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对中硅耐热铸铁中碳硫含量进行了分析及研究,并对坩埚的选择与保存、助熔剂的选择、分析时间的设定及试样的称量都作了较详细的研究,这是一种利用红外碳硫仪及坩埚测定中硅耐热铸铁中碳硫含量的一种快速灵敏的方法。通过试验获得了最佳的分析条件,测碳硫的RSD<1%,结果令人满意。 相似文献
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研究了利用高频红外吸收测定3D打印用镍基合金粉中碳、硫的分析方法.通过实验优化了仪器条件,并对助熔剂的种类、加入量、加入次序、样品称样量等条件进行研究,实验开展了方法精密度、仪器测定下限等实验.实验发现:当助熔剂选择为铜屑和钨粒,样品称样量为0.3g时,碳分析结果RSD在3.12%~8.02%之间,硫分析结果RSD在8... 相似文献
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以吐温/无水乙醇/正己烷/水微乳液为介质,进行Ag(I)—硫代米氏酮的光度测定,得到最佳增敏条件。结果表明,与水体系比较,该微乳液体系有较好的增敏和抗干扰作用,测定条件更为简化。 相似文献
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以上海德凯公司的HCS-140碳硫仪为分析仪器,对没有标样的渣剂类品种采用一种新的量值传递方式,即采用基准CaCO3对红外碳硫仪进行校正后再对试样进行分析。通过对燃烧条件、试样处理、加标回收等相关因素的选择试验,建立了渣剂类中碳的分析方法。检出下限为0.050%,回收率为98.33-101.72%。 相似文献
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电解氯化钠水溶液处理十二碳硫醇恶臭污水 总被引:1,自引:0,他引:1
采用电解氯化钠水溶液配合活性炭催化氧化处理十二碳硫酵恶臭污水.进行了初步的实验并取得了良好的效果.在电流3A条件下电解30g/L的NaCl水溶液,以活性炭作催化剂,反应温度为20℃,反应时间10—30s可以去除十二碳硫酵恶臭物质. 相似文献
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通过观察水泥净浆试件在电脉冲和常规浸泡条件下不同龄期的外观变化,并结合扫描电镜(SEM/EDS)、X射线衍射、红外光谱(FTIR)分析侵蚀产物的组成,对试件遭受硫酸盐侵蚀后碳硫硅钙石的生成速度进行了比较.结果表明:电脉冲明显加速了水泥基材料中碳硫硅钙石的生成速度.在电脉冲作用90~120天时试件内部有一个生成碳硫硅钙石的准备期,作用120天后侵蚀产物中出现大量的碳硫硅钙石;常规浸泡1年后,试件内部只检测到生成碳硫硅钙石所需的中间体,并无大量碳硫硅钙石生成. 相似文献
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Chemolithoautotrophic metabolism of anaerobic extremely thermophilic archaebacteria 总被引:19,自引:0,他引:19
Several types of extremely thermophilic archaebacteria have recently been isolated from solfataric water holes, hot springs and hot sea floors. It has been shown that some of them can live using sulphur respiration of reduced carbon substrates as a source of energy, a type of metabolism previously described for the eubacterium Desulfuromonas. We report here that several extremely thermophilic archaebacteria can live with carbon dioxide as their sole carbon source, obtaining energy from the oxidation of hydrogen by sulphur, producing hydrogen sulphide. They are thus capable of a new type of anaerobic, purely chemolithoautotrophic metabolism, a possible primaeval mode of life. 相似文献
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Widespread anoxia in the ocean is frequently invoked as a primary driver of mass extinction as well as a long-term inhibitor of evolutionary radiation on early Earth. In recent biogeochemical studies it has been hypothesized that oxygen deficiency was widespread in subsurface water masses of later Cambrian oceans, possibly influencing evolutionary events during this time. Physical evidence of widespread anoxia in Cambrian oceans has remained elusive and thus its potential relationship to the palaeontological record remains largely unexplored. Here we present sulphur isotope records from six globally distributed stratigraphic sections of later Cambrian marine rocks (about 499 million years old). We find a positive sulphur isotope excursion in phase with the Steptoean Positive Carbon Isotope Excursion (SPICE), a large and rapid excursion in the marine carbon isotope record, which is thought to be indicative of a global carbon cycle perturbation. Numerical box modelling of the paired carbon sulphur isotope data indicates that these isotope shifts reflect transient increases in the burial of organic carbon and pyrite sulphur in sediments deposited under large-scale anoxic and sulphidic (euxinic) conditions. Independently, molybdenum abundances in a coeval black shale point convincingly to the transient spread of anoxia. These results identify the SPICE interval as the best characterized ocean anoxic event in the pre-Mesozoic ocean and an extreme example of oxygen deficiency in the later Cambrian ocean. Thus, a redox structure similar to those in Proterozoic oceans may have persisted or returned in the oceans of the early Phanerozoic eon. Indeed, the environmental challenges presented by widespread anoxia may have been a prevalent if not dominant influence on animal evolution in Cambrian oceans. 相似文献
