To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantit...To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.展开更多
A kind of excellent CdZnTe crystal has been grown in Yinnel Tech, Inc. in recent years. Based on these CdZnTe crystals and some new techniques, a portable energy-dispersive spectrometer has been constructed which has ...A kind of excellent CdZnTe crystal has been grown in Yinnel Tech, Inc. in recent years. Based on these CdZnTe crystals and some new techniques, a portable energy-dispersive spectrometer has been constructed which has yielded good results. CdZnTe detector has a 3% relative resolution in high-energy field and can detect gamma rays at room temperature. An integrated circuit based on preamplifier and shaping amplifier chips is connected to the detector. Voltage pulses are transformed into digital signals in MCA (multichannel analyzer) and are then transmitted to com- puter via USB bus. Data process algorithms are improved in this spectrometer. Fast Fourier transform (FFT) and nu- merical differentiation (ND) are used in energy peak’s searching program. Sampling-based correction technique is used in X-ray energy calibration. Modified Gaussian-Newton algorithm is a classical method to solve nonlinear curve fitting problems, and it is used to compute absolute intensity of each detected characteristic line.展开更多
The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectr...The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.展开更多
在使用能量色散X射线荧光光谱仪定量分析钼铜矿中低含量Cu和Mo元素过程中,X光管的原级谱对测量结果影响非常大。为了降低这一影响,采用蒙特卡洛软件模拟了用Ag,Cu和Mo,Ti三种材质的滤片,在不同厚度情况下对原级谱的影响。模拟结果显示,1...在使用能量色散X射线荧光光谱仪定量分析钼铜矿中低含量Cu和Mo元素过程中,X光管的原级谱对测量结果影响非常大。为了降低这一影响,采用蒙特卡洛软件模拟了用Ag,Cu和Mo,Ti三种材质的滤片,在不同厚度情况下对原级谱的影响。模拟结果显示,1 mm Ti滤片测铜钼元素效果优于0.2 mm Ag滤片、0.02 mm Cu和0.1 mm Mo滤片。根据模拟结果,在实验室用三种滤片对样品进行了实测,谱线图对比显示,用Cu+Mo作滤片测钼元素时,本底计数大于200,用Ag和Ti作滤片测钼元素,几乎没有本底影响。但相同的样品,用Ti作滤片测得钼最高计数为800左右,而用Ag作滤片时测得钼最高计数为300左右。由此可见,用Ti作滤片测钼元素时,X光管原级谱对被测量元素的干扰影响小,其本底低于用银滤片和铜钼滤片。Ti滤片在降低本底影响的同时,钼的计数率最高,说明射线强度损失最少。用Cu+Mo作滤片测铜元素时,铜最高计数为300,用Ag作滤片时铜最高计数为180左右,而用Ti作滤片铜最高计数为500左右。由此可见,在铜元素含量较低时,用Ti作滤片测铜元素,铜的计数率最高,射线强度损失最少。通过公式计算显示:用1 mm Ti滤片测钼铜矿中铜的检出限为5.63 mg·kg^-1,钼的检出限为1.39 mg·kg^-1,检出限明显降低。采用不同含量的标准样品进行测量与化学分析拟合,通过工作曲线可见,高、低含量的样品均具有良好的线性关系,误差水平符合正常化学分析误差标准,R2为0.99及以上,说明1 mm Ti滤片测量精密度高。同一个样品进行多次重复测量,其Cu元素的RSD(%)=0.59,Mo元素的RSD(%)=0.3,均小于1,表明仪器测量稳定性好,样品测试结果具有重现性。研究结果为使用能量色散X射线荧光光谱仪测定钼铜矿中的钼和铜滤光片的选择及其厚度的确定提供了可信的依据,推荐选用1 mm Ti滤片。经过实际现场的检验。该方法稳定可靠,具有重要的实际应用价值。展开更多
基金Funded by the International Science&Technology Cooperation Program of Hubei Province of China(No.2022EHB024)。
文摘To explore ways to improve the accuracy of quantitative analysis of samples in the micrometer to nanometer range of magnitudes,we adopted analytical transmission electron microscopy(AEM/EDS)for qualitative and quantitative analysis of pyrite materials.Additionally,the k factor of pyrite is calculated experimentally.To develop an appropriate non-standard quantitative analysis model for pyrite materials,the experimentally calculated k factor is compared with that estimated from the non-standard quantitative analytical model of the instrument software.The experimental findings demonstrate that the EDS attached to a TEM can be employed for precise quantitative analysis of micro-and nanoscale regions of pyrite materials.Furthermore,it serves as a reference for improving the results of the EDS quantitative analysis of other sulfides.
