ICP-AES法测定铜精矿中As、Sb、Bi、Ca、Mg、Pb、Co、Zn和Ni

提出采用ICP-AES法同时测定铜精矿中As、Sb、Bi、Ca、Mg、Pb、Zn、Ni、Co的分析方法:样品经王水 HF HClO4溶液后,直接测定。该方法测定As、Sb、Bi、Ca、Mg、Pb、Zn、Ni、Co的回收率在97.9%~102%之间,相对标准偏差在0.23%~2.5%之间。通过和国家标准物质比对及国家标准分析方法的比对,结果准确可靠,现该方法已用于本公司铜精矿的日常分析。     

掺Pb对Bi系超导体性能影响的研究

在使用聚合物-金属复合物(PMC)新型合成工艺制备出性能优良的BiSrCaCuO超导体的基础上,利用PMC法易于掺杂的特点,合成了Bi2-x(Pb)xSr2Ca2Cu2Oy超导体,实验结果表明,掺Pb后,合成时间进一步缩短,高Tc相的形成速率是不掺Pb的4~6倍,所得超导体为单相,掺Pb不影响体系的微观均匀性。     

关于Bi系高T_c超导体的阳离子掺杂研究（Ⅰ）──Al－Pb，Mg－Pb和Mn－Pb二元掺杂后超导体的超导电性和结构

讨论了Ａｌ－Ｐｂ，Ｍｇ－Ｐｂ和Ｍｎ－Ｐｂ等二元阳离子掺杂对Ｂｉ系高Ｔ_ｃ超导相出现时间的影响。试验中发现，前人较少讨论的Ｍｇ~（３＋）或Ａｌ~（３＋）离子在高Ｔ_ｃ相形成时，进入到高Ｔ_ｃ超导体晶格的特定位置，它们在高Ｔ_ｃ超导相中起着各自不同的作用机制，从而影响了高Ｔ_ｃ超导相的结构和超导电性。结果表明，Ｍｇ－Ｐｂ，Ａｌ－Ｐｂ和Ｍｎ－Ｐｂ等二元阳离子的掺杂是加快高Ｔ_ｃ超导相形成和提高Ｂｉ系高Ｔ_ｃ超导相超导电性的有效途径，它们的掺杂有利于Ｂｉ系高Ｔ_ｃ相的形成。     

高价离子掺杂对Bi系成相和结构的影响(II)

In our previous work we have found that the 2223 phase is formed more rapidly and the structural stability can be enhanced by doping high valence cation(Sn~(4+)、Sb~(5+)、V~(5+)、W~(6+)、Mo~(6+) etc.) in the Bi(Pb)SrCaCuO system. In this paper the effects of high valence cations doped on the phase formation and the crystal structure are discussed further.The Aurivillus building and rocksalt building unit coexist in the Bi double layers. The structural variety strongly affects the structural stability. Owing to Pb~(2+) addition the probability of Aurivillus building is increased, the stability of 2223 phase can be promoted. However, the structure is still not stable, since the addition of Pb~(2+) has decreased the valence state of Bi site and the oxygen positions are not fully occupied. By doping high valence cation, especially, when the valence of Pb_x~(2+)M_y~(n+) equals to +3 the structure of the 2223 phase can be stabilized. This result has been observed with examining elemental content of 2223 phase.The melting point of the grain boundaries are much lower after doping high valence cations, therefore the ion diffusion is more rapid and acceleration of the 2223 phase formation is observed.     

