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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    GeoJournal 44 (1998), S. 73-89 
    ISSN: 1572-9893
    Keywords: element fluxes ; forest ecosystem ; acidification ; nitrogen ; base cations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography
    Notes: Abstract Data on element fluxes (Ca, K, N) are presented which were obtained in the course of an extended project on element-cycling in a forested ecosystem near Möhlin, northwestern Switzerland. Current fluxes of Ca, K, and N could be compared with historical fluxes (1969–1993) with the help of soil chemistry inventories since 1969, data on the forest management, and atmospheric deposition. Since 1969, soil chemistry has significantly changed due to a distinct disintegration of humus. The decomposition of organic matter influenced strongly the element cycling. Due to this mineralization high amounts of N were released. It is, however, not fully clear in which chemical form N has been transferred out of the system. Two possible hypotheses on the N losses are defined. According to the calculated proton budget and measured element changes in the soil, it is hypothized that a large part of the mineralized organic N presumably was transformed into N2 or more likely into N2O. A complete nitrification of organically bound N to NO3 − is also discussed but is, however, considered as less probable. In contrast to K, Ca proved to be a very sensitive element: the exchangeable Ca stock has been decreased sharply. The analysis of the current fluxes of Ca, K, and N reveals that nitrogen is abundantly present in the forest system with the consequence that the ecological balance is shifted in favour of N. Accordingly, the supply of base cations is rather scarce for the plants. Furthermore, the influence of forest management on element fluxes seems to be substantial, especially on the fluxes of base cations, but can be reduced with simple measures (e.g. removal of the bark of coniferous trees).
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 68 (1985), S. 220-230 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: β-Functionalized Hydrazines from N-Phthalimidoaziridines and their Hydrogenolytic N,N-Cleavage to AminesThe three N-phthalimido-aziridines 1-3 were reacted with phenol, thiophenol, aniline, p-toluenesulfonic acid, and H2O in selected combinations. These nucleophiles opened the 3-membered ring to yield the N-phthalimidoamines 4a-d, 5a-d, 6a-c, and 6e; all these products (except the carbinol 6e) carry an aryl-substituted functional group on the C-atom vicinal to the N-substituent. Hydrazinolysis of 4, 5, 6a-c, and 6e afforded the β-functionalized hydrazines 7, 8, 9a-c, and 9e. The reducing medium Raney-Ni/N2H4 transformed 4, 5, 6a-c, and 6e to the β-functionalized amines 10, 11, 12a-c, and 12e. By a study with the hydrazide 6a and the hydrazine 9a, it was shown that the N,N-cleavage is a catalytic hydrogenolysis by H2 generated from N2H4 with Raney-Ni and that it does not take place on the hydrazide 6, but rather on the hydrazine 9, generated as intermediate from 6 with N2H4. Spectroscopic data confirmed that the conversions of 1-3 to 4-6 occurred exclusively with inversion and that the resulting configurations remained fully intact during the transformations of 4, 5, and 6 (via 7, 8, and 9) to 10, 11, and 12, respectively.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In-situ-generated phthalimidonitrene was added to five α, β-unsaturated esters containing a chiral secondary O-function at C(γ). The additions were fully suprafacial, inasmuch as the (E)-isomers 1 afforded only the trans-aziridines 2 and 3 (J(β, γ) = 4.8-5.1 Hz) and the (Z)-isomers 4 only the cis-aziridines 5 and 6 (8.2-8.5 Hz). The products 2, 3, 5, and 6 where shown to possess the arabino-, xylo-, ribo-, and lyxo- configuration, respectively, by X-ray structure analysis of 2b, 2d, and 6a. The diastereoface selectivity of the nitrene additions, induced by the chiral substructure around C(γ), resulted in more 2 than 3 from 1, but more 6 than 5 from 4, which means that the preference of attack at the double bond switches from one side to the other depending on the C=C configuration. The preferences were higher at lower temperature. The aziridines 2a, 2d, and 3d exhibit 1H-NMR-visible isomerism at the ring N-atom; the major (78-95 %)invertomer A is always the one with the phthalimido group in trans-position to the (larger) substructure around C(γ). The other aziridines only show 1H-NMR signals of one invertomer, which - by steric reasoning - ought to be A; this is confirmed by a 1H-NMR argument for 3a, 5a, 6a, 5c, and 6c.