The pyrolysis of n-butane and i-butane at low pressure was investigated from 823-1823 K in an electrically heated flow reactor using synchrotron vacuum ultraviolet photoionization mass spectrometry. More than 20 speci...The pyrolysis of n-butane and i-butane at low pressure was investigated from 823-1823 K in an electrically heated flow reactor using synchrotron vacuum ultraviolet photoionization mass spectrometry. More than 20 species, especially several radicals and isomers, were detected and identified from the measurements of photoionization efficiency (PIE) spectra. Based on the mass spectrometric analysis, the characteristics of n-butane and i-butane pyrolysis were discussed, which provided experimental evidences for the discussion of decomposition pathways of butane isomers. It is concluded that the isomeric structures of n-butane and i-butane have strong influence on their main decomposition pathways, and lead to dramatic differences in their mass spectra and PIE spectra such as the different dominant products and isomeric structures of butene products. Furthermore, compared with n-butane,i-butane can produce strong signals of benzene at low temperature in its pyrolysis due to the enhanced formation of benzene precursors like propargyl and C4 species, which provides experimental clues to explain the higher sooting tendencies of iso-alkanes than n-alkanes.展开更多
The identification and evaluation of oil reservoir with logging data are one of most important ways in geologic logging services. For the last decades, with the further development of the oil & gas exploration, gr...The identification and evaluation of oil reservoir with logging data are one of most important ways in geologic logging services. For the last decades, with the further development of the oil & gas exploration, great advances have been achieved in techniques on the acquisition, processing and interpretative evaluation of logging data. How to identify fluid characteristics and evaluate the productivity in light oil reservoir (the crude density being between 0.74g/cm3 and 0.82g/cm3)has become one of the difficulties.With the establishment of the regional interpretation criterion of the study blocks, the optimized logging parameters that reflect the reservoir characteristics have been used to establish the chart for the interpretation of oil-water reservoir combining with well logging parameters. Then, to begin with geologic reserves of crude in single well, we establish evaluation criterion for productivity in oil reservoir with determining lower limit value of the reservoir and applying the relationship between chart parameters. The techniques are verified in production and get better effect.On the basis of the reservoir characteristics analysis of both basin A and B, We established the evaluation method of static productivity on light oil reservoir with getting quantitative evaluation parameters after quantitatively evaluating the date of core, pyrolysis chromatogram and gas chromatogram. It provides new technique 7 for new well interpretation and old well review, as well as evidence for project.design of well testing.展开更多
Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favor...Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favorable method to research the diversity of natural products, and also provides new tools for us to create new approach for producing natural products, we can synthesize compounds with different structures by artificial combination of different synthesis modules.展开更多
Widespread use of azole fungicides and low removal efficiency in wastewater treatment plants(WWTPs) have led to the elevated concentration of azole fungicides in receiving environment. However, there was limited resea...Widespread use of azole fungicides and low removal efficiency in wastewater treatment plants(WWTPs) have led to the elevated concentration of azole fungicides in receiving environment. However, there was limited research about the removal mechanism of azole fungicides in the biological treatment of WWTPs. Imidazole fungicide climbazole and triazole fungicide fluconazole were selected to investigate the biodegradation mechanism of azole fungicides in activated sludge under aerobic conditions. Climbazole was found to be adsorbed to solid sludge and resulted in quick biodegradation. The degradation of climbazole in the aerobic activated sludge system was fitted well by the first-order kinetic model with a half-life of 5.3 days, while fluconazole tended to stay in liquid and had only about 30% of loss within 77 days incubation. Ten biotransformation products of climbazole were identified by high resolution mass spectrometry using suspect and non-target screening method. But no biodegradation products of fluconazole were identified due to its limited removal. The possible biodegradation pathways for climbazole were proposed based on the products identification and pathway prediction system, and involves oxidative dehalogenation, side chain oxidation and azole ring loss. The findings from this study suggest that it should be a concern for the persistence of fluconazole in the environment.展开更多
基金This work is supported by the National. Natural Science Foundation of China (No.51106146, No.51036007, No.U1232127), the China Postdoctoral Science Foundation (No.20100480047 and No.201104326), the Chinese Universities Scientific Fund (No.WK2310000010), the Anhui Science & Technology Department (No.l1040606Q49), and the Chinese Academy of Sciences.
