氢化物原子吸收与常规雾化火焰原子吸收法测定锑的几个问题

本文就氢化物原子吸收法与常规雾化火焰原子吸收法用于锑含量的测定中所存在的共存元素的干扰,"记忆效应"及锑的价态变化等几个方面的问题进行了试验考察和分析,对两种方法的灵敏度、精密度及测定线性范围进行了比较,结果表明:氢化物原子吸收法的最大优点是灵敏度高(可达pp～b级)能满足含有微量锑试样的分析要求。雾化火焰原子吸收法测定锑,由于不存在"记忆"效应,样品之间的更换瞬间即可完成,因而适宜大量样品的检测分析。     

氢化物原子荧光法同时测定痕量砷和锑

采用氢化物原子荧光法,研究了用L－半胱氨酸预还原法同时测定痕量砷、锑的方法和条件。砷的检出限为0．05μg/L,锑的检出限为0．09μg/L.     

铅锑合金的预处理及锑、硒的ICP-AES法测定

用“锯末法”从铅锑合金锭中取样,并用硝酸和酒石酸的混合溶液溶解样品,再经过适当的处理后,用ICP-AES法测定样品溶液中锑和硒的含量。结果表明,锑的加标回收率为96.2%;硒的加标回收率为92.1%,11次测定的RSD(n=11)小于3.56%。方法操作方便,分析速度快,结果准确。方法已用于铅锑合金产品中锑、硒的测定,取得满意的结果。     

ICP-AES法测定三氧化二锑中杂质

本文采用盐酸－氢溴酸溶解样品并除锑后,用ICP-AES法同时测定三氧化二锑中Bi、Be、Ag、W等23种杂质元素,各杂质元素回收率在90％－110％之间。并对样品的溶解方法,主量与杂质元素间的光谱干扰等进行了研究,建立的分析方法,能准确、快速地了解高纯三氧化二锑的品质。     

氢化物-原子吸收光谱法测定地球化学样品中的砷、锑、铋

氢化物-原子吸收光谱法是测定砷、锑、铋等元素的一种快速、灵敏、准确的方法,国内外已有不少报导。但是对共存元素的干扰研究较少,难于直接用于组成复杂的地质样品分析。为了适应大批地球化学样品中砷、锑、铋的分析,本文较详细地研究了用氢化物-原子吸收光谱法在同一份溶液中连续测定砷、锑、铋的仪器工作条件、氢化物发生条件及共存元素的干扰。选出了对砷、锑、铋均为有效的还原抑制剂。在选定的条     

等温平台石墨炉原子吸收光谱法测定高纯铟中痕量杂质镉和锑

石墨炉原子吸收法在等温平台条件下 ,利用标准加入法直接测定了高纯铟中的痕量杂质镉和锑。对石墨炉加热程序中的干燥时间、灰化温度及原子化温度进行了优化 ,考察了介质酸度的影响。在测定锑时 ,加入了基体改进剂钯。镉和锑的特征质量分别为 3.2 pg和 77.1 pg,相对标准偏差平均值分别为 1 .9%和 3.1 % ,加标回收率分别为 86 %— 92 %和 81 %— 91 %。     

ICP-AES法直接测定钢中微量砷、锡、锑

采用ICP-AES法直接测定钢中微量砷、锑、锡的含量。优选了试样溶解方式，最佳分析谱线及仪器工作参数，检出限为砷0.0004%、锑0.0005%、锡0.0003%，方法准确、简便。     

氢化物发生-原子荧光光谱法测定铜精矿中的砷、锑和铋

建立了氢化物发生-原子荧光光谱法同时测定铜精矿中砷、锑、铋的方法,采用了主量元素匹配法来消除基体干扰,优化了反应体系的酸度、还原剂浓度等条件进行了优化。砷、锑、铋的浓度在1—200μg·L~(-1)范围内与荧光强度呈线性关系。方法回收率为92%—101%,相对标准偏差为2.7%—5.5%。     

