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
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Accreditation and quality assurance 3 (1998), S. 425-426 
    ISSN: 1432-0517
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Accreditation and quality assurance 3 (1998), S. 115-116 
    ISSN: 1432-0517
    Keywords: Key words Uncertainty ; Metrology ; Comparability ; Traceability ; Validation ; Bias
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  At the Second EURACHEM Workshop on Measurement Uncertainty in Chemical Analysis the author had the pleasure of chairing a working group on chemical metrology. This note presents some propositions arising from the preparation of, as well as from the discussion at and after, the working group session.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Accreditation and quality assurance 3 (1998), S. 106-110 
    ISSN: 1432-0517
    Keywords: Key words Uncertainty ; Calibration ; Weighted regression ; Covariances
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract  The impact of correlation between the reference points used in determination of a functional relationship by application of least-squares techniques is discussed. Calculations are based on an improved effective-variance approach to the general least-squares problem. From a simulation study, general conclusions about the impact of correlation are drawn. Standard addition as an example of a method using correlated data is discussed in detail.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Accreditation and quality assurance 4 (1999), S. 483-484 
    ISSN: 1432-0517
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Electronic Resource
    Electronic Resource
    Springer
    Accreditation and quality assurance 5 (2000), S. 454-455 
    ISSN: 1432-0517
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 66 (1984), S. 91-110 
    ISSN: 1432-2234
    Keywords: Pólya enumeration theory ; power group theorem ; Burnside's lemma ; symmetry types of mappings ; correlation of symmetries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The power group method of de Bruijn and Harary in enumeration under group action of mappings between finite sets is extended to include correlation of group actions on domain and range. By relaxing the restriction of weight functions to be constant over orbits, more specific results concerning the enumeration of orbits by weight are obtained.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 19 (1970), S. 288-300 
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Das allgemeine Prinzip, Moleküle gleicher Bruttoformel nach „Konfigurationen“ zu klassifizieren, beruht auf der Kombination zweier Abstraktionsprozesse in der Menge starrer Molekülmodelle zu einem gemeinsamen Molekülgerüst mit bezifferten PlÄtzen für Liganden und bezifferten Liganden. Es wird gezeigt, da\ die möglichen Klassifizierungsgesichtspunkte den möglichen Einteilungen von Permutationen einer Gruppe $$\mathfrak{A}$$ in Doppelnebenklassen des Produkts zweier entsprechend ausgewÄhlten Untergruppen $$\mathfrak{B}$$ und $$\mathfrak{S}$$ entsprechen. Ähnlich wie die irreduziblen Darstellungen der Symmetriegruppe einer Observablen die Nomenklatur für die Rassen der Eigenfunktion liefern, stellen die Doppelnebenklassen eine Nomenklatur für Konfigurationen. Das spezielle Klassifizierungsprinzip drückt sich in der Wahl der Gruppen $$\mathfrak{A}$$ , $$\mathfrak{B}$$ und $$\mathfrak{S}$$ aus. Die AbzÄhlung von Konfigurationen führt damit auf das verallgemeinerte Problem der AbzÄhlung von Doppelnebenklassen. Dafür werden drei Formeln abgeleitet. Im Falle der speziellen Gruppe $$\mathfrak{S} = \mathfrak{S}_n $$ ist von G. Pólya eine Anzahlformel entwickelt worden, die im Anhang auf unsere Formeln zurückgeführt wird.
    Abstract: Résumé Les propriétés pseudoscalaires des molécules chirales sont l'object d'une théorie algébrique après une définition convenable des classes de molécules. L'analyse du phénomène de chiralité sur ces classes conduit à des aspects particuliers de la théorie de la représentation des fonctions de chiralité, à une nouvelle structure de réseau des partitions, à des propriétés des groupes de permutation qui y sont liés et donne finalement un aperÇu sur la structure des points de vue approchés pour les fonctions de chiralité. Ainsi le présent article contient des aspects purement mathématiques. Les théorèmes mathématiques qui seront énoncés et prouvés sans référence essentielle à la physique se trouveront dans l'appendice. L'article lui-mÊme présente en premier lieu le phénomène physique; les concepts proposés par le formalisme mathématique tels que: ordre de chiralité, indice de chiralité, nombres de chiralité, complétude qualitative, hypothèse brève, partitions active et inactive des ligands, etc... donnent lieu à une systématisation et à une étude concernant la measure des propriétés liées à la chiralité des molécules. Par example, les points de vue co- et contravariant pour le comportement des fonctions par transformation nozs deux interprétations possibles des fonctions par transformation nous donne deux interprétations possibles des fonctions de chiralité. Nous pouvons considérer les composantes des fonctions appartenant à des représentations irréductibles comme des fonctions de chiralité pour des mélanges d'isomères. De là les opérateurs de projection sont dotés d'une interprétation physique d'opérateurs d'ensemble pour les mélanges d'isomères. Le chapitre 10 esquisse des applications de la théorie de cet article. Les premières comparaisons convaincantes des données expérimentales pour le pouvoir rotatoire des dérivés alléniques avec les valeurs théoriques basées sur les approximations des méthodes présentées aux chapitres 8 et 10 sont disponibles et en voie de publication. Les conséquences mathématiques de la définition du réseau de partition donnée au chapitre 6 seront développées par ailleurs.