文摘The pyrolysis of n-butane and i-butane at low pressure was investigated from 823-1823 K in an electrically heated flow reactor using synchrotron vacuum ultraviolet photoionization mass spectrometry. More than 20 species, especially several radicals and isomers, were detected and identified from the measurements of photoionization efficiency (PIE) spectra. Based on the mass spectrometric analysis, the characteristics of n-butane and i-butane pyrolysis were discussed, which provided experimental evidences for the discussion of decomposition pathways of butane isomers. It is concluded that the isomeric structures of n-butane and i-butane have strong influence on their main decomposition pathways, and lead to dramatic differences in their mass spectra and PIE spectra such as the different dominant products and isomeric structures of butene products. Furthermore, compared with n-butane,i-butane can produce strong signals of benzene at low temperature in its pyrolysis due to the enhanced formation of benzene precursors like propargyl and C4 species, which provides experimental clues to explain the higher sooting tendencies of iso-alkanes than n-alkanes.
文摘The identification and evaluation of oil reservoir with logging data are one of most important ways in geologic logging services. For the last decades, with the further development of the oil & gas exploration, great advances have been achieved in techniques on the acquisition, processing and interpretative evaluation of logging data. How to identify fluid characteristics and evaluate the productivity in light oil reservoir (the crude density being between 0.74g/cm3 and 0.82g/cm3)has become one of the difficulties.With the establishment of the regional interpretation criterion of the study blocks, the optimized logging parameters that reflect the reservoir characteristics have been used to establish the chart for the interpretation of oil-water reservoir combining with well logging parameters. Then, to begin with geologic reserves of crude in single well, we establish evaluation criterion for productivity in oil reservoir with determining lower limit value of the reservoir and applying the relationship between chart parameters. The techniques are verified in production and get better effect.On the basis of the reservoir characteristics analysis of both basin A and B, We established the evaluation method of static productivity on light oil reservoir with getting quantitative evaluation parameters after quantitatively evaluating the date of core, pyrolysis chromatogram and gas chromatogram. It provides new technique 7 for new well interpretation and old well review, as well as evidence for project.design of well testing.
文摘Synthetic biology is one of the rapid developing scientific fields in recent years. Through synthetic biology,we have a better understanding of the natural synthesis process of natural products, which provides a favorable method to research the diversity of natural products, and also provides new tools for us to create new approach for producing natural products, we can synthesize compounds with different structures by artificial combination of different synthesis modules.
基金supported by the National Natural Science Foundation of China(Nos.41473105,41877358 and 21806043)Scientific Research and Technology Development Program of Guangxi(No.2018AB36018)+1 种基金Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety(No.2019B030301008)the Pearl River Talent Plan of Guangdong Province(No.2017GC010244)。
文摘Widespread use of azole fungicides and low removal efficiency in wastewater treatment plants(WWTPs) have led to the elevated concentration of azole fungicides in receiving environment. However, there was limited research about the removal mechanism of azole fungicides in the biological treatment of WWTPs. Imidazole fungicide climbazole and triazole fungicide fluconazole were selected to investigate the biodegradation mechanism of azole fungicides in activated sludge under aerobic conditions. Climbazole was found to be adsorbed to solid sludge and resulted in quick biodegradation. The degradation of climbazole in the aerobic activated sludge system was fitted well by the first-order kinetic model with a half-life of 5.3 days, while fluconazole tended to stay in liquid and had only about 30% of loss within 77 days incubation. Ten biotransformation products of climbazole were identified by high resolution mass spectrometry using suspect and non-target screening method. But no biodegradation products of fluconazole were identified due to its limited removal. The possible biodegradation pathways for climbazole were proposed based on the products identification and pathway prediction system, and involves oxidative dehalogenation, side chain oxidation and azole ring loss. The findings from this study suggest that it should be a concern for the persistence of fluconazole in the environment.