ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1980-1984  (7)
Collection
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 17 (1980), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: In the Fond du Lac River, adult male Arctic grayling defend territories on the spawning ground for up to 7 days. Females do not defend territories and do not exhibit agonistic behaviour during the breeding season.The behaviour patterns exhibited by Arctic grayling during spawning are virtually identical to those exhibited by European grayling. The characteristic large dorsal fin of the grayling is of major importance during the spawning act.Less than 50% of all spawning attempts proceed to completion. Interference by other fish or the improper orientation of one fish may result in one member of the spawning pair moving away. Most often however, incomplete acts are the result of the female moving away for no apparent reason. Females may initially ‘test’ males or may simply not be ready to spawn when approached by males. Homosexual spawning attempts were rarely observed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-9066
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Powder metallurgy and metal ceramics 21 (1982), S. 747-749 
    ISSN: 1573-9066
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-9066
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolabile Hydrocarbons, XIII. 3,4-Dicyclohexyl-3,4-dimethylhexane - Standard Heat of Formation, Thermal Stability, and StructureThe heat of formation of the title compound 2 was determined by combustion calorimetry: ΔHfo(g) = -71.6 (±0.7) kcal · mol-1. The high strain enthalpy HS = 35.0 kcal · mol-1 derived therefrom explains the low thermal stability of 2 [τ1/2 = 1 h at 250°C; ΔH≠ = 52.1 (±1.5) kcal · mol-1; ΔS≠ = 22 (±3) e. u.]. In the X-ray structure of 2 the strain is recognized in long bonds (Cq - Cq = 162.7 pm) and bond angle deformations up to 117.5° within the ethyl- and cyclohexyl groups. The experimental enthalpy- and structural data are compared with those calculated by five different force fields. Allinger's MM 2 force field proved to be superior to the others and provided excellent agreement between experiment and calculations.
    Notes: Die Bildungsenthalpie der Titelverbindung 2 wurde durch Verbrennungskalorimetrie zu ΔHfo(g) = -71.6(±0.7) kcal · mol-1 bestimmt. Die daraus abgeleitete hohe Spannungsenthalpie HS = 35.0 kcal · mol-1 erklärt die geringe thermische Stabilität von 2 [τ1/2 = 1 h bei 250°C; ΔH≠ = 52.1 (±1.5) kcal · mol-1; ΔS≠ = 22 (±3) Clausius]. In der röntgenographisch bestimmten Kristallstruktur von 2 dokumentiert sich die Spannung in langen Bindungen (Cq — Cq = 162.7 pm) und Winkelaufweitungen bis zu 117.5° in den Ethyl- und Cyclohexylresten. Mit fünf verschiedenen Kraftfeldern berechnete Struktur- und Enthalpiedaten werden mit den experimentellen Werten verglichen. Mit dem Kraftfeld MM 2 von Allinger wird eine ausgezeichnete Übereinstimmung erzielt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 116 (1983), S. 3235-3263 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolabile Hydrocarbons, XX. Synthesis, Structure, and Strain of Sym. Tetraalkyl-1,2-diarylethanesThe syntheses of 18 1,1,2,2-tetraalkyl-1,2-diarylethanes 1-4 by dimerisation procedures starting with 10-13 are reported. In the absence of p-substituents X and with increasing alkyl side chains the α, p-dimers 6 or their aromatic counter parts 7 are obtained besides or instead of 1. The relationships between strain enthalpy Hs, bond lengths, bond angles, torsional angles, and rotational barriers are discussed on the basis of force field calculations. They are supported by two additional experimental structure determinations by X-ray diffraction.
    Notes: Die Synthesen von 18 1,1,2,2-Tetraalkyl-1,2-diarylethanen 1-4 durch Dimerisierungsverfahren ausgehend von 10-13 werden beschrieben. Bei fehlenden p-Substituenten X und großen Alkylseitenketten R1 und R2 erhält man neben oder statt 1 α, p-Dimere 6 oder deren aromatische Folgeprodukte 7. Die Zusammenhänge zwischen Spannungsenthalpie Hs und Bindungslängen und -winkeln sowie Torsionswinkeln und Rotationspotentialen werden anhand von Kraftfeldberechnungen diskutiert. Zur Absicherung der Kraftfeldmethode wurden zwei weitere Kristallstrukturanalysen durchgeführt.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 1748-1764 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Thermolabile Hydrocarbons, XXII. Thermolysis of symm. Tetraalkyldiarylethanes and the Resonance Energy of α,α-Dialkylbenzyl RadicalsThe products and the activation parameters for the thermolysis reactions of the hydrocarbons 1 - 10 were determined. From correlations between δG† and the ground state strain Hsp or the change in strain during the dissociation process Dsp10) the steric accelleration of this reaction was analyzed quantitatively. A comparison of this analysis with a corresponding correlation for simple Cq - Cq alkanes8) results in a resonance energy of 8.4 ± 1.1 kcal · mol-1 for α,α-dialkylbenzyl radicals. The origin of the appreciable variation of δS† in this series and for the poorer precision of δH†/Hsp correlations is discussed.
    Notes: Die Produkte und die Aktivierungsparameter der Thermolyse der Kohlenwasserstoffe 1 - 10 wurden bestimmt. Die sterische Beschleunigung des Zerfalls dieser Verbindungen in die Radikale 11 wurde aus der Korrelation der δG†-Werte mit der Grundzustandsspannung Hsp bzw. der Dissoziationsspannung Dsp10) quantitativ analysiert. Durch Vergleich dieser Analyse mit der entsprechenden Korrelation der Thermolysedaten einfacher Cq - Cq-Alkane8) ergibt sich für tert. Benzylradikale eine Resonanzenergie von 8.4 ± 1.1 kcal · mol-1. Die Ursachen der beachtlichen Schwankung der δS†-Werte in dieser Reihe und der geringen Präzision der δH†/Hsp-Korrelationen werden diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...