GLORIA

GEOMAR Library Ocean Research Information Access

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
    Online Resource
    Online Resource
    Berlin [u.a.] : Springer
    Keywords: Computer science ; Database management ; Artificial intelligence ; Data structures (Computer science). ; Information theory. ; Computer Science ; Artificial Intelligence (incl. Robotics) ; Database Management ; Hochschulschrift ; Deduktives Datenbanksystem
    Description / Table of Contents: A standard deductive database system -- An expert deductive database system -- Discarding irrelevant tuples -- Disregarding irrelevant rules -- Explicit termination of recursion -- Preferring useful rules -- Preferring useful tuples -- Summary and outlook.
    Type of Medium: Online Resource
    Pages: Online-Ressource (VI, 155 S.)
    Edition: Online-Ausg. Berlin [u.a.] Springer 2006 Springer lecture notes archive
    ISBN: 9783540470823
    Series Statement: Lecture notes in computer science 479
    RVK:
    RVK:
    Language: English
    Note: Literaturverz. S. [149] - 152 , Zugl.: München, Techn. Univ., Diss.
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    Berlin, Heidelberg : Springer Berlin Heidelberg
    Keywords: Artificial intelligence ; Computer science ; Database management ; Computer Science ; Deduktives Datenbanksystem
    Type of Medium: Online Resource
    Pages: Online-Ressource
    ISBN: 9783540470823
    Series Statement: Lecture Notes in Computer Science 479
    RVK:
    RVK:
    RVK:
    Language: English
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of sol gel science and technology 6 (1996), S. 139-149 
    ISSN: 1573-4846
    Keywords: titanosiloxanes ; siloxanes ; hydrolysis ; condensation ; structural units ; NMR
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structural units in diphenylsilanediol/titanium-isopropoxide solutions with molar ratio Si:Ti between 1:0.1 and 1:5 were examined by means of 29Si and 17O NMR. The main component in solutions with molar ratio Si/Ti=1:0.1 is the chain-like octaphenyltetrasiloxanediol. With increasing Ti-isopropoxide content (1:0.25–1:05) Si−O−Ti units of the spirocyclic titanosiloxane Ti[O5Si4(C6H5)8]2 prevail in the solutions accompanied by the chain-like tetrasiloxanediol. The 29Si NMR spectra of 1:1 solutions indicate a lot of different Si containing building units with chemical shifts mainly between-40 and-46 ppm. The signals with a chemical shift between-40 and-46 ppm are probably caused by Si atoms which are connected via oxygen bridges directly (Si−O−Ti) or indirectly (Si−O−Si−O−Ti) with titanium. Contrary to the 1:1 solutions only one or two different species with Si−O−Ti units are present in high Ti-alkoxide containing solutions (1:5). 29Si and 17O NMR results reveal a quick hydrolysis of the Ti−O−Si bonds to titanium-oxo-hydroxo-polymers and phenylsiloxanediols or their isopropyl esters after the addition of water to the solutions. This separation into species only containing either Ti−O−Ti or Si−O−Si bonds can entail a decreased homogeneity of the reaction products on a molecular level.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of sol gel science and technology 19 (2000), S. 305-309 
    ISSN: 1573-4846
    Keywords: epoxide ; ring-opening ; condensation ; NMR ; hardness ; nanoparticles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Glycidoxypropyltrimethoxysilane (GPTS) is frequently used as precursor for the preparation of sol-gel derived nanoscaled hybrid polymers. The influence of nanoscaled metal oxide sols of silica, boehmite, zirconia and ceria on reactions of GPTS in ethanolic hydrolysates and in corresponding gels (epoxide ring-opening, condensation degree) was examined by liquid- and solid-state 13C and 29Si NMR with regard to a better correlation between structure and material properties. Generally, a higher condensation degree of RSi(O0.5)3 units of GPTS is found after addition of metal oxide sols compared to GPTS without additives. The metal oxide sols (10 mole% series) cause an epoxide ring-opening up to 20% in GPTS hydrolysates after 24 h. A nearly complete ring opening was found in the boehmite and silica containing hybrid gels whereas gels containing ceria and other types of silica only show a low degree of ring-opening. The results show an accelerated ring-opening with increasing content of AlO/OH-species in silica sols. 13C NMR studies reveal that the epoxide ring-opening does not completely lead to polyether structures but to considerable amounts (up to 40%) of ethylether groups which can influence the material properties (hardness).
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...