ICP-AES法测定滑子蘑中的Cd、Cu、Pb和Zn

建立了采用V(HNO3)∶V(HClO4)=15∶2作消解液进行溶样,ICP-AES法同时测定滑子蘑中Cd、Cu、Pb、Zn的分析方法,进行了ICP工作参数的优化,消解条件的选择及消解结果精密度实验。在最佳测定条件下,4种元素标准曲线相关性好(r为0.9990~0.9995),线性范围宽,精密度RSD为0.4%~4.6%,样品加标回收率为91.0%~101.0%,已用于实际样品的测定。     

ICP-AES法测定AuNiGd合金中的Ni、Gd、Pd、Fe和Bi

报道了采用ICP-AES法测定AuNiGd合金中Ni、 Gd、 Pd、 Fe、 Bi.对测定元素的波长、测定条件进行了选择;考察了基体和无机酸对测定的影响;在优化条件下,对试样进行测定,其相对标准偏差(n＝15) Ni 1.6%、 Gd 1.8%、 Pd 13%、 Fe 4.9%、 Bi 13%;回收率 Ni 98%～105%、 Gd 97%～99%、 Pd 101%～105%、 Fe 98%～104%、 Bi 104%～106%.     

Bi2WO6基光催化剂在环境和能源领域的最新研究进展

随着全球经济的快速发展与人口的日益膨胀,随之而来的能源消耗与环境污染也日益成为一个严峻的挑战.半导体光催化技术能够将低密度的太阳能转化为高密度的化学能,此外它能够通过产生活性自由基来降解空气或水中的污染物,因此在解决上述问题中具有巨大潜力,被认为是有着广阔前景的绿色无污染的能源转化和环境修复手段.在过去几十年的研究中,...     

Hg(Ⅱ)和Pb(Ⅱ)-MOF探针研究进展

金属有机框架材料(MOF)是一种由金属离子和桥联配体自组装而成三维网状结晶固体骨架材料,是一种新型的多孔配位聚合物材料。由于其具有孔结构可调节性,结构可设计性和超高比表面积等特点,因此在很多领域展现出广泛的应用前景,尤其是在吸附重金属离子方面的应用受到了很大关注。本文综述了近几年分别由单配和混合方式构筑的MOF材料在吸附Hg(Ⅱ)和Pb(Ⅱ)方面的应用,并对MOF材料在重金属离子吸附领域做出展望。     

核电站电缆料的制备技术及研究进展

能源短缺已成为全球性问题,利用核能发电已经成为解决能源短缺的重要途径之一。核电的发展为核电站电缆料带来了广阔的发展空间。积极研究、开发及应用核电站电缆料对于我国的核能利用具有重要意义。本文介绍了核电站电缆料的种类、性能、生产方法和国内外的研究现状,并对核电站电缆料的发展趋势做了展望。     

Determination of 210Pb, 210Bi and 210Po in natural drinking water

A new method for the radioanalytical determination of the ²²²Rn progenies ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Powill be presented, which has been improved for analyses of water samples fromdifferent regions in Austria. 1–2 liter samples were taken in polyethylenebottles prefilled with conc. HNO₃ to obtain 0.2M acidic solutions,thus avoiding adsorption effects. After adding 1.6 mg of inactive lead carrier,the water sample was evaporated to dryness, converted to the chloride formand dissolved in 1M HCl.     

Estimation of the Annual Effective Dose Due to the Ingestion of 210Pb and 210Po in Crops from a Site of Coal Mining and Processing in Southwest China

The exploitation of mineral resources may cause the environmental release of radionuclides and their introduction in the human trophic chain, affecting public health in the short and long term. A case study of the environmental radiation impact from coal mining and germanium processing was carried out in southwest China. The coal mines contain germanium and uranium and have been exploited for more than 40 years. The farmlands around the site of the coal mining and germanium processing have been contaminated by the solid waste and mine water to some extent since then. Samples of crops were collected from contaminated farmlands in the research area. The research area covers a radius of 5 km, in which there are two coal mines. ²¹⁰Pb and ²¹⁰Po were analyzed as the key radionuclides during the monitoring program. The average activity concentrations of ²¹⁰Pb and ²¹⁰Po in the crops were 1.38 and 1.32 Bq/kg in cereals, 4.07 and 2.19 Bq/kg in leafy vegetables and 1.63 and 1.32 Bq/kg in root vegetables. The annual effective doses due to the ingestion of ²¹⁰Pb and ²¹⁰Po in consumed crops were estimated for adult residents living in the research area. The average annual effective dose was 0.336 mSv/a, the minimum was 0.171 mSv/a and the maximum was 0.948 mSv/a. The results show that the crops grown on contaminated farmland contained an enhanced level of radioactivity concentration. The ingestion doses of local residents in the research area were significantly higher than the average level of 0.112 mSv/a in China, and the world average level of 0.042 mSv/a through ²¹⁰Pb and ²¹⁰Po in crop intake, respectively.     

