." Mineralogical Magazine 64, no. 1 (February 2000): 59–83. http://dx.doi.org/10.1180/002646100549139.

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AbstractAnalytical precision is vital in the interpretation of stable isotope data collected by secondary ion mass spectrometry (SIMS) given the small analysis volumes and the small magnitude of natural isotopic variations. The observed precision of a set of measurements is represented by the standard deviation(precision of an individual measurement) or the standard error of the mean (precision of the mean value). The SIMS data show both systematic variations with time and random Poisson variability, but the former largely cancel out when data for two different isotopes are expressed as a ratio. The precision of a SIMS isotope ratio routinely matches that predicted by Poisson counting statistics and can approach that of conventional bulk analysis techniques for counting times of several hours. All sample analyse must be calibrated for instrumental mass fractionation using SIMS analyses of a standard material. There is often a gradual drift in the mass fractionation with time, but this can be modelled by least-squares regression of the standard isotope ratios. Drift in the sample analyses is eliminated by using the relevant point on this regression line to calibrate each sample. The final precision of a corrected isotope ratio must take into account the scatter in both the sample and the standard data.
2

Halley, Duncan J., Masao Minagawa, Mauri Nieminen та Eldar Gaare. "Preservation in 70% ethanol solution does not affect δ13C and δ15N values of reindeer blood samples – relevance for stable isotope studies of diet". Rangifer 28, № 1 (29 квітня 2008): 9. http://dx.doi.org/10.7557/2.28.1.146.

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We compared duplicate samples of whole blood samples from 18 reindeer that were preserved either by immediate freezing or by immersion in 70 % ethanol. All samples were dried at 60 °C, powdered, treated with 1:1 chloroform: methanol, and dried again before isotope analysis. There were no differences in the values of δ13C and δ15N between the methods of preservation. Isotopic differences were absolutely small (δ13C = 0.1±0.10/00; δ15N=0.2±0.20/00), random in direction, and within the limits of analytical precision for the mass spectrometer. Preservation in ethanol thus appears to be an effective and efficient method for preserving blood samples for stable isotope analysis under field conditions. Abstract in Norwegian / Sammendrag:Konservering av blodprøver fra rein i 70% etanolløsning påvirker ikke verdiene av δ13C and δ15N–verdiene og er en fullgod metode for analyse av stabile isotoperVi sammenlignet to og to prøver av blodprøver fra 18 reinsdyr. Prøvene var enten konservert ved umiddelbar frysing eller ved bruk av 70% etanol. Alle prøver ble tørket ved 60 °C, pulverisert og behandlet med kloroform:metanol i forholdet 1:1. Til slutt ble de tørket på nytt før gjennomføring av isotopanalysen. Vi fant ingen forskjell i verdiene av δ13C and δ15N mellom de to konserveringsmetodene. I absolutte verdier var isotopforskjellene små (δ13C = 0.1±0.1 0/00; δ15N=0.2±0.2 0/00). Forskjellene var tilfeldige og innenfor grensene for massespektrometerets presisjon. Bruk av etanol framstår som en effektiv og fullgod metode til konservering av blodprøver for analyse av stabile isotoper under feltforhold.
3

Dietermann, N., and M. Weiler. "Spatial distribution of stable water isotopes in alpine snow cover." Hydrology and Earth System Sciences 17, no. 7 (July 11, 2013): 2657–68. http://dx.doi.org/10.5194/hess-17-2657-2013.

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<p><strong>Abstract.</strong> The aim of this study was to analyse and predict the mean stable water isotopic composition of the snow cover at specific geographic locations and altitudes. In addition, the dependence of the isotopic composition of the entire snow cover on altitude was analysed. Snow in four Swiss catchments was sampled at the end of the accumulation period in April 2010 and a second time during snowmelt in May 2010 and analysed for stable isotope composition of <sup>2</sup>H and <sup>18</sup>O. The sampling was conducted at both south-facing and north-facing slopes at elevation differences of 100 m, for a total altitude difference of approximately 1000 m. The observed variability of isotopic composition of the snow cover was analysed with stepwise multiple linear regression models. The analysis indicated that there is only a limited altitude effect on the isotopic composition when considering all samples. This is due to the high variability of the isotopic composition of the precipitation during the winter months and, in particular in the case of south-facing slopes, an enrichment of heavy isotopes due to intermittent melting processes. This enrichment effect could clearly be observed in the samples which were taken later in the year. A small altitudinal gradient of the isotopic composition could only be observed at some north-facing slopes. However, the dependence of snow depth and the day of the year were significant predictor variables in all models. This study indicates the necessity to further study the variability of water isotopes in the snow cover to increase prediction for isotopic composition of snowmelt and hence increase model performance of residence time models for alpine areas in order to better understand the accumulation processes and the sources of water in the snow cover of high mountains.</p>
4

Stenroth, Patrik, Niklas Holmqvist, Per Nyström, Olof Berglund, Per Larsson, and Wilhelm Granéli. "Stable isotopes as an indicator of diet in omnivorous crayfish (Pacifastacus leniusculus): the influence of tissue, sample treatment, and season." Canadian Journal of Fisheries and Aquatic Sciences 63, no. 4 (April 1, 2006): 821–31. http://dx.doi.org/10.1139/f05-265.

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Stable isotopes have been used to analyse food webs and (or) trace movements of animals for about 30 years. There has been some debate on the use of different tissues and treatments before isotope analysis, as well as on seasonal effects. We found different crayfish (Pacifastacus leniusculus) tissues (muscle, hepatopancreas, exoskeleton, gill, and whole body) to have different isotope values. Lipid extraction made whole-body carbon isotope values higher but had no effect on nitrogen isotope values. Acidification made whole-body isotope values lower. For crayfish, there was no seasonal or interannual variation in isotope values. In contrast to studies based on gut content analysis, we found adult crayfish to be at least as carnivorous as young-of-the-year crayfish. Earlier studies often have assumed that each food source contributes both nitrogen and carbon in equal proportions. Omnivores do not fit easily into this view. We suggest that nitrogen and carbon in an organism could come from different sources. Adopting this view for a pond food web could render crayfish both predators and detritivores as crayfish prey on nitrogen sources (other invertebrates) and consume large amounts of detritus to satisfy their carbon demand.
5

Laepple, Thomas, Thomas Münch, Mathieu Casado, Maria Hoerhold, Amaelle Landais, and Sepp Kipfstuhl. "On the similarity and apparent cycles of isotopic variations in East Antarctic snow pits." Cryosphere 12, no. 1 (January 17, 2018): 169–87. http://dx.doi.org/10.5194/tc-12-169-2018.

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Abstract. Stable isotope ratios δ18O and δD in polar ice provide a wealth of information about past climate evolution. Snow-pit studies allow us to relate observed weather and climate conditions to the measured isotope variations in the snow. They therefore offer the possibility to test our understanding of how isotope signals are formed and stored in firn and ice. As δ18O and δD in the snowfall are strongly correlated to air temperature, isotopes in the near-surface snow are thought to record the seasonal cycle at a given site. Accordingly, the number of seasonal cycles observed over a given depth should depend on the accumulation rate of snow. However, snow-pit studies from different accumulation conditions in East Antarctica reported similar isotopic variability and comparable apparent cycles in the δ18O and δD profiles with typical wavelengths of ∼ 20 cm. These observations are unexpected as the accumulation rates strongly differ between the sites, ranging from 20 to 80 mm w. e. yr−1 ( ∼ 6–21 cm of snow per year). Various mechanisms have been proposed to explain the isotopic variations individually at each site; however, none of these are consistent with the similarity of the different profiles independent of the local accumulation conditions.Here, we systematically analyse the properties and origins of δ18O and δD variations in high-resolution firn profiles from eight East Antarctic sites. First, we confirm the suggested cycle length (mean distance between peaks) of ∼ 20 cm by counting the isotopic maxima. Spectral analysis further shows a strong similarity between the sites but indicates no dominant periodic features. Furthermore, the apparent cycle length increases with depth for most East Antarctic sites, which is inconsistent with burial and compression of a regular seasonal cycle. We show that these results can be explained by isotopic diffusion acting on a noise-dominated isotope signal. The firn diffusion length is rather stable across the Antarctic Plateau and thus leads to similar power spectral densities of the isotopic variations. This in turn implies a similar distance between isotopic maxima in the firn profiles.Our results explain a large set of observations discussed in the literature, providing a simple explanation for the interpretation of apparent cycles in shallow isotope records, without invoking complex mechanisms. Finally, the results underline previous suggestions that isotope signals in single ice cores from low-accumulation regions have a small signal-to-noise ratio and thus likely do not allow the reconstruction of interannual to decadal climate variations.
6

Macaulay, C. I., A. E. Fallick, R. S. Haszeldine, and C. M. Graham. "Methods of laser-based stable isotope measurement applied to diagenetic cements and hydrocarbon reservoir quality." Clay Minerals 35, no. 1 (March 2000): 313–22. http://dx.doi.org/10.1180/000985500546684.

