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841.
842.
H. G. Bohlen R. Kalpakchieva W. von Oertzen T. N. Massey A. A. Ogloblin G. de Angelis M. Milin Ch. Schulz Tz. Kokalova C. Wheldon 《The European Physical Journal A - Hadrons and Nuclei》2007,31(3):279-302
The structure of 17C has been investigated using the three-neutron transfer reaction (12C,9C) on a 14C target at 231MeV incident energy, the reaction Q-value is Q
0 = - 46.930MeV. Eleven new states up to 16.3MeV excitation energy were identified. The same reaction has also been used on
a 12C target ( Q
0 = - 38.787MeV), and excited states in 15C up to 19MeV were observed. In 17C the three transferred neutrons populate (sd )3 configurations on the 14C core. The comparison of levels populated by the (12C,9C) reaction in 17C, 16C and 15C reveals a strong similarity of their properties. This concerns especially nine states in each of the three carbon isotopes,
which show practically the same excitation energies except a constant mean shift of +5.82MeV for 16C and +6.65MeV for 15C with respect to 17C. The triples of states from the three isotopes, which correspond to each other, have also similar widths and cross-section
ratios. It is concluded that the same (sd )3 structures are populated in the three carbon isotopes. The observed levels of 17C are also compared to the levels of 19O with known assignments and to shell model calculations, and their decay properties are discussed. 相似文献
843.
844.
J. Enders O. Karg P. von Neumann-Cosel V. Yu. Ponomarev 《The European Physical Journal A - Hadrons and Nuclei》2007,31(1):15-22
A comparison between the electric quadrupole (E2) strength distributions in 40, 48Ca with new results from 52Cr is presented. The deduced E2 strength distributions and the exhaustion of the isoscalar energy-weighted E2 sum rule are very different. Microscopic approaches fail to reproduce these differences. A survey of the available data
shows that the exhaustion of the energy-weighted isoscalar E2 sum rule in doubly magic nuclei below the isoscalar giant quadrupole resonance is typically more than two times larger than
in semi-magic nuclei. On the other hand, the E2 strength in this energy region exhausts about 50% of the total E2 strength, independent from shell closures. 相似文献
845.
Th. Kröll T. Behrens R. Krücken V. Bildstein R. Gernhäuser P. Maierbeck I. Stefanescu O. Ivanov J. Van de Walle N. Warr P. A. Butler J. Cederkäll P. Delahaye L. M. Fraile G. Georgiev U. Köster T. Sieber D. Voulot F. Wenander P. E. Kent A. Ekström K.-H. Speidel J. Leske S. Schielke D. Habs R. Lutter P. Thirolf H. Scheit T. Davinson 《The European physical journal. Special topics》2007,150(1):127-129
We report on “safe” Coulomb excitation of neutron-rich 138,140,142Xe
nuclei.
The radioactive nuclei have been produced by ISOLDE at CERN and
post-accelerated
by the REX-ISOLDE facility. The γ-rays emitted by the decay of excited
states have been detected by the MINIBALL array. Recent results are
presented. 相似文献
846.
S. Marcos M. López-Quelle R. Niembro L. N. Savushkin 《The European Physical Journal A - Hadrons and Nuclei》2007,34(4):429-441
In the phenomenological relativistic framework of the Dirac equation for spherical nuclei, we use different kinds of single-particle
central potentials ( ΣS + Σ0 to investigate certain aspects of the spin and pseudospin (PS) symmetries. Neither the splitting of PS doublets (PSDs) nor
the similarity of the radial parts of the small components (F/r of the corresponding Dirac spinors have been found related with the magnitude of ΣS + Σ0 , in the sense predicted by several authors in the last decade. This conclusion is shown to be valid, in particular, for
a potential of Coulomb type. We give a simple explanation for the strong correlation established in the relativistic calculations
between the similarity of the radial parts of the big (small) components of the Dirac spinors of two spin (pseudospin) partners
and the number of their nodes. The direct effects of the so-called PS symmetry-breaking term (and its singularity point) on
the F functions of the PSDs are also analysed. 相似文献
847.
应用不可约张量法和群的理论构造了三角对称晶场中3d3/3d7态离子的可完全对角化的120阶微扰哈密顿矩阵。矩阵中考虑了自旋-轨道相互作用,自旋-自旋相互作用和自旋-其他轨道相互作用,利用该矩阵计算了YAG∶Cr3 晶体的基态能级、零场分裂参量,研究了自旋二重态对基态能级的贡献,理论计算值与实验值相符合,证明二重态对基态的贡献是不可忽略的。在此基础上,进一步研究了自旋-轨道相互作用、自旋-自旋相互作用和自旋-其他轨道相互作用对YAG∶Cr3 晶体的光谱精细结构和零场分裂参量的影响,发现自旋-自旋和自旋-其他轨道相互作用对YAG晶体基态光谱精细结构和零场分裂参量的影响都是不可忽略的。通过理论计算值和实验值的比较,证实了在YAG∶Cr3 晶体光谱中扬-特勒效应的存在。 相似文献
848.
构造了3d3/3d7离子在三角对称晶场中考虑自旋-轨道相互作用,自旋-自旋相互作用和自旋-其它轨道相互作用的120阶微扰哈密顿矩阵.利用完全对角化该矩阵的方法计算了Cr3+∶MgAl2O4晶体的基态能级、零场分裂参量,理论计算值与实验值相符合.定量研究了自旋二重态对基态能级的贡献,证明该贡献是不可忽略的.定量研究了自旋-轨道相互作用、自旋-自旋相互作用和自旋-其它轨道相互作用对Cr3+∶MgAl2O4晶体的光谱精细结构和零场分裂参量的影响,发现自旋-轨道和自旋-自旋相互作用对基态能级和零场分裂参量的影响的程度和方式是不同的,自旋-其它轨道相互作用的影响也是不可忽略的.通过理论计算值和实验值的比较,证实了在Cr3+∶MgAl2O4晶体中Jahn-Teller效应的存在,解释了该晶体的光谱精细结构的成因. 相似文献
849.
车载状态下光电经纬仪的减振防护研究 总被引:1,自引:0,他引:1
针对光电经纬仪等高准确度仪器设备在运输过程中,对车载情况下产生的冲击和振动提出的具体要求,采用一套基于金属钢丝绳减震器的减振系统及加固装置对其进行抗振动防护.分析了车载情况下该减振系统的数学模型,并以某型号经纬仪模型为例,将其放置于满载质量15吨的某型号越野汽车中,在砂石路况下以30km/h的车速进行跑车试验,测得其加速度振动响应小于0.5g,冲击响应小于2.8g. 相似文献
850.
D. E. Appelbe R. A. E. Austin G. C. Ball J. A. Cameron B. Djerroud T. E. Drake S. Flibotte C. D. O’Leary A. Melarangi C. E. Svensson J. C. Waddington D. Ward 《The European Physical Journal A - Hadrons and Nuclei》2000,8(2):153-155
The decays of 2557Mn32 and 2558Mn33 have been studied with the 8π Spectrometer following the reaction 48Ca(13C,pxn)60 − x
Mn at a beam energy of 40 MeV. The level schemes of these two nuclei have been extended, and the multipolarities of the observed
transitions have been determined. 相似文献