关于高炉有害微量元素的控制

随着近些年国内钢铁企业产能的迅速扩大,铁水生产与含铁原料供应增长缓慢的矛盾日趋激化,高炉用料的品质出现了下滑趋势,特别是一些中小企业表现更为突出.为了实现高炉生产的稳定、安全、长寿,邢钢开展了有害微量元素控制的研究.高炉生产实现了安全高效,有害元素实现了有效控制.     

预焙阳极中微量元素的控制与生产实践

本文分析预焙阳极中微量元素的控制和生产实践,阐明预焙阳极中微量元素的来源和主要影响,并对微量元素的控制方法进行总结,用以提高预焙阳极生产质量,供相关人员借鉴参考。     

In vivo study of trace elements in leprous skin

The skin of leprous patients at various stages of the disease was investigated by diagnostic x-ray spectrometry, In the active stage raised iron and slightly raised zinc levels were found. The usefulness of the method in skin investigation is foreseen.     

贵金属饰品中痕量有害元素的分析

近年来,贵金属饰品中存在的有害元素引起了国内外各检测机构的高度关注。这些有害元素不仅对消费者的身体健康产生了极大的危害,对首饰制造行业的生产、销售和贸易也产生了巨大的影响,因此对贵金属饰品中有害元素的含量进行限定是十分必要的。文中对国内外饰品中有害元素的行业标准进行了介绍,并对有害元素分析常用的样品分解方法、分离富集方法以及仪器检测技术进行了总结和评述,同时还对该研究领域的未来发展趋势进行了展望。     

ICP-MS测定铜锌合金中痕量元素

研究了应用电感耦合等离子体质谱法 (ICP MS)测定铜锌合金中Mg ,Al,Ti,Cr ,Mn ,Ni,Cd ,In ,Sn ,Sb ,Tl,Pb ,Bi共13种痕量元素的分析方法。考察铜锌合金中 2 0余种痕量元素的质谱干扰情况及可能的消除方法。通过合适的仪器参数的设置和干扰的校正 ,对个别存在干扰的元素进行了分析 ;研究了非谱干扰对测定痕量元素的影响和内标校正的作用。仅用样品混合酸溶解 ,未进行基体分离或其他样品前处理。实验结果表明 ,对不同质量范围的待测元素以Sc ,La和Re多内标校正信号漂移及     

高铜矿石中微量元素ICP-MS分析方法

电感耦合等离子体质谱法,简称ICP-MS,是一种非常重要的现代测试手段,在地质样品元素测定过程中发挥着非常重要的作用。下文结合实践,就高铜矿石中微量元素测定过程中电感耦合等离子体质谱法的应用进行分析探讨,相较于传统的测试方法,该方法具有非常好的密实性,同时实验测试时消耗的酸量较小,可以大幅的缩减地质样品消解,消解效果非常的好。     

使用散射X-射线的理论强度进行土壤、岩石中微量重元素的X-射线荧光分析

关于土壤、岩石中的Pb,As等微量重元素的X射线荧光分析方法,在求出荧光X射线和散射X射线的强度比,然后制作工作曲线,进行定量的方法已经有所报道.这种方法能够显著地减轻样品固有的矿物效应等因素,达到提高定量分析准确度的效果.然而,近来发展了不仅依据工作曲线,也能依据FP法进行定量的方法.FP法是对定量元素的荧光X射线进行理论强度计算.本文是对散射X射线也进行计算,用于多种样品的定量分析[1].     

Geochemical characteristics and significance of major elements,trace elements and REE of NM copper polymetal deposit in Laos

The NM copper polymetal deposit is located in the middle north part of the Truong Son metallogenic belt in Laos,which is the skarn-typed deposit and located in the contact between Indosinian granite and Lower Carboniferous limestone.All the ore-bodies in NM deposit can be divided into four types according to their occurrences:I copper ore-body as the massive restite developed in inner contact near the granite in north part;Ⅱ-1 zinc-copper ore body and Ⅱ-2 copper-iron ore body developed within contact betwee...     

