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本文考查了一些试剂对石墨炉原子吸收测定痕量钼的增敏作用,确定了用氟化钙作为石墨炉原子吸收光谱法测定钼的基体改进剂,并选择了该体系测定钢中钼的最佳实验条件。实验证明,采用CaF2作基体改进剂,使钼在313.3nm处的原子吸光度提高了5.7倍,特征景由原来42×10-11g/1%提高到51×10-12g/1%。线性范围为0~1000ng/ml钼,检测下限为0.55ng/g。对钼含量为0.0××~×.××%的钢标样测定结果满意。 相似文献
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本文介绍了在0.2mol/LHNO3-0.5mgFe(3+)-0.1mol/L抗坏血酸介质中用电流氧化溶出计时电位法直接测定地质物料中微量铅的新方法。方法检出限0.15μg/g,线性范围2~700ng/ml,Pb的含量水平分别为11.3和58.5μg/g时的精密度(RSD)分别为3.42%和3.08%,回收率95.00%~98.8%。文中对所选测定体系的增敏机理做了研究,考察了40种干扰离子对测定Pb的影响。用本法分析了26个国家一级标准物质中微量Pb,结果与标准值一致。 相似文献
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本文报导了表面活性剂TritonX-100对火焰原子吸收法测定镍的增敏作用。结果表明Triton X-100不但能起到增敏作用,且能抑制干扰离子的干扰。该法测定硅铁合金中镍的线性范围为0.2 ̄0.4μg/ml。检出限为0.04μg/ml。适合大批量样品测定。 相似文献
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对铕(Ⅲ)—钆(Ⅲ)—二苯甲酰甲烷—二乙胺沉淀悬浮液体系进行了系统研究,着重探讨了将沉淀转移到滤纸上制成固体荧光样品及其测量方法。沉淀的纸上荧光法比悬浮液体系的灵敏度可提高约10倍,选择性也得到改善。用于Eu的测定,检出限达1×10-7μg/mLEu2O3,在0~0.04μg/mL浓度范围内,荧光强度与浓度间呈线性关系。成功地用于Gd2O3中痕量Eu的分析。 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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为了保障矿山企业的发展与矿山地质自然环境形成协调的发展模式,应对矿山深层水位的沉降进行检测,水工环地质调查是确定矿山地下水位深度的有效手段之一。基于此,开展对矿山地质构造沉降监测中水工环地质调查的作用分析研究,通过研究得出,水工环地质调查可以提高矿山地质构造沉降监测结果精准度、为矿山地质构造沉降提供应急方案、保障矿山地质构造沉降监测工作效率等作用,对实现矿山企业的精细化施工提供有利条件。 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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加强烧结过程控制与稳定烧结矿质量 总被引:1,自引:0,他引:1
烧结矿的金属性能包括机械强度、氧化还原性和强度稳定性项指标,而影响这些因素种类繁多、错中复杂。介绍了烧结厂通过加强对烧结全过程的控制,稳定烧结矿金属质量的方法和效果。 相似文献
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