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AbstractThe stable isotopic compositions of diagenetic minerals can provide valuable constraints on the sources, precipitation temperatures and relative timing of cements in reservoir rocks. This type of information is essential when trying to understand and predict the distribution of cements in the subsurface, and their impact on reservoir quality. Conventional isotope methods contribute to answers to many diagenetic problems, but where core or time are scarce, or where good mineral separation is unobtainable, laser-based stable isotope methods offer several advantages. These include the ability to analyse carbonates, sulphides and anhydrite in situ with 50–100 μm resolution, simple and clear sample and analysis viewing optics, savings on sample preparation time and greatly reduced sample size requirements.Diagenetic silicates such as quartz and clay cements cannot be analysed in situ by laser but, where in situ analysis of quartz δ18O is demanded, ion microprobe analysis can provide very high resolution (20–30 μm) capability with a precision of ±1%.
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Osipowicz, Grzegorz, Andrzej Bokiniec, Krzysztof Kurzyk, Daniel Makowiecki, Dorota Bienias, Tomasz Górzyński, Michał Jankowski, et al. "The Late Neolithic sepulchral and ritual place of site 14 in Kowal (Kuyavia, Central Poland)." Praehistorische Zeitschrift 89, no. 2 (June 30, 2014): 261–79. http://dx.doi.org/10.1515/pz-2014-0018.

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Zusammenfassung: Forschungsgegenstand dieses Artikels ist ein Begräbnis- und Ritualplatz der Kugelamphoren-Kultur der Fundstätte 14 in Kowal (Zentral-Polen). Die Stätte umfasst einen Submegalithen sowie einen Ritualplatz mit Tiergräbern und einer menschlichen Bestattung. Der Komplex kann auf die Zeit zwischen 3250/3100 und 2400/2150 v. Chr. datiert werden. Analysen haben gezeigt, dass der Platz über eine lange Zeit benutzt wurde, und dass die durchgeführten Rituale sehr komplex waren. Beweise wurden gefunden, dass an einigen Stellen rituelle Handlungen ohne Unterbrechung über viele Jahre durchgeführt wurden und einzelne Tieropfer und Niederlegungen nur durch einen Zeitraum von wenigen Jahren voneinander getrennt waren. Die Fund-Struktur einiger Gruben zeigt eine sehr penible Organisation des geheiligten Platzes und ermöglicht an einigen Stellen sogar eine Unterscheidung in Nutz- und rituelle Zonen. Weitere wichtige Informationen wurden durch die Untersuchung einer menschlichen Grablege an dieser Stätte gewonnen. Die Analyse der Grabbeigaben hat deren Natur als rituelle Gaben gezeigt; weiter weist sie auf eine dominante Rolle von Tieren im täglichen Leben der verstorbenen Person hin. Wichtige Daten wurden durch die paläo-biologische Untersuchung der menschlichen Knochen gewonnen. Die paläo-serologische Analyse ergab die Blutgruppe der bestatteten Person. Dies ist der erste derartige Nachweis in der Geschichte der europäischen neolithischen Forschung. Bei den Ergebnissen der DNA-Analyse handelt es eines Vertreters der Kugelamphoren-Kultur in der Literatur und zudem um eine von nur wenigen solcher Untersuchungen eines neolithischen Menschen. Einige der nachgewiesenen Allele sind die ältesten Beispiele dieses speziellen Allel-Typs, die in menschlichen Überresten bis heute identifiziert wurden. Die DNA-Analysen belegen eine Laktose-Intoleranz der bestatteten Person, sie legen weiter eine genetische Verwandtschaft mit der Bevölkerung aus der Region des Fruchtbaren Halbmondes nahe. Die Analyse des stabilen Sauerstoff-Isotopen-Verhältnisses zeigt Muster für häufigeren Ortswechsel und das Entwöhnungsalter. Analysen von stabilen Kohlenstoff- und Stickstoff-Isotopen-Verhältnissen haben Rückschlüsse auf die Ernährung ermöglicht; besondere Aufmerksamkeit verdient die Tatsache, dass bis zu 25 % der Kohlenhydrat-haltigen Nahrung aus Hirse bestanden hat. Das ist der früheste Isotopen-gestützte Nachweis von Hirse in der menschlichen Ernährung in Mitteleuropa. Résumé: Le site 14 de Kowal en Pologne centrale, un complexe rituel appartenant à la culture des amphores globulaires, forme le sujet de cet article. Le site comporte un sub-mégalithe, une structure rituelle avec des dépôts d’animaux et une sépulture humaine. Il fut occupé pendant une longue période allant de 3250/3100 à 2400/2150 av. J.-C. et les rituels étaient complexes: certains furent célébrés au même endroit pendant longtemps, tandis que les sacrifices et dépôts d’animaux n’étaient séparés que par de courts intervalles de peutêtre quelques années. Le remplissage de plusieurs fosses démontre une organisation précise de l’espace sacré, et il a même été possible de faire une distinction entre les actes de déposition rituelle et les dépôts de type utilitaire à l’intérieur de ces fosses. L’étude de la sépulture humaine a également fourni d’importants indices. Il en ressort qu’un individu intentionnellement choisi parmi les membres de ‘l’aristocratie’ locale a été la victime d’un meurtre rituel. L’analyse du mobilier funéraire indique qu’il s’agit d’offrandes rituelles et suggère que les animaux jouaient un rôle déterminant dans la vie de cet individu. L’étude de ses ossements a fourni un important ensemble de données, y compris les résultats d’une analyse sérologique permettant d’identifier – pour la première fois pour le Néolithique européen – le groupe sanguin de cette homme. Dans une étude également pionnière pour la culture des amphores globulaires, l’analyse ADN a permis de décrire la composition génétique d’un de ses membres, une rareté dans les études sur le Néolithique. Certains allèles sont les plus anciens exemplaires d’un type particulier d’allèles jusqu’à présent découvert dans des restes humains. Les données de l’analyse de l’ADN de cet individu suggèrent qu’il était intolérant au lactose et qu’il avait des affinités génétiques avec le Croissant fertile. Les résultats de l’analyse des isotopes stables de l’oxygène peuvent être interprétés soit en termes de mobilité ou de sevrage. Ceux provenant de l’analyse des isotopes stables du carbone et de l’azote nous permettent de reconstruire l’alimentation de notre individu ; en particulier le millet fournissait jusqu’à 25 % de sa consommation en glucides. Ce résultat constitue le premier indice isotopique de la présence du millet dans l’alimentation des populations de l’Europe centrale. Abstract: Site 14 in Kowal (central Poland), a funerary and ritual place of the Globular amphora culture forms the subject of this article. The site includes a sub-megalith, a ritual feature with animal burials and a human burial. The complex can be dated to a period spanning from 3250/3100 to 2400/2150 BC; it was used over a long period, and the rituals carried out were complex. Rituals were performed over many years in certain areas, while individual acts of animal sacrifice and deposition may have been separated by a short interval of just a few years. The fill of some pits shows that the sacred space was carefully organised and it has been possible to distinguish between some utilitarian and ritual deposits within them. Other important information is provided by the study of a human burial discovered at the site. It is possible that a deliberately chosen individual from the tribal ‘aristocracy’ was the victim of a ritual murder. The analysis of the grave goods reveals that they were ritual offerings, and these suggest that animals played a dominant role in the deceased man’s daily life. The study of his bones provides important new insights, including those from a palaeo-serological analysis revealing his blood group, a first in the history of European Neolithic research. The results of DNA analysis constitute the first description of the genetic traits of a representative of the Globular amphora culture, among very few such DNA profiles available for a Neolithic person. Some of the alleles discovered are the oldest examples of particular alleles among those identified in human remains so far. DNA evidence suggests that the individual was lactose intolerant, and it demonstrates a genetic relationship with the Fertile Crescent. The analysis of stable oxygen isotope ratios shows patterns compatible with either residential mobility or weaning age. The analysis of stable carbon and nitrogen isotope ratios allowed us to reconstruct the individual’s diet; particular attention is drawn to the fact that up to 25 % of his carbohydrate diet consisted of millet. This is the earliest isotopic evidence for the presence of millet in the diet of people living in Central Europe.
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van der Wel, L. G., V. Gkinis, V. A. Pohjola, and H. A. J. Meijer. "Snow isotope diffusion rates measured in a laboratory experiment." Journal of Glaciology 57, no. 201 (2011): 30–38. http://dx.doi.org/10.3189/002214311795306727.

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AbstractThe diffusion of stable water isotopes in snow was measured in two controlled laboratory experiments. Two batches of snow of different isotopic composition were stacked alternately with varying layer thicknesses. The stack was stored in a freezer room at constant temperature for several months, and sampled at regular intervals to analyse the diffusion. Measured isotope profiles were fitted to a theoretical model with diffusion length as the fit parameter. In the first experiment, we observed a difference in diffusion rates between layers of different thicknesses, which is likely caused by layers of snow not being in proper contact with each other. In the second experiment we found very good agreement between measurements and model results. The measured diffusivity is compared with theory, in which we mainly focus on the temperature dependence of the ice–vapour fractionation factors. This temperature dependence is slightly different for the different isotopes of water, which leads to a difference in diffusion rates. We illustrate how our set-up can be used to measure the ratio between ice–vapour fractionation factors of oxygen-18 and deuterium, which determine the relation between the difference in diffusion and the firn temperature.
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Dittmann, Anna, Elisabeth Schlosser, Valérie Masson-Delmotte, Jordan G. Powers, Kevin W. Manning, Martin Werner, and Koji Fujita. "Precipitation regime and stable isotopes at Dome Fuji, East Antarctica." Atmospheric Chemistry and Physics 16, no. 11 (June 6, 2016): 6883–900. http://dx.doi.org/10.5194/acp-16-6883-2016.

