Relativistic Many-Body Perturbation Calculations of Boron-Like Silicon, Si X

Abstract

XVIII. Onthe Strem~tk of Drictile ikluterials under Conabined Stress. B y JAMES J. GUEST *. (Communicated by the Secretaries.) C O N T~" OF ARTICLES. 1. Lack of knowledge of lams of strength. 2. Separation of the isotropic materials into ductile m d brittle, 3, The yield-point in Tension Tests. 4. The yield-point, rather than the ultimate, stl*ess the criterion of strength. 5. Variations of the ultimate and yield-point stresses : annealing. 6. The elastic limit. 7. The elastic-limit effect probably due to the existence of local yield-8. The yield-point, in preference to the clastic limit, selected as the 9. Torsion a case of combined stress. points. criterion of sbrength. 10. First reason for use of thin tubes as specimens. 11. Results of previous torsion experimentd. 12, Previous experiments upon the yield-point under combined stress. 13. Experiments upon ultimate strength under combined stress. 14. Theories of elastic strength under combined stress : the maximum 15, The maximum strain theory. 18, Theorem upon the limiting values of U . 17. The niaximum strain theory not disproved by published experiments.18. The niaximum shearing-stress criterion of elastic strength. 19. Further reasons for adopting thiu tubes as specimens. 20, Range of stress covered by diferent types of experiment. 21. Method of checking the isotropism of the material asregards yield-point 22. Objections to tubes 011 account of want of isotropy. 23, Objections to tubes on account of large effect of defects. 24. The system of Tests. 25, The specimeiis and holders. 28. The tension loads. 57. The application of torque. 28. The friction of the torsion-rigging. 29, The application of the interual pressure. 30. Measurement of the fluid pressure. 31. A new type of pressure-gauge. 32. Measurement of the distorsions. 33. A new Extensometer. stress theory. stresses. * Read May 25,1900. DUCTILE MATERIALS UNDER COMBINED STRESS. 203 34, Errors of extensometer. 35. A nem twist-measuring apparatus. 36. Proof that the torsion-mirrors measwe the twist. 37. Effect of beading. 38. As a transmission dynamometer. 39. The diametral extensometer. 40. Method of inaking the Tests. 41. The determinatioii of the sectional area and thickness of the tubes. 48. Calculation of the stresses. 43. Calculation of the strains. 44. Maxiilium shear and slide aye proportional. 46. Quantities tabulated. 46. Results of the experiruents-the tests on solid bars. 47. The material and shape of tubes satisfactory. 48. The elastic limit phenomenon. 49. Yield-point stresses of the same type nearly constant throughout series on each tube. 50. The variation of the maximimi stress. 51. The variation of the niaxiiiiuin principal strain. 52. The maximum shearing-stress or slide nearly constant. 53. Graphical presentation of variations. 54. Conclusions probable for general type of stress. 55. Effect of a volumetric stress (steel). 56. Convenient view of general type of stress. 57. The copper and brass tests, and diagrams. 68. Practical conclusions and note.

Energies and E1, M1, E2, M2 transition rates for states of the 2s22p, 2s2p2, and 2p3 configurations in boron-like ions between N III and Zn XXVI

“…Spectroscopic data of boron-like ions are highly useful in the diagnostics of solar, astrophysical, and fusion plasmas [1,2]. For many years researchers have studied the boron-like isoelectronic sequence, providing both experimental and theoretical energy levels and transitions rates.…”

MCDHF Calculations and Beam-Foil EUV Spectra of Boron-Like Sodium Ions (Na VII)

“…They have compared their calculated level energies with the results of other advanced calculations and with databases and experimental data for Si X [51], and they find good agreement. We are applying the same ab initio computational approach now to n = 2, 3 and (some) 4 levels of Na VII and compare our results with the results obtained by competing computational approaches and with data of the aforementioned Tordoir et al measurement campaign in the EUV.…”

“…In other sections of the same dataset, Vilkas (using the ab initio multireference Møller-Plesset code developed by Y. Ishikawa and his group) identified more than a hundred lines of Si X (B-like) [51] and determined level positions up to n = 4. The study recognized a number of lines that had been mistakenly subsumed into various data compilations, because the measured wavelengths had been stated with more decimals than used by other authors; however, the underlying line identifications turned out to be incorrect.…”

Two-electron–one-photon M1 and E2 transitions between the states of the 2p3and 2s22p odd configurations for B-like ions with 18 ≤Z≤ 92

“…In the calculations the states of the 2s 2 2p and 2p 3 configurations were simultaneously optimized in an extended optimal level (EOL) scheme. These calculations were followed by calculations with CSF expansions generated by single (S)-and double (D)-excitations from the 2s and 2p shells of the reference configurations 2s 2 2p and 2p 3 to the active set in order to consider valence-valence (VV) correlations. The active set was systematically increased by adding layers of new orbitals.…”

“…B-like ions attract wide attention since they are often found in astrophysical [1][2][3][4] and thermal nuclear fusion plasmas [5][6][7]. Transitions within the n = 2 complex of ions in the B-like isoelectronic sequence, including forbidden and resonance lines, play key roles in diagnosing temperatures, densities and ionic abundances of plasma [8][9][10][11][12][13][14][15].…”