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采用微波消解技术,建立电感耦合等离子体质谱法测定谷物中重金属As,Pb,Hg,Cd含量的方法。完善前处理条件,优化仪器工作参数,选取72Ge,115In,209Bi作为内标元素,有效克服基体效应及仪器波动影响,利用干扰校正方程技术,消除多原子离子干扰。测定元素标准曲线相关系数均在0.999 9以上,各元素检出限在0.000 6~0.016 mg·L-1之间,回收率在90%~110%之间,方法的精密度在5%以内,用国家标准物质评价了方法准确性,用标准溶液进行了共存离子干扰试验。研究表明,该方法线性范围宽、精密度好、准确性高,适用于快速测定谷物中重金属元素As,Pb,Hg,Cd。 相似文献
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碾压混凝土坝层面影响带渐变规律分析模型 总被引:2,自引:0,他引:2
针对碾压混凝土坝层面影响带具有渐变特性,基于复合材料分析思想,利用串联和并联模型,建立了碾压混凝土坝层面影响带渐变规律分析模型;并根据模型的不同状况,提出了,确定层面影响带厚度瞬时弹性模量、延迟弹性模量以及粘性系数等的方法,揭示了决定层面影响带性质的主要计算参数的渐变规律,表征了层面的渐变特性;在上述研究的基础上,建立了相应的三维粘弹性分析模型,研制了相应的各部分分析程序;实例表明,提出的确定层面影响带主要计算参数的方法以及建立的分析模型比较好地反映了碾压混凝土坝的工作性态。 相似文献
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The effect zones of layer face for RCC (rolled control concrete) dam have gradual change characteristics. Based on the analysis thought of complex material, a model was built to analyze above principle of RCC dam by use of series-wound and shunt-wound connection. Some methods were proposed to determine the instantaneous Young's modulus, delayed Young's modulus and viscosity coefficient of effect zones of layer face. Above models and methods were used to mine the principle of gradual change of key calculation parameters which can response the characteristics of effect zones. The principle of gradual change was described. A model was established to analyze the three-dimensional viscoelastic problem of RCC dam. Above programs were developed. The examples show that the proposed models and methods to determine the key calculation parameters of effect zones can reflect the status of RCC dam accurately. 相似文献
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