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Abstract. A unique set of 1-year precipitation and stable water isotope measurements from the Japanese Antarctic station, Dome Fuji, has been used to study the impact of the synoptic situation and the precipitation origin on the isotopic composition of precipitation on the Antarctic Plateau. The Antarctic Mesoscale Prediction System (AMPS) archive data are used to analyse the synoptic situations that cause precipitation. These situations are investigated and divided into five categories. The most common weather situation during a precipitation event is an upper-level ridge that extends onto the Antarctic Plateau and causes strong northerly advection from the ocean. Most precipitation events are associated with an increase in temperature and wind speed, and a local maximum of δ18O. During the measurement period, 21 synoptically caused precipitation events caused 60 % of the total annual precipitation, whereas the remaining 40 % were predominantly attributed to diamond dust. By combining the synoptic analyses with 5-day back-trajectories, the moisture source regions for precipitation events were estimated. An average source region around a latitude of 55° S was found. The atmospheric conditions in the source region were used as initial conditions for running a Rayleigh-type isotopic model in order to reproduce the measured isotopic composition of fresh snow and to investigate the influence of the precipitation source region on the isotope ratios. The model represents the measured annual cycle of δ18O and the second-order isotopic parameter deuterium excess reasonably well, but yields on average too little fractionation along the transport/cooling path. While simulations with an isotopic general circulation model (GCM) (ECHAM5-wiso) for Dome Fuji are on average closer to the observations, this model cannot reproduce the annual cycle of deuterium excess. In the event-based analysis, no evidence of a correlation of the measured deuterium excess with the latitude of the moisture source region or the corresponding conditions was identified. Contrary to the assumption used for decades in ice core studies, a more northerly moisture source does not necessarily mean a larger temperature difference between source area and deposition site, thus a more depleted precipitation in heavy isotopes with a higher deuterium excess.
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Bode, Antonio, and Maria Teresa Alvarez-Ossorio. "Taxonomic versus trophic structure of mesozooplankton: a seasonal study of species succession and stable carbon and nitrogen isotopes in a coastal upwelling ecosystem." ICES Journal of Marine Science 61, no. 4 (January 1, 2004): 563–71. http://dx.doi.org/10.1016/j.icesjms.2004.03.004.

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Abstract Seasonal variations in mesozooplankton (>200 μm) stable carbon and nitrogen isotope abundances were compared with the seasonal species succession pattern off A Coruña (Galicia, NW Spain). Mesozooplankton biomass, numerical abundance, species composition, and natural abundance of stable isotopes, along with water column temperature, salinity, chlorophyll a and dissolved nitrate concentrations, were studied in monthly samples during the years 2000 and 2001 at a coastal station (80-m depth). Biomass and abundance of mesozooplankton followed the annual cycle with maxima in spring and summer (year 2000) and occasionally also in autumn (year 2001). The succession pattern shown by the taxonomic assemblages was recognized in both years of study, despite differences in the timing of upwelling and the large input of continental water during most of 2000. Variations in neither carbon nor nitrogen isotopes were correlated with either abundance or biomass at annual time scales, but heavy isotopes significantly accumulated during periods of zooplankton increase (spring and early summer). The consumption of nitrate during the spring can explain in part the progressive accumulation of heavy nitrogen isotopes during this period. In addition, the abundance of carnivorous zooplankton (mainly carnivorous copepods, siphonophores, and chaetognaths) was linearly related to the increase in heavy isotopes during the spring and, in the case of nitrogen, also during the whole study period. The computed linear relationships between isotope abundances and plankton species composition provided a way to further analyse the pelagic foodweb through the estimation of isotope reference values for primary consumers.

Дисертації з теми "Analyse des isotope stables":

1

Morin, Samuel. "Analyse de la composition isotopique de l'ion nitrate dans la basse atmosphère polaire et marine." Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00326229.

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Les oxydes d'azote atmosphériques (NOx=NO+NO2) sont des composés clefs en chimie de l'environnement, jouant un rôle central pour la capacité oxydante de l'atmosphère et le cycle de l'azote. La composition isotopique du nitrate atmosphérique (NO?3 particulaire et HNO3 gazeux), constituant leur puits ultime, renseigne sur leur bilan chimique. Le rapport 15N/14N donne une indication de leurs sources, alors que l'anomalie isotopique en oxygène (?17O=d17O-0.52×d18O) révèle la nature de leurs mécanismes d'oxydation. Des études couplées de d15N et ?17O d'échantillons de nitrate atmosphérique collectés dans l'Arctique, en Antarctique et dans l'atmosphère marine au dessus de l'Océan Atlantique, où le bilan des NOx est souvent mal connu ont été effectuées. À ces fins, le défi que constitue la mesure simultanée des trois rapports isotopiques du nitrate (17O/16O, 18O/16O et 15N/14N) dans le même échantillon représentant moins d'une micromole a été relevé. La solution adoptée tire avantage des propriétés d'une bactérie dénitrifiante, utilisée pour convertir le nitrate en N2O, dont la composition isotopique totale a été mesurée en utilisant un système automatisé de chromatographie en phase gazeuse et spectrométrie de masse de rapport isotopique. Les principaux résultats obtenus via les isotopes de l'oxygène permettent l'identification claire de transitions saisonnières entre voies d'oxydation des NOx, y compris le rôle majeur des composés halogénés réactifs au printemps polaire en régions côtières. Les isotopes de l'azote ont quant à eux permis d'apporter de nouvelles contraintes sur le cycle de l'azote dans les régions polaires, grâce au fractionnement significatif induit par les phénomènes de remobilisation post-dépôt affectant le nitrate dans le manteau neigeux, et l'émission de NOx qui en découle
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DAY, MARTIN. "Etude de la caracterisation de l'origine geographique des mouts et des vins par analyse conjointe de la composition en isotopes stables et en elements mineraux." Nantes, 1993. http://www.theses.fr/1993NANT2024.

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Les techniques de determination des teneurs en isotopes stables, employant la spectrometrie de masse de rapports isotopiques et la resonance magnetique nucleaire quantitative de deuterium, sont a l'heure actuelle les plus performantes pour la caracterisation exacte de l'origine des produits de la vigne. Il est possible d'effectuer une classification des differentes aires de production avec une bonne discrimination grace a l'influence du climat sur le comportement des isotopes stables. Cependant au sein d'une meme region, cette discrimination est moins facile et il faut faire appel a d'autres techniques pour augmenter le pouvoir discriminant. Les elements traces, par leur relation etroite avec la composition du sol, sont choisis afin d'etudier leurs possibilites supplementaires de discrimination. L'approche conjointe utilisant des isotopes stables et des elements mineraux est testee sur deux cas precis. La premiere etude porte sur un protocole d'evaluation de l'effet des differences eco-geo-pedologiques d'une region precise sur les parametres physico-chimiques et organoleptiques des vins. Le deuxieme cas demontre que, pour un millesime donne (1989 ou 1990), cette approche integree permet de classer de grandes zones francaises de production viticoles et dans certains cas des appellations individuelles. Une discrimination quasi-parfaite des quatre grandes appellations de bourgogne et egalement des groupes d'appellation en val de loire est possible
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Leroy-Dos, Santos Christophe. "Variabilité du cycle hydrologique atmosphérique en régions polaires à partir de mesures des isotopes stables de l'eau dans la vapeur, les précipitations et les carottes de névé A dedicated robust instrument for water vapor generation at low-humidity for use with a laser water isotope analyzer in cold and dry polar regions. A 4.5 year‐long record of Svalbard water vapor isotopic composition documents winter air mass origin Coastal water vapor isotopic composition driven by katabatic wind variability in summer at Dumont d’Urville, coastal East Antarctica Water vapor isotopic signature along the EAIIST traverse (East Antarctica Plateau)." Thesis, université Paris-Saclay, 2021. http://www.theses.fr/2021UPASJ006.

