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1.
Time-resolved spectroscopy and decay-time measurements for the intrinsic and trap emission lines of UO2MoO4 supply experimental evidence for fast energy migration among intrinsic centres and from intrinsic to trap centres. The temperature behaviour of the decay time for the main trap lines reveals an energy transfer rate from trap to intrinsic centres in the order of 5×109s-1, while the transfer rate among intrinsic centres, as estimated from the correlation field splitting, is 3×1011 s-1.  相似文献   

2.
Oscillator strengths and transition probabilities are obtained from an intermediate coupling scheme. The initial basis of the eigenstates is formed inLS-coupling. To obtain the resulting energy matrix,Z-1 perturbation theory is applied. The values of oscillator strengths and transition probabilities for 1s22p2?1s22s2p and 1s22s2p?1s22s2 transitions are calculated and the comparison is made with some recent results. The nuclear charges (Z) involved varied fromZ=4(Be(I)) toZ=35(Br(XXXII)).  相似文献   

3.
Non-relativistic energies of 1s22s and 1s2 np (n⩽9) states for Co24+ ion are calculated by using the full-core plus correlation method. Our results of 1s22s and 1s22p states agree well with the high-precision results of Yan et al. Based on calculating the first-order corrections to the energy from relativistic and mass-polarization effects, we estimate the higher-order relativistic contribution and QED correction to the energy under a hydrogenic approximation. The transition energies, wavelengths and oscillator strengths for the 1s22s−1s2 np (n⩽9) transitions of this ion are calculated. The results agree with the experimental data available in literature satisfactorily. By combining with quantum defect theory, our theoretical predictions on the energy and oscillator strength of this ion are extrapolated to the whole energy region including continuous states.  相似文献   

4.
本文利用受激Raman抽运,选择性地制备了C2H2分子电子基态的红外非激活振动能级的单一转动态(X1g+,v″2=1,J″=9,11,13),并从紫外激光诱导的A1Au(v′3=1)←X1g+(v″2=1)荧光谱,直接测定上述三个转动态的C< 关键词:  相似文献   

5.
The excitation of the 1s 2- and 1s 4-levels of neon and argon by He+-impact has been studied in the energy range of 100 keV to 1000 keV. The total emission cross sections for the 1s 2 levels show pronounced maxima at about 350 keV impact energy, whereas the cross sections for the 1s 4 levels increase with decreasing energy.  相似文献   

6.
在深入分析BF+2注入多晶硅栅F在多晶硅栅中迁移特性的基础上,建立了F在多晶硅栅中的迁移方程.采用有限差分法,模拟了BF+2注入多晶硅栅F在多晶硅栅中的分布.模拟结果与二次离子质谱(SIMS)分析结果相符.给出了80keV,2×1015cm-2 BF+2注入多晶硅栅900℃,30min退火条件下F在多晶硅中的发射系数e=6×10关键词:  相似文献   

7.
本文测定了3Cu(IO3)2·2H2O球晶的电子吸收光谱,吸收峰位于9140cm-1和15250cm-1。首次观察到了高达6110cm-1的低对称晶场分裂。吸收曲线经Gauss分解可得到八个Gauss型吸收峰,分别位于8590,10690,10870,12190,13500,14510,15330和16500cm-1。测量其EPR谱可得g=2.141±0 关键词:  相似文献   

8.
The electronic structure of the binuclear complex Rh2Ac4Cl22? was analysed using X-ray and X-ray photoelectron spectra. The closeness of the structure of Rh2Ac4Cl22? to two boundary structures ClRhRhCl (I) and Cl… RhRh… Cl (II) has been studied. The correlation between Rh2Ac4 Cl22? and RhCl63? has shown that structure I is more in agreement with the experimental data than structure II. The structure of the K-edge of the spectra provides support for weakening of the RhCl bond.  相似文献   

9.
本文采用文献[1—4]所发展的在位缺陷势格林函数方法,计算了3c-SiC中深能级的A1,T2对称波函数。第一次给出了波函数随杂质态能量E的变化趋势,和电子占据距缺陷中心最近邻的几个壳层的几率。并给出数量级与实验相符的3c-SiC:B的超精细结构常数的理论值。 关键词:  相似文献   