金基合金中杂质成分的石墨炉原子吸收测定

金基合金中杂质元素的含量要求:铁<0.2％,铅<0.005％,锑<0.005％,铋<0.005％。本方法分析上述四元素,选用盐酸、硝酸溶解试样,加入硫酸冒烟后,以水合联氨将金还原沉淀,用清液进行铁、铅、锑和铋的石墨炉原子吸收测定。本文就常见牌号金基合金中共存元素对测定铁、铅、锑和铋的影响合成了样品。对回收率、方法精度以及试样分析进行了实验,拟定了测定金基合金中铁、铅、锑和铋的条件,制定了分析方法。实践证明,石墨炉原子吸收是测定金基合命中杂质元素铁、铅、锑和铋的行之有效的方法。     

氢化物—石墨炉原位富集原子吸收光谱法测定痕量锑

本文对标示问题进行了研究，自行设计了氢化物发生器，采用以石墨炉两端输入氢化物方式，载气流向用活塞控制，大幅度减少原子化阶段石墨炉内氢气分压，提高了锑的灵敏度，对氢化锑的石墨炉表面分解沉积和原子化机理进行了讨论，方法有于矿泉水和自来水痕量锑的测定，结果令人满意，锑的特征浓度为３０ｐｇ／０．００４４Ａ。     

锑的形态分析概述

对近年来锑的形态分析方法进行了综述。按不同的锑化合物分类,重点阐述了各种联用技术在锑化合物形态分析中的应用,并对锑的形态分析方法前景作了展望。     

Determination of phosphorus contamination during antimony implantation by measurement and simulation

Experimental determination of phosphorus cross-contamination during antimony implantation is presented. As a suitable structure for this experiment, a buried layer was employed which is created by implanting antimony followed by a long diffusion process. The samples implanted in different implanters were analysed by secondary ion mass spectrometry (SIMS), four-point probe and spreading resistance methods. The obtained results were compared with those calculated by program SUPREM-IV. Methods that can and cannot be used to determine phosphorus contamination during antimony implantation and to estimate the fluence of phosphorus being co-implanted with antimony are described in detail.     

Structure and reactivity of bimetallic electrochemical interfaces: infrared spectroscopic studies of carbon monoxide adsorption and formic acid electrooxidation on antimony-modified Pt(100) and Pt(111)

The influence of predosed antimony on the adlayer structures of carbon monoxide and on the electro-oxidation kinetics of formic acid on Pt(100) and Pt(111) in 0.1M HClO₄ is examined by means of in-situ infrared spectroscopy in conjunction with cyclic voltammetry. Preadsorbed antimony inhibits the adsorption of CO on these surfaces, the attenuation in CO coverage being accompanied by a selective removal of the two-fold bridging geometry as deduced from the relative ν_CO band intensities. At saturation antimony coverages, the CO binding is exclusively terminal on Pt(100) and Pt(111). These findings are consistent with the adsorption of antimony at multi-fold sites, yielding microscopically intermixed adlayers with CO. The electro-oxidation rates of formic acid are enhanced substantially by preadsorbed antimony on Pt(100) and Pt(111). The real-time infrared spectra in the C-O stretching region and the CO coverages thereby deduced in the presence of predosed antimony under reactive voltammetric conditions suggest that the metal adatoms are actively involved in the dissociation of formic acid. The origins of the enhanced electrocatalytic activity of the bimetallic Sb/Pt surfaces are discussed in terms of geometric and chemical effects.     

Non-empirical valence-electron molecular orbital calculations: spin-orbit splitting in the ion states of the tin and antimony halides

The non-empirical valence-electron (NEVE) molecular orbital method can accommodate molecules containing p-block atoms up to the fourth row in a minimum STO basis calculation. Unlike many MO methods in current use, the NEVE method allows comparisons down the Periodic Table. The present study illustrates this for the tin tetrahalides and antimony trihalides. The calculated orbital eigenvalues correlate well with the photoelectron spectra of these compounds, and by using a semi-empirical spin-orbit hamiltonian theoretical spin-orbit splitting patterns are obtained. The calculated splittings are generally smaller for the antimony trihalides, and a revised assignment of the photoelectron spectrum of antimony tri iodide is suggested.     