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Dans un contexte de réchauffement climatique, appréhender l'évolution de la hausse du niveau des mers est un enjeu majeur. Pour cela un des éléments clefs est de comprendre l'évolution du cycle hydrologique atmosphérique dans les régions polaires qui influence directement le bilan de masse de surface des calottes Arctique et Antarctique (les deux plus gros réservoirs d'eau douce de la planète). Des enregistrements existent grâce aux données satellites depuis 50 ans et quelques rares données météo depuis 70 ans en Antarctique mais ces enregistrements sont trop courts pour étudier les modes de variabilité pluri-annuels ainsi que la différence entre signal anthropique et signal naturel. Pour avoir accès à des enregistrements plus longs, une des meilleures solutions est d'utiliser les traceurs climatiques dans les carottes de névé. La composition isotopique de l'eau dans ces carottes est largement utilisée pour reconstruire les variations de température passée. Cela dit, le lien entre température et composition isotopique n'est pas très bien contraint car de nombreux autres paramètres influencent la composition isotopique de la neige au moment de sa formation (i.e. température, altitude, humidité, origine de la masse d'air) ou après le dépôt de neige en surface (i.e. échange atmosphère-neige, diffusion du signal, sublimation de la neige de surface).L'objectif de cette thèse est de mieux comprendre le cycle hydrologique atmosphérique et son influence sur la composition isotopique de la vapeur et de la précipitation dans les régions polaires avec en tête l'idée d'améliorer l'interprétation des carottes de névé dans ces régions. Ce travail se décompose en 3 parties.Dans un premier temps, nous avons développé une solution technique qui répondait au défi de la mesure de la composition isotopique de la vapeur toute l'année en région polaire. En effet, l'hiver étant très sec dans ces régions (jusqu'à 10 ppmv à Dome C, l'hiver), l'utilisation d'un analyseur laser Picarro était limité car il est très sensible aux variations d'humidité en dessous de 2000 ppmv. L'hiver est une saison clé dans les régions polaires car elle est synonyme d'une importante variabilité climatique du fait de nombreux évènements synoptiques. Durant cette thèse, la fabrication de 2 prototypes de générateur de très basse humidité (LHLG) a permis de calibrer les analyseurs Picarro sur une gamme de 200 à 2500 ppmv.Ensuite, j'ai analysé la plus longue série de mesures de la composition de la vapeur et de la précipitation jamais effectuée en région polaire: 4,5 années en continu, à 78°N au Svalbard. J'ai montréque le site de mesure était très peu influencé par des processus locaux agissant sur la composition isotopique de la vapeur d’eau. Grâce à cela, j'ai pu attribuer les variations observées, l'hiver, à des évènements synoptique et ainsi attribuer une signature isotopique différente aux masses d'air en fonction de leur origine (Nord Atlantique ou Arctique).Enfin, j'ai installé le nouvel instrument de calibration fabriqué au début de mon doctorat à Dumont D'Urville (DDU), sur la côte en Terre Adélie. Grâce à cela, la première campagne de mesure continue de la composition isotopique de la vapeur à DDU initiée en janvier 2019 est toujours en cours. Je présente ici les 22 premiers mois de ce nouvel enregistrement. Cette série unique permet de documenter la signature isotopique du cycle hydrologique atmosphérique en Terre Adélie toute l'année. J'ai étudié l'influence des vents catabatiques, de la glace de mer et des rivières atmosphériques sur le signal enregistré dans la vapeur. Ces résultats préliminaires ouvrent des perspectives pour l'interprétation des carottes de névé récemment forées dans le cadre du programme ASUMA
In a global warming context, understanding the evolution of sea level rise is a major challenge. It is key to estimate the evolution of the atmospheric hydrological cycle in the polar regions, which directly influences the surface mass balance of the Arctic and Antarctic ice caps (the two largest freshwater reservoirs on the planet). Records are available from satellite data for the last 50 years and a few rare weather data since the 50's in Antarctica, but these records are too short to study the patterns of interannual variability and the difference between anthropogenic and natural signals. One of the best ways to access longer records is to use climate proxies in snow cores. The water isotopic composition in these cores is widely used to reconstruct past temperature variations. However, the link between temperature and isotopic composition is not very well constrained because many other parameters influence the isotopic composition of snow at the time of its formation (i.e. temperature, altitude, humidity, origin of the air mass) or after snow deposition on the surface (i.e. atmosphere-snow exchange, signal scattering, sublimation of surface snow).The objective of this thesis is to better understand the atmospheric hydrological cycle and its influence on the isotopic composition of vapour and precipitation in polar regions with the idea of improving the interpretation of snow core records in these regions. This work is divided into 3 parts.Firstly, we developed a technical solution to meet the challenge of measuring the vapor isotopic composition all year round in polar regions. Indeed, winter being very dry in these regions (down to 10 ppmv at Dome C in winter), the use of a Picarro laser analyzer is limited because it is very sensitive to humidity variations below 2000 ppmv. Winter is a key season in the polar regions as it is associated with significant climate variability due to numerous synoptic events. During this thesis, the fabrication of 2 prototypes of low humidity level generator (LHLG) allowed the calibration of the Picarro analyzers over a range of 200 to 2500 ppmv.Then, I analyzed the longest series of vapor and precipitation isotopic composition measurements ever performed in a polar region: 4.5 years continuously at 78°N in Svalbard. I showed that the water isotopic composition at this measurement site was unsignificantly influenced by local processes. Thanks to this, I was able to attribute the observed winter variability to synoptic events and thus assign a different isotopic signature to the air masses according to their origin (North Atlantic or Arctic).Finally, I installed the new calibration instrument (LHLG) built at the beginning of my PhD at Dumont D'Urville (DDU), on the coast in Terre Adélie. Thanks to this, the first continuous measurement campaign of the vapor isotopic composition at DDU initiated in January 2019 is still ongoing. I present here the first 22 months of this new record. This unique series makes possible to document the isotopic signature of the atmospheric hydrological cycle in Terre Adélie all year round. I have studied the influence of katabatic winds, sea ice and atmospheric rivers on the signal recorded in the vapor. These preliminary results open perspectives for the interpretation of recently drilled cores from the ASUMA program
4

Schäuble, Annette. "Stadt - Land - Meer Ernährungsrekonstruktion dreier mittelalterlicher Bevölkerungen anhand der Analyse stabiler Isotope und Spurenelemente." Saarbrücken VDM Verlag Dr. Müller, 2005. http://d-nb.info/988702630/04.

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5

Tran, Thi Nhu Trang. "Analyses mutli-isotopiques (¹³C/¹²C, ²H/¹H) par spectrométrie de masse des rapports isotopiques et analyse énantio-sélective : application aux arômes pour le contrôle de l'authenticité des produits alimentaires et pharmaceutiques." Lyon 1, 2006. http://www.theses.fr/2006LYO10152.

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Les huiles essentielles sont des substances odorantes volatiles contenues dans les végétaux et utilisées comme produit de base dans les fragrances et comme substances aromatiques dans les aliments, breuvages, cosmétiques et détergents. L'adultération des huiles essentielles est multiforme et complexe. La chromatographie en phase gazeuse énantio-sélective avec une colonne à base de cyclodextrine et la chromatographie en phase gazeuse couplée à la spectrométrie de masse des rapports isotopiques stables sont utilisées pour caractériser plus à fond l'authenticité d'une huile essentielle. L'utilisation de l'Analyse en Composantes Principales (ACP) comme outil statistique devient alors nécessaire à l'expertise de naturalité. La combinaison de l'analyse énantio-sélective, de l'analyse des rapports isotopiques (13C/12C, D/H) et de l'ACP est indispensable pour s'assurer de la naturalité des huiles essentielles à base de citronnellal et citral. La combinaison des valeurs isotopique D/H du thymol, carvacrol, -terpinène et p-cymène contenus dans les huiles essentielles phénoliques et des facteurs de fractionnement isotopique thymol/p-cymène et carvacrol/p-cymène permet de mettre en évidence des adultérations. En traçant une droite de Henry – distribution ajustée convenablement à la loi normale (Gauss-Laplace) – avec les valeurs isotopique D/H du trans-cinnamaldéhyde dans les huiles essentielles naturelles de cannelle, des bornes de distribution inférieures et supérieures sont mises en évidence pour aider au contrôle de naturalité
6

Cresson, Pierre. "Fonctionnement trophique des récifs artificiels de la baie du Prado (Marseille, France) : Origine et devenir de la matière organique." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4017.

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L'installation de récifs artificiels est une solution classiquement proposée pour soutenir la petite pêche artisanale. C'est dans ce but qu'a été déployé dans la baie de Marseille le plus grand ensemble de récifs artificiels de Méditerranée. Ce système offre une opportunité de comprendre le fonctionnement trophique de ces structures par (1) la caractérisation des sources de matière organique (MO) (2) la détermination de leur utilisation par les consommateurs et (3) leur devenir au sein des réseaux trophiques. Ces questions ont été appréhendées à l'aide des isotopes stables du C et du N, de la caractérisation biochimique des sources de MO et de l'analyse des contenus stomacaux des poissons.Les sources de MO présentent des différences isotopiques et biochimiques, reflet de leurs fonctionnements différents. La MO particulaire en suspension est un pool variable influencé par les apports allochtones et soumis aux forçages climatiques. Elle est la source principale de MO sur les récifs artificiels. La production primaire benthique est très hétérogène et de qualité nutritionnelle faible. Elle contribue aux réseaux trophiques des récifs par le biais des détritus qu'elle produit. Enfin, la MOS est un pool détritique de faible qualité nutritionnelle. Les récifs artificiels ne modifient pas la structure et le fonctionnement des communautés naturelles de poissons et leur offrent des ressources alimentaires variées et importantes. L'ensemble des résultats acquis, via les isotopes stables et les contenus stomacaux, montrent que les récifs artificiels sont des producteurs de biomasse à partir des productions primaires locales
Artificial reefs are a classical tool used to sustain small scale fisheries. In Marseille's Bay, the largest Mediterranean artificial reef system was deployed for this purpose. This system is a valuable opportunity to better understand the trophic functioning of artificial reefs, by (1) characterizing the organic matter (OM) sources, (2) determining how they are used by low trophic level consumers and (3) following their fate in the trophic networks. These issues were assessed by three approaches:C and N stable isotope ratios, biochemical composition of OM sources and fish stomach content.OM sources display isotopic and biochemical differences reflecting their functioning. Suspended POM is variable, under the influence of allochtonous inputs and controlled by climatic forcing. POM represents the main OM source of the artificial reef food webs. The benthic primary production has heterogeneous C and N stable isotope ratios and exhibits mainly high insoluble carbohydrates contents. Benthic primary production is integrated into trophic networks mainly in the form of detritus. Eventually the sediment organic matter is a detrital pool, characterized by a low variability and a poor nutritional quality.Artificial reefs do modify the organization and the functioning of natural fish communities, and provide diversified and important food resources. Stable isotope and stomach content analyses confirm the consumption of artificial reef invertebrates by small carnivorous fishes, preyed themselves by piscivorous predators. All these results confirm that artificial reefs can efficiently increase fish biomass by local production based on phytoplanktonic and local benthic OM sources
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Rigaudier, Thomas. "Analyse isotopique des inclusions fluides des matériaux de la croûte terrestre : caractérisation des sources des fluides et reconstitutions paléoclimatiques." Phd thesis, Université Claude Bernard - Lyon I, 2010. http://tel.archives-ouvertes.fr/tel-00733643.

