排序方式: 共有20条查询结果,搜索用时 281 毫秒
1.
J. Jureta S. Cvejanović M. Kurepa D. Cvejanović 《Zeitschrift für Physik A Hadrons and Nuclei》1982,304(2):143-153
A high resolution electron impact threshold spectroscopy technique was used to examine the excitation of Cl2 in the 2–14 eV region. This study complements previous photon absorption and emission measurements, because it is capable of detecting transitions which are optically forbidden. In the region up to 7.5 eV, broad dissociative structures are correlated with optically active valence states, although relative intensities in the threshold spectrum differ considerably and indicate a substantial contribution from the optically forbidden transitions. At 7.46 eV a series of 5 equidistant sharp peaks is detected and interpreted as arising from the2 π g Feshbach resonance, which differs from the ground state positive ion Cl 2 + by a pair of Rydberg electrons: (4sσ)2. The decay channels responsible for the appearance of the resonance in a threshold spectrum are discussed and it is suggested that they include several valence states of the (2431) and (2341) configurations, whose potential energy curves cross the Cl 2 ? ,2πg curve in the region of energy at which the resonance state is formed. At higher incident electron energies and up to ionisation, Rydberg states predominate, starting with (2430) 4s3,1 π g states detected for the first time. The absence of broad peaks above 8 eV and the irregular appearance of Rydberg bands is consistent with the strong Rydberg-valence configuration mixing proposed by Peyerimhoff and Buenker. Where our resolution permits comparison, good general agreement is found with recent synchrotron radiation absorption measurements of optically allowed transitions. 相似文献
2.
3.
4.
Aequationes mathematicae - 相似文献
5.
Absolute Balmer line emission cross sections are determined. The Balmer emission is obtained by dissociative electron excitation in propane, propylene and n-butane. The optical excitation functions measured for these lines are investigated in the medium energy range of 50–700 eV and normalized by a He bench-mark procedure. The measured data are corrected by an apparatus collection efficiency factor F to compensate for the loss of optical signal due to non-thermal energies of H-excited molecular fragments. The obtained results are determined with an accuracy of ± 15%. The absolute Balmer line cross sections are analysed according to the Bethe theory to get some information on primary excited parent molecular states. The power-law dependence for Balmer series has been determined. 相似文献
6.
Aequationes mathematicae - 相似文献
7.
8.
9.
Alfonso Castro Alexandra Kurepa 《Transactions of the American Mathematical Society》1996,348(2):781-798
In this paper we show that, for each , the set of radially symmetric solutions to the boundary value problem
is bounded. Moreover, we establish geometric properties of the branches of solutions bifurcating from zero and from infinity.
10.
Absolute emission cross sections for Hβ radiation are presented. The Hβ emission is obtained by dissociative electron excitation of propane, propylene, n-butane and 1-butene under binary collision conditions. Optical excitation functions measured for these transitions are normalized by the “helium excitation standard” procedure, using the 4 1S-2 1P transition in He as a standard at an electron impact energy of 100 eV. The results obtained are determined with an accuracy of ± 15%. The investigated energy interval is 50–500 eV. The experimental results show that the emission cross sections for Hβ radiation are not independent of the number of atoms in the parent molecule. 相似文献