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1.
Thirty-one levels in 164Ho have been observed up to an excitation energy of 994 keV utilizing 12 MeV deuterons and the reaction 165Ho(d, t)164Ho. The ground state Q-value was determined to be −1730±15 keV. The spectrum has been interpreted in terms of the coupling of the [523↑] Nilsson proton orbital with the neutron orbitals prominent in the (d, t) spectrum of 163Dy. Based on this interpretation, the singlet-triplet splitting energies for the [523↓], [642↑], [521↑], [402↓] and [400↑] neutron orbitals coupled to the [523↑] proton orbital were determined to be −144, +67, +171, −85 and +102 keV, respectively. Theoretical calculations of these energies made for a zero-range spin-dependent central potential gave values of −248, +74, +160, −82 and +73 keV, respectively. 相似文献
2.
In order to clear up important discrepancies amongst previous investigations, the decay of 168Lu, produced through the 169Tm (α, 5n) reaction, has been re-investigated. Instead of the well-known 7 min activity, evidence has been obtained for two distinct decays with half-lives of 5.5 min and 6.7 min. The corresponding Q-values have been determined to be respectively 4470±80 keV and 4690±100 keV. The decay schemes are given for each isomeric state. The assignments 6−(p404↓+n523↓) and 3+(p541↓+n523↓) are proposed for 168gLu (5.5 ruin) and 168mLu (6.7 min), respectively. The structure of the levels are discussed in the framework of current nuclear models. 相似文献
3.
The levels of151Eu have been investigated in the (n,n′γ) reaction using nuclear reactor fast neutrons. The energies, intensities and angular distributions of theγ-rays have been measured with the Ge(Li) spectrometer. Four rotational bands with the following band heads and Nilsson configurations have been identified: ground state band, 5/2+ [402]; 21.5 keV, 7/2+[404]; 196.5 keV, 3/2+[411]; 260.5 keV, 5/2+[413]. The low spin states at 332.2 and 336.2 keV have been tentatively assigned to the l/2+[411] Nilsson orbital, but 522.8, 580.0 and 587.0 keV states to the 1/2+[420] Nilsson orbital. The negative parity levels at 353.7, 522.1 and probably 546.2 keV have been proposed basing on theh 11/2 proton state. 相似文献
4.
5.
Raymond A. Dewberry Raymond K. Sheline Robert G. Lanier Romedan Lasijo 《Zeitschrift für Physik A Hadrons and Nuclei》1982,307(4):351-364
Fifty-six levels in166Ho have been observed up to an excitation energy of 2,000 keV using the167Er(t,α)166Ho reaction with 17.0-MeV tritons. An anomalously small spectroscopic factor for the states in the [411↑±633↑] configuration has been observed, which has been interpreted as evidence for a large amount of configuration mixing with the states in the [523↑±521↑] configuration. Residual interaction calculations with a finite range central force have failed to account for the large configuration mixing observed. New assignments for 29 rotational states have been proposed. An anomalous singlet-triplet splitting is observed in the [404↓±633↑] configuration. 相似文献
6.
本文利用相干态正交化展开方法, 对两格点两电子Hubbard-Holstein极化子模型的能谱以及动力学特性进行了精确求解. 讨论了耦合强度g、平均声子数n以及电子 初态对纠缠演化特性及系统冯诺依曼熵的影响. 数值计算结果表明: 1)纠缠度随时间的演化呈现出良好的周期性, 当其他的参数固定时, 演化周期随耦合强度g增大逐渐减小, 与平均声子数n无关; 2)系统冯诺依曼熵同电子状态占有率表现出严格的同步演化特性; (3) 在弱耦合强度和低平均声子数下, 初始电子态c2↑+ c2↓+|O>e或c1↑+ c1↓+ |O>e较c1↑+c2↓+—c1↓+ c2↑+具有更大的最大冯诺依曼熵, 并随耦合强度增大、平均声子数的增加而逐渐接近. 相似文献
7.
B. Pfeiffer G. Lhersonneau H. Gabelmann K. -L. Kratz 《Zeitschrift für Physik A Hadrons and Nuclei》1995,352(1):1-2
A t1/2=85 ns isomer has been identified at 1619 keV in100Sr. The halflife is attributed to a K=4 hindered decay. The configuration is proposed to be built on the [411]3/2 and the [532]5/2 neutron quasiparticle orbitals.Communicated by: P. Armbruster 相似文献
8.
M. Finger P. Galan T. J. Galanová J. Lipták J. Vrzal J. Urbanec 《Czechoslovak Journal of Physics》1969,19(8):1017-1032
Gamma-ray spectra in the decay of160Tb were measured with the aid of two coaxial Ge(Li) spectrometers. Absolute intensities and multipolarities were obtained. Three new transitions of 486·5 keV, 1069 keV, and 1102·5 keV were found and introduced into the decay scheme. The level scheme is discussed from the point of view of the generalized model of the nucleus. Experimental data show the 1264·4 keV level to be a two-quasi-particle state of the p p (411–523) type. The beta-transition from the ground state of160Tb (p 411+n 521) to this two-quasi-particle state with logft=8·00 ± 0·05 is interpreted as -forbidden.The authors are indebted to Prof. K. E. Alexandrov, K. A. Gromov, and E. P. Grigoriev for useful remarks and interest concerning the work. 相似文献
9.