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 69 (1986), S. 1442-1460 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of Racemic Aminosugar Lactones: xylo- and lyxo-2,3-Diacetylamino-5-acetoxypentan-4-olide and -2,3,5-Triacetylaminopentan-4-olideStarting with 5-hydroxy-2-penten-4-olide (1), the tricyclic intermediate 4 was prepared via the chloride 2, the acyl azide 3, and an intramolecular nitrene addition (Scheme 3). Azide ion opened the aziridine ring in 4 at C(α) to give 5, which was transformed via 7 into one of the title compounds, the triacetylated diamino-hydroxy-lactone 13 (Scheme 4). An alternative conversion of 4 into 13 involved the synthesis of the N-acetylaziridine 10, the opening of the 3-ring of 10 with N3- to form 12, and a final reductive acetylation (Scheme 5). The third N-substituent was introduced at C(δ) of 13 by the following sequence: hydrolysis of the AcO group (→14), mesylation (→15), substitution by N3- (→ 16), and reductive acetylation to yield the other title compound, the triacetylated triaminolactone 17 (Scheme 6). Since the ring opening of aziridines by nucleophiles occurs by inversion, the primary products 5a and 12a of the N3- reactions as well as the substances derived from them, i.e. 6a, 7a, and 13a-17a, have the xylo-configuration (a-series). Under some of the reaction conditions, the primary xylo-products suffered a partial epimerization at C(α) to yield mixtures containing the corresponding lyxo-products (b-series): The equilibrium between the xylo- and lyxo-isomers was estimated for 5a/5b=1:3, 12a/12b=5:2, 13a/13b=3:1, and 16a/16b=2:1. Since the stereoisomers of the a- and the b-series were always separable, the other lyxo-products, i.e. 6b, 7b, could be prepared from 5b and 12b.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Publication Date: 2023-08-22
    Description: The sampling campaign took place in August/September 2017 as part of the project HILLSCAPE, Hillslope Chronosequence and Process Evolution. This dataset comprises different pore parameters measured by Computed Tomography. Parameters of the pores include volume, radius, area and equivalent diameter. The Skeleton files include graph, segment and node statistics.
    Keywords: Age, relative, number of years; Alps; chronosequence; Computed Tomography; DATE/TIME; Depth, bottom/max; DEPTH, soil; Depth, top/min; Event label; File format; File name; File size; HILLSCAPE; HILLSlope Chronosequence And Process Evolution; Klausenpass; Klausenpass_K-A1; Klausenpass_K-A2; Klausenpass_K-B1; Klausenpass_K-B2; Klausenpass_K-C1; Klausenpass_K-C2; Klausenpass_K-D1; Klausenpass_K-D2; Landform; LATITUDE; Location; LONGITUDE; moraine; Operation number; Parent material; Sample ID; Soil; SOIL; Soil profile; Sustenpass; Sustenpass_S-A1; Sustenpass_S-A2; Sustenpass_S-B1; Sustenpass_S-B2; Sustenpass_S-C1; Sustenpass_S-C2; Sustenpass_S-D1; Sustenpass_S-D2; Uniform resource locator/link to file; XRT
    Type: Dataset
    Format: text/tab-separated-values, 207 data points
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  • 6
    Publication Date: 2023-12-18
    Description: The late Holocene development of a raised ombrotrophic peat bog in the Thuringian Forest in Central Germany was investigated using pollen, plant macrofossils, lipid biomarker, elemental, and radiocarbon analyses. In October 2019, a 3.4 m core was recovered from the Beerberg peatland located in the Vessertal-Thuringian Forest Biosphere Reserve. Radiocarbon dating and a resulting age-depth model indicated that the age of the peatland is ca. 2600 yr BP. The purpose of the study was twofold: establishing a paleovegetation record with a reliable chronology for the Thuringian Forest and comparing the results of the pollen and plant macrofossil analyses to that of the lipid biomarker analysis to determine what additional insight the biomarkers could provide. Along with the counting of pollen and plant macrofossils, the carbon and nitrogen concentrations and their stable isotope values were measured from the bulk samples via elemental analyzer, and the absolute concentrations of n-alkanes, n-alkanols, and n-fatty acids were measured by gas chromatography flame ionization detection. The radiocarbon dates were measured by Accelerator Mass Spectrometry. Modern plant samples were also collected from the peatland during sampling, separated into leaf, stem, and root tissue as much as was possible, and the absolute concentrations of the n-alkanes, n-alkanols, and n-fatty acids were measured for each plant part.
