Ca8Mg(SiO4)4Cl2中Ce3+和Eu2+的光谱性质和能量传递

首次合成了Ｃｅ＾３＋和Ｅｕ＾２＋共激活氯硅酸镁钙Ｃａ８Ｍｇ（ＳｉＯ４）４Ｃｌ２：Ｃｅ＾３＋，Ｅｕ＾２＋高效绿色荧光粉，报道了它们的漫反射光谱、激发和发射光，观察到氯硅酸镁钙中Ｃｅ＾３＋ Ｅｕ＾２＋     

UCFC晶体场理论方法（I）——UCFC方法基本概念与d^4组态空间标准基

作为以ｄ４／ｄ６离子为例系统地介绍“ＵＣＦＣ（统一晶场偶合）图象晶体场理论方法”（简称ＵＣＦＣ方法）的系列论文的第一篇，首先介绍了ＵＣＦＣ方法的基本概念，然后介绍了ｄ４／ｄ６离子ＵＣＦＣ方法基本内容的第一部分：ｄ４离子全组态空间标准基链的构造方法。第二篇将介绍如何在标准基链中建造能量矩阵链。第三篇将介绍ｄ４／ｄ６离子ＵＣＦＣ方法的ＥＰＲ理论部分。ＵＣＦＣ方法不仅是一种考虑ｄ电子组态全部多重态的完全计算方法，而且是一种统一的、规范化的、简洁的理论方法体系。它克服了强场、弱场等传统逐次对角化方法的局限性，不须区分晶体场的强弱，因而原则上可通用于任意过渡金属络合物。     

Energies and widths of triply excited states of lithiumlike oxygen and neon

Seven low-lying triply exited states of lithium-like oxygen and neon are calculated with the multichannel saddle-point and saddle-point complex-rotation methods. The term energies are given for these excited states, along with level shifts and partial Auger widths from dominant decay channels. The mass polarization effect and relativistic corrections are included. The radiative transition rates are also calculated. These results are compared with other theoretical data in the literature. Received: 25 May 1998 / Revised: 28 July 1998 / Accepted: 25 August 1998     

类锂等电子系列(1s2p2p)~4 P~e和(1s2s2p)~4 P~0态的能量和精细结构研究

利用改进的马鞍点方法,截断变分方法,并考虑能量的相对论修正和质量极化效应,计算和研究了类理等电子系列的两个四重态（１ｓ２ｐ２ｐ）４Ｐ０和（１ｓ２ｓ２ｐ）４Ｐｅ态的精细结构和平均跃迁波长,并与实验和其它理论计算结果进行了比较。     

Multiple ionization of argon in coincidence with projectile ions in 60–120 MeV Si q+-Ar collisions

A projectile ion-recoil ion coincidence technique has been employed to study the multiple ionization and the charge transfer processes in collisions of 60–120 MeV Si ^q+ (q = 4−14) ions with neutral argon atoms. The relative contribution of different ionization channels, namely; direct ionization, electron capture and electron loss leading to the production of slow moving multiply charged argon recoil ions have been investigated. The data reported on the present collision system result from a direct measurement in the considered impact energy for the first time. The total ionization cross-sections for the recoil ions are shown to scale as q ^1.7/E _p ^0.5 , where E _p is the energy in MeV of the projectile and q its charge state. The recoil fractions for the cases of total- and direct ionizations are found to decrease with increasing recoil charge state j. The total ionization fractions of the recoils are seen to depend on q and to show the presence of a ‘shell-effect’ of the target. Further, the fractions are found to vary as 1/j ² upto j = 8+. The average recoil charge state 〈j〉 increases slowly with q and with the number of lost or captured electrons from or into the projectile respectively. The projectile charge changing cross-sections σ _qq′ are found to decrease with increasing q for loss ionization and to increase with q for direct-and capture ionization processes respectively. The physics behind various scaling rules that are found to follow our data for different ionization processes is reviewed and discussed.     

氢化物发生辅助溶液阴极辉光放电光谱技术检测水体中痕量汞和锡

溶液阴极辉光放电技术作为一种新型的光谱检测技术,被广泛应用于环境污染物的分析和检测等方面.虽然该技术具有结构简单以及成本低等优势,但是在重金属检测方面,其灵敏度还有待提高.针对上述问题,搭建了氢化物发生-溶液阴极辉光放电光谱测量系统,实现了对水体中痕量汞(Hg)和锡(Sn)的简单高效检测.为了得到更优的检测效果,实验选...     

New designed helical resonator to improve measurement accuracy of magic radio frequency

Based upon the new designed helical resonator, the resonant radio frequency (RF) for trapping ions can be consecutively adjusted in a large range (about 12 MHz to 29 MHz) with high Q-factors (above 300). We analyze the helical resonator with a lumped element circuit model and find that the theoretical results fit well with the experimental data. With our resonator system, the resonant frequency near magic RF frequency (where the scalar Stark shift and the second-order Doppler shift due to excess micromotion cancel each other) can be continuously changed at kHz level. For ⁸⁸Sr⁺ ion, compared to earlier results, the measurement accuracy of magic RF frequency can be improved by an order of magnitude upon rough calculation, and therefore the net micromotion frequency shifts can be further reduced. Also, the differential static scalar polarizability Δα₀ of clock transition can be experimentally measured more accurately.     

类锂硅离子能级结构及软X射线激光光谱理论计算

本文采用Hartree-Fock自洽场方法,从理论上计算出类锂硅离子1s~2nl(n=2～7,l=0～5)各能级能量,并给出在极紫外(波长小于400(?))范围内各跃迁谱线的光谱性质、波长、振子强度和跃迁几率.对实验中已实现软X射线激光的跃迁(5d-3p,5f-3d,6d-3p,6f-3d),计算所得的跃迁波长与实验值完全相符.与现有文献的波长比较,相对误差不超过1%.     

Effect of Li2O content on physical and structural properties of vanadyl doped alkali zinc borate glasses

The effect of Li₂O content in vanadyl doped 20ZnO+xLi₂O+(30−x)Na₂O+50B₂O₃ (5≤x≥25) glasses has been studied with respect to their physical and structural properties. The absence of sharp peaks in XRD spectra of these glass samples confirms the amorphous nature. The physical parameters like density, refractive index, ionic concentration and electronic polarizability vary non-linearly with x mol% depending on the diffusivities of alkali ions. EPR and optical absorption spectra reveal that the resonance signals are characteristics of VO²⁺ ions in tetragonally compressed octahedral site. Spin-Hamiltonian, crystal field, tetragonal field and bonding parameters are found to be in good agreement with the other reported glass systems. The tetragonal distortion (g_⊥-g_∥) and Dt reveals that their values vary non-linearly with Li₂O content and reaches a minimum at x=10 mol%. An anomaly of character has been observed in all the properties of vanadyl doped glass systems, which gives a clear indication of mixed alkali effect.