TcⅩⅢ离子能级和振子强度的理论计算

利用组态相互作用理论和参数外推方法,计算了类镓等电子系列TcⅩⅢ离子4s~24p—4s4p~2、4s~24p—4s~24d和4s4p~2—4p~3跃迁的能级、谱线波长和电偶极振子强度     

KrVI离子能级和振子强度的理论计算

利用组态相互作用理论和参数外推法,计算了KrVI离子4s~24p—4s4p~2、4s~24p—4s~24d和4s4p~2—4p~3跃迁的能级、谱线波长和振子强度。与已有实验结果比较表明:波长的理论计算值与观测值在0.7A内很好符合,振子强度的理论计算值较大的跃迁均是实验中观测到的跃迁。     

TcⅪ离子的4s~24p~3—4s4p~4跃迁

通过对KrⅣ—MoⅩ离子4s4p~4组态能级结构的组态相互作用理论分析,找出了其沿等电子系列变化的规律性。在此基础上预言了TcⅪ离子的4s4p~4组态能级。结合前人对4s~24p~3组态的研究结果,进一步计算了4s~24p~3—4s4p~4跃迁的谱线波长和振子强度。     

类氮VXVII CrXVIII MnXIX和FeXX精细结构能级和跃迁波长的相对论多组态Dirac-Fock计算

本文用相对论多组态Dirae—Fock广义平均模型(MCDF-EAL)计算了可能成为激光工作物质的类氮VXVII、CrXVIII、MnXIX和FeXX的2s~22p~3、2s2p~4、2p~5、2s~22p~23s、2~2s2p~23p组态的各44个精细结构能级和33个3s—3p组态跃迁波长。其中关于VXVII、CrXVIII、MnXIX离子3s、3P组态的计算值是本文首次预言的。     

类氖RbⅩⅩⅧ,Sr ⅩⅩⅣ和YⅩⅩⅩ2p~53l-2p~54l~1跃迁波长和能级的相对论多组态Dirac—Fock计算

本文用MCDF-EAL计算模式,计算了可能成为超真空紫外区的类氖等离子体激光工作物质的Rb XXVIII、Sr XXIX和YXXX类氖离子的1s~22s~22p~53l与1s~22s~22p~54l组态的精细结构能级的能量,首次预言了3l—4l’各精细结构能级间可能的跃迁波长值.     

CoⅩⅧ离子2s~22p~53l2s2p~63l、2s~22p~54l组态的能级及跃迁波长计算

本文用相对论多组态Dirac-Fock广义平均能级(MCDF-EAL)模型,计算了可能形成超真空紫外区相干辐射的类氖等离子体激光工作物质的CoXVⅢ离子2s~22p~53l、2s2p~63l、2s~22p~54l组态精细结构能级的能量值,以及3l、4l-2p~6(~1S_0)、3l-3l＇、3l-4l＇、4l-4l＇多重态之间的跃迁波长值。3l、4l-2p~6(~1S_0)跃迁波长计算值与已知观测值符合相当好。     

类氮SⅩ、PⅨ精细结构能级和跃迁波长的相对论多组态Dirac-Fock计算

本文用相对论多组态Dirac-Fock广义平均模型(MCDF-EAL)计算了可能成为激光工作物质的类氮SX、PⅨ的2s~22p~3、2s2p~4、2p~5、2s~2p~23s、2s~22p~23p组态的各44条精细结构能级和32条3s-3p组态跃迁波长。其中关于SⅩ的3s、3p组态的能级和PⅨ的3p组态能级的计算值是本文首次预言的。     

41≤z≤48类氟离子精细结构能级和跃迁波长的相对论多组态狄拉克-福克的计算

本文用相对论多组态狄拉克-福克(Draic-Fock)广义平均能级(MCDF-EAL)模型计算可能成为激光工作物质的类氟NbXXXIII、MoXXXIV、TcXXXV、RuXXXVI、RhXXXVII、PdXXXVIII、AgXXXIX和CdXXXX的2s~22p~5、2s2p~6、2s~22p~43s、2s~22p~43p组态的各30个精细结构能级和若干3s—3p组态跃迁波长。除最低两级外的所有计算值都是本文首次作出的理论预言。     

铜到钼的类钠离子能级结构及软X射线光谱理论计算

本文采用Hartree-Fock自洽场方法,从理论上计算了铜到钼的类钠离子1s~22s~22p~6nl(n=3～6,l=O～5)各能级能量。给出了有可能实现软X射线激光的跃迁(5g—4f,5f—4d,6g—4f,6f—4d)的光谱性质:跃迁波长、振子强度,并和实验值进行了比较,跃迁波长的相对误差不超过千分之二。从计算结果可知,Se的6f—4d跃迁,Br的6g—4f跃迁,Zr的5f—4l跃迁,Nb的5g—4f跃迁都已进入水窗波段。     

