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  • General Chemistry  (51)
  • Life Sciences  (6)
  • SOLID Retrieval/Processing System  (6)
  • 1
    ISSN: 1573-8787
    Schlagwort(e): Transparent Query Language ; Mathematically Complete Language ; Philosophically Closed Language ; SOLID Retrieval/Processing System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract This part, PART IIB [2], of the document “HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL)” [1–6] contains the specifications for the operations that provide the arithmetic capabilities for Transparent Query Language. PART IIB references PART IIA [1] and PART IIC [3]. Concise definitions of Transparent Query Language terms, Conclusions and Acknowledgments are given in PART IIF [6].
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  • 2
    ISSN: 1573-8787
    Schlagwort(e): Transparent Query Language ; Mathematically Complete Language ; Philosophically Closed Language ; SOLID Retrieval/Processing System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract This part, PART IIC [3], of the document “HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL)” [1–6] is a continuation of [2] and should be studied immediately after reading PART IIB [2]. It describes (i) the security system that can be easily invoked to deny unauthorized access to any item of information in any database; (ii) the special codes that can be used to specify virtually any degree of uncertainty; (iii) the registry numbers which terminate information paths; and (iv) the command structure for the Transportable Query Language. PART IIC references PART IIA [1], PART IIB [2], PART IID [4] and PART IIF [6]. Concise definitions of Transparent Query Language terms, Conclusions and Acknowledgments are given in PART IIF [6].
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  • 3
    ISSN: 1573-8787
    Schlagwort(e): Transparent Query Language ; Mathematically Complete Language ; Philosophically Closed Language ; SOLID Retrieval/Processing System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract In the six parts of the document “HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL)” [1–6], the Transparent Query Language (TQL) that is the mathematical basis for the SOLID Retrieval/Processing System [7] is described and its use demonstrated. TQL is directly responsible for the speed, versatility, security and information/question-type independence of the SOLID System. It can be viewed as a Mathematically Complete (or Philosophically Closed) [8] data structure or content/context independent language capable of describing individual or classes of descriptors in any combination with any degree of specificity. The security system is easily used to prevent unauthorized access to any item in any file. TQL is sufficiently general to be used outside the context of information retrieval. It is capable of concisely representing and manipulating a wide variety of time dependent or static numeric and non-numeric information. The six parts of this document [1–6], are as follows. The first part, PART IIA [1], contains a review of the literature and then introduces the Transparent Query Language. It references PART IIB [2], PART IIC [3], PART IID [4], PART IIE [5] and PART IIF [6]. Concise definitions of Transparent Query Language terms, Conclusions and Acknowledgments are given in PART IIF [6]. Section III in PART IIA [1] contains information for converting citations of sections and subsections in the original document to their locations in the partitioned document.
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  • 4
    ISSN: 1573-8787
    Schlagwort(e): Transparent Query Language ; Mathematically Complete Language ; Philosophically Closed Language ; SOLID Retrieval/Processing System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract This part, PART IID [4], of the document “HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL)” [1–6] is about normalization and manipulation of information representations. It references PART IIA [1], PART IIB [2] and PART IIC [3]. Concise definitions of Transparent Query Language terms, Conclusions and Acknowledgments are given in PART IIF [6].
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  • 5
    ISSN: 1573-8787
    Schlagwort(e): Transparent Query Language ; Mathematically Complete Language ; Philosophically Closed Language ; SOLID Retrieval/Processing System ; Sequel (SQL) ; Relational Algebra ; QUEL ; Query-By-Example (QBE)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract In this part, PART IIE [5], of the document “HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL)” [1–6] the conversion of queries coded in SQL, Relational Algebra, QUEL and Query-By-Examples (QBE) to TQL are demonstrated. PART IIE references PART IIA [1], PART IIB [2], PART IID [3] and PART IIF [6]. Concise definitions of Transparent Query Language terms, Conclusions and Acknowledgments are given in PART IIF [6].
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  • 6
    ISSN: 1573-8787
    Schlagwort(e): Transparent Query Language ; Mathematically Complete Language ; Philosophically Closed Language ; SOLID Retrieval/Processing System
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Informatik
    Notizen: Abstract This part, PART IIF [6], concludes the document “HIGH-SPEED TOOLS FOR GLOBAL INFORMATION MANAGEMENT. II. Specifications and Uses of the Transparent Query Language (TQL)” [1–6]. It describes novel applications of TQL, the key data structures, and contains a dictionary of Transparent Query Language terms. PART IIF references PART IIA [1], PART IIB [2], PART IIC [3], PART IID [4], and PART IIE [5] and contains Conclusions and Acknowledgements.
