Hydrogeophysical characterization of the porous and fractured media (chalk aquifer in the Beauvais,France)     

Lahcen Zouhri  Pascale Lutz 《Environmental Earth Sciences》2016,75(4):343

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Composition of organic matter in subducted and unsubducted sediments off the Nicoya peninsula, Costa Rica (ODP Leg 170, Sites 1039 and 1040)     

Rüdiger Lutz  Birgit Gieren  Andreas Lückge  Heinz Wilkes  Ralf Littke 《Organic Geochemistry》2000,31(12)

Investigation of sediment samples from Sites 1039 and 1040 (ODP Leg 170) drilled off the Nicoya peninsula (Costa Rica) by organic geochemical and organic petrological methods has revealed that subduction has only little influence on the composition of the sedimentary organic matter. Organic carbon contents reached 1.5% in the Pleistocene samples but Miocene and Pliocene sediments had an average organic carbon content of less than 0.5%. Organic carbon/sulfur ratios are generally below 2.8, reflecting an intense sulfate reduction in the uppermost sediments which was enhanced by sulfate supply both from sea water and deeper strata. Microscopical examinations indicate that the organic matter is mainly derived from marine sources. A small amount of terrigenous organic matter is, however, present as well according to n-alkane and fatty acid distributions. The alkenone unsaturation index U₃₇^k′ shows only a slight decrease during the Miocene and Pliocene, and stronger variations in the Pleistocene, probably indicating more stable sea surface temperatures during the Miocene and Pliocene. Variations in the Pleistocene can possibly be related to glacial/interglacial changes.  相似文献   

Palaeobotanical evidence for warm summers in the East Siberian Arctic during the last cold stage     

Frank Kienast  Lutz Schirrmeister  Christine Siegert  Pavel Tarasov 《Quaternary Research》2005,63(3):175-300

Plant macrofossils from the “Mamontovy Khayata” permafrost sequence (71°60′N, 129°25′E) on the Bykovsky Peninsula reflect climate and plant biodiversity in west Beringia during the last cold stage. 70 AMS and 20 conventional ¹⁴C dates suggest sediment accumulation between about 60,000 and 7500 ¹⁴C yr B.P. The plant remains prove that during the last cold-stage arctic species (Minuartia arctica, Draba spp., Kobresia myosuroides) coexisted with aquatic (Potamogeton vaginatus, Callitriche hermaphroditica), littoral (Ranunculus reptans, Rumex maritimus), meadow (Hordeum brevisubulatum, Puccinellia tenuiflora) and steppe taxa (Alyssum obovatum, Silene repens, Koeleria cristata, Linum perenne). The reconstructed vegetation composition is similar to modern vegetation mosaics in central and northeast Yakutian relict steppe areas. Thus, productive meadow and steppe communities played an important role in the Siberian Arctic vegetation during the late Pleistocene and could have served as food resource for large populations of herbivores. The floristic composition reflects an extremely continental, arid climate with winters colder and summers distinctly warmer than at present. Holocene macrofossil assemblages indicate a successive paludification possibly connected with marine transgression, increased oceanic influence and atmospheric humidity. Although some steppe taxa were still present in the early Holocene, they disappeared completely before 2900 ¹⁴C yr B.P.  相似文献   

Characterization of sediments in an abandoned mining area; a case study of Mansfeld region,Germany   总被引：1，自引：0，他引：1  

Rainer?WennrichEmail author  Jürgen?Mattusch  Peter?Morgenstern  Klaus?Freyer  Hanns-Christian?Treutler  Hans-Joachim?St?rk  Lutz?Brüggemann  Albrecht?Paschke  Birgit?Daus  Holger?Weiss 《Environmental Geology》2004,45(6):818-833

The distribution of selected heavy metals, including some radionuclides, metalloids and non-metals was determined in stream sediments in a region influenced by abandoned copper mining and ore processing activities. A considerable amount of the ore processing waste with a very complex composition and highly elevated concentrations of zinc, sulfur, lead, copper, arsenic, and a lot of other elements in the range between 100 and 1,000 mg/kg (Sb, Mn, Ni, Cr, Cd, Hg, and Ag) was piled up on mine dumps. The dispersion of the pollutants originating from this source and their environmental impact were investigated. Both, sediments and original waste material were studied to indicate the pathways and the mobilization behavior of different pollutants. For this purpose, the process of the elution of pollutants by application of different fractionation schemes was studied. The capabilities of different analytical techniques are shown for the analysis of solid samples (X-ray fluorescence spectrometry, Gamma-spectrometry) and liquid ones (ICP-atomic emission spectrometry, ICP-mass spectrometry and different techniques of atomic absorption). Additionally, the coupling of ion chromatography and ICP-MS detection was used to study the distribution of arsenic species in the sediment cores of a lake which acts as a natural sink for the region.  相似文献   

Regional distribution and temporal trends of some contaminants in the water of the Baltic Sea     

Lutz Brügmann  Horst Gaul  Karl-Heinz Rohde  Udo Ziebarth 《Ocean Dynamics》1991,44(4):161-184

During a cruise on board RV Gauss in May/June 1988, joint investigations into organochlorine compounds, dissolved trace metals, petroleum hydrocarbons and basic hydrography were carried out at representative stations of the Baltic Monitoring Programme (BMP). The aim of the cruise was to study distribution patterns and — using previous data — to establish temporal trends if at all discernible.Each group of contaminants investigated showed specific characteristics, with differences even between compounds within the same group. The differences are due to:

–	- the partition of contaminants between dissolved and adsorbed form;
–	- the response to redox conditions;
–	- the influence of microbial decay, organic production or changes in speciation.