10.
Accurate configuration interaction wavefunctions for the 2s2(1S), 2p2(1S), 2s3s(1S) and 2s2p (1P) states of B(II) are calculated in a single optimized orbital basis of 7s, 6p and 4d Slater-type orbitals. 95, 84, 57 and 90% of the correlation energies, respectively, are realized by these wavefunctions. Oscillator strengths for the three 1S-1P transitions are calculated from these and from less accurate wavefunctions in the same orbital basis. The length values obtained from our most accurate wavefunctions, in order of increasing 1S energy, are 0.9885, 0.202 and 0.007. The degree of accuracy of these oscillator strengths is estimated by noting the convergence to final values as increasing percentages of correlation energies are included in the wavefunctions together with the increasing agreement between length and velocity formulas. The exact theoretical oscillator strength for the resonant line is projected to be 0.985 with an error almost certainly not greater than ±0.015. The theoretical oscillator strengths for the other lines are considered to be 0.21±0.02 and less than 0.007, respectively.  相似文献   

11.
Based on relativistic multichannel theory, this paper calculates the energy levels of autoionization Rydberg series 4s^2nf(n=4- 23)J^π -(7/2)° of scandium at different levels of approximation within the framework of multichannel quantum defect theory. The present results show that the dipole polarizations play an important role. Considering the dynamical dipole polarization effects, this paper finds that the difference between calculated and experimental quantum defects for the 4s^2nf(n=4- 23)J^π -(7/2)° series is generally about 0.01- 0.03. Furthermore, the reason that 4s^216f is obscured in experimental spectra is suggested to be the interaction with the neighbouring resonance state converged to 3d^2(^1G4) of Sc^+.  相似文献   

12.
李景德 《物理学报》1966,22(2):188-196
计算O-2在晶体场中出现的Jahn-Teller效应,得到具有电矩的2pπ3s3d0杂化原子轨道。BO6八面体共价性质决定了ABO3晶体的各种极化相。理论给出Ps比值、钛位移大小和热力学参数ξ′,ζ′均接近于实验结果。统一解释了钛酸钡的三个相转变。相变条件给出七种晶体中氧的屏蔽常数平均值与Slater的值一致。  相似文献   

13.
蔡鲁戈 《物理学报》1965,21(12):1977-1995
本文分别计算了含Co2+与含Ni2+铁氧体的感生单轴各向异性。前者从Iida提出的物理机构出发,考虑了阳离子缺位对Co2+能级和波函数的影响;后者从Schnettler-Gyorgy所提出的物理机构出发,考虑了四面体位置中Ni2+的Jahn-Teller效应,求出了它的能级和波函数。由此算得此二类物质的感生单轴各向异性和实验结果符合得较好。另外,还解释了θu和θα产生偏离的原因。  相似文献   

14.
The rotational dynamics of P4O6S and P4O7 in the solid state were studied by means of 31P NMR spectra of spinning and static powder samples in the temperature range of 153–295 K and 295–388 K, respectively. All spectra were simulated to confirm the type of the motion and to extract the time scales as a function of the temperature. Good agreement between experimental and theoretical data was obtained on the basis of a three-site jump model. For P4O6S, the activation energy and the pre-exponential factor derived from the lineshape simulations amount to 51(2) kJ/mol and 6(3)·1015 s−1. For P4O7, the spectral analysis yields an activation energy of 67(1) kJ/mol and a pre-exponential factor of 6(2)·1014 s−1. The dynamic behavior was checked independently by lineshape analyses under both MAS and static conditions. Activation energies are consistent within the errors for the lineshape analyses. Additionally, we have analyzed spin–lattice relaxation measurements, which show the correct trends for the activation energies.  相似文献   

