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1.
以Racah的群表示论和Slater的波函数理论为基础,分别建立了4f2组态离子Pr3+在三角晶体场C3v和C3h中的91×91完全能量矩阵,并对Pr3+离子掺杂在卤化物CsCdBr3和GdCl3中的Stark能级做了计算与分析. 结果显示计算值与实验值吻合很好,表明在分析由稀土离子掺杂体系的能级分裂时,完全能量矩阵方法是有效的方法. 此外,将两种具有不同点群对称的体系的能级分裂情况作了比较,结果显示六阶晶体场参量对能级分裂的影响是不能忽略的,而且CsCdBr3:Pr3+和GdCl3:Pr3+将产生不同程度的畸变.  相似文献   

2.
金等离子体中Au51+能级寿命的相对论多组态计算   总被引:5,自引:1,他引:4  
根据扩展的相对论多组态 Dirac-Fock理论,采用"多功能相对论原子结构程序(Grasp2) ",选用二参数Fermi有限核模型计算类镍Au51+ 的能级寿命和能级宽度及光谱跃迁波长、跃迁几率和振子强度,计算所得波长值与实验值符合得很好,能级寿命与能级宽度的大小关系符合海森堡的能量与时间测不准原理.  相似文献   

3.
在室温和78K下对六种LaOBr1-xClx:Tb3+(x=0、0.2、0.4、0.6、0.8、1.0)粉末样品的4f75d1激发谱进行了研究,在78K下观察到了Tb3+离子的4f75d1激发态的能级分裂。利用点电荷模型计算得到了LaOBr1-xClx:Tb3+晶体中Tb3+的4f75d1激发态能级的分裂值。考虑到LaOBr1-xClx:Tb3+化合物的共价性等因素,三个因子α=0.32,β=0.67-1.08,γ=0.32-0.40相应地引入到Akm展开式中与O.X.La有关的各项中。计算得到的能级分裂值和实验值相差小于20cm-1。  相似文献   

4.
激光金等离子体中Au52+静态能级寿命的相对论多组态计算   总被引:3,自引:1,他引:2  
根据扩展的相对论多组态Dirac-Fock理论,采用"多功能相对论原子结构程序(GRASP2)",计算类钴Au52+的能级寿命、能级宽度和光谱跃迁波长,计算所得波长值与实验结果符合较好.能级寿命与能级宽度的大小关系符合海森堡的能量与时间测不准原理.  相似文献   

5.
任金生  张思远 《发光学报》1989,10(3):206-212
本文利用光谱方法测定了SmP5O14晶体中Sm3+离子的能级,通过拟合定出晶场参数,利用这些参数所计算的能级和实验能级符合得很好。  相似文献   

6.
介绍了一种基于从头计算的DV-Xα方法和有效哈密顿量模型,它可以计算晶体中掺杂离子的晶体场参数和旋轨耦合参数,尤其适合计算低对称性的晶体.对于低对称性的晶体,参数的数目比能级的数目多,因此通过实验能级拟合确定所有的参数不太准确,而从头计算法可以准确地确定所有的晶体场参数和旋轨耦合参数.首先用这种模型计算了Yb3+掺杂GdTaO4晶体中的晶体场参数和旋轨耦合参数,然后给出了Yb3+在GdTaO4中的能级结构,并分析了Yb3+:GdTaO4的发射谱形成一个连续的发射带.这有利于激光的调谐和锁模激光输出,预言了Yb3+:GdTaO4有望成为新型全固态超短脉冲激光工作物质.同样用这种模型分别计算了Yb3+掺杂YTaO4和ScTaO4中的晶体场参数和旋轨耦合参数,并给出了Yb3+在YTaO4和ScTaO4中的能级结构,得到了与Yb3+:GdTaO4晶体类似的结论.  相似文献   

7.
根据扩展的全相对论多组态Dirac-Fock理论,采用"多功能相对论原子结构程序GRASP2(General-Purpose Relativistic Atomic Structure Program 2,1992),考虑量子电动力学(QED)效应和Breit修正,结合惯性约束聚变(ICF)实验室等离子体中已经观察到的激光照射Au元素所产生的一些多重电荷态离子的外壳层共振线跃迁光谱,选取重要的电子组态,计算激光金等离子体中类镓Au48+离子的光谱跃迁波长、能级寿命和能级宽度.计算所得波长值与实验值符合较好,能级寿命与能级宽度的大小关系符合海森堡的能量与时间测不准原理.计算结果对金等离子体中的离子平均寿命、电荷态分布和平均电离度的研究具有一定的参考价值.  相似文献   