    Keywords: Biomarkers; Central Germany; Late Holocene; macrofossil; peat; Pollen; radiocarbon
    Type: Dataset
    Format: application/zip, 7 datasets
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  • 7
    Publication Date: 2023-12-08
    Keywords: Accelerator mass spectrometry (AMS); Age, dated; Age, dated material; Age, dated standard deviation; Beerberg_peatland_2019; Biomarkers; Central Germany; DEPTH, sediment/rock; Fraction modern carbon; Fraction modern carbon, standard deviation; Late Holocene; macrofossil; peat; PEATC; Peat corer; Pollen; radiocarbon; Sample ID; Thuringia, Germany; δ13C; δ13C, standard deviation
    Type: Dataset
    Format: text/tab-separated-values, 96 data points
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  • 8
    Publication Date: 2023-12-08
    Keywords: Age, 14C calibrated, IntCal20 with Bacon 2.2 (Blaauw and Christen, 2011); Beerberg_peatland_2019; Biomarkers; Calendar age, maximum/old; Calendar age, mean; Calendar age, median; Calendar age, minimum/young; Central Germany; DEPTH, sediment/rock; Late Holocene; macrofossil; peat; PEATC; Peat corer; Pollen; radiocarbon; Thuringia, Germany
    Type: Dataset
    Format: text/tab-separated-values, 1364 data points
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  • 9
    Publication Date: 2023-12-08
    Keywords: Abies alba; Acer; Aesculus hippocastanum; Agrostemma githago; Alnus indeterminata; Anthemis-type; Apiaceae indeterminata; Arnium; Artemisia; Aster-type; Avena-type; Beerberg_peatland_2019; Betula indeterminata; Biomarkers; Brassicaceae indeterminata; Calluna vulgaris; Caltha-type; Campanula; Carpinus betulus; Caryophyllaceae indeterminata; Centaurea cyanus; Centaurea jacea-type; Central Germany; Cerastium-type; Cercophora; Cerealia indeterminata; cf. Humulus lupulus; Chaetomium; Charcoal, particles; Chenopodiaceae; Cichoriaceae indeterminata; Cirsium/Carduus; Coniochaeta ligniaria; Cornus mas; Corylus avellana; Counted; Cyperaceae indeterminata; DEPTH, sediment/rock; Diphasium tristachyum; Drosera rotundifolia; Ericaceae indeterminata; Fagus sylvatica; Filicales monoletes; Filipendula; Frangula alnus; Fraxinus excelsior; Galium-type; Gelasinospora; Geranium; Hordeum-type; Hypericum; Jasione montana; Juglans; Knautia arvensis; Kretzschmaria deusta; Larix; Late Holocene; Lathyrus indeterminata; Ligustrum vulgare; Lysimachia-type; macrofossil; Menyanthes trifoliata; Mercurialis perennis; Neurospora; Nymphaea alba; Palynomorpha, non-pollen; peat; PEATC; Peat corer; Phacelia tanacetifolia; Picea abies; Pinus sylvestris-type; Plantago lanceolata; Plantago major-media; Poaceae indeterminata; Podospora; Pollen; Pollen, corroded; Polygonum aviculare-type; Populus; Prunus-type; Quercus; radiocarbon; Ranunculaceae indeterminata; Ranunculus acris-type; Ranunculus arvensis; Rosaceae indeterminata; Rumex acetosa/R. acetosella; Rumex obtusifolius; Salix indeterminata; Sambucus nigra/S. racemosa; Schizothecium conicum; Scleranthus perennis; Secale cereale; Silene indeterminata; Solanum nigrum-type; Sorbus; Sordaria; Sordariales; Sparganium-type; Sphagnum; Sporormiella; Taxus baccata; Thalictrum; Thelypteris cf. palustris; Thuringia, Germany; Tilia cordata; Trifolium pratense-type; Triticum-type; Ulmus; Urtica dioica; Vaccinium-type; Varia; Verbascum-type; Viburnum-type; Vicia-type
    Type: Dataset
    Format: text/tab-separated-values, 7245 data points
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  • 10
    Publication Date: 2023-12-08
    Keywords: Beerberg_peatland_2019; Biomarkers; Carbon; Carbon, standard error; Central Germany; Depth, bottom/max; DEPTH, sediment/rock; Depth, top/min; Elemental analyser isotope ratio mass spectrometer (EA-IRMS), Thermo Fisher Scientific, FLASH 2000-HT Plus; coupled with ConFlo IV to DELTA V Plus IRMS; Late Holocene; macrofossil; Nitrogen; Nitrogen, standard error; peat; PEATC; Peat corer; Pollen; radiocarbon; Sample code/label; Thuringia, Germany; δ13C; δ13C, standard error; δ15N; δ15N, standard error
    Type: Dataset
    Format: text/tab-separated-values, 935 data points
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