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为弥补标准检测方法的不足,建立了石墨消解-ICP-MS法同时检测铜精矿中Pb、Cd、As 和Hg等4种有害元素。确定了样品前处理和仪器分析条件。用铜精矿标准样品和参考样品分别进行7次重复实验,Pb、Cd和As的检测结果均在标准值范围内,Hg的检测结果与参考值基本一致。7次重复检测结果的变异系数符合GB/T 27417-2017《合格评定 化学分析方法确认和验证指南》要求。选择5种不同物相铜精矿作为待测样品,通过与标准方法比对,两种方法检测结果的绝对差符合标准方法的再现性要求,说明本方法适用于不同种类的铜精矿。本方法操作简单,可同时测定多种有害元素,实用性强。 相似文献
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枳壳炮制前后微量元素的测定 总被引:5,自引:0,他引:5
采用等离子体原子发射光谱法对枳壳进行了炮制前后32种微量元素含量的测定比较.结果表明:枳壳经麸炒后,微量元素的含量有不同程度的变化。为深入研究枳壳炮制机理提供了参考依据. 相似文献
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针对液态云微物理特性精确反演的迫切需求, 综合主被动传感器的探测优势, 联合CloudSat雷达反射率和Aqua光学厚度资料, 提出基于最优估计理论的液态云微物理参数反演算法.通过假设粒子谱服从对数正态分布, 基于前向物理模式建立测量变量与反演变量的函数关系, 借助谱分布参数的先验信息、通过算法迭代得到谱参数的最优解, 进而利用前向物理模式反演液态云微物理参数, 并根据误差传递理论计算反演不确定度.通过设计反演方案, 基于实测个例数据并与CloudSat官方发布产品和经验算法反演结果对比验证.结果表明: 基于最优估计理论、联合主被动传感器资料的液态云微物理参数反演结果与官方发布产品一致性较好, 弥补了经验算法误差大、扩展性差的不足, 对于开展国内星载和机载W波段毫米波雷达液态云微物理参数反演研究具有重要的借鉴意义.
关键词:
CloudSat
Aqua
液态云
最优估计理论 相似文献
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Singular perturbation reaction-diffusion problem with Dirichlet boundary condition is considered. It is a multi-scale problem. Presence of small parameter leads to boundary layer phenomena in both sides of the region. A non-equidistant finite difference method is presented according to the property of boundary layer. The region is divided into an inner boundary layer region and an outer boundary layer region according to transition point of Shishkin. The steps sizes are equidistant in the outer boundary layer region. The step sizes are gradually increased in the inner boundary layer region such that half of the step sizes are different from each other. Truncation error is estimated. The proposed method is stable and uniformly convergent with the order higher than 2. Numerical results are given, which are in agreement with the theoretical result. 相似文献
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Initiation of vacuum breakdown and failure mechanism of the carbon nanotube during thermal field emission 下载免费PDF全文
The carbon nanotube(CNT)-based materials can be used as vacuum device cathodes. Owing to the excellent field emission properties of CNT, it has great potentials in the applications of an explosive field emission cathode. The falling off of CNT from the substrate, which frequently appears in experiments, restricts its application. In addition, the onset time of vacuum breakdown limits the performance of the high-power explosive-emission-cathode-based diode. In this paper, the characteristics of the CNT, electric field strength, contact resistance and the kind of substrate material are varied to study the parameter effects on the onset time of vacuum breakdown and failure mechanism of the CNT by using the finite element method. 相似文献
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