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Un des enjeux majeurs en Science de la Terre ces dernières décennies est de comprendre les interactions entre les différentes enveloppes terrestres. Le but poursuivi par ce travail est d'aborder quelques aspects de ces interactions du point de vue des cycles géochimiques des éléments volatils H2O et CO2 en se basant sur l'étude des inclusions fluides piégées dans des roches variées de la croûte terrestre, depuis sa surface jusqu'à l'interface croûte-manteau. La première partie de mon travail présente des travaux expérimentaux effectués sur de la halite. L'étude du fractionnement isotopique de l'oxygène et des cinétiques d'équilibration entre H2O et CO2 lors de l'évaporation de saumures a montré l'importance des corrections à effectuer sur les mesures isotopiques de l'oxygène pour des solutions de haute salinité. L'élaboration d'un protocole expérimental de précipitation de halite en milieu contrôlé a permis de mettre en évidence le potentiel des inclusions fluides pour les reconstitutions paléoclimatiques. La combinaison des données microthermométriques et des compositions isotopiques de l'hydrogène et de l'oxygène des inclusions aqueuses permet d'estimer les sources et la température de l'eau de formation de la halite ainsi que la vitesse du vent à l'interface eau-air pendant la croissance du cristal. Cette méthode a été ensuite appliquée aux dépôts de halite de Sicile datés du Messinien. La deuxième partie de mon travail est consacrée à l'identification des compositions chimiques et des sources des fluides circulant dans la croûte et à l'interface croûte-manteau à travers l'analyse des compositions isotopiques des inclusions fluides des granites et granulites.
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KERR, ROBERT. "L'utilisation des isotopes stables dans les etude des transformations metaboliques : application aux orthomethoxybenzamides." Université Louis Pasteur (Strasbourg) (1971-2008), 1988. http://www.theses.fr/1988STR1D173.

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9

Neuberger, Ferdinand M. "Serielle Analyse stabiler Isotope an Haarkeratin zur post mortem Rekonstruktion von Lebenslaufparametern in forensisch relevanten Fällen von Unterernährung." Diss., Ludwig-Maximilians-Universität München, 2013. http://nbn-resolving.de/urn:nbn:de:bvb:19-159798.

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Die Diagnose einer Unterernährung bei Kindern und Erwachsenen ist in der Pädiatrie und Geriatrie ein wichtiges Thema. Aber auch in der Forensik spielt sie eine große Rolle, gerade im Falle von Vernachlässigung und Missbrauch schutzbefohlener Personen. Derzeit existieren kaum Methoden, um zuverlässig den Zeitrahmen einer Unterernährung rückwirkend zu bestimmen. Die Analyse der stabilen Stickstoff- und Kohlenstoffisotope (δ15N-, δ13C-Wert) im Haarkeratin ist in der Anthropologie ein etabliertes Verfahren zur Untersuchung der menschlichen Ernährung und des individuellen Ernährungszustandes. Bei einem mangelhaften Ernährungszustand müssen die körpereigenen Protein- und Energiereserven angegriffen und wiederverwertet werden. Dieser sogenannte Hungerstoffwechsel zeigt sich auch in der biochemischen Zusammensetzung des Haarkeratins. Mithilfe von seriellen Analysen an Haarproben wird nach spezifischen Signaturen der N- und C-Isotope gesucht, welche sich während einer Unterernährung ausbilden. So soll ein verlässlicher Indikator entwickelt werden, welcher es ermöglicht, den Beginn und die Dauer einer Unterernährung zu rekonstruieren. Bei dieser Arbeit liegt der Schwerpunkt auf der Analyse von Haarproben aus der Rechtsmedizin. Jeder dieser 17 Fälle weist eine ausgeprägte Unterernährung auf. Daneben wurden in einer kleinen Vorstudie vier Haarprobe von Magersuchtpatienten untersucht. Trotz unbekannter Ernährungsgewohnheiten kann mit Hilfe der Isotopendaten in den meisten Fällen ein mangelhafter Ernährungszustand diagnostiziert werden. In einigen Fällen ist es sogar möglich, einzelne Unterernährungsphasen voneinander abzugrenzen. Zudem lassen sich mitunter auch Erholungsphasen erkennen, in denen sich der Ernährungszustand scheinbar kurzfristig gebessert hat. Jedoch ist es bisher noch nicht gelungen, allgemein gültige Erkennungsmerkmale aufzustellen, welche bei allen Fällen ausnahmslos zur Bestimmung einer Unterernährung angewendet werden können. Folglich muss weiterhin jeder einzelne Unterernährungsfall individuell analysiert und ausgewertet werden. Des Weiteren wurde an acht Haarproben aus der Rechtsmedizin die spezifische Aminosäurezusammensetzung des Haarkeratins während eines schlechten Ernährungszustandes analysiert. Dabei wurde versucht, der Unterernährungssignatur der δ-Werte weiter auf die Spur zu kommen. Die Daten zeigen, dass vor allem die Aminosäure Prolin während der Unterernährungsphasen vermehrt im Haarkeratin zu finden ist. Zwar lässt sich zwischen dem Verlauf der δ-Werte und der erhöhten Prolinmenge noch kein direkter Zusammenhang erkennen, jedoch wird deutlich, dass sich die Ergebnisse der Isotopendaten und der Aminosäureanalyse gegenseitig stützen und so zu einer besseren Aufklärung von Unterernährungsfällen beitragen können. Da die Entwicklung und der spezifische Verlauf der δ13C-Werte während einer Unterernährung noch nicht vollständig geklärt sind, wurde ein weiteres Probandenkollektiv in dieser Arbeit untersucht. Hierfür wurden Haarproben von sechs Probanden gesammelt, welche an einer medizinisch betreuten Fastentherapie teilnahmen. Durch Haaranalysen und weitere Untersuchungen sollte geklärt werden, ob 12C-Isotope aus den abgebauten, körpereigenen Fettreserven auch als Bausteine für das Haarkeratin Verwendung finden und so für das Absinken des δ13C-Wertes bei einigen Unterernährungsfällen verantwortlich sind. Es konnte mithilfe dieser Fastenstudie allerdings nicht bewiesen werden, dass leichte Kohlenstoffisotope aus den abgebauten Fettreserven ins Keratin eingebaut werden. Die Ergebnisse aus den drei Probandenkollektiven bestätigen jedoch eindeutig, dass mit Hilfe der seriellen Isotopenanalytik an Haaren sowohl eine Umstellung der Ernährung erkannt, als auch die Qualität des individuellen Ernährungszustandes beurteilt werden kann. Aufgrund dessen könnte gerade diese Methode bei der Aufklärung von Vernachlässigungsfällen, aber auch bei der Prävention gute Dienste leisten. Dennoch gilt es in zukünftigen Forschungsansätzen noch einige Problemstellungen zu überwinden, um dieses Ziel vollständig zu erreichen.
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Perga, Marie-Elodie. "Origines et flux de carbone en lacs : étude par analyse de la composition en isotopes stables du carbone et de l'azote du zooplancton et des poissons." Chambéry, 2004. http://www.theses.fr/2004CHAMS031.

