Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    The drift of a one-dimensional self-repellent random walk with bounded increments (1994)
    Springer
    Probability theory and related fields 100 (1994), S. 513-544 
    Details
    ISSN: 1432-2064
    Keywords: 60K35 ; 58E30 ; 60F10 ; 60J15
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary Consider a one-dimensional walk (S k ) k having steps of bounded size, and weight the probability of the path with some factor 1−α∈(0,1) for every single self-intersection up to timen. We prove thatS n /S S converges towards some deterministic number called the effective drift of the self-repellent walk. Furthermore, this drift is shown to tend to the basic drift as α tends to 0 and, as α tends to 1, to the self-avoiding walk's drift which is introduced in [10]. The main tool of the present paper is a representation of the sequence of the local times as a functional of a certain Markov process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01268992
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The drift of a one-dimensional self-avoiding random walk (1993)
    Springer
    Probability theory and related fields 96 (1993), S. 521-543 
    Details
    ISSN: 1432-2064
    Keywords: 60K35 ; 58E30 ; 60F10 ; 60J15
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Summary We prove that a self-avoiding random walk on the integers with bounded increments grows linearly. We characterize its drift in terms of the Frobenius eigenvalue of a certain one parameter family of primitive matrices. As an important tool, we express the local times as a two-block functional of a certain Markov chain, which is of independent interest.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01200208
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Phosphorylating Power of Red Phosphorus towards Aldehydes in Basic and in Acidic Media (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 861-868 
    Details
    ISSN: 1434-193X
    Keywords: Red phosphorus ; Phosphane PH3 ; Phosphorylations ; Ultrasound irradiation ; Redox chemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: -The reactivity of red phosphorus towards aldehydes was investigated under basic and acidic media. It was demonstrated that the real phosphorylating agent involved in the reaction was phosphane (PH3) in basic media, and hypophosphorous acid (H3PO2) in acidic media. A convenient one-pot synthesis of (α-hydroxyalkyl)phosphinic acids from red phosphorus and aldehydes in basic media was realized under sonication. The same reaction under acidic media in the presence of hydriodic acid led to the corresponding phosphonic acids. The (α-hydroxyalkyl)phosphinic acids were readily prepared under sonication from hypophosphorous acid and aldehydes in the presence of catalytic amounts of hydrochloric acid. The mechanism of the addition reaction of PH3 to benzaldehyde was elucidated and shows the complexity of the reaction as a function of the experimental conditions.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 4
    Electronic Resource
    Electronic Resource
    Changing the Reactivity of Enediynes by Metal-Ion Coordination (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 381-385 
    Details
    ISSN: 1434-193X
    Keywords: Enynes ; Macrocycles ; Coordination chemistry ; Crown compounds ; Radicals ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The complex molecular structure and interesting activation mechanisms of naturally occurring enediynes have inspired the synthesis of a variety of simpler model systems to mimic their properties. While in most model compounds nucleophilic attack, isomerization or bioreduction are used to activate the unsaturated system for diradical cyclization, some attempts have been made to employ metal-ion coordination for this purpose. Significant enhancement of the thermal reactivity has been achieved by metal-ion induced conformational and electronic changes of suitably substituted enediynes, such as 1, 5, 6, 17 and 18. Enediyne activation by stoichiometric or catalytic formation of vinylidene complexes, such as 22, from terminal alkynes has also been investigated. This paper summarizes recent results pursuing the activation of enediyne diradical cyclization by metal ions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 5
    Electronic Resource
    Electronic Resource
    Synthesis and Metal-Ion Extraction Properties of para-tert-Butylcalixareneglycine Ester Acetamides (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1557-1562 
    Details
    ISSN: 1434-1948
    Keywords: Calixarenes ; Macrocycles ; Silver ; Radiotracer technique ; Metal-ion extraction ; Radiochemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Calixareneglycine ester acetamides 4a-c have been synthesized from calixareneacetyl chlorides 5a-c and glycine ethyl ester (6). Their ion-binding properties have been investigated by liquid-liquid extraction with radiotracer techniques. The experiments reveal a moderate affinity towards silver(I) ions, which increases with calixarene ring size.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 6