文摘A kind of excellent CdZnTe crystal has been grown in Yinnel Tech, Inc. in recent years. Based on these CdZnTe crystals and some new techniques, a portable energy-dispersive spectrometer has been constructed which has yielded good results. CdZnTe detector has a 3% relative resolution in high-energy field and can detect gamma rays at room temperature. An integrated circuit based on preamplifier and shaping amplifier chips is connected to the detector. Voltage pulses are transformed into digital signals in MCA (multichannel analyzer) and are then transmitted to com- puter via USB bus. Data process algorithms are improved in this spectrometer. Fast Fourier transform (FFT) and nu- merical differentiation (ND) are used in energy peak’s searching program. Sampling-based correction technique is used in X-ray energy calibration. Modified Gaussian-Newton algorithm is a classical method to solve nonlinear curve fitting problems, and it is used to compute absolute intensity of each detected characteristic line.
基金supported by the National Key R&D Project of China(No.2017YFC0602100)the National Natural Science Foundation of China(No.41774147)Sichuan Science and Technology Support Program(No.2015GZ0272)
文摘The full-spectrum least-squares(FSLS) method is introduced to perform quantitative energy-dispersive X-ray fluorescence analysis for unknown solid samples.Based on the conventional least-squares principle, this spectrum evaluation method is able to obtain the background-corrected and interference-free net peaks, which is significant for quantization analyses. A variety of analytical parameters and functions to describe the features of the fluorescence spectra of pure elements are used and established, such as the mass absorption coefficient, the Gi factor, and fundamental fluorescence formulas. The FSLS iterative program was compiled in the C language. The content of each component should reach the convergence criterion at the end of the calculations. After a basic theory analysis and experimental preparation, 13 national standard soil samples were detected using a spectrometer to test the feasibility of using the algorithm. The results show that the calculated contents of Ti, Fe, Ni, Cu, and Zn have the same changing tendency as the corresponding standard content in the 13 reference samples. Accuracies of 0.35% and 14.03% are obtained, respectively, for Fe and Ti, whose standard concentrations are 8.82% and 0.578%, respectively. However, the calculated results of trace elements (only tens of lg/g) deviate from the standard values. This may be because of measurement accuracy and mutual effects between the elements.
文摘在使用能量色散X射线荧光光谱仪定量分析钼铜矿中低含量Cu和Mo元素过程中,X光管的原级谱对测量结果影响非常大。为了降低这一影响,采用蒙特卡洛软件模拟了用Ag,Cu和Mo,Ti三种材质的滤片,在不同厚度情况下对原级谱的影响。模拟结果显示,1 mm Ti滤片测铜钼元素效果优于0.2 mm Ag滤片、0.02 mm Cu和0.1 mm Mo滤片。根据模拟结果,在实验室用三种滤片对样品进行了实测,谱线图对比显示,用Cu+Mo作滤片测钼元素时,本底计数大于200,用Ag和Ti作滤片测钼元素,几乎没有本底影响。但相同的样品,用Ti作滤片测得钼最高计数为800左右,而用Ag作滤片时测得钼最高计数为300左右。由此可见,用Ti作滤片测钼元素时,X光管原级谱对被测量元素的干扰影响小,其本底低于用银滤片和铜钼滤片。Ti滤片在降低本底影响的同时,钼的计数率最高,说明射线强度损失最少。用Cu+Mo作滤片测铜元素时,铜最高计数为300,用Ag作滤片时铜最高计数为180左右,而用Ti作滤片铜最高计数为500左右。由此可见,在铜元素含量较低时,用Ti作滤片测铜元素,铜的计数率最高,射线强度损失最少。通过公式计算显示:用1 mm Ti滤片测钼铜矿中铜的检出限为5.63 mg·kg^-1,钼的检出限为1.39 mg·kg^-1,检出限明显降低。采用不同含量的标准样品进行测量与化学分析拟合,通过工作曲线可见,高、低含量的样品均具有良好的线性关系,误差水平符合正常化学分析误差标准,R2为0.99及以上,说明1 mm Ti滤片测量精密度高。同一个样品进行多次重复测量,其Cu元素的RSD(%)=0.59,Mo元素的RSD(%)=0.3,均小于1,表明仪器测量稳定性好,样品测试结果具有重现性。研究结果为使用能量色散X射线荧光光谱仪测定钼铜矿中的钼和铜滤光片的选择及其厚度的确定提供了可信的依据,推荐选用1 mm Ti滤片。经过实际现场的检验。该方法稳定可靠,具有重要的实际应用价值。