Influence of age and health on immune functions and trace elements

Apparently healthy elderly donors were screened according to a simple protocol that included clinical examination and the determination of hematological and biochemical values. This screening was performed to detect subclinical alterations which might interfere with immune responses and trace element status. The elderly were divided into two groups. The first group consisted of 22 (age 76 +/- 1 years) positively selected elderly (PSE), i.e. healthy subjects with no hematological and laboratory alterations, the second one comprised 13 (age 75 +/- 1 years) negatively selected elderly (NSE). Data were then compared with those obtained from 40 (age 35 +/- 2 years) healthy young controls. In both groups of elderly donors, plasma zinc levels were normal, while plasma copper concentrations were increased. Intracellular values of zinc and copper in mono- and polymorphonuclear cells from both groups of elderly were within reference limits. After in vitro activation, granulocyte chemiluminescence activity was impaired only in NSE. A decrement in the number of circulating CD3 lymphocytes and an increase in CD8d, CD57 cells were found in PSE, while NSE showed an increased number of CD3,DR cells and CD8d, CD57, CD8b,CD57 and CD16,CD56 positive cells. Our results indicate that only plasma copper levels were affected by age, whereas subclinical alterations in hematological or biochemical values appear to impair immune responses in the elderly.     

The effects of platinum chemotherapy on essential trace elements

The defecation habits of cats and dogs in three sandpits in urban public parks were observed by camcorder. Cats were the main cause of fecal contamination of these sandpits. Most (80%) feline defecations occurred at night between 6:00 pm and 6:00 am. Each of the sandpits was used habitually as a defecation site by 4-24 cats, but these cats seemed to defecate elsewhere, as well. Fecal deposits within the sandpits were evenly distributed and did not tend to be concentrated in one area, suggesting that the cats avoided previously deposited feces when choosing a place to defecate. One sandpit was strongly contaminated and two were weakly contaminated with Toxocara eggs. Because sandpits are widely used as play areas for young children, effective sanitation measures should be implemented to prevent the contamination of sandpits by Toxocara eggs.     

激光诱导击穿光谱法测定痕量金属元素

基于等离子体诱导的电流归一化,开发了一种相关方法分析由电喷雾离子化电针产生的试样液滴。研究发现时间分辨诱导击穿(LIB)光谱发射的强度与以单激发为基础同时检测的电流强度呈线性相关。即使基质盐度增至2 000 mg/L,碱金属元素分析所得检出限(LOD)仍可小于1 mg/L。电流归一化法可降低信号波动,并能使基体效应引起的干扰最小化。利用本方法得到的钠元素的检出限比激光诱导击穿/背景法(LIB/背景)得到的结果好20倍。考察了两种归一化方法中的冲击激光能量的影响,结果显示,激光能量在严格限制的小范围变化时,背景归一化才有线性相关关系。当用双线比来说明等离子体温度时,它的线性特征才有显著改善。结合用流动注射系统进行预浓缩和基体分离,激光诱导击穿光谱可以分析铝盐液滴,检出限可以达到1.5 mg/L,几乎比未进行预浓缩时低一个数量级,而线性动态范围要高于两个数量级。     

Effect of some trace elements on Heterakis gallinarum invasion

It was found that sodium chloride at the rate of 0.5 per cent in the mixtures lowers by 25 times the survival of the Heterakis helminths in birds, prevents the manifestation of verminous typhlitis, alters the ratio between the female and the male worms in favour of the latter, contributes to the increase in body weight and rises the level of the total protein in the blood serum, and changes the protein spectrum raising the level of globulins. Positive results at a lower size were established in feeding cobaltinitrite and soduim selenite to birds. Last ranked the effects produced with the offer of zinc sulfate. The admixture of sodium chloride at the rate of 0.5 per cent of birds is suggested both from the standpoint of Heterakis control and prophylaxis and from the point of view of pathogenesis.     

High temperature embrittlement of NI and Ni-Cr alloys by trace elements

The effects of Sb, Sn, and Zr additions on the creep properties of Ni and Ni + 20 pct Cr are reported. Antimony and tin additions (~1 wt pct) induce extensive grain boundary cavitation in nickel, while smaller antimony additions had little effect on Ni + 20 pct Cr. Addition of 0.11 pct Zr to Ni + 20 pct Cr greatly inhibited grain boundary cavitation and reduced its Coble creep rate. Auger electron spectroscopy of cavitated specimens provided direct evidence of impurity segregation to cavity surfaces. Residual sulfur segregated most strongly, and was observed on cavity surfaces in all cavitated specimens. Tin segregated somewhat less intensely than sulfur, and antimony segregated only slightly. Segregation of antimony and sulfur to uncavitated portions of Ni + 1 pct Sb grain boundaries was also observed. These results are discussed in terms of segregation effects on energetic and transport properties of the grain boundaries and cavity surfaces. This paper is based on a presentation made at the symposium “The Role of Trace Elements and Interfaces in Creep Failure” held at the annual meeting of The Metallurgical Society of AIME, Dallas, Texas, February 14-18, 1982, under the sponsorship of The Mechanical Metallurgy Committee of TMS-AIME.     