    Electronic Resource
    Electronic Resource
    A New Tyrosine Kinase Inhibitor from a Marine Isolate of Ulocladium botrytis and New Metabolites from the Marine Fungi Asteromyces cruciatus and Varicosporina ramulosa (1999)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 2949-2955 
    Details
    ISSN: 1434-193X
    Keywords: Marine fungi ; Tyrosine kinase ; Natural products ; Macrodiolides ; Polyketides ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The sponge-derived fungi Ulocladium botrytis and Asteromyces cruciatus, and the algal-derived fungus Varicosporina ramulosa, were isolated and extracts from cultures investigated for their metabolite production. Investigations of the extract of the culture of U. botrytis guided by bioassay yielded the new tyrosine kinase (p56lck) inhibitor ulocladol (1) together with 1-hydroxy-6-methyl-8-(hydroxymethyl)xanthone (3), which showed antifungal activity. The extract of the culture medium of A. cruciatus yielded the new metabolite (+)-2,4-dimethyl-4,5-dihydrofuran-3-carbaldehyde (4) together with the known compounds (3S,5R)-dimethyldihydrofuran-2-one (5) and tri-O-acetyl glycerol. From V. ramulosa the five macrodiolides grahamimycin A1 (6), colletoketol (7), (6R,11R,12R,14R)-colletodiol (8), 9,10-dihydro-(6R,11S,12S,14R)-colletodiol (9) and 9,10-dihydro-(6R,11R,12R,14R)-colletodiol (10) together with ergosterol were obtained, 9 and 10 being new fungal metabolites.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 7
    Electronic Resource
    Electronic Resource
    Novel Chiral Pyridine N-Oxide Ligands and Their Application in the Enantioselective Catalytic Reduction of Ketones and the Addition of Diethylzinc to Aldehydes (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 1001-1007 
    Details
    ISSN: 1434-1948
    Keywords: Pyridine N-oxide ; Pyridine ; Asymmetric catalysis ; Amino acids ; Amino alcohols ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Starting from picolinic acids 3 and 4, the amino acid-derived 2-aminoacylpyridine N-oxides 1a,c-e and 2,6-bis(aminoacyl)pyridine N-oxides 2b-e can be prepared in two steps by the coupling of picolinic acid N-oxides 5 and 6 under Appel conditions with the corresponding L-amino acid ester or (1R,2S)-norephedrine. Compounds 1 and 2 were used as chiral ligands in two different asymmetric catalyses. In the catalytic addition of diethylzinc to benzaldehyde 11, low enantioselectivities (2-29% ee) were obtained regardless of the amino acid moiety. However, the corresponding 2,6-bis(aminoacyl)pyridines 7 and 8 led to increased ee values (55% ee). In the catalytic reduction of ketones 9a-c to alcohols 10a-c low enantioselectivities were observed for alanine-, valine-, and leucine-derived N-oxides 1a,c and 2b,c. An increase of selectivity was observed for bis-methionine ligand 2d (32-38% ee) relative to that of mono-methionine ligand 1d (7-16% ee). However, mono-norephedrine ligand 1e (≤ 64% ee) and the corresponding bis-norephedrine ligand 2e (≤ 51% ee) displayed the highest selectivities. The influence of the N-oxide moiety on the enantioselectivity was demonstrated by the observation that 2,6-bis(aminoacyl)pyridines 7 and 8 gave much lower selectivities than the corresponding pyridine N-oxides 2d and e.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 8
    Electronic Resource
    Electronic Resource
    1.3-Dipolare Additionen der Ketocarbene (1961)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 73 (1961), S. 368-371 
    Details
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bei der Thermolyse und Photolyse von Diazocarbonyl-Verbindungen treten die Ketocarbene als echte Zwischenstufen auf, die sich mit geeigneten Mehrfachbindungssystemen in 1.3-Dipolarer Addition abfangen lassen. Ketocarbene sind normalerweise „heiße“ Zwischenstufen, die sich rasch in Ketene umlagern. Es bedarf spezieller Diazocarbonyl-Verbindungen und besonderer Reaktionsbedingungen, um mit der Wolff-Umlagerung erfolgreich zu konkurrieren.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ange.19610731105
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Darstellung und Struktur von Diphenyl-zinn (1962)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 74 (1962), S. 215-215 
    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.19620740610
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Acetylnitrat-Explosion (1955)
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 67 (1955), S. 157-157 
    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.19550670508
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...