A sapphire fiber thermal probe with Cr^3＋ ion-doped end was grown using the laser heated pedestal method. The fluorescence thermal probe offers advantages of compact structure, high performance and the ability to sus...A sapphire fiber thermal probe with Cr^3＋ ion-doped end was grown using the laser heated pedestal method. The fluorescence thermal probe offers advantages of compact structure, high performance and the ability to sustain high temperature from the room temperature to 450℃. Based on the fast fourier transform （FFT）, the fluorescence lifetime is obtained from the tangent function of the phase angle of the first non-zeroth item of FFT result. Compared with other traditional fitting methods, our method has advantages such as fast speed, high accuracy and being free from the influence of the base signal. The standard deviation of FFT method is about half of that method. In addition, since the FFT method is immunity to analysis can be skipped. of the Prony method and close to the one of the Marquardt the background noise of the signal, the background noise展开更多
Through the experimental design and theoretical analysis, three technologies used for characterizing the two-photon absorption(TPA) properties, such as nonlinear transmission experiment and theory, Z-scan technology a...Through the experimental design and theoretical analysis, three technologies used for characterizing the two-photon absorption(TPA) properties, such as nonlinear transmission experiment and theory, Z-scan technology and two-photon induced fluorescence method, are introduced. The properties of the three experiments to be utilizable and realizable under desirable limitation are simply analyzed. The advantages of the measurements for TPA characterization are also analyzed.展开更多
Using ultra high purity NaF-NaKCO3 in the Fluorescence spectrometry, determination of sub ppb levels of Uranium in the electronic materials has been achieved. The method could be applied to determination of Uranium in...Using ultra high purity NaF-NaKCO3 in the Fluorescence spectrometry, determination of sub ppb levels of Uranium in the electronic materials has been achieved. The method could be applied to determination of Uranium in any electronic materials.展开更多
When X-ray fluorescence （XRF） technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal＇s uneven surface and the particle size. In order to improve th...When X-ray fluorescence （XRF） technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal＇s uneven surface and the particle size. In order to improve the accuracy of sulfur concentration measurement, an online measurement system, consisting of a portable X-ray fluorescence instrument and an auxiliary distance correction module, was developed in this paper. By measuring the standard coal samples of known sulfur concentration, we obtained a calibration curve that can be used to analyze the sulfur concentration. We studied the relationship between the X-ray fluorescence intensity （I） and the distance （D） from surfaces to instrument. The results showed that there was a good linear re- lationship between 1 and D when the sulfur content was certain. Based on these knowledge, the distance correction formula of X-ray fluorescence intensity was proposed. By applying the distance correction formula to experimental sulfur concentration measurement, we demonstrated that the measurement accuracy can be significantly increased.展开更多
基金the Natural Science Research Foundation of Education Bureau of Hebei Province, China (Grant No.2001265)
文摘A sapphire fiber thermal probe with Cr^3＋ ion-doped end was grown using the laser heated pedestal method. The fluorescence thermal probe offers advantages of compact structure, high performance and the ability to sustain high temperature from the room temperature to 450℃. Based on the fast fourier transform （FFT）, the fluorescence lifetime is obtained from the tangent function of the phase angle of the first non-zeroth item of FFT result. Compared with other traditional fitting methods, our method has advantages such as fast speed, high accuracy and being free from the influence of the base signal. The standard deviation of FFT method is about half of that method. In addition, since the FFT method is immunity to analysis can be skipped. of the Prony method and close to the one of the Marquardt the background noise of the signal, the background noise
基金Key Laboratory for Supramolecular Structure and Materials of Ministry of Education, Jilin University(KLSSM-200607)
文摘Through the experimental design and theoretical analysis, three technologies used for characterizing the two-photon absorption(TPA) properties, such as nonlinear transmission experiment and theory, Z-scan technology and two-photon induced fluorescence method, are introduced. The properties of the three experiments to be utilizable and realizable under desirable limitation are simply analyzed. The advantages of the measurements for TPA characterization are also analyzed.
文摘Using ultra high purity NaF-NaKCO3 in the Fluorescence spectrometry, determination of sub ppb levels of Uranium in the electronic materials has been achieved. The method could be applied to determination of Uranium in any electronic materials.
基金supported by the National Natural Science Foundation of China(Grant No.11375087)Provincial Training Programs of Innovation and Entrepreneurship for Undergraduates(Grant No.201310287102)
文摘When X-ray fluorescence （XRF） technology is used to measure the sulfur concentration in coal online, the measurement accu- racy is affected by the coal＇s uneven surface and the particle size. In order to improve the accuracy of sulfur concentration measurement, an online measurement system, consisting of a portable X-ray fluorescence instrument and an auxiliary distance correction module, was developed in this paper. By measuring the standard coal samples of known sulfur concentration, we obtained a calibration curve that can be used to analyze the sulfur concentration. We studied the relationship between the X-ray fluorescence intensity （I） and the distance （D） from surfaces to instrument. The results showed that there was a good linear re- lationship between 1 and D when the sulfur content was certain. Based on these knowledge, the distance correction formula of X-ray fluorescence intensity was proposed. By applying the distance correction formula to experimental sulfur concentration measurement, we demonstrated that the measurement accuracy can be significantly increased.
