Characterization of isomers of the nucleus154Pm

Consideration of the expected two-quasiparticle structures and their estimated band head energies, and the selection rules for beta transition rates for the¹⁵⁴Nd →¹⁵⁴Pm →¹⁵⁴Sm decays are used to deduce the configurations for the isomers and the low-spin structures in the neutron rich doubly odd nucleus ₆₁ ¹⁵⁴ Pm₉₃. The 2.68 m high spin isomer and the 1.73 m low spin isomer are respectively assigned the spin-parity 4⁺ and 1⁺ with the configuration {p:5/2⁻ [532↑] +n:3/2⁻ [521↑]} with the 2.68 m isomer lying lower in energy, and thus forming the¹⁵⁴Pm ground state. Two-quasiparticle character of the beta-connected states in¹⁵⁴Nd decay and¹⁵⁴Pm decay is discussed.     

Level structures in the odd-odd nucleus180Re

Experimental data on energy levels of the odd-odd deformed nucleus¹⁸⁰Re obtained from radioactive-decay and heavy-ion reaction studies are analysed to deduce spin-parity and configuration assignments for the six observed rotational bands based on the selection rules for fast beta transitions, criteria for the relative-energy ordering of the triplet and singlet bandheads, two-particle-plus-rotor model calculations including Coriolis mixing, rotational energy systematics involving staggering features, and considerations of gyromagnetic ratios, signature splittings and rotational band alignments.     

磁超精细相互作用引起的原子能级分裂及能级图

超精细相互作用是"原子物理学"课程中的重要内容之一.目前在国内外的教材中,著者只给出了有无外磁场时原子核磁偶极超精细相互作用引起的原子能级分裂的表达式和列举了一些原子能级分裂的研究实例.本文详细导出和讨论了无外磁场和有强弱磁场时磁超精细相互作用引起的原子能级分裂的公式,并举例说明如何判断和在能级图上标注这些能级的高低顺序.该文将有助于师生学习理解和真正掌握本部分的课程内容.     

Signature inversion in theK=4− band in doubly-odd152Eu and156Tb nuclei: Role of theh 9/2 proton orbital

The phenomenon of signature inversion in the doubly-odd nuclei¹⁵²Eu and¹⁵⁶Tb is understood within the framework of a two-quasiparticle plus rotor model. It is shown that theh _9/2:1/2[541] proton orbital plays a crucial role in reproducing this phenomenon.     

SH（D）和OH（D）自由基基态的结构与势能函数

采用QCISD（T）/ 6-311++G（3df,2pd） 和QCISD/6-311++G（3df,2pd）方法计算优化了SH（D）和OH（D）自由基分子基态X²Π的分子结构和离解能.并采用最小二乘法拟合Murrell-Sorbie 函数得到了相应的势能函数,由此计算的振转常数与实验光谱数据符合得相当好. 关键词： SH和OH自由基分子 X²Π）')" href="#">基态（X²Π） Murrell - Sorbie函数 势能函数     

An energy law preserving C finite element scheme for simulating the kinematic effects in liquid crystal dynamics

In this paper, we use finite element methods to simulate the hydrodynamical systems governing the motions of nematic liquid crystals in a bounded domain Ω. We reformulate the original model in the weak form which is consistent with the continuous dissipative energy law for the flow and director fields in W^1,2+σ(Ω) (σ > 0 is an arbitrarily small number). This enables us to use convenient conformal C⁰ finite elements in solving the problem. Moreover, a discrete energy law is derived for a modified midpoint time discretization scheme. A fixed iterative method is used to solve the resulted nonlinear system so that a matrix free time evolution may be achieved and velocity and director variables may be solved separately. A number of hydrodynamical liquid crystal examples are computed to demonstrate the effects of the parameters and the performance of the method.     

Kinetic energy and charge state effects in the X-ray emission of Mo surface induced by Xe q + ( q = 25, 29) ions

L-shell X-ray spectra of Mo surface induced by Xe²⁵⁺ and Xe²⁹⁺ were measured. The X-ray intensity was obtained in the kinetic energy range of the incident ions from 350 to 600 keV. The relationship of X-ray intensity with kinetic energy of the projectile and its charge state were studied, and the simple explanation was given. Supported by the Science and Technology Ministry Foundation of China (Grant No. 2002CCA00900) and the Foundation of National Key Laboratory of Vacuum & Cryogenics Technology and Physics     

Spectra and structure of energy levels of Pr3+ in crystals of yttrium and gadolinium oxyorthosilicates

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 6, pp. 123–129, November–December, 1995.     