S. J. Chae J. C. Kim C. S. Lee C. -B. Moon T. Komatsubara J. Mukai J. Lu T. Hayakawa M. Matsuda T. Watanabe K. Furuno 《Zeitschrift für Physik A Hadrons and Nuclei》1994,350(2):89-90
154Ho was studied via141Pr(16O,3n) reaction at beam energy of 75 MeV. We found two new rotationally aligned bands made of neutron h9/2 and f7/2 orbitals coupled to a proton h11/2 orbital. As with several new high-spin states, up to I=20, the ground state band with odd parity starts to show anomalous signature splitting at I=13 in this doubly odd154Ho. The observed rotational bands in154Ho are quite consistent with the onset of collectivity which appears in general at neutron number of 87 in neutron-deficient rare-earth nuclei. 相似文献
10.
BEC-BCS crossover, phase transitions and phase separation in polarized resonantly-paired superfluids
We study resonantly-paired s-wave superfluidity in a degenerate gas of two species (hyperfine states labeled by ↑, ↓) of fermionic atoms when the numbers N↑ and N↓ of the two species are unequal, i.e., the system is “polarized.” We find that the continuous crossover from the Bose-Einstein condensate (BEC) limit of tightly-bound diatomic molecules to the Bardeen-Cooper-Schrieffer (BCS) limit of weakly correlated Cooper pairs, studied extensively at equal populations, is interrupted by a variety of distinct phenomena under an imposed population difference ΔN ≡ N↑ − N↓. Our findings are summarized by a “polarization” (ΔN) versus Feshbach-resonance detuning (δ) zero-temperature phase diagram, which exhibits regions of phase separation, a periodic FFLO superfluid, a polarized normal Fermi gas and a polarized molecular superfluid consisting of a molecular condensate and a fully polarized Fermi gas. We describe numerous experimental signatures of such phases and the transitions between them, in particular focusing on their spatial structure in the inhomogeneous environment of an atomic trap. 相似文献
11.
Using a semi-classical approach, Hood, Falicov and Penn have studied the effects of interfacial roughness on the magnetoresistance (MR) of iron based trilayers (Fe/Cr/Fe and Fe/Cu/Fe). We extend their theory to magnetic metallic multilayers composed of N bilayers ferromagnetic-normal metal. The in plane MR of Co/Cu multilayers is calculated for correlated quasiperiodic interfaces. The averaged effects due to impurities, interdiffusion, band structure, etc. are included in a simple way using two phenomenological parameters S↑ and S↓ for two directions of spin. MR variation with S↑, S↓ and relaxation time is reported. We analyse also recent experimental data giving the influence of number of bilayers on the MR of Co/Cu multilayers for different temperatures. 相似文献
12.
T. Seo A. -M. Schmitt H. Ahrens J. P. Bocquet N. Kaffrell H. Lawin G. Lhersonneau R. A. Meyer K. Shizuma K. Sistemich G. Tittel N. Trautmann 《Zeitschrift für Physik A Hadrons and Nuclei》1984,315(2):251-253
The nucleus103 Nb 62 has been studied through the ß? decay of the fission product103Zr at LOHENGRIN and JOSEF. The energies of the lowlying levels and the γ transitions indicate rotational bands based on the Nilsson proton configurations [422 5/2+] [303 5/2?] and [301 3/2?] at 0, 164 and 248 keV, respectively. The measured half-lives of (4.7±0.5) ns and (2.0±0.6) ns of the levels at 164 and 248 keV are consistent with the Nilsson-model estimates including pairing. 相似文献
13.
We theoretically study physical properties of solutes placed in a straight line and at regular intervals. The solute is a rigid-body and has an arrow-like shape, which changes its direction up (↑) or down (↓). If the rigid solutes are immersed in a continuum solvent, nothing happens in the system (it is an obvious fact). However, the property of the directions differs in a granular solvent (e.g., hard-sphere solvent). Depending on the distance between the nearest-neighbor solutes, the directional correlation between them is periodically changed as follows: “parallel-tendency (↑↑)” ↔ “random” ↔ “antiparallel-tendency (↑↓)”. Studying a newly created nanosystem, it is able to discover interesting properties hiding in the nanosystem. We believe that such an approach contributes to the development of nanotechnology. 相似文献
14.
The electronic structure of high-T
c copper based superconductors has been studied using the quasirelativistic INDO molecular orbital method. Model clusters of YBa2Cu3O
y
systems have been investigated fory ranging between 6·0 and 7·0. Monomeric units [Ba8Cu3O
x
]
q
and [Y4Ba8Cu4O
x
]
q
, dimeric units [Ba12Cu6O
x
]
q
and [Y6Ba12Cu8O
x
]
q
as well as tetrameric units [Ba18Cu12O
x
]
q
over 300 valence orbitals have been studied. From the set of occupied molecular orbitals the density of states (DOS) function has been calculated along with its d-orbital projection. The highest occupied molecular orbitals cover the oxygen p-band whereas the copper d-band lies at lower energies. Superconducting phase models (y=6·75 to 7·0) have a higher d-DOS function at higher energies with respect to the non-superconducting phase (y=6·0). 相似文献
15.
