Deuteron-induced reaction studies of the nuclear structure of178Hf

The level structure of¹⁷⁸Hf is interpreted on the basis of the population of the states following¹⁷⁸Hf (d, d′),¹⁷⁷Hf (d, p) and¹⁷⁹Hf (d, t) reactions. Evidence for quadrupole and octupole vibrational bands and unmixed and intermixed two-quasiparticle configurations is presented.     

Shock adiabat features,phase transition macrokinetics,and spall fracture of iron in different phase states

Abstract

Results are presented of systematic experimental investigations of shock adiabat and evolution of multiwave configurations for a number of steels in the range up to 100GPa; of stress relaxation kinetics in the front of the elastic and phase precursor from different initial states: uσ_x = 15, 25, 49, and 59GPa; and of data on spa11 fracture of iron in α —, ε —, γ —, and liquid phases under conditions of uniaxial deformation as well as under volumetric omnidirectional tension. Changes in material microstructure and microhardness of samples subjected to shock wave loads of 15, 25, 200, and 1000 GPa are analyzed.

Investigations of steels with the initial state in α and γ phases of iron and with different original heat treatment show that, in stress waves of low intensity (σ_x? 10–25 GPa), as well as under quasi-static tension-compression tests and impact tests, differences in their behavior and properties are clearly displayed. As the amplitude of longitudinal stresses increases up to 200–250 GPa, differences in their compressibility and in the character of spal1 fracture begin to smooth down.     

Explanation of Discrete Electric Relaxation Peak of CeO2: Gd3☎

Low-temperature loss peaks of Gd^3? doped CeO₂ have been investigated with defect calculation of computer simulation. Two types of possible origin of dielectric loss, low symmetry configuration around dopant and defect clusters with net dipole moment, have been modeled. The simulation has suggested that the dipole poling of defect cluster normally occurring at high temperature is the cause of the observed low-temperature loss peaks of CeO₂: Gd^3?.     

On the Structure of Semiovals of Small Size

The classification of all semiovals and blocking semiovals in PG(2, 8) is determined. Also, new theoretical results on the structure of semiovals containing a ‐secant and some nonexistence results are presented.     

类钠离子的电子碰撞电离截面

利用相对论修正扭曲波玻恩交换近似,计算了8个类钠离子的电子碰撞直接电离和激发自电离截面.基于这些结果,给出了计算类钠等电子系离子(18≤Z≤39)直接电离和激发自电离截面的高精度拟合公式.计算结果与现有的实验值和其他理论值比较,相当一致 关键词： 电离截面 组态相互作用 扭曲波玻恩交换近似 拟合公式     

Nb XIII离子3d94s2, 3d94s4p, 3d94p2 组态能级结构与跃迁的理论研究

用准相对论Hartree-Fock方法对Nb XIII离子二电子激发组态3d⁹4s², 3d⁹4s4p, 3d⁹4p² 的能级结构做了全面系统的理论计算研究.在对已有研究结果分析的基础上, 运用最小二乘方法对径向积分参数进行了优化计算, 得到了与这些组态有关的电偶极允许跃迁的谱线波长和跃迁概率.计算结果与最新的实验值做了对比分析, 表明本文计算结果是准确的. 研究发现, 波长40.92 nm的谱线, 属于3d⁹4s(¹D)4p²F_7/2–3d⁹ (²D)4s^{2 2}D_5/2 的跃迁谱线, 而不属于3d⁹4s (¹D)4p⁴D_7/2–3d⁹(²D)4s^{2 2}D_5/2 的跃迁谱线, 即上谱项能级为²F_7/2, 而不是⁴D_7/2. 关键词： Nb XIII离子 二电子激发组态 谱线波长 跃迁概率     

Structure of odd–odd La at high spin

The high spin states in the N=79 odd–odd ¹³⁶La nucleus have been investigated by in-beam γ-spectroscopic techniques following the ¹³⁰Te(¹¹B, 5n)¹³⁶La reaction at E=52 MeV using an array, consisting of eight Compton-suppressed clover germanium detectors. Thirty nine new γ rays have been assigned to ¹³⁶La on the basis of γ ray singles and γγ-coincidence data. The level scheme of ¹³⁶La has been extended above the known 115 ms isomer upto an excitation energy of 4.6 MeV and spin 18. Thirty one new levels have been proposed and spin-parity assignments for most of the newly proposed levels have been made on the basis of the deduced asymmetry ratios and polarisation information for the de-exciting transitions. The observed positive parity yrast band has been compared with the theoretical calculation, done within the framework of particle rotor coupling model (PRM) where the two odd quasi-particles are coupled to an axially symmetric core. The level structure has been discussed in the light of the known systematics of the neighbouring N=79 isotonic nuclei.     

Effect of uniaxial strain on the structure of self-localized excitons in alkali halide crystals

We have used luminescence spectroscopy to establish the effect of low-temperature (100 K) elastic uniaxial strain on the configuration of a self-localized exciton (SLE) in alkali halide crystals (AHCs) at the instant of radiative relaxation. In face-centered (fc) alkali halide crystals, redistribution of the luminescence intensity occurs from the asymmetric SLE configuration to the symmetric SLE configuration (type III → II → I), while conversely in body-centered (bc) alkali halide crystals the redistribution occurs in favor of the asymmetric (polarized) SLE configuration (type I → II). External strain along the 〈100〉 direction leads to effective slip of the anions in the alkali halide crystals along the 〈110〉 direction, coinciding with the direction of compression of the SLE, which promotes creation of preferentially the symmetric SLE configuration, while strain along the 〈110〉 direction, acting perpendicularly to the length of the SLE, leads to elongation of the SLE, which promotes creation of the asymmetric SLE configuration with a higher degree of polarization. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 74, No. 1, pp. 67–72, January–February, 2007.