    Notes: Abstract The general principle of classifying molecules of a common gross formula according to “configurations” is founded on the combination of two abstractions among rigid molecular models with a common molecular frame, numbered places for ligands, and numbered ligands. It is shown that the various points of view, which can be taken for the classification are determined by two accordingly chosen subgroups $$\mathfrak{A}$$ and $$\mathfrak{B}$$ of a permutation group $$\mathfrak{S}$$ , the configurations being defined by the double cosets of the product $$\mathfrak{A}\mathfrak{B}$$ . Just as the irreducible representations of the symmetry group of an observable furnish the nomenclature for different types of eingenfunctions the double cosets here provide a nomenclature for the configurations. The special principle of classification is given by the choice of $$\mathfrak{A}$$ , $$\mathfrak{B}$$ and $$\mathfrak{S}$$ . Thus, the enumeration of configuration leads to the generalised problem of enumerating double cosets. For this, three formulas are derived. In case of the special group $$\mathfrak{S} = \mathfrak{S}_n $$ G. Pólya found a formula of enumeration which is shown to reduce to our formulas in the appendix.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 29 (1973), S. 259-268 
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Umordnungen von Liganden, die auf vorgegebene Plätze eines bestimmten Molekülgerüstes verteilt sind, können nach zwei Prinzipien klassifiziert werden: Symmetrieäquivalenz, gekennzeichnet durch dieselbe Permutation von Objekten bezogen auf symmetrieäquivalente Gerüstplätze, und Rotationsäquivalenz, dadurch charakterisiert, daß die entstehenden Isomere sich nur durch ihre Orientierung unterscheiden. Die Kombination dieser beiden Prinzipien führt zu einer Klassifikation, die zur Interpretation von Experimenten benötigt wird. Es wird gezeigt, daß diese Klassifikation auf Doppelnebenklassen führt, mit denen die Umordnungen einer Klasse auf formale Weise leicht zu finden sind und die Anzahl der unterscheidbaren Klassen für jedes vorgegebene Problem bestimmt werden kann.
    Notes: Abstract Rearrangements of ligands attached at given sites of a certain skeleton may be classified according to two principles: symmetry equivalence, where the same permutation of objects is related to symmetry equivalent sites and rotational equivalence, where the resulting isomers differ just by their orientation. The combination of both these principles leads to a classification wanted by experimentalists. This latter classification is shown to be correlated to double cosets, which easily allow to find the rearrangements belonging to a class in a formal way and to enumerate the distinguishable classes for any given problem.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 67 (1985), S. 339-367 
    ISSN: 1432-2234
    Keywords: Enumeration under group action ; symmetry of derivatives ; automorphism group of patterns ; table of marks
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Pólya's enumeration theory and its generalizations are refined to count derivatives of symmetrical parent compounds with any specified subsymmetry. Equivalently, enumeration of orbits of mappings, upon which a group acts by acting on their domain and their range, is refined to count orbits with stabilizers in any specified conjugacy class of subgroups.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 70 (1986), S. 119-121 
    ISSN: 1432-2234
    Keywords: Rényi entropies ; Mixing character ; Majorization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Since the advent of the notion of mixing character in statistical mechanics, it has been conjectured over and over again that the Rényi entropies provide a mixing isomorphic family, that is: given two probability distributions p and q, the mixing character of q exceeds that of p, m[q]〉 m[p], if and only if I α(q)≥I α(p) for any positive α. This conjecture is disproved by means of counterexamples.
    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...