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
    Photovoltaic output limitation of n-FeS2 (pyrite) Schottky barriers: A temperature-dependent characterization (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 5721-5728 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Metal/n-pyrite (metal=Pt, Au, Nb) Schottky barrier type diodes were fabricated on electrochemically reduced either synthetic or natural (100) and (111) surfaces of single crystalline n-FeS2. The temperature dependence of I-V curves in darkness were analyzed in the range of 200–350 K on the basis of thermionic emission and recombination models. The calculated effective barrier height was ∼0.60 eV and the activation energy for recombination ∼0.50 eV for all investigated n-FeS2/Pt samples. The doping density and the extrapolated potential (pseudo flatband situation) from the Mott–Schottky plot, obtained from capacities deduced from potentiostatic complex impedance measurements, were 2.0×1016 cm−3 and 0.25 eV vs Pt for the synthetic n-pyrite crystal, respectively. From the donor density and barrier height a band bending of 0.5 eV was deduced. Photovoltaic parameters like open-circuit photovoltage and short-circuit photocurrent were studied down to temperatures of 200 K. The main phenomenon preventing the generation of a photopotential approaching the band bending (0.50 eV) appears to be the pinning of the Fermi-level by recombination centers located in the middle of the band gap (Eg=0.95 eV) of pyrite.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351925
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Ein neues Interface für die GC/MS-Kopplung von Glaskapillarsäulen (1978)
    Springer
    Chromatographia 11 (1978), S. 295-300 
    Details
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bei der Kombination Gas-Chromatographie — Massenspektroskopie kann die Verwendung von Pt-Ir-Kapillaren zu starken Peak-Deformationen, zu Tailing oder sogar zur vollständigen Adsorption der gas-chromatographisch getrennten Substanzen führen. Zur Reduzierung dieser Störquellen haben wir für die GC/MS-Kopplung von Glaskaplillarsäulen ein Allglas-Interface entwickelt, dessen Effektivität an Hand einiger ausgewählter Beispiele demonstriert wird. Einzelheiten des mechanischen Aufbaus sowie der Desaktivierung mit Hexamethyldisilazan werden beschrieben und diskutiert.
    Notes: Summary In combined gas chromatography — mass spectrometry the use of Pt-Ir interfaces may cause severe peak broadening and tailing or even total adsorption of the chromatographically separated compounds. Therefore an all-glass interface was developed, the efficiency of which is demonstrated using n-alkanes with high C-numbers, an adsorption/polarity test mixture and steroids as examples. Details of the mechanical arragement and the deactivation procedure with hexamethyldisilazane are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02282956
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Ein modifiziertes Interface für die GC/MS-Kopplung von Glaskapillarsäulen (1978)
    Springer
    Chromatographia 11 (1978), S. 372-375 
    Details
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Für die Herstellung des von uns kürzlich publizierten Allglas-Interfaces werden einige einfache Ergänzungen beschrieben und ihre Effektivität am Beispiel der chromatographisch besonders kritischen Trimethylsilylester langkettiger Fettsäuren demonstriert. Weiterhin wird gezeigt, daß die Qualität der GC/MS-Chromatogramme durch Zersetzungs- und Adsorptionsprozesse innerhalb der lonenquelle des Massenspektrometers sehr nachteilig beeinflußt werden kann.
    Notes: Summary To improve the inertness of the all-glass GC/MS interface which has been described recently some simple modifications in the preparation procedure are presented. The efficiency is demonstrated with a series of long-chain fatty acids as their trimethylsilylesters, which are very suitable for critical quality tests in gas chromatography. Moreover it is shown that even the ion source of the mass spectrometer may deteriorate the quality of the GC/MS-chromatograms due to decomposition or adsorption processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02312647
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Ein einfaches Verfahren zur Beseitigung des „Septumbleedings” bei der Kopplung Gas-Chromatographie-Massenspektroskopie (1975)
    Springer
    Chromatographia 8 (1975), S. 9-12 
    Details
    ISSN: 1612-1112
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bei der Kombination Gas-Chromatographie — Massenspektroskopie führt das „Septumbleeding” zu peakreichen Untergrundspektren hoher Intensität. Zur Beseitigung dieser Störquelle wurde ein einfacher luftgekühlter Septumhalter entwickelt, dessen Effektivität durch Wiedergabe der entsprechenden Massenspektren demonstriert wird.
    Notes: Summary In combined gas chromatography — mass spectroscopy background spectra with numerous peaks of high intensity are caused by septum bleeding. To eliminate the sources of error, a simple, air-cooled septum holder was developed, the efficiency of which is demonstrated by presenting the corresponding mass spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02279273
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Stereoselektive Synthese von 3-substituierten Cyclobutanolen und Folgeprodukten (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 2759-2763 
    Details
    ISSN: 0009-2940
    Keywords: Dichloroketene ; Stereoselective ketone reduction ; Mitsunobu reaction ; Cyclobutyl bromides ; Cross-coupling reaction ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stereoselective Synthesis of 3-Substituted Cyclobutanols and Products Derived Therefrom3-Substituted cyclobutanones 2 are prepared by alkene/dichloroketene cycloadditions and subsequent dehalogenation. Reduction with LiAlH(OtBu)3 furnishes cis-cyclobutanols 3 in 95-100% selectivity. Mitsunobu inversion turned out to be the only practical method to get trans isomers 4 in high selectivity. A stereoselective cyclobutanol→bromocyclobutane conversion could be achieved only by a modified Mitsunobu reaction. Cross coupling between zinc derivatives of bromocyclobutanes 9 and aromatic bromides is not stereoselective.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19931261228
    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...