Resin Ion Exchange and Liquid-Liquid Extraction of Indium and Thallium from Chloride Media

Separation procedures of indium and thallium for both future investigation of superheavy element 113 and fundamental research of its light homologues have been developed. Two chemical methods, namely ion exchange and solvent extraction, have been applied. Cation exchange behavior in hydrochloric acid media and the reversibility of the In and Tl elution order due to oxidation state of the latter are described. Extraction of Tl(I), Tl(III), and In(III) from aqueous HCl solutions with and without tri-n-butyl phosphate into the ionic liquid 1-butyl-3-methyl imidazolium bis(trifluoromethanesulfonyl)imide has been investigated. The extraction efficiencies of Tl(I) and In(III) have been found to be much lower than those of Tl(III) both with and without an organic ligand. The extraction mechanism is suggested. Suggestions for both liquid and gas phase experiments aimed at element 113 studies have been considered based on the results observed.     

降低NaI（Tl）γ谱仪探测限的技术探讨

核爆后其放射性元素种类复杂、量少,用NaI（Tl）γ谱仪监测时,多种核素峰重叠在能谱的散射区内难以识别,因此对谱仪的稳定性,能量分辨率,解谱技术以及最小可探测活度有很高的要求.本文通过实验和MCNP模拟,分析了对某NaI（Tl）γ谱仪探测限的影响因素以及降低探测限的措施,提出了通过屏蔽来降低本底,提高其最小可探测活度的方法,实验表明,通过选择合理的屏蔽尺寸,有效的降低了本底,提高了谱仪的低水平放射性监测能力.     

电感耦合等离子体质谱法测定铅锌矿中镓铟锗铊

稀散元素是铅锌矿石中重要的伴生元素,为了综合利用铅锌矿资源,在地质、选矿上经常要考查稀散元素镓、锗、铟、铊的含量。研究了利用电感耦合等离子体质谱法测定铅锌矿中镓、铟、锗、铊4种稀散元素,选取了最佳仪器分析条件,通过在线加入内标校正基体效应和接口效应,检出限分别为0.02μg·g-1、0.01μg·g-1、0.03μg·g-1和0.05μg·g-1,相对标准偏差(RSD)为0.85%~2.84%,回收率在93.3%~102.3%之间,明显优于其他分析方法。该方法样品前处理简便、快捷,测定结果准确,令人满意。     

PPC和PFS联用去除水源水中Tl和Sb复合污染

为了去除地表水源水加标模拟的重金属铊(Tl)和锑(Sb)复合污染,采用了高锰酸盐复合药剂(PPC)和聚合硫酸铁(PFS)联用强化常规工艺;通过静态烧杯实验和微型移动式平台优化工艺参数,对去除铊和锑复合污染的影响因素(PPC投量、PFS投量和pH)进行分析.实验结果表明,组合工艺可保证水源水在Tl超标2～3倍(0.21 ～0.35 μg·L-1),Sb超标3～4倍(15 ～20 μμg·L-1)的场合出水达标,对应的工艺参数是:pH控制在5.7 ～6.3,PPC投量控制在3mg·L-1以上,聚铁投量控制在40 mg·L-1以上.PPC和PFS联用强化常规工艺可有效去除地表水源水加标模拟的铊(Tl)和锑(Sb)复合污染,并且PPC投量是影响Tl去除的主要因素,PFS投量和pH是影响Sb去除的主要因素.     

高温气冷堆球流检测系统中CsI(Tl)探测器温度影响研究

为保证球床式高温气冷堆（PB-HTGR）球流检测系统投影数据获取过程中输出信号的稳定性,需对探测模块输出暗电流的稳定性进行分析。本文随机选取了2组CsI(Tl)探测器模块作为研究对象,并专门设计了温度及暗电流的控制和测量装置,分析了模块暗电流的输出特性及其控制要求。实验结果表明：各探测单元输出暗电流随温度的变化呈近似指数变化,且室温下温度波动±2 ℃时第32路单元的暗电流波动达8 pA。因此需对探测系统进行温度控制,同时分析实验数据并结合暗电流稳定性的控制要求,提出检测系统的最佳温控范围为（18~22） ℃,对应的温控精度为（±0.92~±0.21） ℃。     

Methods to Produce Tl(1223) Tapes with Improved Properties

Different methods to prepare superconducting mono- and multifilamentary T1(I223) tapes were developed. High-purity ceramics could be produced by ex-situ or in-situ reaction under a high isostatic gas pressure. Tapes prepared by the PIT method and an in-situ reaction carried out close to the melting point of the oxide were relatively dense and textured. Interesting results were obtained for samples where part of the oxygen atoms in Tl(1223) had been substituted by fluorine. Critical current densities up to 20'000 A/cm² (77 K, 0 T) were reached for tapes produced by the PIT method. Well textured samples were obtained by electrophoretic deposition, the deposited Tl(1223) grains being produced by a synthesis involving substantial melting.     

γ射线闪烁体探测器响应函数模型研究

建立了一种可用于γ射线能谱分析的CsI(Tl)闪烁体探测器响应函数(DRF)模型,并对0.05~1.5 MeVγ射线能谱进行了拟合。描述γ射线能谱特征的每个函数均是基于对射线作用机制的分析,采用权重最小二乘法实现了22 Na、60 Co、137 Cs、238Pu实验能谱的拟合,并同时得到了函数中与射线能量相关的非线性参数。最后利用该DRF模型对CsI(Tl)探测器测量152 Eu源的γ射线能谱进行了拟合,结果表明,此DRF模型可较好地应用于γ射线能谱的分析。     

半定量法201Tl双时相显像鉴别诊断甲状腺冷结节

为探讨甲状腺冷结节2 0 1Tl双时相显像的实用价值 ,取甲状腺单个冷结节患者 87例 ,静脉注射2 0 1Tl 12 1MBq后 15min显像及 12 0min延迟显像。按半定量法分别进行感兴趣区计数 ,计算结节组织与正常组织摄取比 (15min记为ER ,延迟记为DR)及滞留指数 [RI =(DR -ER) /ER×10 0 %]。结果表明 ,ER、DR和RI的恶性与非恶性组之间差异显著 (P <0 .0 5 )。囊性腺瘤者ER、DR和RI均明显低于恶性者 (P <0 .0 1) ;炎症者与恶性者比较差异不显著 (P >0 .0 5 )。半定量法的灵敏度、特异性和诊断正确率明显优于目视法 ,ER分别与DR、RI之间比较有显著性差异 (P <0 .0 5 )。显像结果提示 ,半定量法2 0 1Tl诊断显像可明显提高甲状腺单个冷结节的良、恶性质的诊断效率 ,具有临床应用价值。     

Preparation of High - Purity Tl(1223) Ceramics

The influence of changes in the nominal composition and preparation conditions on the formation of Tl(1223) under a high isostatic gas pressure was studied. Optimization of the cation substitution allowed to increase the phase purity, whereas substitution of small amounts of oxygen by fluorine decreased the formation temperature of the Tl(1223) phase and extended the temperature range favorable for grain growth. A two-step reaction involving substantial melting produced well shaped, plate-like grains.