The fractionation and determination procedures for the speciation of Pb and Po in soil samples

A method for speciation and determination of ²¹⁰Pb and ²¹⁰Po in soil samples was developed. The speciation was carried out by fractionating the soil samples into five fractions which are water soluble or exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and bound to residue. After mineralisation, 10% solution of each fraction was used to spontaneously deposit polonium on a silver disk at 85-90 °C and pH 1.5, and ²¹⁰Po was measured by α-spectrometry; the remain solution was used to separate lead by anion-exchange resin and purified by precipitation as PbS and PbSO₄, and ²¹⁰Pb was determined by a low background β-counter. The IAEA-327 reference material (soil) was studied for ²¹⁰Pb and ²¹⁰Po speciation. The results show that: (1) the average yields are 88.7 ± 6.4% for ²¹⁰Pb and 93.8 ± 8.2% for ²¹⁰Po; (2) if compared to the total ²¹⁰Pb activity in the sample, ²¹⁰Pb fractions are 0.95% in exchangeable form, 10.6% bound to carbonates, 14.3% bound to Fe-Mn oxides, 7.0% bound to organic matter and 67.2% bound to residue or acid soluble, and the corresponding values for ²¹⁰Po are 0.17%, 0.97%, 21.0%, 0.47% and 77.4%, respectively; and (3) the obtained ²¹⁰Pb concentration is in good agreement with the recommended value given by the IAEA.     

Presence and forms of210Pb,210Bi and210Po in ground level aerosols

A scheme of fractionation of²¹⁰Pb,²¹⁰Bi,²¹⁰Po forms present in air aerosols based on the combination of methods of radiochemical analysis and radiometric deteemination with leaching by different agents has been developed. The ratio between the²¹⁰Pb,²¹⁰Bi,²¹⁰Po present in the aerosol samples was determined experimentally. Carbonate of²¹⁰Pb, and²¹⁰Po and²¹⁰Bi forms connected with oxides prevai in the aerosol component of atmospheric air.     

Quantification of measurement uncertainty in the sequential determination of <Superscript>210</Superscript>Pb and <Superscript>210</Superscript>Po by liquid scintillation counting and alpha-particle spectrometry

Methodologies for the quantification of measurement uncertainties associated with the determination of ²¹⁰Pb- and ²¹⁰Po-specific activities by liquid scintillation counting (LSC) and alpha-particle spectrometry are presented, and are demonstrated using the soil reference material IAEA-326. Major contributors to the combined uncertainty associated with the measurement result of ²¹⁰Pb were the uncertainties of net count rates in the ²¹⁰Pb energy region of the sample spectrum and in the ²¹⁰Bi energy region of the blank spectrum. The predominant sources of uncertainty in the measurement of ²¹⁰Po were the uncertainties of net count rates in the regions of interest of ²⁰⁹Po and ²¹⁰Po. The relative standard uncertainty of ²¹⁰Po exponentially increases with the time interval between the sampling date and the separation date of Po, and this effect is strongly dependent on the ²¹⁰Po/²¹⁰Pb activity ratio. When the specific activity of ²¹⁰Pb is much higher than that of ²¹⁰Po in the sample, the relative standard uncertainty of the ²¹⁰Po determination increases significantly within a short time interval between the sampling date (or reference date) and the separation date of Po in samples.     

