The Jurassic-Cretaceous (J/K) and Cretaceous-Paleogene (K/Pg) boundaries/transitions are found in Pakistan especially well exposed on the western continental margin of the Indo-Pakistan plate (part of Gondwana) like K...The Jurassic-Cretaceous (J/K) and Cretaceous-Paleogene (K/Pg) boundaries/transitions are found in Pakistan especially well exposed on the western continental margin of the Indo-Pakistan plate (part of Gondwana) like Kirthar, Sulaiman and Kohat and Potwar basins. Its lithology is variable both lateral and also vertical. The J/K and K/Pg transitions are represented by terrestrial and marine strata like laterite, bauxite, vary colored shale, sandstones and conglomerates and rare limestone beds. Mesozoic vertebrates found so far belong to archosaurs like poripuchian titanosaurs (sauropods), theropods, mesoeucrocodiles, pterosaurs, snake and bird are briefly overviewed here.展开更多
The transition energies and electric dipole （El） transition rates of the K, L, and M lines in neutral Np have been theoretically determined from the MultiConfiguration Dirac-Fock （MCDF） method. In the calculations...The transition energies and electric dipole （El） transition rates of the K, L, and M lines in neutral Np have been theoretically determined from the MultiConfiguration Dirac-Fock （MCDF） method. In the calculations, the contributions from Breit interaction and quantum electrodynamics （QED） effects （vacuum polarization and self-energy）, as well as nu- clear finite mass and volume effects, are taken into account. The calculated transition energies and rates are found to be in good agreement with other experimental and theoretical results. The accuracy of the results is estimated and discussed. Furthermore, we calculated the transition energies of the same lines radiating from the decaying transitions of the K-, L-, and M-shell hole states of Np ions with the charge states Np1＋ to Np6＋ for the first time. We found that for a specific line, the corresponding transition energies relating to all the Np ions are almost the same; it means the outermost electrons have a very small influence on the inner-shell transition processes.展开更多
The x-ray energies and transition rates associated with single and double electron radiative transitions from the double K hole state 2s2p to the 1s2s and 1s^2 configurations of 11 selected He-like ions(10 ≤ Z ≤ 47)...The x-ray energies and transition rates associated with single and double electron radiative transitions from the double K hole state 2s2p to the 1s2s and 1s^2 configurations of 11 selected He-like ions(10 ≤ Z ≤ 47) are calculated using the fully relativistic multi-configuration Dirac–Fock method(MCDF). An appropriate electron correlation model is constructed with the aid of the active space method, which allows the electron correlation effects to be studied efficiently. The contributions of the electron correlation and the Breit interaction to the transition properties are analyzed in detail. It is found that the two-electron one-photon(TEOP) transition is correlation sensitive. The Breit interaction and electron correlation both contribute significantly to the radiative transition properties of the double K hole state of the He-like ions. Good agreement between the present calculation and previous work is achieved. The calculated data will be helpful to future investigations on double K hole decay processes of He-like ions.展开更多
文摘The Jurassic-Cretaceous (J/K) and Cretaceous-Paleogene (K/Pg) boundaries/transitions are found in Pakistan especially well exposed on the western continental margin of the Indo-Pakistan plate (part of Gondwana) like Kirthar, Sulaiman and Kohat and Potwar basins. Its lithology is variable both lateral and also vertical. The J/K and K/Pg transitions are represented by terrestrial and marine strata like laterite, bauxite, vary colored shale, sandstones and conglomerates and rare limestone beds. Mesozoic vertebrates found so far belong to archosaurs like poripuchian titanosaurs (sauropods), theropods, mesoeucrocodiles, pterosaurs, snake and bird are briefly overviewed here.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.91126007,11274254,10964010,and 11064012)
文摘The transition energies and electric dipole （El） transition rates of the K, L, and M lines in neutral Np have been theoretically determined from the MultiConfiguration Dirac-Fock （MCDF） method. In the calculations, the contributions from Breit interaction and quantum electrodynamics （QED） effects （vacuum polarization and self-energy）, as well as nu- clear finite mass and volume effects, are taken into account. The calculated transition energies and rates are found to be in good agreement with other experimental and theoretical results. The accuracy of the results is estimated and discussed. Furthermore, we calculated the transition energies of the same lines radiating from the decaying transitions of the K-, L-, and M-shell hole states of Np ions with the charge states Np1＋ to Np6＋ for the first time. We found that for a specific line, the corresponding transition energies relating to all the Np ions are almost the same; it means the outermost electrons have a very small influence on the inner-shell transition processes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1832126 and 11874051)the National Key Research and Development Program of China(Grant No.2017YFA0402300)。
文摘The x-ray energies and transition rates associated with single and double electron radiative transitions from the double K hole state 2s2p to the 1s2s and 1s^2 configurations of 11 selected He-like ions(10 ≤ Z ≤ 47) are calculated using the fully relativistic multi-configuration Dirac–Fock method(MCDF). An appropriate electron correlation model is constructed with the aid of the active space method, which allows the electron correlation effects to be studied efficiently. The contributions of the electron correlation and the Breit interaction to the transition properties are analyzed in detail. It is found that the two-electron one-photon(TEOP) transition is correlation sensitive. The Breit interaction and electron correlation both contribute significantly to the radiative transition properties of the double K hole state of the He-like ions. Good agreement between the present calculation and previous work is achieved. The calculated data will be helpful to future investigations on double K hole decay processes of He-like ions.
