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对国标短碘量法测定高镁铜精矿铜量[1]加以优化,进行了镁干扰实验、样品返色实验及与经典法国标长碘量法进行结果对照,准确度、精密度、加标回收率实验等,判断分析方法的可行性。方法操作简便,精密度好、准确度高。测定范围:含镁量:10.00%~25.00%。 相似文献
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采用过氧化钠在高温下熔融钨精矿样,用盐酸酸化提取。使用电感耦合等离子体光谱法,同时测定出钨精矿中硫、锡的含量。实验中选取了仪器最佳工作参数,选择了合适的分析谱线,调节了溶液适当的介质酸度,有效地降低了共存元素对测定的干扰。进行了精密度实验和方法对比,结果表明,该实验方法操作简单,准确度高,精密度高,适用于钨精矿杂质元素硫、锡的日常分析工作。 相似文献
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介绍了采用电感耦合等离子体发射光谱法(ICP-OES)同时测定高硅钢中硅、锰、磷含量的方法。样品经过硝酸和少量氢氟酸溶解后,经电感耦合等离子体发射光谱在约0.8 mol/L的酸介质中进行测定。对样品溶解方法、酸介质的选择做了相关的试验,采用溶解标准物质建立校准曲线,同时进行了一系列的精密度、准确度和加标回收实验。实验结果表明,该方法简便、快速,各元素精密度RSD均小于3.5%,加标回收率为95%~105%,准确度良好,结果满足要求。 相似文献
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针对高卤废水含氟低,含氯、溴高的特性,通过实验研究建立了采用IC-离子选择电极法联测高卤废水中氟、氯和溴的方法。该实验通过将试样稀释为不同的稀释倍数,在选定的仪器工作条件下,测得校正曲线线性和各元素的检出限,并根据试样处理方法、测定介质、基体元素对测定元素的影响选定最佳测定条件。在此条件下进行了方法的精密度、准确度试验,得到3个被测元素的检出限均在0.02~0.03μg/mL,相对标准偏差(n=7)为0.643%~1.588%,加标回收率在95.9%~104.8%之间,证明本方法精密度好,准确度高,适用于联测高卤废水中氟、氯和溴。 相似文献
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本文研究了燃烧-中和滴定法测定高镍锍中硫量的方法,对助熔剂、气体流量、燃烧温度、燃烧时间和吸收液体积等条件进行了选择实验。实验结果表明,采用本文拟定的分析方法测定高镍锍中15%~25%的硫量,方法快速、简便,准确度和精密度均能满足测定要求。 相似文献
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Crack Growth Prediction by Manifold Method 总被引:2,自引:0,他引:2
The prediction of crack growth is studied by the manifold method. The manifold method is a new numerical method proposed by Shi. This method provides a unified framework for solving problems dealing with both continuums and jointed materials. It can be considered as a generalized finite-element method and discontinuous deformation analysis. One of the most innovative features of the method is that it employs both a physical mesh and a mathematical mesh to formulate the physical problem. The physical mesh is dictated by the physical boundary of a problem, while the mathematical mesh is dictated by the computational consideration. These two meshes are interrelated through the application of weighting functions. In this study, a local mesh refinement and auto-remeshing schemes are proposed to extend the manifold method. The proposed model is first verified by comparing the numerical results with the benchmark solutions, and the results show satisfactory accuracy. The crack growth problems and the stress distributions are then investigated. The manifold method is proposed as an attractively new numerical technique for fracture mechanics analysis. 相似文献
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利用观察法、岩相法和X射线衍射法定量分析了某钢厂高炉渣中非晶态含量,得到该高炉渣中非晶态含量大于95%的结论。三种方法中,观察法最简单,但易受人主观因素影响;岩相法需要一定的经验来判断;利用X射线衍射法可以较客观定量高炉渣中非晶态含量。 相似文献
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在CuSO4-H2SO4介质中,以次甲基兰为指示剂,借测量电解时所消耗的电量建立了定量测定铁的恒电流库仑分析新方法。该方法的准确度高,操作简单,对矿石的适应性好,应用于实际样品的测定,结果令人满意。 相似文献
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Jinsong Huang 《Canadian Metallurgical Quarterly》2002,15(2):64-71
By adopting the energy method, a method of calculating the stability of the rotational composite shell is presented that takes into account the influence of nonlinear prebuckling deformations and stresses on the buckling of the shell. The relationships between the prebuckling deformations and strains are calculated by nonlinear Karman equations. The numerical method is used to calculate the energy of the whole system. The nonlinear equation is solved by combining the gradient method and the amended Newton iterative method. A computer program is also developed. Examples are given to demonstrate the accuracy of the method presented in this paper. 相似文献
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In-Won Lee Hyung-Jo Jung Man-Cheol Kim Arthur R. Robinson 《Canadian Metallurgical Quarterly》1999,125(11):1286-1292
A solution method that can calculate the eigenproblem for large structures with multiple or close natural frequencies is presented. The method is formulated by the accelerated Newton-Raphson method for the transformed problem. The method can calculate the natural frequencies and mode shapes without any of the numerical instability that may be encountered in the inverse iteration process with a shift of the well-known methods, such as the subspace iteration method or the determinant search method, which have been widely used for solving an eigenproblem. The efficiency of the method is verified by comparing convergence and solution times for numerical examples with those of the subspace iteration method and the determinant search method. 相似文献
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分别采用液相还原改性法和微乳液法制备超细铁颗粒,用乙醇-水体系制备镍包覆铁颗粒的Fe/Ni双金属颗粒,用来进行硝酸盐的降解实验,并用扫描电镜(SEM)和X射线衍射(XRD)分析超细粉末的物相结构及形貌.结果表明:通过液相还原改性法制备的超细铁粉,颗粒形状不规则,颗粒大小在0.2~0.3 μm之间;而用乙醇-水体系制备的铁/镍粉颗粒为等轴晶粒,颗粒大小也在0.2~0.3 μm之间;加入PEG-6000可改善液相改性法和醇-水法制备的铁粉的分散性.微乳液法制备的铁粉为球形颗粒,存在较明显的团聚现象,颗粒大小在0.5~ 1μm之间.在相同条件下,不同方法制备的超细铁粉降解硝酸盐的能力由高到低依次为:微乳液法制备的铁粉>乙醇-水体系法制备的Fe/Ni双金属粉>液相还原改性制备的铁粉>不加PEG的乙醇-水体系制备的铁粉. 相似文献