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61.
Falko Lorenz 《Mathematische Annalen》1971,195(2):315-320
Ohne Zusammenfassung 相似文献
62.
H. Essel K. Hartel W. Henning P. Kienle H. J. Körner K. E. Rehm P. Sperr W. Wagner H. Spieler 《Zeitschrift für Physik A Hadrons and Nuclei》1979,289(3):265-271
Mass and charge transfer was investigated for the system136Xe+208Pb at 5.9 MeV/nucleon incident energy with aΔE —E-time of flight telescope. The angle and energy integrated cross section for the strongly damped events was found to be 510 mb, very close to the total reaction cross section. The width of the mass distribution as function of the total kinetic energy loss was measured and is compared to the width of the corresponding charge distribution. An upper limit of 1 μb has been found for processes with very large mass transfer. 相似文献
63.
64.
Photoelectrons ejected from cesium atoms by circularly polarized light of certain wavelengths are highly spinpolarized according to Fano's theory. Measurements of the spinpolarization of photoelectrons along the wavelength spectrum are reported. The highest degree of spinpolarization obtained experimentally is 100%. Our results reveal a small deviation from the theoretically predicted spinpolarization. Apart from giving information on the influence of spin-orbit interaction on the photoionization process, the Fano-effect turns out to be a simple and efficient method for producing polarized electron beams. Though not designed as a polarized electron source, our present apparatus yields a beam of 0.3·10?10 Ampere with a polarization of 81 ± 3% when a broad unfiltered spectral band is irradiated. 相似文献
65.
P. Sperr W. Wagner H. Essel K. Hartel W. Henning P. Kienle H. J. Körner K. E. Rehm J. Weber 《Zeitschrift für Physik A Hadrons and Nuclei》1978,287(1):57-60
The production of superheavy elements in binary reactions of the type208Pb (136Xe, X) Y was investigated atE c.m.=470 MeV. The experiment was designed to search for delayed fission products from elements withZ between 108 and 116 and fission lifetimes ofΤ?10?12 s. No fission events were observed the upper limit for the formation cross section being 1.2 Μbarn. 相似文献
66.
Falko Lorenz 《Archiv der Mathematik》1979,32(1):458-468
Ohne Zusammenfassung 相似文献
67.
S. Hüfner P. Kienle D. Quitmann P. Brix 《Zeitschrift für Physik A Hadrons and Nuclei》1965,187(1):67-84
The isomer shift of the 21.7 keVγ transition in Eu151 has been studied for various divalent and trivalent europium compounds using the Mössbauer technique. Theγ energy is lower by up to 1.1·10?6 eV in divalent compounds than in trivalent compounds. Using data from atomic spectroscopy it is estimated that the electron density at the nucleus is larger by about 1.9·1026cm?3 for the configuration 4f 6 than for 4f 7 due to different shielding of thes 2 shells. The difference of the mean square radii of the 21.7 keV state and the ground state is thenδ〈r2〉=+0.03 fm2. The measured isomer shift between trivalent and metallic europium and the relatives-electron densities in the rare earth metals measured by the positron annihilation rates are used to establish a calibration scheme for isomer shifts in rare earth metals. This calibration scheme is used to deduce a changeδ〈r 2〉=+0.0055 fm2 between the 26 keV state and the ground state of Dy161. 相似文献
68.
Electrochemical Formation of Δ1,2-Norbornene The electrochemical reduction of 1,2-dihalogen norbornanes in tetrahydrofuran/furan leads to a mixture of two isomeric cycloadducts 6 and 7. The ratio of these adducts corresponds to those which have been found in reductive bisdehalogenation of 1 and 2 by butyllithium. 相似文献
69.
Kampschulte L Griessl S Heckl WM Lackinger M 《The journal of physical chemistry. B》2005,109(29):14074-14078
Stable adsorption of 1,3,5-tris(4-pyridyl)-2,4,6-triazine (TPT) molecules from the liquid phase was only observed in binary solutions, that is, in the presence of a second (adsorptive) species. The process of mediated coadsorption of a molecular species at the liquid-solid interface was accomplished through complexation of TPT with a second type of molecule acting as a "molecular glue" via hydrogen bonds. Scanning tunneling microscopy (STM) was utilized to investigate the structure of the coadsorbed monolayers at the liquid-solid interface. Trimesic acid (TMA) and terephthalic acid (TPA)--both benzene rings with disposed carboxylic acid groups-were appropriate to precipitate the stable adsorption of TPT. According to the different symmetry and number of carboxylic acid groups, various networks were observed. 相似文献
70.
We consider the effect of distributed delays in predator-prey models and ecological food webs. Whereas the occurrence of delays in population dynamics is usually regarded a destabilizing factor leading to the extinction of species, we here demonstrate complementarily that delay distributions yield larger stability regimes than single delays. Food webs with distributed delays closely resemble nondelayed systems in terms of ecological stability measures. Thus, we state that dependence of dynamics on multiple instances in the past is an important, but so far underestimated, factor for stability in dynamical systems. 相似文献