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  • 1
    Electronic Resource
    Electronic Resource
    Copper and nutrition in Helix pomatia (L.) (1979)
    Springer
    Oecologia 42 (1979), S. 241-251 
    Details
    ISSN: 1432-1939
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary 1. In Helix pomatia the efficiency of assimilation of both food (lettuce) and copper is always high, even when the food has been artificially enriched with copper. In short-term feeding experiments with lettuce containing 1390 (±420)ppm copper about 97% of the metal ingested remains in the snail. 2. The availability of copper in the faeces is independent of the type of food and does not differ much from the availability of the metal in untreated lettuce. About half of the metal can be extracted by 0.1 M HCl, whereas the other half is liberated only by ashing. 3. The concentration of copper in the organs of a natural population of H. pomatia varied between 20 and 120 ppm (dry weight). Being by far the largest organ the foot contains most of this copper. After the snails have fed on copper-enriched food for three weeks the concentration of copper increases mainly in the alimentary tract and in the midgut gland, but no one organ is capable of concentrating copper to a much higher degree than another. In winter animals which had been feeding on copper-enriched food prior to hibernation, the concentration of copper in several organs may reach values that are from 10 to 40 times higher than those in summer animals. 4. When snails begin to feed on copper-enriched food the concentration of the metal increases quickly in the anterior alimentary tract. After three days a striking increase in the midgut gland takes place, followed, after five days, by a further accumulation of copper in the tissues of the alimentary tract, mainly of the intestine. In the albumen gland and in the foot the concentration of copper remains more or less constant. 5. In midgut and albumen gland more than 90% of the total copper is so tightly bound that it can be liberated only by ashing, whereas in the walls of the alimentary tract between 55 and 70% of the copper can be extracted with 0.1 M HCl. 6. If gastropods and isopods are compared with regard to the efficiency of their assimilation of copper it can be shown that this remains high as long as the ingestion of food (dry weight) does not exceed approximately 3% of fresh body weight per day.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00344860
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  • 2
    Electronic Resource
    Electronic Resource
    Die Konstanten der Internationalen Temperaturskala oberhalb des Goldpunktes (1948)
    Springer
    Naturwissenschaften 35 (1948), S. 60-61 
    Details
    ISSN: 1432-1904
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00626793
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Transport and retention of matter in riparian ecotones (1993)
    Springer
    Hydrobiologia 251 (1993), S. 95-101 
    Details
    ISSN: 1573-5117
    Keywords: Land/stream ecotones ; bank runoff ; aerial drift ; retention ; carbon ; nitrogen ; phosphorus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The ‘stream’ ecosystem is described as a three-layered system, vertically as well as horizontally. The land/stream ecotone is defined as the area where lotic and edaphic characters overlap at the time of observation. The study site — ‘Oberer Seebach’, near the Biological Station Lunz — and the methods employed are described. Only a surprisingly small fraction (less than 10 %) of total imports is transported across the surface ecotones. The driving variables determining bank runoff and aerial drift are described and discussed. The importance of channel areas which are periodically flooded is stressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00007169
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  • 4
    Electronic Resource
    Electronic Resource
    Phosphororganische Verbindungen, 51. Die Einführung von Arylresten in tertiäre Phosphine mit Hilfe von Komplexen der übergangsmetalle (Komplexsalzmethode)Vorgetragen auf dem IUPAC-Symposium Organo-Phosphorous Compounds in Heidelberg 20.-22. Mai 1964. (1966)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 99 (1966), S. 2782-2788 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Unter Mitwirkung der Chloride und Bromide von NiII, CoII, ZnII, CuII, MnII und FeII werden tertiäre Phosphine mit Arylchloriden, -bromiden und -jodiden in der Schmelze oder in siedendem Benzonitril in hohen Ausbeuten quartärisiert.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19660990910
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  • 5
    Electronic Resource
    Electronic Resource
    Phosphororganische Verbindungen, 52. Beitrag zum Mechanismus der Arylphosphoniumsalzbildung aus tertiären Phosphinen nach der „Kobaltsalz-Methode“ (1966)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 99 (1966), S. 2789-2802 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die bei der Kharasch-Reaktion erzeugten Aryl-Radikale werden von tertiären Phosphinen unter Aufbau einer P-Arylbindung abgefangen. Die Ausbeuten an quartären Phosphoniumsalzen werden studiert in Abhängigkeit von der Menge an Kobaltsalz, von der Natur des Lösungsmittels, von der Lösungsmittelmenge, von der Natur des Arylhalogenids, vom Anion des Kobaltsalzes, von der Reihenfolge der Substanzzugabe und von der Menge an gelöstem Kobaltchlorid in Diäthyläther.  -  In aliphatisch und aliphatisch-aromatisch substituierten tertiären Phosphinen werden die aliphatischen Liganden  -  mit hoher Wahrscheinlichkeit auf der Stufe der tertiären Phosphine  -  durch Aryl-Radikale verdrängt. Die experimentellen Befunde für diesen Radikalprozess werden mitgeteilt; ein Mechanismus wird zur Diskussion gestellt.
    Additional Material: 7 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19660990911
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  • 6
    Electronic Resource
    Electronic Resource
    Heizwertbestimmung fester Brennstoffe (1937)
    Springer
    Fresenius' Zeitschrift für analytische Chemie 111 (1937), S. 131-136 
    Details
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01363980
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    Paper (German National Licenses)
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