类N等电子数序CoⅩⅩⅠ—CuⅩⅩⅢ的2P~3—2P~23d及2S~22P~3—2S2P~4跃迁的波长及相对强度计算

本文利用原子结构的半经验计算程序ZEALOTS,详细分析了类N等电子数序离子CoXXⅠ——CuXXⅢ的2p~3—2p~23d及2s~2 2p~3—2s2p~4的跃迁光谱,并与实验观察值进行了比较。指出了文献中关于这些谱线归类出现的差错。     

Predictions of γ(4S)→h_b(1P,2P)π^+π^- transitions

We study the contributions of intermediate bottomonium-like Zb states and the bottom meson loops in the heavy quark spin flip transitionsγ(4 S)→hb(1 P,2 P)π+π-.Depending on the constructive or destructive interferences between the Zb-exchange and the bottom meson loops mechanisms,we predict two possible branching ratios for each process:BRγ(4 S)→hb(1 P)π+π-≈(1.20.40.8×10^-6)or(0.5-0.20.5×10^-6),and BRγ(4 S)→(2 P)π+π-≈(7.1-1.1+1.7×10^-10)or(2.4-0.10.2×10^-10)).The contribution of the bottom meson loops is found to be considerably larger than that of the Zbexchange in the T(4 S)→hb(1 P)ππtransitions,while its decay rates are not comparable to those of heavy quark spin conservedγ(4 S)→γ(1 S,2 S)ππprocesses.We also predict the contribution of the charm meson loops in the branch fractions ofΨ(3 S,4 S)→hc(1 P)ππ.     

Calculation of the Isotope Shifts on 5S1/2 → 4D3/2,5/2 Transitions of 87,88Sr+

A simple method is applied to calculating the isotope shifts (ISs) on 5S1/2 → 4D3/2,5/2 transitions of 87,88Sr+. First we have calculated the ISs of lower transitions on a series of alkali-like systems such as B2+, Ca+ and Ba+, which are in agreement with other works. Then the ISs on 5S1/2 → 4D3/2,5/2 transitions of 87,88Sr+, which are useful to study the Sr+ optical frequency standard, are evaluated.     

Ca4LaNbMo4O20:Pr3+荧光粉的发光性质

采用高温固相法成功制备出荧光粉Ca₄LaNbMo₄O₂₀:Pr³⁺,通过X射线衍射分析了样品的结构,其结构与CaMoO₄结构相似。在Ca₄LaNbMo₄O₂₀:Pr³⁺的激发光谱中出现了NbO₄^3-和MoO₄^2-的电荷迁移(CTS)吸收和Pr³⁺离子的4f→4f5d激发跃迁,以及Pr³⁺-金属离子的价间电荷迁移(IVCT)吸收;另外在420~520 nm处,还观测到属于Pr³⁺离子的典型f-f激发跃迁。发射光谱中,在452 nm激发下,主要出现绿光和红光两种发射,其峰值位于490 nm和607 nm处,分别是Pr³⁺的³P₀→³H₄和¹D₂→³H₄的跃迁作用;在紫外287 nm激发下出现NbO₄^3-和MoO₄^2-发射和Pr³⁺离子的4f5d→4f跃迁宽带,以及Pr³⁺离子的4f→4f发射峰。     

Examining coupled-channel effects in radiative charmonium transitions

Coupled-channel effects due to coupling of charmonia to the charmed and anticharmed mesons are of current interest in heavy quarkonium physics. However, the effects have not been unambiguously established. In this Letter, a clean method is proposed in order to examine the coupled-channel effects in charmonium transitions. We show that the hindered M1 radiative transitions from the 2P to 1P charmonia are suitable for this purpose. We suggest to measure one or more of the ratios Γ(h(c)'→χ(cJ)γ)/Γ(χ(cJ)'→χ(cJ)π(0)) and Γ(χ(cJ)'→h(c)γ)/Γ(χ(cJ)'→χ(cJ)π(0)), for which highly nontrivial and parameter-free predictions are given. The picture can also be tested using both unquenched and quenched lattice calculations.     

Optical transitions of Eu2+ IONS in RbMgF3 crystals

Because of the need for tunable solid state lasers in the blue region of the spectrum, a number of recent studies have been on the optical properties of Eu²⁺ in various crystals lattices. The absorption and emission from Eu²⁺ ions in fluoride hosts arise from both 5d→4f and 4f→4f transitions. The absorption is in the ultra-violet and the emission is in the blue. The 4f-4f transitions are very sharp and are located around 360 nm. The 5d→4f emission bands at 405 nm and 525 nm are broad and host lattice dependent. We have studied the temperature dependence of the optical properties of RbMgF₃:Eu²⁺ including absorption, emission, and excitation. In the case of the emission studies both temperature dependence and the lifetimes of the transitions have been measured. These transitions are discussed in detail.     

