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
Filter
  • pressure  (2)
  • 23.40.-s  (1)
  • 1
    Electronic Resource
    Electronic Resource
    β-Delayed neutron emission of15B,18C,19,20N,34,35Al and39P (1988)
    Springer
    The European physical journal 330 (1988), S. 63-68 
    Details
    ISSN: 1434-601X
    Keywords: 25.70.Np ; 23.40.-s ; 27.30.+ t
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The isotopes15B,18C,19,20N,34,35Al and39P have been produced as projectile-like fragments from the interaction of a86Kr beam of 45 MeV/u from GANIL with a181Ta target. Separated by the 0° magnetic analyser LISE, the nuclei are identified by means of aΔE- E semiconductor telescope. It is surrounded, in a geometry close to 4π, by a thin plastic scintillator (NE 102) and a large volume liquid scintillator (NE 213) for the detection of betas and neutrons, respectively, from the decay of the implanted nuclei. By observation of theβ-delayed neutrons, the half-livesT 1/2 and neutron emission probabilitiesP n have been measured. TheT 1/2 of18C,20N,35Al,39P and Pn of18C,19,20N,34,35Al and39P are determined for the first time. For the isotopes17C,36,37Si and38P upper limits of Pn are deduced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01287265
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    In situ high temperature and high pressure exafs studies of Pt/Al2O3 Catalysts. Part II: Carbon removal (1991)
    Springer
    Catalysis letters 8 (1991), S. 297-304 
    Details
    ISSN: 1572-879X
    Keywords: EXAFS ; Pt/Al2O3 catalyst ; temperature ; pressure ; carbon deposition ; carbon removal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract EXAFS has been used to follow in situ the structural evolution of a Pt/Al2O3 catalyst during removal of carbon by hydrogenation, after reduction and carbon deposition. After reduction at 350 °C, the total hydrogen pressure was raised to 3 atm. and n-heptane was injected over the sample. EXAFS measurements at the Pt edge were carried out with simultaneous on-line EXAFS analysis of the spectra. After observing the rapid formation of a carbon-platinum bond which is unmodified with time, we stopped the heptane flow, raised the temperature to 450 °C, and maintained hydrogen flow at 3 atm. The disappearance of the platinum-carbon bond during heat treatment in hydrogen was monitored via on-line analysis. No sintering of the metal particles was observed. EXAFS is thus proven to be an efficient tool to study not just structural changes of a catalyst during a hydrocarbon reaction [1], but also to use it as a technique to study other catalytic phenomena as well.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00764191
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    In situ high temperature and high pressure exafs studie of Pt/Al2O3 catalysts. Part I: Reduction and deactivation (1991)
    Springer
    Catalysis letters 8 (1991), S. 283-295 
    Details
    ISSN: 1572-879X
    Keywords: EXAFS ; Pt/Al2O3 catalysts ; chlorine ; temperature ; pressure ; reduction ; deactivation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract EXAFS has been used to follow in situ the structural evolution of a chlorinated and non-chlorinated Pt/Al2O3 catalyst during reduction in the temperature range of 300–500 °C. Smaller metal clusters are formed from the hydrogen reduction of the chlorinated catalyst, in contrast to the larger cluster formed from the non-chlorinated one. At 460 °C, the total hydrogen pressure was raised to 5 atm. and n-heptane was injected over the samples. EXAFS measurements at the Pt edge were carried out while hydrocarbon conversion was monitored with a gas Chromatograph. We observe the rapid formation of a carbon-platinum bond. This is unmodified while turnover rates and selectivities indicate evidence for deactivation. From this structural information supplied by EXAFS, correlated with the data obtained from gas chromatography, we find that our results are consistent with a model proposed by others where deactivation is due to the build-up of a multilayer of carbon.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00764190
    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...