P. Bischof R. Gleiter M.J. Kukla L.A. Paquette 《Journal of Electron Spectroscopy and Related Phenomena》1974,4(3):177-184
The photoelectron spectra of tricyclo[3.3.0.02,6]octene (1) and tricyclo[3.3.0.02,6]octane (2) have been recorded. The first bands in these spectra are correlated with orbitals which are linear combinations of the Walsh orbitals and of the olefinic π-orbital. This assignment is based on a zero differential overlap molecular orbital model as well as on the results of extended Hückel calculations. The resonance integral <π|H|W > for 1 is found to be ?1.34 eV. 相似文献
16.
T. Tuurnala R. Katajanheimo E. Hammarén 《Zeitschrift für Physik A Hadrons and Nuclei》1977,280(3):309-316
Theβ ?-decay of 66 167 Dy produced through the fast neutron reaction170Er(n, α)167Dy has been investigated by using several kinds of detectors and a high-capacity two-parameter recording system. The half-life andβ ?-decay energy of167Dy were determined to beT 1/2 = 6.20 ± 0.08min andQ β-=2.35±0.06, respectively. The observed level scheme of 67 167 Ho (completely unknown previously) contains 12 states, among them a 6.0±0.1 μsM2 isomer at 259.3 keV. On the basis of theoretical and systematic considerations combined with multipole determinations, the following Nilsson model assignments are proposed for the lowest states of167Ho: 0 keV (7?/2 [523]), 259.3 keV (3+/2[411]), 319.8 keV (5/2 3+/2[411]), 392.5 keV (1+/2[411]), 410.0 keV (3/2 1+/2[411]), 569.7 keV (3?/2{7?/2[523], 2+}). Theβ-decay proceeds mainly to the proposed gamma-vibrational state at 569.7 keV with an anomalously low logft value 5.4, indicating similarity between the microscopic structures of this state and the famous ¦K 0?2¦ gamma vibration of165Ho. 相似文献
17.
We study the effect of spin Coulomb drag on the magnetoresistance and the spin-current injection efficiency of a layered structure consisting of a nonmagnetic semiconductor sandwiched between two ferromagnetic electrodes of spin polarization p. The calculations are done within the framework of the drift-diffusion theory, which we generalize to include the spin trans-conductivity σ↑↓. We find that for p close to 100% the spin drag enhances the magnetoresistance, while for smaller values of p it reduces it. A new approach to the measurement of σ↑↓ is suggested. 相似文献
18.
G. Lhersonneau H. Gabelmann B. Pfeiffer K. -L. Kratz 《Zeitschrift für Physik A Hadrons and Nuclei》1995,352(3):293-301
The low-energy level scheme of theN=63 nucleus101Sr has been obtained from a β-decay study of101Rb. The ν[532]5/2 and ν[411]3/2 orbitals are well established as the ground state and a band head at 271.2keV, respectively. The general properties of the level scheme indicate a quadrupole deformation ofβ ? 0.4, confirming the unique feature of saturation of deformation inN ≥ 60 Sr isotopes. The energies of theK=3/2 intraband transitions in the odd-neutron neighbours99Sr61 and101Sr63 are very similar. More generally, the identical bands at low spin in98–101Sr nuclei are correlated with the mass-independent moments of inertia in this region. 相似文献
19.
We synthesized TPP[FeIII(Pc)(CN)2]2, PTMAx[FeIII(Pc)(CN)2]·y(MeCN), and PXX [FeIII(Pc)(CN)2], a new series of charge-transfer salts containing the axially-substituted phthalocyanine (Pc), [FeIII(Pc)(CN)2]−. In this molecular unit, the π conduction electron derived from the Pc-ring coexists with the d electron which is a potential source of a local magnetic moment. Therefore various phenomena associated with the interplay between local magnetic moments and conduction electrons are expected. We observed the giant negative magnetoresistance (GNMR) in all the three salts. The GNMR is highly anisotropic for the magnetic-field direction, and reflects the g-tensor anisotropy of the local magnetic moment in the [FeIII(Pc)(CN)2]− unit. This indicates that the GNMR in these salts originates from the strong π-d interaction in the [FeIII(Pc)(CN)2]− unit. 相似文献
20.
The excitation and emission spectra of CsCdCl3 crystal grown by the Bridgman growth technique, are observed. Its dominant excitation spectra correspond to the transitions between the electronic energy levels of the face-shared [CdCl6]4− octahedron complexes with C3v symmetry. With the help of the molecular orbital diagram of the [CdCl6]4− molecule complex, an approximate electronic energy level diagram of this crystal is constructed using one-electron approximation. 相似文献