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Les communautés piscicoles sont situées au sommet des chaînes trophiques. Cette position dans le réseau trophique lacustre leur confère, de ce fait, un rôle potentiel d'intégrateurs des processus sous- jacents, à l'échelle de l'écosystème. De plus, la composition en isotopes stables d'un organisme dépend des voies qui transfèrent le carbone jusqu'à cet organisme. Notre hypothèse de base était donc que la composition en isotopes stables des poissons pourrait donc constituer un indicateur relatif de fonctionnement trophique des lacs. Pour valider cette hypothèse, nous avons employé, dans un premier temps, le corégone, Coregomus lavaretus, un salmoniforme zooplanctonophage commun dans les lacs alpins, comme modèle biologique. Une étude préalable avait révélée que la composition en isotopes stables du carbone des corégones était très variable au sein des lacs alpins. Selon notre hypothèse, cette variabilité serait le reflet de différences dans les voies de transferts du carbone dans les réseaux trophiques de ces lacs. Les facteurs explicatifs de cette variabilité inter-lacs ont donc, dans un premier temps, été étudiés. Au terme de cette première partie, la composition isotopique du corégone s'est montrée être effectivement un indicateur du fonctionnement trophique des lacs. Les perturbations peuvent modifier les flux de carbone au sein des systèmes et devraient, de fait, conduire à des changements dans les compositions isotopiques des communautés de poissons. L'effet de deux perturbations d'origine anthropique sur la composition isotopique des poissons a, par la suite, été analysé: la première est relative à l'eutrophisation -restauration de deux lacs alpins, la seconde concerne le marnage dans deux réservoirs africains. Les résultats de ces deux études indiquent que des modifications majeures, engendrées par ces perturbations, dans l'origine et les flux de carbone dans les réseaux trophiques, sont enregistrées dans l'histoire isotopique des communautés piscicoles
Fish communities occupy the top of food chains. How fish obtain their constitutive carbon depends consequently of all the carbon pathways at the downer levels of the food web. This trophic position confers to fish a potential role of integrators of the underlying processes, at the ecosystem scale. Moreover, stable isotopes composition of an organism depends on all the pathways that transfer carbon up to this organism. Consequently, we wondered in what extent the stable isotopes composition of fish could be a proxy of the trophic functioning of lakes. To address this assumption, whitefish, Coregonus lavaretus, a zooplanktivorous salmonid common in alpine lake, was, in a first time, used as biological model. A preliminary study had revealed the stable isotope composition of whitefish was quite variable among alpine lakes. According to our idea, this variability mirrors differences in the carbon pathways of the food web of these lakes. To understand what was reflected by this variability, we studied initially in what extent it resulted from intrinsic factors (such as lake size or trophic status). This study has then lead us to deepen the role played by the zooplankton compartment in carbon pathways up to Whitefish. In the final stage of this first part, the isotopic composition of whitefish appeared as a proxy for lake trophic functioning. Changes in environmental factors can alter carbon pathways in food webs. If fish are efficient integrators of carbon pathways, impacts of perturbations should be mirrored on their isotopic compositions. Impacts of two anthropogenic perturbations of stable isotope composition of fish were then evaluated : the first one relates to eutrophication - restoration of two alpine lakes, the second one to water levels changes in two Malian reservoirs. Results from these two studies reveal that major changes, ensuing from these perturbation, in carbon origins and fluxes within lake food webs are recorded in the isotopic history of fish communities

Книги з теми "Analyse des isotope stables":

1

Meier-Augenstein, Wolfram. Stable isotope forensics: An introduction to the forensic application of stable isotope analysis. Chichester, West Sussex: J. Wiley, 2010.

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2

Meier-Augenstein, Wolfram. Stable isotope forensics: An introduction to the forensic application of stable isotope analysis. Chichester, West Sussex: J. Wiley, 2010.

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3

Wolfe, Robert R. Radioactive and stable isotope tracers in biomedicine: Principles and practice of kinetic analysis. New York: Wiley-Liss, 1992.

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4

J, Sullivan Michael. An evaluation of the importance of algae and vascular plants in salt marsh food webs using stable isotope analyses. [Ocean Springs, Miss.?]: Mississippi-Alabama Sea Grant Consortium, 1988.

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5

Pratt, L. M. Preliminary results of organic geochemical and stable isotope analyses of Newark supergroup rocks in the Hartford and Newark Basins, eastern U.S. [Denver, CO]: Dept. of the Interior, U.S. Geological Survey, 1986.

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6

Heier, Anke. Nachweis der geografischen Herkunft von Pistazien anhand der Stabilisotopenverhältnisse. Berlin: Bundesinstitut für Risikobewertung, 2007.

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7

Hemer, Katie A., and Jane A. Evans. The Contribution of Stable Isotope Analysis to the Study of Childhood Movement and Migration. Edited by Sally Crawford, Dawn M. Hadley, and Gillian Shepherd. Oxford University Press, 2018. http://dx.doi.org/10.1093/oxfordhb/9780199670697.013.27.

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Stable isotope analysis is firmly established as a method for the investigation of past population mobility. The distinction between local and non-local individuals within a cemetery population relies on identifying an individual’s place of childhood residence through the analysis of strontium and oxygen isotopes present in human tooth enamel. Traditionally, studies investigating mobility focus on the analysis of a single tooth. More recently, however, it has become apparent that in order to investigate the mobility of an individual during childhood—and thus to consider the importance of children in the migration process—it is necessary to analyse a series of teeth which form at different stages during the early years of life. This chapter will consider the potential of—and challenges surrounding—this scientific approach to the investigation of childhood mobility in the past.
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O'Rourke, Dennis, Justin Tackney, Joan Coltrain, and Jennifer Raff. Ancient DNA and Stable Isotopes. Edited by Max Friesen and Owen Mason. Oxford University Press, 2016. http://dx.doi.org/10.1093/oxfordhb/9780199766956.013.3.

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Genetic diversity in modern Arctic communities provides a baseline from which to assess population history. This is augmented by documenting patterns of genetic variation in prehistoric populations using ancient DNA methods, and inferring dietary resource information and adaptive strategies derived from stable isotope analyses. This chapter uses this multidisciplinary approach to examine population history and colonization events in the Aleutians of South Alaska, and the origin and population history of Paleoeskimo and Neoeskimo populations of the North American Arctic. The power to identify past demographic events relies on knowledge of both genetic and isotopic signatures of demographic events, and on acquisition of securely dated and well provenienced samples for analysis.
9

Meier-Augenstein, Wolfram. Stable Isotope Forensics: Methods and Forensic Applications of Stable Isotope Analysis. Wiley & Sons, Incorporated, John, 2017.

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10

Meier-Augenstein, Wolfram. Stable Isotope Forensics: Methods and Forensic Applications of Stable Isotope Analysis. Wiley & Sons, Limited, John, 2017.

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Частини книг з теми "Analyse des isotope stables":

1

Matyssek, Rainer, and Werner B. Herppich. "Sauerstoffmessung und Analyse stabiler Isotope." In Experimentelle Pflanzenökologie, 327–55. Berlin, Heidelberg: Springer Berlin Heidelberg, 2019. http://dx.doi.org/10.1007/978-3-662-53465-6_18.

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2

Matyssek, Rainer, and Werner B. Herppich. "Experimentelle Pflanzenökologie: Sauerstoffmessung und Analyse stabiler Isotope." In Handbuch der Geodäsie, 1–29. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53493-9_18-1.

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3

Helle, Gerhard, Maren Pauly, Ingo Heinrich, Karina Schollän, Daniel Balanzategui, and Lucas Schürheck. "Stable Isotope Signatures of Wood, its Constituents and Methods of Cellulose Extraction." In Stable Isotopes in Tree Rings, 135–90. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_5.

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AbstractIn this chapter, we give some basic information on the chemical and isotopic properties of wood constituents and describe their relative contribution to the isotopic signature of wood. Based on these considerations we review studies that have compared stable isotope signals of wood with those of corresponding cellulose. We exemplify how relationships of wood-based tree-ring stable isotope sequences with climate can be affected by varying proportions of wood constituents like cellulose, lignin and extractives. A majority of benchmarking studies suggests that cellulose extraction may not be necessary. However, based upon existing research, a general statement cannot be made on the necessity of cellulose extraction. Changes in wood composition can particularly influence environmental signal strength during periods of low isotope variability. Cellulose extraction removes any effects from changing wood composition. We present the three established chemical approaches of extraction, outline how to test the purity of isolated cellulose and present user-friendly efficient experimental setups allowing to simultaneously process hundreds of samples in one batch. Further, we briefly address the analysis of stable isotopes of lignin methoxyl groups because of easy sample preparation and its potential additional value for studies on fossil wood.
4

Pfahler, V., J. Adu-Gyamfi, D. O’Connell, and F. Tamburini. "The Use of the δ18OP to Study P Cycling in the Environment." In Oxygen Isotopes of Inorganic Phosphate in Environmental Samples, 1–15. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-97497-8_1.

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AbstractPhosphorus (P) fertilizers are known to increase crop productivity; however, when applied in excess, it can cause serious environment pollution. Monitoring P pollution in natural environments using stable isotopes has been difficult because P has only one stable isotope (31P) making the use of P stable isotope tracing not an option. Radioactive P isotopes (32P and 33P) have been used but its drawbacks are the short half-life, health risks and safety procedures required to apply them in agricultural catchments. Phosphorus in organic and inorganic P forms is strongly bonded to oxygen (O), which has three stable isotopes, providing a system to track P cycling in agricultural catchments and environment using the stable isotopes of O in phosphate (δ18O-PO4). In recent years, various studies have indicated that the analysis of the stable isotopic composition of oxygen (O) bound to P (δ18Op) to better understand P cycling in the environment, has become a promising tracer (surrogate) to investigate soil P transformation, plant P uptake and to trace the sources of P from the soil to water bodies and the environment. The chapter outlines the background and examples of δ18Op studies in sediments, soils, fresh water, mineral fertilizers and plants.
5

Leavitt, Steven W., and John Roden. "Isotope Dendrochronology: Historical Perspective." In Stable Isotopes in Tree Rings, 3–20. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_1.

