Wavelength sweep technique （WST） is introduced into intra-cavity fiber laser （ICFL） for low concentration gas detection. The limitation induced by noise can be eliminated using this method, and the performance of ...Wavelength sweep technique （WST） is introduced into intra-cavity fiber laser （ICFL） for low concentration gas detection. The limitation induced by noise can be eliminated using this method, and the performance of the system is improved. The sensitivity of the system is reduced to less than 300 ppm. With WST, sweeping characteristic of the ICFL can be described according to known gas absorption spectra.展开更多
The infrared emission spectra of methane, H, CH' and C_2 hydrocarbons in natural gas were measured. The processes of methane decomposition and formation of C_2 hydrocarbons were studied. The experiment shows that ...The infrared emission spectra of methane, H, CH' and C_2 hydrocarbons in natural gas were measured. The processes of methane decomposition and formation of C_2 hydrocarbons were studied. The experiment shows that methane decomposition can be divided into three periods as the reaction proceeds. In the first period, a large number of free radicals were formed. While in the last period, the formation of C_2 hydrocarbons and the decrease of free radicals were observed. The time and conditions of methane decomposition and formation of C_2 hydrocarbons are different.展开更多
Analytical chemistry plays an important role in the qualitive and quantitative analysis for molecules in the various circumstances,especially for the high-resolution analysis.The dual-comb spectroscopy(DCS)technology ...Analytical chemistry plays an important role in the qualitive and quantitative analysis for molecules in the various circumstances,especially for the high-resolution analysis.The dual-comb spectroscopy(DCS)technology with the characteristics of high resolution,high sensitivity and instantaneous sampling exhibited a great potential in high-resolution in-situ spectral methods and has been active in the fields of spatial ranging,air composition analysis,reaction monitoring and so on.In this review,we will summarize the principle of DCS according to the different wavelength coverage and overview the applications of DCS in analytical chemistry.展开更多
基金supported by the National Natural Science Foundation of China under Grant No. 60577013the New Century Support Program for Talented Young Teachers in Universities under Grant No. NCET-04-0241
文摘Wavelength sweep technique （WST） is introduced into intra-cavity fiber laser （ICFL） for low concentration gas detection. The limitation induced by noise can be eliminated using this method, and the performance of the system is improved. The sensitivity of the system is reduced to less than 300 ppm. With WST, sweeping characteristic of the ICFL can be described according to known gas absorption spectra.
基金Financially supported by aspecial fund of the Education Committee of Shaanxi province(No.2000K13-G19and2002K09-G21)
文摘The infrared emission spectra of methane, H, CH' and C_2 hydrocarbons in natural gas were measured. The processes of methane decomposition and formation of C_2 hydrocarbons were studied. The experiment shows that methane decomposition can be divided into three periods as the reaction proceeds. In the first period, a large number of free radicals were formed. While in the last period, the formation of C_2 hydrocarbons and the decrease of free radicals were observed. The time and conditions of methane decomposition and formation of C_2 hydrocarbons are different.
基金financially supported by National Natural Science Foundation of China(No.21974030)Medical Engineering Fund of Fudan University(No.XM03211184)。
文摘Analytical chemistry plays an important role in the qualitive and quantitative analysis for molecules in the various circumstances,especially for the high-resolution analysis.The dual-comb spectroscopy(DCS)technology with the characteristics of high resolution,high sensitivity and instantaneous sampling exhibited a great potential in high-resolution in-situ spectral methods and has been active in the fields of spatial ranging,air composition analysis,reaction monitoring and so on.In this review,we will summarize the principle of DCS according to the different wavelength coverage and overview the applications of DCS in analytical chemistry.
