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  • Chemistry  (3)
  • 27.70.+q  (2)
  • Abiotic factors  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Growth and alkaloid contents in leaves of Tabernaemontana pachysiphon Stapf (Apocynaceae) as influenced by light intensity, water and nutrient supply (1996)
    Springer
    Oecologia 107 (1996), S. 160-169 
    Details
    ISSN: 1432-1939
    Keywords: Monoterpene indole alkaloids ; Tropical trees ; Abiotic factors ; Growth ; C/N balance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The growth of Tabernaemontana pachysiphon (Apocynaceae) plants and the alkaloid content of leaves were investigated in the greenhouse at three levels of nutrient supply under two contrasting water and light regimes. We determined height increment, above-ground biomass production, leaf size, specific leaf weight and the content of the alkaloids apparicine, A2, isovoacangine, tubotaiwine and tubotaiwine-N-oxide. The effects of major controlling factors such as light, water and nutrient supply could be directly correlated with growth and were largely independent of each other. In contrast, leaf-alkaloid contents were influenced by interdependencies among the main factors and individually affected in a synergistic or antagonistic manner which deviated from the effects on growth. The following general trends could be identified with respect to the quantitatively predominant alkaloids apparicine, tubotaiwine and isovoacangine. Increasing nutrient supply had a positive effect on both growth and alkaloid content. Drought increased alkaloid content, but retarded growth. High light intensity lowered alkaloid content but promoted growth. We investigated the relationship between primary production and the production of secondary metabolites with respect to relative and total alkaloid content as well as in relation to the leaves' nitrogen status. Our results showed that under conditions of low nutrient supply, higher proportions of leaf nitrogen were allocated to alkaloids than at moderate or high nutrient supply. Under conditions of drought and low light, all plants allocated almost equal proportions of leaf nitrogen to alkaloids, regardless of fertiliser. Total alkaloid content per plant, however, increased with fertilisation. With respect to the N-allocation strategy, we found no indication of a trade-off between primary production and the production of secondary metabolites in this species. Rather, our results are in accordance with the carbon nutrient balance hypothesis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00327899
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    High-spin spectroscopy of162Hf (1988)
    Springer
    The European physical journal 329 (1988), S. 289-299 
    Details
    ISSN: 1434-601X
    Keywords: 21.10.Re ; 23.20.Lv ; 27.70.+q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Excited states in162Hf were investigated up to spinI ≈ 38 using the anti-Comptonspectrometer array HERA with 21 detectors. In addition, some information was obtained on161Hf. The analysis of triple coincidences was crucial for the construction of the level schemes. The results are interpreted within the framework of the cranked shell model and are compared to neighbouring isotopes and isotones, showing Fermi level and deformation effects. The systematic behaviour of the band crossings in the Hf isotopes and theN=90 isotones is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01290234
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  • 3
    Electronic Resource
    Electronic Resource
    High-spin states in165Hf (1992)
    Springer
    The European physical journal 344 (1992), S. 235-241 
    Details
    ISSN: 1434-601X
    Keywords: 21.10.Re ; 23.20.Lv ; 27.70.+q
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract High-spin states in165Hf, populated in the130Te(40Ca, 5n) reaction, were investigated using the Berkeley HERA γ-ray spectrometer array. The previously known level scheme of165Hf is appreciably extended. Intrinsic configurations, band crossing frequencies and aligned angular momenta are interpreted within the frame-work of the cranked shell model. It is suggested that the alignments of the second neutron pair and of the first proton pair in165Hf occur at ħω≈0.44 MeV and ≈0.48 MeV, respectively. The systematic trend of these alignment frequencies for the Hf isotopes and for theN=93 isotones is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01303016
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  • 4
    Electronic Resource
    Electronic Resource
    Eni naturwissenschaftliches Literaturkarussell. Biologie (1993)
    Weinheim : Wiley-Blackwell
    Chemie in unserer Zeit 27 (1993), S. III 
    Details
    ISSN: 0009-2851
    Keywords: Chemistry ; Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ciuz.19930270209
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    Disproportionierung der Sulfinsäuren und die Struktur der Sulfinsäureanhydride (1958)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 70 (1958), S. 268-269 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19580700904
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    Synthesis and properties of a cellulose exchanger with the crown ether diaminodibenzo-17-crown-5 as anchor group (1995)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 227 (1995), S. 101-110 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Ein Cellulose- Austauscher wurde aus “o-Aminophenol-Cellulose” durch Diazotieren und Kuppeln mit Diaminodibenzo-17-krone-5 hergestellt. Die Verteilungskoeffizienten für Ca2+, Sr2+, Ba2+, Na+ und K+ wurden in Wasser/Methanol-Mischungen als Funktion des Wassergehaltes bestimmt. Die Trennung von Ca2+, Na+ und K+ und die Fraktionierung der Calciumisotope 48Ca und 40Ca wurde untersucht. Der Anreicherungsfaktor ε = 4.9 · 10-3 für 48Ca2+ ist merklich größer als der für Kationenaustauscher mit SO3H-Gruppen gefundene, aber niedriger als der in der Literatur für bestimmte Kryptanden angegebene Wert.
    Notes: A new cellulose exchanger was synthesized from “o-aminophenolcellulose” by diazotation and coupling with diaminodibenzo-17-crown-5. The distribution coefficients for Ca2+, Sr2+, Ba2+, Na+ and K+ were determined in water/methanol mixtures as a function of the water content. Separation of Ca2+, Na+ and K+ and fractionation of the calcium isotopes 48Ca and 40Ca were investigated. The enrichment factor ε = 4.9 · 10-3 for 48Ca2+ is appreciably higher than that found for cation exchange resins with —SO3H groups, but lower than that reported for certain cryptands.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1995.052270110
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