A muonic X-ray study of the charge distribution of 144, 148, 150, 152, 154Sm

We report the measurement of the energies of the 4f → 3d, 3d → 2p and 2p → Is muonic atomic transitions in separated isotopes of ^{144, 148, 150, 152, 154}Sm, and that of the 2s → 2p transitions of ¹⁵²Sm as well. Using these transition energies as well as the hyperfine splittings of the 2p levels, we have interpreted our data in terms of a deformed Fermi distribution for the charge density and obtained good fits. A model independent analysis of the isotope shifts in terms of generalized R_h moments has been made and is in good agreement with electronic X-ray and optical isotope shifts. The static quadrupole moments and the isomer shifts of the first excited state of ^{152, 154}Sm have been determined from the 2p hyperfine structure.     

掺铥钨酸盐晶体的光谱研究

采用丘克拉斯基法生长出Tm3+:BaWO4单晶,并在室温下测量了掺铥钨酸钡晶体的吸收光谱。Tm3+:BaWO4晶体在268nm和362nm光源激发下,可以分别观测到位于477.2 nm(1G4→3H6)和455.5nm(1D2→3F4)的可见荧光。本文还报道了在Nd:YAG激光器产生波长1.06μm强脉冲激光激发ZnWO4:Tm3+单晶时,测得Tm3+离子1G4至3H6跃迁的波长在484 nm范围的蓝色上转换荧光光谱。     

SrAl12O19∶Pr3+中的热激发

研究了SrAl12O19∶Pr3+的光谱中3P1 和1I6的发射. 用3P1→3H5与3P0→3H5发射强度之比测量了温度，通过1I6→1G4与3P0→1G4发射强度之比，讨论了热激发对3P0可见光发射效率的影响. 关键词： 热激发 温度测量 三价镨离子     

Further insights into the “ρπ puzzle”

Based on a systematic investigation of J/ψ(ψ) → VP,where V and P stand for light vector and pseudoscalar mesons,we identify the role played by the electromagnetic(EM) transitions and intermediate meson loop transitions,which are essential ingredients for understanding the J/ψ and ψ couplings to VP.We show that on the one hand,the EM transitions have relatively larger interferences in ψ→ρπ and K*K+c.c.as explicitly shown by vector meson dominance(VMD).On the other hand,the strong decay of ψ receives relatively larger destructive interferences from the intermediate meson loop transitions.By identifying these mechanisms in an overall study of J/ψ(ψ)→VP,we provide a coherent understanding of the so-called "ρπ puzzle".     

氟氧化物玻璃陶瓷中铒激活中心的双光子三光子与四光子近红外量子剪裁发光

研究了掺铒的氟氧化物玻璃陶瓷的双光子、三光子与四光子近红外量子剪裁发光.我们测量了掺铒的氟氧化物玻璃陶瓷的X 射线衍射谱、吸收谱、从可见到近红外的发光光谱与激发光谱.当Er3+浓度从0.5％增加到2.0％,发现铒离子的4I15/2→2G7/2,4I15/2→4G9/2,4I15/2→4G11/2,4I15/2→2H9/2,4I15/2→(4F3/2,4F5/2),4I15/2→4F7/2,4I15/2→2H11/2,4I15/2→4S3/2,4I15/2→4F9/2,与4I15/2→4I9/2红外激发谱峰的强度增加了大约5.64,4.26,2.77,7.31,6.76,4.75,2.40,11.14,2.88,和4.61倍,同时,铒离子的4I15/2→2G7/2,4I15/2→4G9/2,4I15/2→4G11/2,4I15/2→2H9/2,4I15/2→(4F3/2,4F5/2),与4I15/2→4F7/2的可见激发谱峰的强度减小了1.36,1.93,3.43,1.01,2.24和2.28倍.也就是说我们发现红外发光与激发的强度都增强了2～11倍,与此相伴的可见的发光与激发强度都减小了一到三倍.而且,1 543.0与550.0 nm发光的激发谱不仅在峰值波长而且也在波峰形状上非常相近.上述实验结果证实了所看到的现象为多光子近红外量子剪裁发光现象.为了更好的分析量子剪裁的过程与机理,还测量了主要的可见与红外发光强度随激发强度的改变;发现所有可见和红外发光强度都基本上是随激发强度成线性变化关系;其中,可见的发光强度随激发强度的改变呈略大于线形一次幂的变化关系,它是由于小的激发态吸收造成的;而1 543.0 nm红外发光强度随激发强度的变化呈略小于线形一次幂的变化关系,它即是量子剪裁发光的特征现象.还发现4I9/2能级的双光子量子剪裁主要由{4I9/2→4I13/2,4I15/2→4I13/2} ETr31-ETa01交叉能量传递所导致;4S3/2能级的三光子量子剪裁主要由{4S3/2→4I9/2,4I15/2→4I13/2} ETr53-ETa01和{4I9/2→4I13/2,4I15/2→4I13/2} ETr31-ETa01交叉能量传递所导致;2H9/2能级的四光子量子剪裁主要由{2H9/2→4I13/2,4I15/2→4S3/2} ETr91-ETa05,{4S3/2→4I9/2,4I15/2→4I13/2} ETr53-ETa01和{4I9/2→4I13/2,4I15/2→4I13/2} ETr31-ETa01交叉能量传递所导致.上述研究结果对目前的全球热点新一代量子剪裁太阳能电池很有价值.