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R. Broda P. J. Daly Z. W. Grabowski H. Helppi M. Kortelahti J. McNeill R. V. F. Janssens R. D. Lawson D. C. Radford J. Blomqvist 《Zeitschrift für Physik A Hadrons and Nuclei》1985,321(2):287-295
The level structure of theN=81 nucleus147Dy has been studied byγ-ray spectroscopy following reactions of 230–250 MeV58,60Ni beams on89Y and90,92Zr targets. Yrast and near-yrast levels in147Dy above the known 59-s 11/2? state are established up to ~3.7 MeV; they include isomeric levels at 2,681, 3,407 and 3,650 keV. Guided by the results of shell model calculations, we interpret most of the observed level as senioritythree states arising from the coupling ofs 1/2,d 3/2, andh 11/2 neutron holes withπh 11/2 2. 相似文献
46.
Purple arsenomethane crystallises in the orthorhombic system, space group Ima2 (C) with a = 5.81, b = 5.79, c = 13.64 Å and 8 units of CH3As in the cell. The structure is polymeric, the arsenic atoms lying on infinite coplanar ladders parallel to a. The distance between two arsenic atoms on one rung of the ladder is 2.4 Å, the distance between two arsenic atoms on the same upright and adjacent rungs is 2.9 Å, and the shortest distance between two arsenic atoms in neighbouring ladders is 3.4 Å. Each arsenic atom is bonded to one methyl group (1.97 Å), and along the ladder upright or on any one rung these methyl groups lie on alternate sides of the ladder. 相似文献
47.
P. Kleinheinz M. Ogawa R. Broda P. J. Daly D. Haenni H. Beuscher A. Kleinrahm 《Zeitschrift für Physik A Hadrons and Nuclei》1978,286(1):27-29
Conversion electron measurements confirm the 3? assignment recently proposed for the 1579 keV first excited state in146Gd. Fromγγ- ande ? γ-coincidence data the half life of that state has been determined asT 1/2=1.06±0.12 ns. 相似文献
48.
P. J. Daly P. Kleinheinz R. Broda S. Lunardi H. Backe J. Blomqvist 《Zeitschrift für Physik A Hadrons and Nuclei》1980,298(3):173-185
The yrast states of148Dy and149Dy have been studied by γ-ray and conversion electron measurements in (α, xn) and (16O,xn) reactions on enriched152Gd and135Ce targets. Level schemes to above 4 MeV for the two nuclei are reported. The πh 2 11/2 spectrum identified in148Dy and the πh 11/2 effective chargee eff=1.52±0.05e, derived from the measuredE2 transition rate between the (πh 2 11/2) 10+ and 8+ states, are discussed and compared with results for other two-particle nuclei. The yrast cascades in148Dy and149Dy continue above the (πh 2 11/2) 10+ and πh 2 11/2 vf 7/2) 27/2? states by ~ 1 MeVE1 transitions de-exciting the lowest members of octupole multiplets built on these states. The energy shifts for the observed members of the πh 2 11/2 × 3? multiplet are analyzed in terms of twoparticle-phonon exchange coupling using an empirical coupling strength extracted from the one valence particle nucleus147Tb. The dominantvf 7/2×3? character of low-lying 13/2+ isomers in149Dy and otherN=83 nuclei is emphasized. 相似文献
49.
Abstract A model of sustainable economic growth in an economy with two types of exhaustible resources is analyzed. The resources are assumed to be perfect substitutes with marginal rate of substitution varying over time. The optimal control framework is used to characterize the optimal paths under the maximin criterion. It is shown that the resource with increasing productivity is not used before the constant productivity resource is depleted. Afterwards the resource with an increasing productivity is asymptotically depleted as well. The results are based on an assumption that transversality conditions hold. A new sufficient condition for the transversality conditions is derived. Finally, an analogue of Hartwick’s rule for this non‐autonomous case is established. 相似文献
50.
This study examined how the signals of interest (SOI) effect on the backscattering measurement numerically based on 3-D finite-difference time-domain (FDTD) method. High resolution microstructure mappings of bovine cancellous bones provided by micro-CT were used as the input geometry for simulations. Backscatter coefficient (BSC), integrated backscatter coefficient (IBC) and apparent integrated backscatter (AIB) were calculated with changing the start (L1) and duration (L2) of the SOI. The results demonstrated that BSC and IBC decrease as L1 increases, and AIB decreases more rapidly as L1 increases. The backscattering parameters increase with fluctuations as a function of L2 when L2 is less than 6 mm. However, BSC and IBC change little as L2 continues to increase, while AIB slowly decreases as L2 continues to increase. The results showed how the selections of the SOI effect on the backscattering measurement. An explicit standard for SOI selection was proposed in this study and short L1 (about 1.5 mm) and appropriate L2 (6 mm-12 mm) were recommended for the calculations of backscattering parameters. 相似文献