Characterization of host-lattice emission and energy transfer in BaMgAl10O17:Eu

Host-lattice emission, energy transfer and degradation processes are characterized in undoped and Eu-doped BaMgAl₁₀O₁₇. Undoped BaMgAl₁₀O₁₇ exhibits a broad emission centered at 265 nm when excited at wavelengths shorter than 190 nm. This emission is assigned to exciton recombination at Ba-O groups in the cation layer of the lattice. The emission exhibits excellent overlap with the excitation band of Eu²⁺ in this host, providing a means of host-to-activator energy transfer in the doped phosphor. The exciton emission is relatively stable to thermal damage, but undergoes a peak shift and significant decrease in intensity after exposure to VUV radiation. Heating of VUV-damaged materials in air leads to some repair of the spectral properties.     

Exciton model of the primary processes of bacterial photosynthesis: Spectra and kinetics of energy transfer

Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 2, pp. 77–82, March–April, 1995.     

The formation mechanism and the binding energy the body—centred regular tetrahedral structure of He5^＋

We propose the formation mechanism of the body-centred regular tetrahedral structure of the He5^ cluster,The total energy curve for this structure has been calculated by using a modified arrangement channel quantum mechanics method.The result shows that a minimal energy of -13.9106 a.u.occurs at a separation of 1.14a0 between the nucleus at the centre and nuclei at the apexes.Therefore we obtain the binding energy of 0.5202a .u.for this structure.This means that the He5^ cluster may be stable with a high binding energy in a body-centred regular tetrahedral structure.     

Photoinduced energy transfer from the triplet state of naphthalene moiety in the Tb/Eu complexes of a specially designed naphthalene cryptand

The paper reports time-resolved emission and energy transfer (ET) studies of metal ion complexes of a specially designed rigid macrocyclic naphthalene cryptand (L) under different conditions. Complex formation of L with Li⁺ and H⁺ causes an appreciable increase in singlet state quantum yield and lifetime of L implying photoinduced electron transfer (PET) from the cryptand moiety to naphthalene unit in the free L. The system exhibits photoinduced ET at 77 K in its Tb³⁺ and Eu³⁺ complexes with either NO₃⁻¹ or Cl⁻¹ as counter-anion. The extent of ET is higher for the Tb³⁺ complex as compared to that for the Eu³⁺ complex. In both Tb³⁺ and Eu³⁺ complex, the NO₃⁻¹ ions influence the relative orientation of donor (L) and acceptor (Ln³⁺) more in favour of ET than the Cl⁻¹ ions. The rate constants for the ET from the naphthalene moiety of L to the acceptor (Ln³⁺) have been evaluated at 77 K. The results suggest ET from the triplet state of naphthalene using an exchange mechanism. The ground state geometries of the system L and its complexes with Li⁺, Cs⁺ and Tb³⁺ have been determined using DFT methods to interpret our results.     

Crystal field energy levels of the laser crystal Gd3Ga5O12: Nd

The crystal field energy levels of laser crystal Gd₃Ga₅O₁₂: Nd³⁺ are calculated using the diagonalization (of energy matrix) method. From the calculations, the 93 observed crystal field energy levels are explained reasonably and the root-mean-square (r.m.s.) deviation σ(≈25.6 cm⁻¹) and the scalar crystal-field strength parameter Nv (≈3847 cm⁻¹) are obtained. The results are discussed.     

Stark structure of the energy spectrum of the Am3+ ion in LaCl3

We have analyzed the structure of the energy spectrum of the Am³⁺ ion in LaCl₃ in the weak and intermediate configuration interaction approximation. We have established that in the intermediate configuration interaction approximation, the mean-square deviation of the calculated values of the Stark level energies from the experimental values is 53% smaller than in the weak configuration interaction approximation. We have determined the even and odd crystal field parameters and the covalency parameters. We conclude that based on analysis of the Stark structure of the energy spectrum, we can make quantitative estimates of the intensity characteristics. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 5, pp. 637–640, September–October, 2006.     

Studies of the crystal field energy levels and g factors for Ce in LiYF4 crystal

The five observed crystal field energy levels and EPR g factors g_//and g_⊥ for Ce³⁺-doped LiYF₄ crystal are calculated together from a complete diagonalization (of energy matrix) method. In the method, the contributions to g factors of ground Kramers doublet from all the rest doublets within the ground and excited manifolds ²F_5/2 and ²F_7/2 are included. The calculated results show reasonable agreement with the experimental values. The calculations suggest that the crystal field parameter B₂₀ > 0 in LiYF₄: Ce³⁺ crystal. The opinion of the parameter B₂₀ < 0 in the previous paper is not correct. Since this opinion is based on the calculation of g factors using a very simple method where only the contributions to g factors from the doublets within the ground manifold ²F_5/2 are considered, it is suggested that this simple method is not effective in the calculation of g factors for 4f¹ ions in crystals.