The Savitzky-Golay(SG)filter,which employs polynomial least-squares approximations to smooth data and estimate derivatives,is widely used for processing noisy data.However,noise suppression by the SG filter is recogni...The Savitzky-Golay(SG)filter,which employs polynomial least-squares approximations to smooth data and estimate derivatives,is widely used for processing noisy data.However,noise suppression by the SG filter is recognized to be limited at data boundaries and high frequencies,which can significantly reduce the signal-to-noise ratio(SNR).To solve this problem,a novel method synergistically integrating Principal Component Analysis(PCA)with SG filtering is proposed in this paper.This approach avoids the is-sue of excessive smoothing associated with larger window sizes.The proposed PCA-SG filtering algorithm was applied to a CO gas sensing system based on Cavity Ring-Down Spectroscopy(CRDS).The perform-ance of the PCA-SG filtering algorithm is demonstrated through comparison with Moving Average Filtering(MAF),Wavelet Transformation(WT),Kalman Filtering(KF),and the SG filter.The results demonstrate that the proposed algorithm exhibits superior noise reduction capabilities compared to the other algorithms evaluated.The SNR of the ring-down signal was improved from 11.8612 dB to 29.0913 dB,and the stand-ard deviation of the extracted ring-down time constant was reduced from 0.037μs to 0.018μs.These results confirm that the proposed PCA-SG filtering algorithm effectively improves the smoothness of the ring-down curve data,demonstrating its feasibility.展开更多
Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cr...Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.展开更多
食品重金属污染日趋严重,为了证明LIBS快速检测大米中重金属元素含量的可行性,采用LIBS技术对经实验室含Cd溶液浸泡过的大米中Cd元素进行分析。首先采用LIBS和AAS技术,获取5个浓度系列的大米中Cd元素的LIBS光谱及真实浓度信息,再采用一...食品重金属污染日趋严重,为了证明LIBS快速检测大米中重金属元素含量的可行性,采用LIBS技术对经实验室含Cd溶液浸泡过的大米中Cd元素进行分析。首先采用LIBS和AAS技术,获取5个浓度系列的大米中Cd元素的LIBS光谱及真实浓度信息,再采用一元一次和一元二次定标分析模型,对Cd元素的特征光谱Cd II 214.4、Cd II226.5和Cd I 228.8进行定量分析。结果表明,原子谱线Cd I 228.8具有较高的线性相关性,并且一元二次回归模型具有较好的预测精度。试验结果表明,LIBS技术用于大米中重金属Cd元素的快速检测在理论和实践上具有可行性。展开更多
文摘The Savitzky-Golay(SG)filter,which employs polynomial least-squares approximations to smooth data and estimate derivatives,is widely used for processing noisy data.However,noise suppression by the SG filter is recognized to be limited at data boundaries and high frequencies,which can significantly reduce the signal-to-noise ratio(SNR).To solve this problem,a novel method synergistically integrating Principal Component Analysis(PCA)with SG filtering is proposed in this paper.This approach avoids the is-sue of excessive smoothing associated with larger window sizes.The proposed PCA-SG filtering algorithm was applied to a CO gas sensing system based on Cavity Ring-Down Spectroscopy(CRDS).The perform-ance of the PCA-SG filtering algorithm is demonstrated through comparison with Moving Average Filtering(MAF),Wavelet Transformation(WT),Kalman Filtering(KF),and the SG filter.The results demonstrate that the proposed algorithm exhibits superior noise reduction capabilities compared to the other algorithms evaluated.The SNR of the ring-down signal was improved from 11.8612 dB to 29.0913 dB,and the stand-ard deviation of the extracted ring-down time constant was reduced from 0.037μs to 0.018μs.These results confirm that the proposed PCA-SG filtering algorithm effectively improves the smoothness of the ring-down curve data,demonstrating its feasibility.
文摘Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.
文摘食品重金属污染日趋严重,为了证明LIBS快速检测大米中重金属元素含量的可行性,采用LIBS技术对经实验室含Cd溶液浸泡过的大米中Cd元素进行分析。首先采用LIBS和AAS技术,获取5个浓度系列的大米中Cd元素的LIBS光谱及真实浓度信息,再采用一元一次和一元二次定标分析模型,对Cd元素的特征光谱Cd II 214.4、Cd II226.5和Cd I 228.8进行定量分析。结果表明,原子谱线Cd I 228.8具有较高的线性相关性,并且一元二次回归模型具有较好的预测精度。试验结果表明,LIBS技术用于大米中重金属Cd元素的快速检测在理论和实践上具有可行性。
