Library

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
    New York, NY : Wiley-Blackwell
    Rapid Communications in Mass Spectrometry 6 (1992), S. 298-302 
    ISSN: 0951-4198
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A conventional fast-atom bombardment (FAB) ion source was used to achieve matrix-assisted laser desorption (MALD) in a high-mass, double-focusing, magnetic mass spectrometer. The pulsed ion signals generated by irradiation of a mixture of sample and matrix (2,5-dihydroxybenzoic acid) with either a XeF excimer Laser (353 nm) or a nitrogen laser (337 nm) were recorded with a focal-plane detector. A resolution (full-width at half maximum) of 4500 was achieved at m/z 1347.7 (the peptide substance P), 2500 for CsI cluster ions at m/z 10005.7, and 1250 for the isotope cluster of the small protein cytochrome c (horse) [M+H]+=m/z 12360 (average). Sensitivity is demonstrated with 11 fmol of substance P. A survey scan is taken to prodluce a better signal-to-noise ratio. In addition to higher sensitivity and lower matrix interference, lthe advantage of MALD over FAB is the former's lower susceptibility to the presence of salts, and competition between hydrophobic and bydrophilic components of a mixture. This feature is demonstrated by the complete MALD spectrum of a crude partial tryptic digest of spedrm-whale apomyoglobin, containing 24 peptides, representing the entire sequence of this protein.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1975 (1975), S. 509-520 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions between Benzyl Derivatives of Titanium and AluminiumThe reaction between tribenzylaluminium (AlBz3) and tetrabenzyltitanium (TiBz4) or tris(p-methylbenzyl)aluminium (AlXy3) and tetrakis(p-methylbenzy1)titanium (TiXy4) with elimination of toluene or xylene respectively, which yields catalytic systems for α-olefin polymerization, has been investigated using cryoscopy, MS, and 1H-NMR spectroscopy. The extent of the reaction depends on the Al/Ti ratio, reaching a maximum for values between 4 and 5. The reaction is accompanied by a reduction of Ti(IV) to Ti(III). On mixing tetrabenzyltitanium (TiBz4) with dibenzylzinc (ZnBz2) [Zn/Ti = 1.23] only titanium reduction occurs. This system does not polymerize 4-methyl-1-pentene.
    Notes: Die Reaktion zwischen Tribenzylaluminium (AlBz3) und Tetrabenzyltitan (TiBz4) oder Tris(p-methylbenzyl)aluminium (AlXy3) und Tetrakis(p-methylbenzyl)titan (TiXy4) unter Eliminierung von Toluol bzw. Xylol, welche katalytische Systeme für die Polymerisation von α-Olefinen liefert, wurde durch Kryoskopie, MS- und 1H-NMR-Spektroskopie untersucht. Das Reaktionsausmaß hängt von dem Al/Ti-Verhältnis ab und erreicht ein Maximum für Al/Ti zwischen 4 und 5. Die Reaktion wird von einer Reduktion von Ti(IV) zu Ti(III) begleitet. Beim Mischen von Tetrabenzyltitan (TiBz4) mit Dibenzylzink (ZnBz2) [Zn/Ti = 1.23] findet nur die Reduktion des Titans statt. Dieses System polymerisiert 4-Methyl-1-penten nicht.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Materialwissenschaft und Werkstofftechnik 11 (1980), S. 361-367 
    ISSN: 0933-5137
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Mechanische Eigenschaften von SiliciumnitridDie mechanischen Raumtemperatureigenschaften von reaktionsgebundenem und heißgepreßtem Siliciumnitrid werden unter Berücksichtigung des Gefüges dieser Werkstoffe besprochen.Materialbedingte Gefügeeigenschaften zeigen einen ausgeprägten Einfluß auf die Festigkeit. Bei reaktionsgebundenem Siliciumnitrid sind dies der Volumenanteil der Porosität und die Porengrößenverteilung im Werkstoff. Im Falle des heißgepreßten Siliciumnitrids beeinflussen der Volumenanteil der während der α/β-Phasenumwandlung gebildeten stäbchenförmigen β-Körner und deren Korngrößenverteilung die Festigkeit.
    Notes: The room temperature mechanical properties of reaction bonded and hot-pressed silicon nitride are reviewed with respect to the microstructure of the material. It is shown that the strength of these compounds is predominantly controlled by microstructural features. These are the volume fraction of porosity and the pore size distribution for reaction bonded Si3N4, and the volume fraction of elongated transformed β grains and their grain size for hot-pressed Si3N4.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 58 (1975), S. 1512-1517 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The cyclisation of either 1a or 3a with acid yielded the cis-fused erythrinanone 2; no trans-isomer could be detected. The structure of this unexpected product was determined by NMR. and confirmed by an X-ray analysis. Various tetrahydro- and hexahydro-2-indolinones were prepared to facilitate the interpretation of the NMR.-spectrum of 2.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...