共查询到20条相似文献,搜索用时 109 毫秒
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采用氢氧化钠溶液和双氧水溶解样品,加入酒石酸钾钠溶液消除Fe3+的干扰,加入硫脲溶液提高Cu2+的允许量,在稀硫酸介质中,增敏剂阿拉伯树胶存在下,钛与显色剂百里香酚蓝发生反应形成稳定的蓝紫色络合物,建立了百里香酚蓝分光光度法测定铝合金中钛的方法。结果表明:络合物最大吸收峰位于590nm,溶液中钛质量浓度在0.1~2μg/mL范围内符合比尔定律,方法检出限为 0.03μg/mL,表观摩尔吸光系数为3.7×104 L·mol-1·cm-1。方法用于铝合金标准样品中钛含量的测定,测定值与认定值基本一致,钛测定结果的相对标准偏差(RSD,n=6)为2.3%和3.4%。 相似文献
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研究了2-羟基-3-甲氧基苯基荧光酮(HMPF)与钛的显色反应,建立了一种直接测定钢铁中微量钛的光度分析方法。在硫酸介质中,表面活性剂OP作用下,2 羟基3 甲氧基苯基荧光酮与钛形成一种红色络合物,络合物的组成为钛∶HMPF=1∶3(物质的量比),其最大吸收峰位于536nm,表观摩尔吸光系数为1.9×105,络合物在7h内稳定。在25mL溶液中,钛质量在0~3μg范围内符合比尔定律。显色反应有良好的选择性,方法简单、灵敏,可不经分离直接测定钢铁中微量钛,结果满意。 相似文献
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试样以混酸溶解 ,经高氯酸氧化后 ,进行残渣回收。在约 0 35mol/L的硫酸介质中 ,磷与酒石酸锑钾、钼酸铵生成络合物 ,以抗坏血酸还原为磷钼蓝 ,在约 2 4mol/L盐酸介质中 ,以抗坏血酸还原三价铁 ,钛与二安替比林甲烷 (DAPM )生成黄色络合物。1 实验部分1 1 主要仪器和试剂72 1型分光光度计。磷、钛标准溶液 :1 0 μg/mL磷和 1 0 0 μg/mL钛 ,按常规方法配制 ;盐酸和溴氢酸混合酸 :1 + 2 ;混合熔剂 :碳酸钠∶硼酸 =2∶1 ;DAPM溶液 :5 % ,以 1mol/L盐酸配制。1 2 分析方法1 2 1 试样处理 :称取 0 2 0 0 0… 相似文献
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本文研究了钛 3 ,5-二溴水杨基荧光酮 (DBSF) 吐温 60三元络合物的显色反应条件及应用。结果表明 ,在 0.0 48~0.0 64mol/L盐酸介质中 ,形成了摩尔比为Ti ∶DBSF∶Tween 80 =1∶2∶4的三元络合物 ,最大吸收在 54 1nm波长处 ,表观摩尔吸光系数为 1.74× 1 0 5 ,钛含量在 0~ 1 1 μg/ 2 5mL遵守比尔定律 ,方法灵敏 ,选择性较高 ,操作简便 ,可不经分离直接测定钢铁样品中微量钛 ,结果满意。 相似文献
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作者在研究钛的铍试剂Ⅲ四元络合物时发现,铝和铍试剂Ⅲ的反应灵敏,且络合物形成后不被大量的EDTA破坏,本文对此作了进一步探讨,证明铝在pH5.5~6.5的乙酸-乙酸钠缓冲液介质中显色,络合物的吸光度基本一致,其极大吸收波长为555nm,摩尔吸光系数c=2.75×10~4,铝在0~45鹏g/50ml服从比尔定律,络合物的组成为铝:铍试剂Ⅲ=1:2,EDTA存在下至少可稳定2小时,本文以EDTA为掩蔽剂,拟出了锌合金、镁合金中铝的铍试剂Ⅲ光度测定法,并取得了满意的分析结果。 一、主要试剂和仪器 铝标准溶液 相似文献
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倪志安 《Canadian Metallurgical Quarterly》2011,23(3)
马克思主义唯物论是一种物本主义形态的唯物论,还是一种超越物本主义形态、从实践理解世界的本质相关问题的实践的唯物主义的唯物论?这是一个我们必须搞清楚的有关马克思主义唯物论的本质规定性和精神实质的重大问题.在考察物本主义的唯物论及其思维方式的局限性的基础上,揭示了马克思主义唯物论是现代的、实践的唯物主义,并重点研讨了马克思主义唯物论关于从实践理解世界的物质性和自然世界的先在性的原理,以期为马克思主义唯物论进一步阐明人类世界的实践性原理奠定基础. 相似文献
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D. N. Reznikov 《Metallurgist》1962,6(12):535-537
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The data are presented on changes in the rat arcuate nuclear neuron ultrastructure after using cyproheptadine (peritol, Egyt Pharmaceutical Works, Hungary) in a water suspension at a dose of 20 mg/kg once daily during 7 successive days and twice a day within 10 days. It was shown that cyproheptadine decreases the functional activity of the arcuate nuclear neurons, depending on the total amount of the drug used. Cyproheptadine-induced inhibition of the forming neurohormone release from neurons is likely to be one of the mechanisms of its therapeutic effect in Itsenko-Cushing's disease. 相似文献
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Vasomotor responses from the nasal mucosa and tongue, and contractions of the nictitating membrane, were recorded on stimulation of the cervical sympathetic or internal carotid nerves. Preganglionic sympathetic nerve fibres which elicited a membrane response possessed a lower threshold than those which evoked nasal vasoconstriction, while the latter displayed a lower threshold than fibres which evoked tongue vasoconstriction. The sympathetic vasodilator fibres to the tongue whose activity was revealed after alpha-receptor blockade, had a similar threshold to the vasoconstrictor fibres. Membrane contraction, nasal vasoconstriction and occasionally tongue vasoconstriction could be evoked by stimulating the internal carotid nerve. The postganglionic fibres innervating the nasal mucosa had a similar threshold to those of the nictitating membrane, which may indicate that there are small myelinated fibres innervating the mucosa. The preganglionic compound nerve action potential had four major components, S1-S4. S1, S2 and usually S3 fibres were associated with membrane contraction; S2, S3 and sometimes S1 fibres were associated with nasal vasoconstriction; and S3, usually S2 and occasionally S1 fibres were associated with vasoconstriction in the tongue. It is concluded that each of these three groups of nerve fibres, but not S4 fibres, may include fibres associated functionally with the three effectors. There was a considerable difference between the relative amplitude of the responses of the three effectors elicited by stimulation of the cervical sympathetic nerve at frequencies between 0.2 and 2 Hz. Vasoconstrictor responses were relatively larger than membrane contractions suggesting differences in the mechanisms of neurotransmission at the neuroeffector junctions. 相似文献
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