8.
张雷  殷春浩  黄志敏  焦杨 《光子学报》2007,36(10):1893-1898
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   

9.
YAlO3晶体中pr3+的4f2能级   总被引:1,自引:1,他引:0  
赖昌  王广川 《发光学报》2011,32(9):885-889
YAlO3∶pr3+是一种受到广泛关注的发光体系,本文根据文献中给出的YAlO3∶pr3+晶体中Pr3+的晶体场能级,从Nd3+离子的晶体场参数和Pr3+的准自由离子参数出发,采用f-shell计算软件包对pr3+的能级参数进行了研究,并对获得的参数进行了讨论.用拟合获得的参数计算了pr3+的4f2电子构型的所有能级.  相似文献   

10.
采用强场方案和三角基,通过对角化三角畸变立方场的d3电子组态完全能量矩阵,拟合得到BeAl2O4:Cr3+的能谱和波函数.利用获得的波函数,计算出了基态g因子和R1 、R2线能谱压致移位值,计算值和实验结果相符合.各参数对能级压力移位率的影响也被定量计算,揭示了R1和R2线压力移位的物理起源.  相似文献   

11.
The kaon nucleus (KN) interaction in dense nuclear matter is predicted to be repulsive and increasing with density. However, determined values for this potential are not yet consistent with each other (Benabderrahmane et al., Phys Rev Lett 102:182501, 2009; Agakishiev et?al., Phys Rev C 82:044907, 2010; Büscher et?al., Eur Phys J A 22:301–317, 2004). We analyze $K^0_S$ mesons identified with the HADES detector in p+p and p+?93Nb reactions at 3.5?GeV kinetic beam energy. To determine the KN potential at normal nuclear density we propose to compare the $K^0_S$ differential distributions in p+?93Nb and p+p collisions. High statistics of low p t -kaons (p t ?<?100?MeV/c) ensure the sensitivity of our measurements to the nuclear matter effects. We present the data analysis method and first results.  相似文献   

12.
An all-metal hollow-cathode laser tube consisting of a perforated cylindrical cathode surrounded by a coaxial cylindrical anode has been operated as a He?Ne laser at 0.6328, 1.15 and 3.39 μm, and as a He?Cd laser at red, green and blue visible wavelengths, using both de and pulsed-plus-dc excitation. Laser oscillation in He?Zn, Ne?Cd, Xe?Cd and Ar?Cd mixtures has also been obtained. The hollow-cathode discharge consists primarily of an intense cathode glow inside the cathode cylinder, giving a quiet, stable, low-voltage, positive-resistance discharge. Results for the He?Ne and He?Cd laser output versus partial and total pressures and discharge currents are presented. The unoptimized laser performance for the He?Ne case approaches but does not yet equal the conventional positive-column case, while the He?Cd performance for the charge-transfer-pumped green 5378Å line appears particularly promising.  相似文献   

13.
Gamma-ray energy correlations have been measured for several reactions leading to light-mass Hf isotopes with 160 ?A?166. The correlation spectra show ridge-valley structures up to high rotational frequencies from which a drop in J c (2) is deduced at high frequencies. This drop suggests that a large portion of the angular momentum is generated by aligning particles. It may also be explained by the theoretically predicted triaxial states with large deformation.  相似文献   

14.
15.
K+-Na+二次离子交换制作玻璃波导   总被引:4,自引:4,他引:0  
黄腾超  沈亦兵  侯西云  侯昌伦  白剑 《光子学报》2003,32(11):1325-1328
通过数值计算模拟了K+Na+二次扩散玻璃波导的折射率轮廓,阐述了利用K+Na+二次离子交换的方法,在BK7玻璃上制作波导的过程,分析了极化率不同的扩散离子对的选择对波导有效折射率变化的影响,以及扩散平衡时体积变化对表面折射率的影响,描述了扩散引起的波导内部诱导应力变化设计了测试波导损耗以及波导表面折射率改变的实验装置,对尺寸10mm×10mm×1.5mm和10mm×5mm×1.5mm两组BK7玻璃基片上的玻璃波导进行了测试,测试结果与理论吻合较好.  相似文献   

