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电感耦合等离子体发射光谱法快速测定钼铁合金中的钼 总被引：1，自引：1，他引：0
用电感耦合等离子体发射光谱法测定钼铁中的钼,优化了仪器操作条件,克服了常规重量法测定钼铁中钼步骤繁琐、耗时长、工作量大的不足。方法简便易行,快速准确,分析误差在化学分析允许的误差范围内,能替代原有的化学分析方法,基本满足生产和科研的要求。 相似文献
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We present the results of the quasi‐static cyclic tensile tests of Cu–Al–Mn shape memory alloy (SMA) bars of 4 and 8 mm diameters to examine their superelasticity and other mechanical properties closely related to seismic applications. The present Cu–Al–Mn SMA bars have achieved the recovery strains of over 8% and the fracture strains of over 17%. Low‐cycle fatigue was observed in neither of the bars. The mechanical properties obtained from the test, along with the lower material cost and higher machinability than Ni–Ti SMAs, demonstrate the high potential of the present Cu–Al–Mn SMA bars to be used in seismic applications. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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Some resource-based economies become wealthy while others stay poor and Norway belongs to the first category. This paper argues that part of the answer to why Norway has managed to benefit from its rich natural resources is found in the formation of a well-functioning national innovation system. The paper integrates the innovation system approach with a historical approach through the concept of co-evolution. The empirical study investigates how innovation systems evolve in natural resource industries through analysing the co-evolution between industry, knowledge organisations and national policy in the Norwegian aluminium and petroleum sectors. Parallels are found in the development of these two sectors, which are: (i) the deliberate use of concession laws to seize value creation and technological development from foreign direct investments, (ii) the establishment and prioritisation of state-owned companies and (iii) the more or less intentional formation of a national innovation system. The paper points to the relevance of analysing the historical evolution of national innovation systems to understand the creation of their specific path-dependent characteristics, to analyse how policy influences the creation and working of innovation systems, to use a multilevel approach in studies of innovation systems and to consider how innovation processes in different industries are linked in value chains and through knowledge flows. 相似文献
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利用正交试验的配比方法炼制了不同Zn、In、Mg、Ti含量Al-Zn-In-Mg-Ti牺牲阳极9组,采用恒电流和极化曲线方法评价了牺牲阳极的电化学性能。结果表明:电流效率随着钛含量的增加呈上升趋势,随着铟含量的增加而呈下降趋势,随着锌、镁含量的增加先下降后升高。阳极为均匀溶解,未出现钝化现象,溶解过程表现出2种放电过程。最佳阳极配比(wt%)为:Zn 6.0,In 0.020,Mg 1.5,Ti 0.080,余量为Al。 相似文献
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Portable water plays a vital role in improving human life, particularly in controlling the spread of diseases. However, problems associated with lack of potable water are still common especially in developing countries including Malawi. Until now little information exists on the effectiveness of available commercial coagulants used by national water boards in Malawi. Therefore, this study was undertaken in Southern Region Water Board (SRWB) to investigate the efficiency of polymeric coagulants (sufdfloc 3850 and algaefloc 19s) in turbidity reduction comparative with inorganic coagulant (aluminium sulphate) at Zomba, Liwonde, Mangochi, Chikwawa and Mulanje Treatment plants. The jar test method was used to determine the effectiveness of the water coagulants. The results revealed that sudfloc 3850 was most effective in reducing turbidity at Mangochi (99.4 ± 0.06%) and Liwonde (97.2 ± 0.04%) using 0.4 mg L−1 flocculant dose. The Zomba, Mulanje and Chikwawa plants gave 19.56 ± 0.03%, 29.23 ± 0.02% and 9.43 ± 0.02% total reductions respectively. Algaefloc 19s afforded the highest turbidity reduction at Liwonde and Mangochi plants (98.66 ± 0.06 and 97.48 ± 0.05% at a dose of 0.4 and 0.6 mg L−1 respectively), while Chikwawa provided the lowest (9.52 ± 0.01%). At the Zomba and Mulanje plants 20.5 ± 0.03% and 28.4 ± 0.04% reductions were obtained respectively. The inorganic flocculant, alum provided a 99.0 ± 0.05% and 98.6 ± 0.04% reduction at a dose of 4.0 mg L−1 and 6.0 mg L−1 at Zomba and Liwonde plants respectively. The lowest reductions in turbidity were achieved at Chikwawa (7.50 ± 0.01%), Mangochi (12.97 ± 0.02%) and Mulanje (25.00 ± 0.02). The best and optimum pH ranges for polymeric and inorganic coagulants were 7.20–7.80 and 7.35 to 7.57 respectively. The results further revealed that sudfloc 3850 and algaefloc 19s achieved faster formation of heavy flocs than alum. At 0.4 mg L−1 flocculant dosage sudfloc 3850 and algaefloc 19s required ten times lower dosages than alum. Therefore, the polymeric coagulants could be used instead of alum, the choice dependant on the type of water. 相似文献
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利用可见光谱数字化分析系统将铝合金中镁元素Mg518.36nm分析谱线组谱图转变为数字化的电子谱图,使用计算机自动分析代替人眼视觉判断,解决了谱图的量化分析和记录难题。对6种不同镁元素含量的铝合金标准样品进行了数字化分析测定,探索了选用Mg518.36nm作为分析谱线,分别选用Cu510.55nm和Fe510.75nm作为比较谱线进行定量测定的方法。数据显示,分析谱线和比较谱线的强度比值与镁元素含量呈正比。研究了数字化系统指导视场定位和谱线辨别的途径,降低了可见光谱分析的技术难度并提高了快速分析的可靠性。结果表明,数字化技术保持快速分析特点的同时可以达到定量分析的目的,能够有效解决铝合金中镁元素的快速定量分析及材料牌号鉴别问题。 相似文献
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