15.
阎世英  朱正和 《中国物理 B》2008,17(12):4498-4503
The density functional theory (DFT) method (b3p86) of Gaussian 03 is used to optimize the structure of the Ni2 molecule. The result shows that the ground state for the Ni2 molecule is a 5-multiple state, symbolizing a spin polarization effect existing in the Ni2 molecule, a transition metal molecule, but no spin pollution is found because the wavefunction of the ground state does not mingle with wavefunctions of higher-energy states. So the ground state for Ni2 molecule, which is a 5-multiple state, is indicative of spin polarization effect of the Ni2 molecule, that is, there exist 4 parallel spin electrons in Ni2 molecule. The number of non-conjugated electrons is greatest. These electrons occupy different spatial orbitals so that the energy of the Ni2 molecule is minimized. It can be concluded that the effect of parallel spin in the Ni2 molecule is larger than that of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters of the ground state and other states of the Ni2 molecule are derived. The dissociation energy De for the ground state of the Ni2 molecule is 1.835 eV, equilibrium bond length Re is 0.2243 nm, vibration frequency we is 262.35 cm^-1. Its force constants f2, f3 and f4 are 1.1901 aJ.nm^-2, -5.8723 aJ.nm^-3, and 21.2505 aJ.nm^-4 respectively. The other spectroscopic data for the ground state of the Ni2 molecule ωeχe, Be and αe are 1.6315cm 2, 0.1141 cm^-1, and 8.0145× 10^-4 cm^-1 respectively.  相似文献   

16.
贾祥富  杨威 《物理学报》1998,47(11):1783-1789
利用修正的BBK理论,考虑入射道的库仑相互作用及出射电子的交换对称性,在共面-等能分享-垂直角度碰撞几何中,分别计算了能量为79.6,105.6,227.6和375.6eV的入射电子碰撞Li+(1s2)(e,2e)反应三重微分截面(TDCS).结果表明:在接近阈能的碰撞中,两出射电子连线平行于入射电子方向时,TDCS最大;两出射电子连线垂直于入射电子方向时,TDCS最小;入射电子能量达5倍的电离阈能时,主要为单次双体碰撞,而且入射道库仑场对决定低能碰撞的TDCS起着重要作用. 关键词:  相似文献   

17.
李名复  任尚元  茅德强 《物理学报》1983,32(10):1263-1272
木文在文献[5,6]所发展的在位缺陷势格林函数方法基础上,进一步讨论Si中短程缺陷势引入的T2对称深能级波函数性质。第一次给出了Si禁带中部很宽能量范围之内T_2对称波函数的完整数据。波函数在缺陷最近邻四个格点的占据几率P1有一高达50%以上峰值。该部分相当于四个最近邻格点指向缺陷的杂化轨道准悬键的T2组合。第0,1,2三个格点壳层波函数占据几率之和约为70%。波函数其余部分较平缓地分布在一相当大空间。波函数的以上特征与禁带中部能量位置关系不灵敏。但在靠近导带Ec和满带E_v的浅能量区,以上P1峰趋于消失,整个波函数在空间的分布趋于平坦。Si空位在禁带引入一个T2对称深能级,位于Ev以上0.51eV处。 关键词:  相似文献   

18.
The a.c. hopping conductivity is investigated in VO2 between 25 kHz and 109 Hz as a function of temperature. The ωs law with 0.7 < s < 1 is observed over a large range of frequencies, which is interpreted in terms of electron hopping among a wide distribution of localized levels. A detailed analysis of the results leads to the conclusion that two hopping processes are involved: a low frequency process, thermally excited with an activation energy of 30 meV, with a cutoff frequency of about 108 Hz, and a high frequency process, extending to very high frequencies and nearly temperature independent.  相似文献   

19.
程诚  高翔  青波  张小乐  李家明 《中国物理 B》2011,20(3):33103-033103
Using the multi-configuration Dirac-Fock self-consistent field method and the relativistic configuration-interaction method,calculations of transition energies,oscillator strengths and rates are performed for the 3s 2 1 S 0-3s3p 1 P 1 spinallowed transition,3s 2 1 S 0-3s3p 3 P 1,2 intercombination and magnetic quadrupole transition in the Mg isoelectronic sequence(Mg I,Al II,Si III,P IV and S V).Electron correlations are treated adequately,including intravalence electron correlations.The influence of the Breit interaction on oscillator strengths and transition energies are investigated.Quantum electrodynamics corrections are added as corrections.The calculation results are found to be in good agreement with the experimental data and other theoretical calculations.  相似文献   

20.
用时间分辨的激光诱导荧光光谱方法测量了10—300K温度范围内Ni2+:BeAl2O4晶体的红外荧光光谱和荧光寿命。通过荧光寿命的温度变化特性分析,得出3T2g态的内禀辐射衰减寿命为123±7.2μs。无辐射弛豫的Mott激活能为1147cm-1,并导出了此晶体发光量子效率随温度的变化关系式。Ni2+:BeAl2O4关键词:  相似文献   

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