火焰原子吸收法连续测定氧化锑中铅、铜、铁含量

确立了火焰原子吸收测定氧化锑中铅、铜、铁含量的方法,探讨了样品的前处理、酸度、及共存元素的干扰情况,确定了各元素测定的最佳条件,回收率在95.4％-112.1％之间,精密度RSD%不大于5.9％,该方法能满足氧化锑中铅、铜、铁元素的测定。     

FLAPW calculations of the EFG in semimetallic arsenic and antimony under varying pressure

The variation of the electric field gradient (EFG) at nuclear sites with pressure in semimetallic arsenic and antimony has been calculated using the full-potential linearized augmented plane wave (FLAPW) method. The results are compared with NQR data, which are available up to a pressure of 2 GPa. The calculated EFG depends sensitively on the values of the lattice parameters used. A theoretical investigation of the relationship between c/a and the internal parameter z, using FLAPW methods, has been carried out and compared with available X-ray diffraction data for arsenic and antimony. For antimony, the FLAPW calculations give results which are consistent with the experimental pressure variation of both the lattice parameters and the EFG. In the As case, the use of theoretical values of z leads to good agreement with the measured pressure variation of the EFG. This revised version was published online in August 2006 with corrections to the Cover Date.     

基于拉曼光谱高斯分峰拟合的硫化锑含量检测方法

针对硫化锑含量采用化学分析方法检测存在操作复杂、检测时间长的问题,提出了一种基于拉曼光谱高斯分峰拟合的硫化锑含量快速检测方法。采用拉曼光谱系统测定锑矿样品的拉曼谱图,对原始拉曼谱图进行平滑去噪、背景扣除、谱段选择及归一化等预处理。基于高斯曲线的高斯峰、峰面积、半高宽和峰位置等信息,建立单个高斯峰的数学模型,提出高斯分峰拟合算法对光谱进行拟合,采用状态转移算法对高斯峰模型进行优化求解,得到表征光谱信息的特征参量,结合偏最小二乘回归方法,确定特征参量和硫化锑含量之间的关系,从而建立模型,实现对硫化锑含量的预测。实验中通过训练样本建立校正模型,对测试样本进行预测,同时从训练样本中随机挑选出检验样本,利用已建立的模型,对其硫化锑含量进行预测,以检验模型的正确性和外推性。实验结果表明：与预处理后全光谱建模相比,采用高斯分峰拟合后建立的预测模型的预测效果更好,证明了模型的正确性和良好外推性。因此,拉曼光谱结合高斯分峰拟合算法应用于锑矿中硫化锑含量的检测是可行的,且测量过程更简单,适用于矿物成分的快速分析。     

Relaxation of Small Molecules: an ab initio Study

The formation mechanism for the equilateral triangle structure of the He3^ cluster is proposed.The curve of the total energy versus the internuclear distance R for this structure has been caclulated by the method of a modified arrangement channel quantum mechanics,The result shows that the curve has a minimal -7.81373 a.u.at R=1.55 a0. The binding energy of He3^ with respect to He He^ He was calculated to be 0.1064 a.u.(about 2.89 eV).This means that the He3^ cluster may be formed in the equilateral triangle structure stable by the interaction of He^ with two helium atoms.     

Improved determination of phosphorus contamination during ion implantation by SRP and simulations

Experimental determination of phosphorous cross-contamination during antimony implantation is presented. As a suitable structure for this experiment, a buried layer was employed which is created by implanting antimony followed by a long diffusion process. The implanted samples were analysed by SIMS and spreading resistance (SRP) methods. SRP method has been improved by applying a correction for the carrier spilling effect. A conversion chart for p-n junction depth dependence on phosphorus doping has been calculated by program SUPREM-IV. Comparison of SRP and SIMS methods has shown that SRP method can be used for monitoring the phosphorus cross-contamination and can be easily implemented as an in-line monitor and present an alternative to expensive and time consuming SIMS analysis.     

Rutherford backscattering study of crystal orientation dependent annealing effects in high-dose antimony implanted silicon

High dose implantations (10¹⁶ ions/cm²) of antimony in silicon result in concentrations far above the solid solubility of antimony in silicon. Rutherford backscattering was used to study the behaviour of damage and antimony concentration profiles for 〈100〉 and 〈111〉 substrates. The measurements were performed for various annealing treatments, implantation temperatures and implantation energies. A crystal orientation dependent outdiffusion of antimony towards the surface, a highly supersaturated phase of substitutional antimony at 600°C and a strong reverse annealing effect at higher temperatures were found.