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Hydrogen bonding in basic copper salts: a spectroscopic study of malachite,Cu2(OH)2CO3, and brochantite,Cu4(OH)6SO4     

M. Schmidt  H. D. Lutz 《Physics and Chemistry of Minerals》1993,20(1):27-32

Infrared and Raman spectra of the basic copper salts malachite, Cu₂(OH)₂CO₃, and brochantite, Cu₄(OH)₆SO₄, as well as of deuterated and ¹³C substituted samples are presented and discussed in terms of group theory and the hydrogen bonds present. The main results are that (i) the hydrogen donor strengths of the OH^? ions are strongly increased due to the very great synergetic effect of the copper ions, (ii) the acceptor strengths of the H-bond acceptor groups (SO₄ ^2-, CO₃ ^2-, and OH^? ions) are significantly modified by the linkage and coordination of the acceptor atoms — this complicates true assignment of the OH bands observed to the two and six different OH^? ions present in malachite and brochantite, respectively -, and (iii) the Cu — O stretching modes at 430–590 cm^?1 and 420–520 cm^?1 for malachite and brochantite, respectively, exhibit strong, partially covalent Cu — O bonding.  相似文献   

Shift — fortran IV program for shift and share-analysis     

Dr. Dipl. Math. Lutz Blumhagen  Dr. Gert Eichler 《GeoJournal》1977,1(6):17-24

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On the contribution of spray droplets to evaporation     

Lutz Hasse 《Boundary-Layer Meteorology》1992,61(3):309-313

The effect of spray droplets in the marine surface layer on evaporation is considered. Independent evidence from energy constraints, from visibility and from sea salt content of air is used. The estimation shows that, except perhaps for hurricane wind strength, the increase of total evaporation from evaporating droplets is negligible. This is in agreement with recent experimental evidence.  相似文献   

Heavy metals in the Baltic Sea     

Lutz Brügmann 《Marine pollution bulletin》1981,12(6):214-218

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Der Brechungsindexgradient für elektromagnetische Wellen (Cm-bis M-Band) in der maritimen Grenzschicht der Atmosphäre     

Karl Brocks  Lutz Hasse 《Ocean Dynamics》1956,9(5):217-221

Zusammenfassung Für ein in der Abhandlung von K. Brocks [1955] abgeleitetes Verfahren der Berechnung von Brechungsindex-Profilen unmittelbar über dem Meer werden weitere Hilfsmittel angegeben, insbesondere eine graphische Psychrometertafel (Tafel 8), aus der der Dampfdruck der Luft [in mb] als Funktion der Temperatur des feuchten und trockenen Thermometers entnommen werden kann, und ein Diagramm des Wasserdampfdrucks und des Sättigungsdampfdruckes der Luft sowie der relativen Luftfeuchtigkeit als Funktion der Lufttemperatur (Tafel 9).Es wird ferner ein Kurzverfahren mitgeteilt, das eine schnelle Berechnung des Brechungsindexprofils über dem Meer ermöglicht aus Messungen der Lufttemperatur, Luftfeuchtigkeit, Windgeschwindigkeit und Wassertemperatur. Hierfür wird ein Diagramm gegeben (Tafel 10), das den BrechungswertN=(n–1) 10^–6 als Funktion der Temperatur des trockenen und des feuchten Thermometers bzw. der Wassertemperatur enthält.

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On the gradient of the refractive index of electro-magnetic waves (centimetre-to metre-waves) in the maritime boundary layer of the atmosphere. 2^nd article

Summary The present paper adds further aids to the method developed by K. Brocks [1955] for the computation of the curves of the refractive index occurring immediately above the sea surface. These aids, before all, consist in a graphical psychrometer plate (plate 8) and a diagramme (plate 9). Plate 8 permits to derive from it the vapour pressure of the air [in mb] as a function of temperature to be read from dry bulb and a wet bulb thermometres. Plate 9 represents the water vapour pressure and the saturation pressure of the air as well as relative humidity of the air as a function of air temperature.Besides, an abbreviated method is discussed permitting a time-saving computation of the curves of the refractive index above sea surface from measurements of air temperature, atmospheric moisture, wind velocity, and water temperature. This computation is carried out with the aid of a diagram (plate 10), giving the refractive valueN=(n–1) 10^–6 as a function of the temperature, measured with a dry bulb and a wet bulb thermometre, or as a function of the water temperature, respectively.

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Sur le gradient de l'indice de réfraction des ondes électromagnétiques (de 0,1 m à 1m), présentes dans la couche limite maritime de l'atmosphère. 2^e article

Résumé Le travail actuel ajoute à la méthode développée par K. Brocks [1955] d'autres moyens pour le calcul des courbures du gradient de l'indice de réfraction se présentant immédiatement au-dessus de la surface de la mer. Ces moyens se composent surtout d'une représentation graphique des valeurs psychométriques (planche 8) et d'un diagramme (planche 9). La planche 8 permet d'en tirer la pression de vapeur de l'air [en mb] en fonction de températures indiquées sur de thermomètres mouillés ou sur de thermomètres secs. La planche 9 montre la pression de vapeur d'eau et la tension de vapeur saturante de l'air ainsi que l'humidité relative de l'air en fonction de la température de l'air.De plus, une méthode abbréviée est présentée qui permet de calculer, sans perdre beaucoup de temps, au moyen des mesures de la température de l'air et de l'eau, de l'humidité de l'air et de la vitesse du vent, la courbure de l'indice de réfraction au-dessus de la mer. Ce calcul se fait à l'aide d'un diagramme (planche 10) qui donne la valeur de réfractionN=(n}-1) 10^–6 en fonction de la température du thermomètre sec et du thermomètre mouillé ou la représente respectivement en fonction de la température de l'eau.

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