226Ra, 210Pb, 210Bi and 210Po deposition and removal from surfaces and liquids

Deposition of ²²⁶Ra from water on nylon was investigated. Measurements performed for different pH and different radium concentrations in the water gave similar absolute activities deposited on the foil surface. Obtained results were used to estimate the amount of ²²⁶Ra plated-out on the nylon scintillator vessel in the solar neutrino experiment BOREXINO during filling of the detector. Another problem studied in the frame of BOREXINO was the removal of ²¹⁰Pb from its organic liquid scintillator by applying distillation and water extraction. After several tests had been performed for both methods it was found that after the water extraction the initial lead content in the scintillator sample was reduced only accordingly to the ratio of the volumes of the applied liquids (simple dilution). In contrast to this, distillation was very effective providing in the best case a ²¹⁰Pb reduction factor higher than 100. Removal efficiencies of the long-lived ²²²Rn daughters during etching from surfaces of standard and high purity germanium were investigated in the frame of the GERDA experiment, which aims to search for neutrino-less double beta decay of ⁷⁶Ge. The standard etching procedure of Canberra used during production of high purity n-type germanium diodes was applied to germanium discs, which had been exposed earlier to a strong ²²²Rn source for its progenies deposition. In contrast to copper and stainless steel, ²¹⁰Pb, ²¹⁰Bi and ²¹⁰Po was removed from germanium very efficiently. An evidence of a reverse process was also observed—the isotopes were transferred from the etchant to the clean germanium surface.     

铅中毒及其防治研究进展

综述了铅中毒及其防治研究进展,包括：急性及慢性铅中毒,铅中毒的分子机理及铅中毒的防治。     

电感耦合等离子体原子发射光谱法(ICP-AES)测定铜砷滤饼中的Pb、Fe、Bi三种元素

采用硝酸、盐酸、氢氟酸、高氯酸分解样品,氢溴酸-盐酸挥发消除砷基体,优化仪器测定参数,选取最佳工作条件,建立了电感耦合等离子体原子发射光谱(ICP-AES)法测定铜砷滤饼中Pb、Fe、Bi元素的分析方法。其测定范围为：ω(Pb):0.12%~2.09%;ω(Fe):0.081%~2.10%;ω(Bi):1.20%~6.14%。各元素检出限为Pb:0.010μg/mL;Bi:0.006μg/mL;Fe:0.003μg/mL。加标回收率为95.5%~101.7%。该方法简便,准确,可靠,适用于铜砷滤饼中Pb、Fe、Bi元素的同时测定。     

The role of Cherenkov and liquid scintilation counting in evaluating the anion-exchange separation of210Pb−210Bi−210Po

Using as eluent a sequence of 3M HCl, 12M HCl, and 8M HNO₃, a mixture of²¹⁰Pb,²¹⁰Bi, and²¹⁰Po may be clearly separated on a column of Dowex 1×2−100 anion exchange resin. A Cherenkov count in H₂O and the variation in count rate with time confirm that the nuclides emerge in the order²¹⁰Pb→²¹⁰Bi→²¹⁰Po. If 12M HCl is replaced by 1.5M H₂SO₄/2.3 M Na₂SO₄, a clean separation also results, but recovery of²¹⁰Po becomes considerably more difficult. All three nuclides are readily detectable by liquid scintillation counting, with the efficiency for²¹⁰Pb in the 60–70% range. The Cherenkov aqueous counting efficiency for²¹⁰Bi is ∼14–15%.     

Determination of (210)Pb, (210)Bi and (210)Po in natural waters and other materials by electrochemical separation

An improved method for determination of (210)Pb, (210)Bi and (210)Po in both natural waters and solid materials has been developed. Polonium-210 is spontaneously plated onto a silver disc from dilute hydrochloric acid medium. Bismuth-210 is then electro-deposited onto a platinum gauze cathode directly from the same solution, with a graphite rod as anode. Finally, (210)Pb is electro-deposited from a fluoroborate medium onto the same platinum gauze, used as the anode. All three nuclides are subsequently measured by standard low-level alpha and beta counting techniques. The speed of this method (approximately 6 hr per sample after pretreatment) is a distinct advantage over existing techniques, as (210)Bi must be quickly separated from (210)Pb because of its 5.02-day half-life. Another advantage of this method is that the chemical form of the sample solution is suitable for use of established separation schemes for determining other decay-series isotopes (U, Th, Pa, etc.) after the three short-lived nuclides have been processed.