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The global carbon and sulphur cycles are central to our understanding of the Earth's history, because changes in the partitioning between the reduced and oxidized reservoirs of these elements are the primary control on atmospheric oxygen concentrations. In modern marine sediments, the burial rates of reduced carbon and sulphur are positively coupled, but high-resolution isotope records indicate that these rates were inversely related during the Early Cretaceous period. This inverse relationship is difficult to reconcile with our understanding of the processes that control organic matter remineralization and pyrite burial. Here we show that the inverse correlation can be explained by the deposition of evaporites during the opening of the South Atlantic Ocean basin. Evaporite deposition can alter the chemical composition of sea water, which can in turn affect the ability of sulphate-reducing bacteria to remineralize organic matter and mediate pyrite burial. We use a reaction-transport model to quantify these effects, and the resulting changes in the burial rates of carbon and sulphur, during the Early Cretaceous period. Our results indicate that deposition of the South Atlantic evaporites removed enough sulphate from the ocean temporarily to reduce biologically mediated pyrite burial and organic matter remineralization by up to fifty per cent, thus explaining the inverse relationship between the burial rates of reduced carbon and sulphur during this interval. Furthermore, our findings suggest that the effect of changing seawater sulphate concentrations on the marine subsurface biosphere may be the key to understanding other large-scale perturbations of the global carbon and sulphur cycles. 相似文献
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高性能活性炭制备技术新进展 总被引:6,自引:0,他引:6
根据活性炭制备过程的特点,概述了活性炭制备前期、中期、后期过程中的主要制备技术,比较了不同制备阶段不同制备技术的特点,为制备高性能活性炭及其应用提供了参考. 相似文献
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采用单克隆抗体作为试剂,建立了直接用于快速检测粪便中福氏痢疾杆菌的一种新方法即固相致敏红细胞吸附技术。检测210份疑以细菌性痢疾患者粪便标本的结果证明,用常规培养法检测阳性者,SPASE法检测阳阳性,两类方法的条例率为81.9%;常规培养法阳性率43.3%而SPASE法则为61.5%。SPASE法全过程仅需2.5-3小时,可检出10^3-10^4个/ml细菌,这快速免疫法不仅能检出完整的细菌,而且 相似文献
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本采用金相、扫描和透射等手段,研究了高速钢高温形变和动态再结晶行为,建立了动态再结晶的微观模型。分析了高温形变时的动态析出过程,并讨论了动态析出与动态再结晶之间的关系。结果表明,高速钢由于形变时基体中存在大量的残余碳化物以及在形变过程中大量的动态析出,其形变再结晶行为远比低碳低合金钢复杂。钢中的动态再结晶方式与析出十分密切。不同的形变条件下变形会发生不同的动态析出,从而引起不同的动态再结晶方式。高速钢中存在两种最基本的动态再结晶方式,即形核长大方式和晶粒碎化方式。 相似文献
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采用FeC二元合金的紊流、凝固传热及溶质传输三维耦合模型,针对铸坯不同碳质量分数对凝固过程溶质分布的影响进行数值模拟,凝固过程以柱状晶生长方式进行,遵循局部热力学平衡·研究发现,与低碳钢相比,高碳钢的凝固坯壳较薄,等温曲线较为光滑,糊状区范围较大·碳质量分数较高的钢种,偏析较轻;而低碳钢,偏析较为严重 相似文献
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硫在Ti-IF钢中的作用 总被引:1,自引:0,他引:1
IF钢成分设计的基本思想是将钢中间隙固溶的C3N原子完全清除,但通过热力学分析和对析出物的TEM分析表明,由于碳硫析出的的存在,S在固定C原子方面起到了积极的作用,据此,保持钢中适度的S/C比,可充分发挥S的作用,以形成有利的固定C的产物。 相似文献
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本文以我国新开发的大煤田─灵武煤田部分矿区煤及乌兰煤为对象,对其煤质特征和煤成浆性及浆体流变性进行了较详细的研究。结果表明,灵武煤田三矿区煤具有低灰、低硫,高挥发分和高发热量的优良特性,煤灰成分以硅、铝为主,灰熔点较低,属轻微结渣型。乌兰煤属高硫焦煤,灰熔点较高。四矿区煤岩相组成差别较大,其中灵武磁窑堡煤丝质组合量高达61.3%,这在中国煤岩相组成中属少见,在最佳制浆工艺条件下,四种煤均能制备出具有良好的流动性和静态沉降稳定性的假塑性水煤浆流体,但除乌兰煤外,灵武三矿区煤所能达到的煤浆浓度普遍偏低,属难制浆煤。同时发现,最高煤浆农度与煤最高内在水分间有良好的线性相关性,灵武煤最高内在水分偏高是其难制浆的重要原因。 相似文献
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介绍了碳纳米管和现有的几种高强度聚合物材料的性能及碳纳米管的功能化.功能化的碳纳米管,尤其是以高强度聚合物接枝的碳纳米管,即“聚合物枝化碳纳米管”可能是今后超高强度材料的主要组分,是制备太空缆索的希望. 相似文献