辉光放电质谱法测定高温合金中的痕量元素

研究了用辉光放电质谱法(GDMS)同时测定高温合金中的痕量元素.通过对分析元素同位素干扰情况的考察,对辉光放电参数如电流、电压、预溅射时间和积分时间的优化,建立了测定高温合金中B,P,Sc,Cu,Ga,Ge,As,Ag,In,Sn,Sb、Te,Hf,Tl,Pb和Bi共16种痕量元素的方法,该方法具有很好的准确度和精密度.     

Changes in the concentrations of trace elements in human milk during lactation

Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine 18 trace elements (Ba, Be, Bi, Cd, Co, Cs, Cu, La, Li, Mn, Mo, Pb, Rb, Sb, Sn, Sr, Tl, and Zn) in 55 human milk samples from 46 healthy mothers collected during lactation periods extending to 293 days after birth. Se was quantified by hydride generation atomic absorption spectrometry (HG-AAS). To test the accuracy and the precision of the analytical procedure, milk powder reference materials (BCR 063 and BCR 150) were analyzed. The results obtained by ICP-MS and HG-AAS showed good agreement with the certified values. Whenever available, trace element concentrations determined in the human milk samples were compared to reliable literature data. The concentrations of Be (< 0.05 to 0.9 microgram/kg), Bi (< 0.09 to 2.0 micrograms/kg), Cs (1.7 to 7.7 micrograms/kg), La (< 0.05 to 3.7 micrograms/kg), Rb (440 to 1,620 micrograms/kg), and Tl (< 0.08 to 0.5 microgram/kg) are the first to be reported for human milk. The concentrations of the essential trace elements Cu (p < 0.005), Mn (p < 0.05), Mo (p < 0.0005), Se (p < 0.001), and Zn (p < 0.0005) significantly decreased and the concentrations of cobalt significantly increased (p < 0.005) in human milk during the course of lactation. All concentrations for the essential trace element tin in the human milk samples were below the method detection limit of 0.3 microgram/kg. Among the not essential and toxic elements-with the exception of Ba, Pb, and Tl-the trend toward lower concentrations with continuing lactation is much less pronounced than for the essential trace elements. With the exception of Se, the daily intakes of essential trace elements of fully breast-fed infants are considerably lower than dietary recommendations.     

Extrachromosomal elements in a variety of strains representing the Bacteroides fragilis group of organisms

Previous nucleic acid association studies have identified at least nine deoxyribonucleic acid (DNA) homology classes of the Bacteroides fragilis group of organisms. Using these classes as a taxonomic framework, we have screened representative strains of the B. fragilis group for the presence of extrachromosomal (plasmid) DNA. [3H]thymidine-labeled cell lysates were subjected to sodium dodecyl sulfate-salt precipitation, and supernatant fractions from such preparations were analyzed using cesium chloride-ethidium bromide equilibrium centrifugation. One strain from each group was examined in this fashion. Five of the strains were judged to contain no detectable plasmid DNA; however, four strains were observed to yield satellite bands corresponding to covalently closed circular plasmid DNA. Plasmid DNA from such gradients was subjected to velocity sedimentation through both neutral and alkaline sucrose gradients to determine molecular size. A 23 X 10(6)-molecular-weight plasmid was found in a B. fragilis strain representing one DNA homology group of this species, whereas a 3 X 10(6)-molecular-weight plasmid was found in a B. fragilis strain representing a second homology group. Similarly, a 31 X 10(6)-molecular-weight plasmid was found in a Bacteroides thetaiotaomicron strain representing one DNA homology group of this species, whereas a 3 X 10(6)-molecular-weight plasmid was found in a B. thetaiotaomicron strain representing a second homology group. In all instances, the small-molecular weight plasmids were present to the extent of about 15 copies per chromosomal equivalent, whereas the large plasmids were present to the extent of approximately 1 copy per chromosomal equivalent. The biological function of these plasmids is unknown.     

On interactions amongst trace and alloying elements at the grain boundaries of a low alloy steel

Interactions amongst segregants at the grain boundaries of a low alloy steel have been studied using the technique of Auger electron spectroscopy in the temperature range of 750–900 K. Segregation isotherms delineate three kinetically distinct regimes. The first of these is characterized by rapid cosegregation of Cr and N with desegregation of C followed by segregation of V which occurs at relatively higher temperatures. The second stage involves rapid segregation of P which initially attains a maximum coverage and then subsequently decreases with time. The third regime noted at higher temperatures shows slow segregation of S, Sn and Sb. This regime, however, exhibits high sensitivity of site competition to temperature.