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AbstractAlthough the fields of dendrochronology and light stable-isotope mass spectrometry emerged at different times in the first half of the 20th Century, their convergence with the earliest measurements of isotope composition of tree rings is now ca. 70 years old. Much of the early stable isotope analysis (including on wood) explored natural variation of isotopes in the environment, but those researchers making the measurements were already contemplating the role of the isotope composition of the source substrates (e.g., water and CO2), biochemical fractionation, and environment as contributors to final tree-ring isotope values. Growing interest in tree-ring isotopes was heavily motivated by paleoclimate or paleoatmosphere reconstruction, but this new field rapidly developed to generate greatly improved mechanistic understanding along with expanded applications to physiology, ecology, pollution, and more. This chapter primarily charts the historical progression in tree-ring C-H-O isotope studies over those seven decades, but it also identifies potential productive emerging and future directions.
6

Rinne-Garmston, Katja T., Gerhard Helle, Marco M. Lehmann, Elina Sahlstedt, Jürgen Schleucher, and John S. Waterhouse. "Newer Developments in Tree-Ring Stable Isotope Methods." In Stable Isotopes in Tree Rings, 215–49. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_7.

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AbstractThe tree-ring stable C, O and H isotope compositions have proven valuable for examining past changes in the environment and predicting forest responses to environmental change. However, we have not yet recovered the full potential of this archive, partly due to a lack understanding of fractionation processes resulting from methodological constraints. With better understanding of the biochemical and tree physiological processes that lead to differences between the isotopic compositions of primary photosynthates and the isotopic compositions of substrates deposited in stem xylem, more reliable and accurate reconstructions could be obtained. Furthermore, by extending isotopic analysis of tree-ring cellulose to intra-molecular level, more information could be obtained on changing climate, tree metabolism or ecophysiology. This chapter presents newer methods in isotope research that have become available or show high future potential for fully utilising the wealth of information available in tree-rings. These include compound-specific analysis of sugars and cyclitols, high spatial resolution analysis of tree rings with UV-laser, and position-specific isotope analysis of cellulose. The aim is to provide the reader with understanding of the advantages and of the current challenges connected with the use of these methods for stable isotope tree-ring research.
7

Brooks, J. Renée, William D. Rugh, and Roland A. Werner. "Tree-Ring Stable Isotope Measurements: The Role of Quality Assurance and Quality Control to Ensure High Quality Data." In Stable Isotopes in Tree Rings, 191–213. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_6.

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AbstractQuality assuranceand quality control(QA/QC) are important components of every study. In this chapter, we give an overview of QA/QC specific for tree-ring stable-isotope analysis from the perspective of the entire research project, rather than from the operation of Isotope Ratio Mass Spectrometers (IRMS). We address how users of stable isotope tree-ring data can quantify the quality of their data for reporting in publications by calculating accuracy and precision. We cover some of the potential sources of error that can occur during sample processing and isotopic measurements, basic principles of calibration to the appropriate isotopic scales, and how researchers can detect error and calculate uncertaintyusing duplicatesand quality control standards.
8

Marshall, John D., J. Renée Brooks, and Alan F. Talhelm. "Forest Management and Tree-Ring Isotopes." In Stable Isotopes in Tree Rings, 651–73. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_23.

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AbstractForest management can be improved by the mechanistic understanding that tree-ring stable isotopes provide. Key management tools include genetic selection, competing vegetation control, thinning, and fertilization. These tools frequently change environmental conditions and physiological processes, such as photosynthesis, stomatal conductance, water uptake, and nitrogen cycling, which may leave isotopic signatures in tree-rings, providing detailed responses to management over decadal time periods. While data sets remain small, some trends have emerged from previous forest management studies using stable isotopes. Genotype selection sometimes shows isotopic evidence of maladaptation, especially in the presence of climate change. Competition control and thinning have different isotopic reactions depending on the dryness of the site; they generally obtain different responses depending on whether competition is primarily for aboveground (light) or belowground (water and nutrient) resources. Fertilization responses recorded in tree rings appear to be driven by initial increases in photosynthesis, and later by increases in leaf area index. Tree-ring isotopic applications can provide key insights to a much broader range of silvicultural objectives than included here, and we encourage their application in large-scale silvicultural experiments to reduce uncertainties and explain mechanisms of response. In future work, we suggest that management studies wishing to utilize tree-ring stable isotopic analysis include key ancillary measurements, especially leaf nitrogen concentrations, leaf-area index, xylemwater sources, and canopy temperature, to help support interpretation of the isotopic data.
9

van der Sleen, Peter, Pieter A. Zuidema, and Thijs L. Pons. "Stable Isotopes in Tree Rings of Tropical Forests." In Stable Isotopes in Tree Rings, 631–49. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_22.

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AbstractThe study of stable isotopes in tree rings is relatively new, but growing research field in tropical forests. In this chapter, we review 53 studies that measured stable isotopes of C, O and/or N in tree rings of a total of 83 tropical tree species. Tree growth in tropical forests is generally determined by seasonality of precipitation, and not temperature. Consequently, temporal variation in both δ13C and δ18O has often been correlated to precipitation and variability of the El Niño Southern Oscillation (ENSO), which can affect weather systems throughout the tropics and subtropics. Currently, stable isotopes research in the tropics has mainly focused on (i) quantifying the effects of rising atmospheric CO2 concentration and climate change on tree physiology, (ii) identifying the drivers of growth variability and reconstruction of past climate, and (iii) the identification of annual rings in wood lacking anatomically distinct growth boundaries. In addition, some initial studies used tree-ring δ15N as a tool to assess anthropogenic change of the nitrogen cycle in tropical forests. Although stable isotope analyses in the tropics still faces methodological and interpretation issues, it is becoming an important tool for understanding the functioning of tropical forests and their resilience to global change.
10

van der Sleen, Peter, Pieter A. Zuidema, and Thijs L. Pons. "Stable Isotopes in Tree Rings of Tropical Forests." In Stable Isotopes in Tree Rings, 631–49. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92698-4_22.

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Анотація:
AbstractThe study of stable isotopes in tree rings is relatively new, but growing research field in tropical forests. In this chapter, we review 53 studies that measured stable isotopes of C, O and/or N in tree rings of a total of 83 tropical tree species. Tree growth in tropical forests is generally determined by seasonality of precipitation, and not temperature. Consequently, temporal variation in both δ13C and δ18O has often been correlated to precipitation and variability of the El Niño Southern Oscillation (ENSO), which can affect weather systems throughout the tropics and subtropics. Currently, stable isotopes research in the tropics has mainly focused on (i) quantifying the effects of rising atmospheric CO2 concentration and climate change on tree physiology, (ii) identifying the drivers of growth variability and reconstruction of past climate, and (iii) the identification of annual rings in wood lacking anatomically distinct growth boundaries. In addition, some initial studies used tree-ring δ15N as a tool to assess anthropogenic change of the nitrogen cycle in tropical forests. Although stable isotope analyses in the tropics still faces methodological and interpretation issues, it is becoming an important tool for understanding the functioning of tropical forests and their resilience to global change.

Тези доповідей конференцій з теми "Analyse des isotope stables":

1

Furghieri Bylaardt Caldas, Priscila, Jonathan Snatic, and Kurt Kronenberger. "Quality Isotope Analysis at the Wellsite: Two Case Studies that Validate GC-C-IRMS Mud Gas Isotope Logging for Deepwater Exploration and Development." In SPE Annual Technical Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/210384-ms.

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Abstract Geochemical analysis of gases produced during the drilling process is a common study on oil and gas exploration and development wells. This process typically includes the use of gas sample containers or other vessels that allow for single point samples to be collected for shipment to an offsite laboratory. Laboratories use high precision devices to obtain valuable information for reservoir characterization including stable carbon isotope ratios. In recent years there have been efforts to provide similar analyses during the drilling process, using ruggedized equipment suitable for wellsite deployment. This paper demonstrates that a Gas Chromatograph-Combustion-Isotope Ratio Mass Spectrometer (GC-C-IRMS) analyzer, using similar technology to what is most widespread in offsite laboratories (Dashti et al, 2018), can be successfully deployed to the rig site. This type of advanced gas analysis, commonly known as Mud Gas Isotope Logging (MGIL), provides continuous sampling of stable carbon isotopes of methane (δ13C1), ethane (δ13C2), and propane (δ13C3). The service, performed with a GC-C-IRMS analyzer, was proven and validated for an operator through two case studies. 98 The first case compares real time data with discrete gas sample tubes analyzed in an offsite laboratory. It shows how accurate results are possible, even with the presence of artificial gases generated by drill bit metamorphism (DBM) (Wenger et al, 2009). This example also demonstrates how the service enabled immediate analysis for operational decisions by indicating the presence of biodegraded thermogenic fluid. The second case study demonstrates how this wellsite service could corroborate the geological prognosis in a complex field influenced by salt tectonics. In this basin an upthrown reservoir changed the typical behavior observed in conventional wells of increased oil maturity with depth. Stable carbon isotope readings obtained in real time, integrated with cuttings analysis, indicated the presence of out of section lithology. This information allowed for estimating the thermogenic fluid maturity of reservoirs and diagnosis of geological formations that were out of sequence in terms of age (uplifted).
2

Swearingen, Jerry, and Yani Araujo De Itriago. "Advanced Analytical Tools for Fingerprinting, Production Allocation, & Improved/Enhanced Oil Recovery Monitoring." In SPE Annual Technical Conference and Exhibition. SPE, 2022. http://dx.doi.org/10.2118/210060-ms.