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  • 7
    ISSN: 1434-193X
    Schlagwort(e): Indiumallyl compounds ; Vinylcyclopropanes ; α,β-Unsaturated carbonyl compounds ; Diastereoselectivity ; Dibenzylideneacetone ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: ---Allylindium reagents, prepared from excess allylic halide (Br or I) and indium metal, react with α,β-unsaturated ketones and aldehydes to give, after aerobic acidic workup, homoallyl-substituted vinylcyclopropanes. This process was explored and developed after a chance discovery arising from a side reaction in an attempted Pd-catalysed process. The structure of the cyclopropane arising from the reaction of bis(p-chlorobenzylidine)acetone was confirmed by X-ray crystallography. Whilst bis-α,β-unsaturated ketones give rise to a single homoallylcyclopropane species, α,β-unsaturated ketones and aldehydes give diastereomeric mixtures whose relative stereochemistry were assigned by NOE experiments. Crotylindium reagents react with good to perfect regioselectivity to afford tetrasubstituted cyclopropanes but prenylindium reagents fail to generate the analogous pentasubstituted rings.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1434-193X
    Schlagwort(e): Indium ; Vinylcyclopropanes ; Ring closing metathesis ; Norcarenes ; Kinetic diastereoselection ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: ---Homoallyl-substituted vinyl cyclopropanes 1a-c, which are readily prepared by reaction of allylindium reagents with α,β-unsaturated ketones and aldehydes, undergo Ru-catalysed RCM reactions with Grubbs catalyst to give [4.1.0]bicyclooct-2-ene (norcarene) type bicyclic products. Noncyclisable ‘trans’ homoallyl-substituted vinyl cyclopropanes 1b and 1c are separated from their ‘cis’ diastereomers by RCM to 5b and 5c - but only with moderate efficiency due to a competing homo-cross metathesis (‘dimerisation’) to give 7b and 7c, respectively. However, the four diastereomers of the (homoallyl)distyrylcyclopropane 14a obtained from indium-mediated reaction of dibenzylideneacetone and crotyl bromide undergo remarkable kinetic diastereoselection in their RCM reactions to give a 4,7-dimethyl[4.1.0]bicyclohept-2-ene-type product 15a. This process allows recovery of a single diastereomer (〉 95%) of 14a without dimerisation being a significant side reaction. Furthermore, the RCM product 15a is obtained rich in one diastereomer (ca. 90%). The kinetic diastereoselection and lack of dimerisation can be rationalised by considering developing transannular interactions and a pseudo-A1,3 strain model.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1434-1948
    Schlagwort(e): Coordination modes ; Cyclophanes ; Macrocycles ; Sandwich complexes ; Solid-state structures ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A novel mode of containment for metal ions which participate in longer-range interactions with aryl rings (≥ 2.5 Å) is demonstrated in the preorganized cylindrical host 1. Three equatorial sulfur atoms in 1 hold metals in a trigonal planar ligand field between two apical benzene centroids at an M-Ar distance of about 3 Å. Evidence of an interaction between the π electrons and the metals is gained by 1H NMR spectroscopy of the complexes, and support for the general description of metal-arene contacts in the 2.5-3.5 Å range as ‘‘bonds’’ is derived from a statistical study of η6-coordination in the solid state. Crystal structures of [Ag(1)]BF4 and [Cu(1)]BF4 confirm the first examples of arene AgI and CuI sandwich complexation and indeed the only structurally characterized CuI-aryl centroid interaction. The two isomeric tris-sulfoxides derived from 1 show less tendency to interact with metals ions.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1434-1948
    Schlagwort(e): Chirality ; Ruthenium ; Chiral resolution ; Nitrogen heterocycles ; Carbonyl complexes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A range of chiral building blocks of the type Δ- or Λ-[Ru(pp)2(CO)2]2+ {pp = bidentate ligands bpy (2,2′-bipyridine), phen (1,10-phenanthroline) and Me2bpy (4,4′-dimethyl-2,2′-bipyridine)} have been synthesized, and their enantiomeric purity and absolute configurations determined by CD and NMR studies. Decarbonylation using trimethylamine oxide in the presence of the respective pp ligand at room temperature produced the corresponding tris(bidentate) species [Ru(pp)3]2+ with retention of configuration at the ruthenium(II) centre. A general chromatographic technique for resolution of tris-homoleptic complexes of the type [Ru(pp)3]2+ was investigated, with the absolute configurations of the resolved complexes confirmed by CD studies, and the X-ray structural analyses of Δ-(-)-[Ru(Me2bpy)3]{(-)-O,O′-dibenzoyl-L-tartrate} and Λ-(+)-[Ru(phen)3]{(+)-O,O′-di-4-toluoyl-D-tartrate}. Resolution is also reported for the analogous species containing three potential bridging ligands, [Ru(bpm)3]2+ and [Ru(HAT)3]2+ (bpm = 2,2′-bipyrimidine; HAT = 1,4,5,8,9,12-hexaazatriphenylene). The versatility of the chromatographic procedure was demonstrated by the resolution of a series of bis-heteroleptic complexes [Ru(pp)2(pp′)]2+ {pp′ = dpq (dipyrido[3,2-d:2,3′-f]quinoxaline), dpqc (dipyrido[3,2-a:2,3-d]-6,7,8,9-tetrahydrophenazine), and dppz {dipyrido[3,2-a:2,3′-d]phenazine)}.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
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