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
    Photofission of235U and238U at intermediate energies: absolute cross sections and fragment mass distributions (1994)
    Springer
    The European physical journal 350 (1994), S. 249-261 
    Details
    ISSN: 1434-601X
    Keywords: 25.20.Dc ; 25.85.Jg ; 27.90.+b
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The total photofission cross section σγ,F for235U and238U has been measured in the energy range 50≤E γ≤800 MeV at the 855 MeV Mainz Microtron MAMI using energy and time tagged photons (Glasgow Tagger) and a 4π arrangement of position sensitive fragment detectors. Besides the absolute photofission cross section σγF , which almost completely exhausts the total photon absorption cross section for these nuclei, fragment mass distributions in this energy domain were determined via time of flight techniques (TOF). The results for the total photofission cross sections σγ,F normalized to the atomic numberA for both isotopes coincide, and agree in theΔ-resonance region, within the systematic errors, with the socalled“Universal Curve” σγ,T /A of the total photon absorption cross section σγ,T . At higher energies the cross sections exhibit a smooth behaviour. In particular, it is shown for the first time that there isno resonance-like shape near the D13 resonance (at ≈710 MeV) as observed for the free proton. This complete suppression of the D13 resonance in complex nuclei is not yet understood on a microscopic level. The fragment mass distributions show a predominantly mass symmetric fission. However, contributions from mass asymmetric fission at some photon energies may give a hint of an increased mass asymmetric fission after the onset of the pion and two pion channels.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01289589
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Measurement of the πmeson polarizabilities via the γp → γπ+n reaction (2005)
    Springer
    The European physical journal 23 (2005), S. 113-127 
    Details
    ISSN: 1434-601X
    Keywords: 12.38.Qk Experimental tests ; 13.40.-f Electromagnetic processes and properties ; 13.60.Le Meson production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. An experiment on the radiative π{+}-meson photoproduction from the proton ( γp → γπ{+}n) was carried out at the Mainz Microtron MAMI in the kinematic region 537MeV 〈 Eγ 〈 817MeV, 140°≤ $ \theta_{{\gamma \gamma ^{\prime }}}^{{{{\rm cm}}}}$ ≤180°. The π{+}-meson polarizabilities have been determined from a comparison of the data with the predictions of two different theoretical models, the first one being based on an effective pole model with pseudoscalar coupling while the second one is based on diagrams describing both resonant and nonresonant contributions. The validity of the models has been verified by comparing the predictions with the present experimental data in the kinematic region where the pion polarizability contribution is negligible ( s1 〈 5mπ2) and where the difference between the predictions of the two models does not exceed 3%. In the region, where the pion polarizability contribution is substantial ( 5 〈 s1/mπ2 〈 15, -12 〈 t/mπ2 〈 - 2), the difference $\ensuremath{(\alpha -\beta )_{\pi^{+}}}$ of the electric (α) and the magnetic (β) polarizabilities has been determined. As a result we find $\ensuremath{(\alpha -\beta )_{\pi^{+}}=(11.6\pm 1.5_{{\rm stat}}\pm 3.0_{{\rm syst}}\pm 0.5_{{\rm mod}})\times 10^{-4}{}{\rm fm^{3}}}$ . This result is at variance with recent calculations in the framework of chiral perturbation theory.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1140/epja/i2004-10056-2
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Die Kristallstrukturen der Diquecksilber(I)-Salze von AminobenzolsulfonsäurenProfessor Rudolf Hoppe zum 65. Geburtstage am 29. Oktober 1987 gewidmet (1987)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 553 (1987), S. 35-49 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structures of Dimercuri (I) Salts of p- and m-Sulfanilic AcidsThe crystal structures of the compounds Hg2(p-H2N-C6H4-SO3)2 (1), Hg2(m-H2N-C6H4-SO3)2 (2), and Hg2(m-H2N-C6H4-SO3)2 · 2H2O (3) contain leaf-structures (1 and 3) or chain-structures (2), with nearly linear groups N-Hg-Hg-N, Hg-O-contacts and hydrogen-bridging bonds. The smaller density of 3 compared with 1-caused by the steric hindrance through the ligand - declared the incorporation of water for raising the stabilising interaction in the crystals. The compound 3 is the kinetic controlled, the compound 2 the thermodynamic controlled product.
    Notes: Die Kristallstrukturen der Verbindungen Hg2(p-H2N-C6H4-SO3)2 (1), Hg2(m-H2N-C6H4-SO3)2 (2) und Hg2(m-H2N-C6H4-SO3) 2 · 2H2O (3) enthalten Blattstrukturen (1 und 3) oder Kettenstrukturen (2), die durch Verknüpfung der nahezu linearen Baueinheiten N-Hg-Hg-N durch koordinative Hg-O-Kontakte und Bildung von Wasserstoffbrückenbindungen entstehen. Die geringere Dichte von 3 verglichen mit 1 - bedingt durch größere sterische Hinderung des Liganden - läßt den Einbau von Kristallwasser zur Erhöung der stabilisierenden Wechselwirkungen innerhalb des Kristalles plausibel erscheinen. Die Verbindung 3 ist das kinetisch kontrollierte, die Verbindung 2 das thermodynamisch kontrollierte Produkt.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19875531005
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Die Kristallstruktur von BaHg(CN)4 · 4 PyridinProfessor Walter Rüdorff zum 75. Geburtstage am 3. Oktober 1984 gewidmet (1984)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 516 (1984), S. 30-34 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Crystal Structure of BaHg(CN)4 · 4 PyridineThe structure of the tetragonal BaHg(CN)4 · 4 Pyridine (space group I4, a = 1119.4(7), c = 1 057.9(7) pm, Z = 2, dc = 1.87 g · cm-3) contains tetrahedral Hg(CN)4 and bisdisphenoide Ba(NC)4(py)4 groups, which are linked together by Hg—CN—Ba bridges. The BaHg(CN)4 framework consists of a 3-dimensional network of all round edge-sharing tetrahedrons. The analogous strontium compound is isotype with a = 1 108.2(9) and c = 1 035.3(14) pm.
    Notes: In der Struktur des tetragonalen BaHg(CN)4 · 4 Pyridin (Raumgruppe I4, a = 1119,4(7), c = 1 057,9(9) pm, Z = 2, dc = 1,87 g · cm-3) sind tetraedrische Hg(CN)4- und bisdisphenoide Ba(NC)4(py)4-Gruppen über Hg—CN—Ba-Brücken zu einem Raumnetz verknüpft. Dem BaHg(CN)4-Gerüst liegt ein Aufbau aus allseitig eckenverknüpften Tetraedern zugrunde. Die analoge Strontium-Verbindung ist isotyp mit a = 1 108,2(9) und c = 1 035,3(14) pm.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19845160905
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Ueber die Bildung von Graphit bei der Contactmetamorphose (1891)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 24 (1891), S. 1884-1886 
    Details
    ISSN: 0365-9496
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.189102401323
    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...