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Abstract Demands are being placed on service companies to provide non-evasive analytical solutions that measure the contribution of individual hydrocarbon streams in a commingled system. This often involves being able to differentiate fluids which have similar compositions. An advanced analytical workflow has been developed which includes chromatographic techniques along with a suite of stable isotope ratio analyses that look at unique Natural Tracers/Markers in individual hydrocarbon or brine streams. This paper will look at how the Natural Tracer methodology can be applied to fingerprinting, production allocation and IOR/EOR projects. A variety of laboratory-based techniques were used to evaluate end member fluids, commingled fluids, and various synthetic blends. Gaseous streams were analyzed using compound specific stable isotope ratio mass spectrometry systems (CS-IRMS) looking at carbon and hydrogen isotopes of the carbon dioxide, methane, ethane, etc. present. Aqueous streams were analyzed using a combination of conventional physiochemical (complete water) and water oxygen and hydrogen stable isotope analysis. Liquid hydrocarbon systems were assessed using conventional high-resolution gas chromatography and 2-dimentional gas chromatography (GCxGC). Analysis of the data includes simple plots to visualize differences between fluid sources and a linear regression analysis to look at the mixing relationships between synthetic blends and commingled field samples. The advanced analytical workflow allowed for the allocation determination of hydrocarbon systems with both similar and contrasting compositions. The GCxGC method, for hydrocarbon liquids, allows for a higher resolution separation where a single peak using conventional gas chromatography can be composed of multiple types of compounds. In this instance the conventional GC and GCxGC yielded comparable allocation results. For gas phase allocation, using carbon and hydrogen isotope ratios (δ13C and δ2H) of methane and ethane yielded linear mixing relationships in the two-production systems that were analyzed. Allocation values were successfully calculated for these binary systems with an outlying datapoint resulting in the client initiating an investigation to confirm flow meter readings. For an IOR/EOR application, the δ13C of methane show sufficient contrast between injected and produced gases that were sampled from a variety of wells. In this instance the gas molar compositions were similar so the only means to identify injection gas breakthrough in producing wells was by the CS-IRMS analysis technique. Complete physiochemical and water isotope ratio (δ18O and δ2H) analysis also show contrasting signatures between injection and produced water. An advanced analytic workflow was developed to incorporate commercially available, non-evasive techniques to production allocation and IOR/EOR projects. For production allocation, this technique will not replace traditional metering but can be used as a tool to identify problems with the metering/monitoring systems in the field.
3

Gillham, Robert B., Carrie A. Menold, and William S. Bartels. "STABLE ISOTOPE ANALYSES OF TOOTH ENAMEL IN EOCENE CROCODYLIANS." In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-283532.

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4

Morgan, Naomi, Laura Toran, Adrienne Donaghue, and Erica McKenzie. "STABLE ISOTOPE ANALYSIS OF NITRATE PATTERNS IN BIORETENTION BASINS." In Northeastern Section-56th Annual Meeting-2021. Geological Society of America, 2021. http://dx.doi.org/10.1130/abs/2021ne-361477.

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5

Murnick, Daniel E., M. J. Colgan, H. P. Lie, and D. Stoneback. "Stable isotope analysis of breath using the optogalvanic effect." In Photonics West '96, edited by Daniel L. Farkas, Robert C. Leif, Alexander V. Priezzhev, Toshimitsu Asakura, and Bruce J. Tromberg. SPIE, 1996. http://dx.doi.org/10.1117/12.239534.

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6

Wedel, Steven, Sierra V. Petersen, Jade Zhang, Ian Z. Winkelstern, and Kyger C. Lohmann. "TEMPERATURE AND OXYGEN ISOTOPE SEASONALITY OF THE LAST INTERGLACIAL (MIS-5E) FROM ANALYSIS OF STABLE AND CLUMPED ISOTOPES OF BERMUDA BIVALVES." In 54th Annual GSA North-Central Section Meeting - 2020. Geological Society of America, 2020. http://dx.doi.org/10.1130/abs/2020nc-347790.

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7

Popov, E. E., I. K. Chubchenko, K. M. Grigorenko, A. V. Polishchuk, and V. V. Vitkin. "Gas Analyzer for Investigating Stable Carbon Isotopes Concentration." In 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall). IEEE, 2019. http://dx.doi.org/10.1109/piers-fall48861.2019.9021616.

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8

Jesmok, Greg, Deepshikha Upadhyay, Deepshikha Upadhyay, Xing Jian, Xing Jian, Mahala Herron-Rutland, Mahala Herron-Rutland, Aradhna Tripati, and Aradhna Tripati. "TEMPERATURE MEASUREMENTS AND PALEOCLIMATE ANALYSES OF SEDIMENTARY CARBONATES FROM THE CENOZOIC QAIDAM BASIN, QINGHAI PROVINCE, CHINA, USING STABLE ISOTOPES AND CLUMPED ISOTOPE THERMOMETRY." In GSA Annual Meeting in Indianapolis, Indiana, USA - 2018. Geological Society of America, 2018. http://dx.doi.org/10.1130/abs/2018am-325077.

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9

Smith, Gregory J., and Larisa R. G. DeSantis. "GOMPHOTHERE PALEOECOLOGY IN NORTH AMERICA AS INFERRED FROM STABLE ISOTOPE ANALYSIS." In GSA Annual Meeting in Seattle, Washington, USA - 2017. Geological Society of America, 2017. http://dx.doi.org/10.1130/abs/2017am-307894.

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10

Stukova, Olga, Konstantin Gribanov, Vyacheslav Zakharov, Olivier Cattani, and Jean Jouzel. "Precipitation water stable isotope measurements and analyses in Middle and Polar Ural." In XXI International Symposium Atmospheric and Ocean Optics. Atmospheric Physics, edited by Oleg A. Romanovskii. SPIE, 2015. http://dx.doi.org/10.1117/12.2205489.

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Звіти організацій з теми "Analyse des isotope stables":

1

Burke, F. P., R. A. Winschel, and M. S. Lancet. Stable carbon isotope analysis of coprocessing materials. Office of Scientific and Technical Information (OSTI), June 1989. http://dx.doi.org/10.2172/5717939.

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2

Cesar, J. R., and O. H. Ardakani. Organic geochemistry of the Montney Formation: new insights about the source of hydrocarbons, their accumulation history and post accumulation processes. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329788.

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This study consists of a non-traditional molecular and stable isotope approach to analyze organic matter (soluble bitumen and produced oil/condensate) from the Montney Formation low-permeability reservoirs, with the purpose of identifying source(s) of hydrocarbons, accumulation history and post accumulation processes. The same approach bases on the distribution of compound classes such as aromatic carotenoids, polycyclic aromatic hydrocarbons (PAHs), bicyclic alkanes, and oxygen-polar compounds. The geochemical screening has been enhanced with performing compound specific isotope analysis (CSIA) of n-alkanes and selected aromatic hydrocarbons. Widely spread PAHs, the presence of molecular indicators of euxinia, and hydrocarbon mixtures identified using CSIA profiles, are some of the key findings from this research, which will improve our understanding of the Montney petroleum system(s).
3

Short, R. T., and Gottfried P. Kibelka. Development of an In-Situ Mass Spectrometer for Stable Isotope Analyses. Fort Belvoir, VA: Defense Technical Information Center, August 2002. http://dx.doi.org/10.21236/ada626604.

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4

Short, R. T., Gottfried P. Kibelka, Robert H. Byrne, and David Hollander. Development of an In-Situ Mass Spectrometer for Stable Isotope Analysis. Fort Belvoir, VA: Defense Technical Information Center, September 2003. http://dx.doi.org/10.21236/ada620413.

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5

Lee, Brady D., James J. Moran, Megan K. Nims, and Danielle L. Saunders. Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Groundwater Samples. Office of Scientific and Technical Information (OSTI), March 2018. http://dx.doi.org/10.2172/1439697.

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6

Lee, Brady D., James J. Moran, Megan K. Nims, and Danielle L. Saunders. Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples. Office of Scientific and Technical Information (OSTI), April 2017. http://dx.doi.org/10.2172/1358516.

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7

Burke, F. P., R. A. Winschel, and M. S. Lancet. Stable carbon isotope analysis of coprocessing materials: Quarterly technical progress report, October 1--December 31, 1988. Office of Scientific and Technical Information (OSTI), March 1989. http://dx.doi.org/10.2172/6058419.

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8

Burke, F. P., R. A. Winschel, and M. S. Lancet. Stable carbon isotope analysis of coprocessing materials: Quarterly technical progress report, July 1--September 30, 1988. Office of Scientific and Technical Information (OSTI), January 1989. http://dx.doi.org/10.2172/6177436.

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9

Kuder, Tomasz, Monika Klisch, R. P. Philp, and Thomas McHugh. Use of Compound Specific Stable Isotope Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs. Fort Belvoir, VA: Defense Technical Information Center, January 2012. http://dx.doi.org/10.21236/ada579119.

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10

McHugh, Thomas, Tomasz Kuder, Monika Klisch, and R. P. Philp. Use of Compound-Specific Stable Isotope Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs. Fort Belvoir, VA: Defense Technical Information Center, January 2012. http://dx.doi.org/10.21236/ada579218.

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