16.
The rate constant for the 3 body atom recombination N + H + M with M = Ar has been measured over the temperature range 550 to 750 K in an Ar ? N2 ? H2 microwave flowing discharge. A temperature dependence for the rate constant is reported.  相似文献   

17.
Nanoparticles of Y2O3:Dy3+ were prepared by the solution combustion method. The X-ray diffraction pattern of the 900°C annealed sample shows a cubic structure and the average crystallite size was found to be 31.49?nm. The field emission scanning electron microscopy image of the 900°C annealed sample shows well-separated spherical shape particles and the average particle size is found to be in a range 40?nm. Pellets of Y2O3:Dy3+ were irradiated with 100?MeV swift Si8+ ions for the fluence range of 3?×?1011_3?×?1013 ions cm?2. Pristine Y2O3:Dy3+ shows seven Raman modes with peaks at 129, 160, 330, 376, 434, 467 and 590?cm?1. The intensity of these modes decreases with an increase in ion fluence. A well-resolved thermoluminescence glow with peaks at ~414?K (Tm1) and ~614?K (Tm2) were observed in Si8+ ion-irradiated samples. It is found that glow peak intensity at 414?K increases with an increase in the dopant concentration up to 0.6?mol% and then decreases with an increase in dopant concentration. The high-temperature glow peak (614?K) intensity linearly increases with an increase in ion fluence. The broad TL glow curves were deconvoluted using the glow curve deconvoluted method and kinetic parameters were calculated using the general order kinetic equation.  相似文献   

18.
A series of nano-crystalline ceria-based solid solution electrolyte, Ce0.8La0.2?x MgxO2?δ (x?=?0.0, 0.05, 0.10, 0.15, and 0.2), were synthesized via the polyvinyl alcohol (PVA) assisted combustion method, and then characterized to the crystalline structure, powder morphology, sintering micro-structure, and electrical properties. Present study showed that Ce0.8La0.2?x Mg x O2?δ was exceedingly stable as a cubic phase in all temperature range and exhibited fine crystals ranging from 15 to 20 nm. After sintering at 1,400 °C, the as-prepared pellets exhibited a dense micro-structure with 96 % of theoretical density. The electrical conductivity was studied using AC impedance spectroscopy and it was observed that the composition Ce0.8La0.1?Mg0.1O2?δ showed higher electrical conductivity of 0.020 S?cm?1 at 700 °C. The thermal expansion was measured using dilatometer technique in the temperature range 30–1,000 °C. The average thermal expansion coefficient of Ce0.8La0.1?Mg0.1O2?δ was 12.37?×?10?6 K?1, which was higher than that of the commonly used SOFC electrolyte YSZ (~10.8?×?10?6 K?1).  相似文献   

19.
The derivation and solution of integrable nonlinear evolution partial differential equations in three spatial dimensions has been the holy grail in the field of integrability since the late 1970s. The celebrated Korteweg-de Vries and nonlinear Schr?dinger equations, as well as the Kadomtsev-Petviashvili (KP) and Davey-Stewartson (DS) equations, are prototypical examples of integrable evolution equations in one and two spatial dimensions, respectively. Do there exist integrable analogs of these equations in three spatial dimensions? In what follows, I present a positive answer to this question. In particular, I first present integrable generalizations of the KP and DS equations, which are formulated in four spatial dimensions and which have the novelty that they involve complex time. I then impose the requirement of real time, which implies a reduction to three spatial dimensions. I also present a method of solution.  相似文献   

20.
A study of the leptonic coupling types in K+π+?+?? (? = e, μ) provides come model-independent distinction between the various underlying mechanism: lowest order weak cum electromagnetic vs higher order weak interactions vs genuine strangeness-changing semileptonic neutral currents. This distinction is necessary in order to know the existence of these neutral currents. Pion energy spectrum for ? = e and the ratio of the total rate for ? = e to that for ? = μ is useful for this purpose, and the pion energy spectrum for ? = μ is of further help. Available data (? = eonly) are inadequate to provide the above distinction. Estimates of various coupling strengths are made from the observed ? = e rate.  相似文献   

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