Unilateral power supply system has been used because of the management status of the power grid system, while, bilateral power supply system is adopted in the Soviet Union and France. The feasibility that whether bila...Unilateral power supply system has been used because of the management status of the power grid system, while, bilateral power supply system is adopted in the Soviet Union and France. The feasibility that whether bilateral system can be put applied in China is discussed. Compared with unilateral power supply system, bilateral system has better reliability and better capability of supply power system, which gives bilateral system more advantages over unilateral system on both engineering investment and operating efficiency. In this paper, voltage losses under the two different systems are calculated and also compared, the advantages of bilateral system is explored and then conclusion is drawn by referring to the practical data of passenger transport lines.展开更多
Understanding the emission sources of volatile organic compounds(VOCs)is critical for air pollution mitigation.Continuous measurements of atmospheric VOCs were conducted from January to February in Hangzhou in 2021.Th...Understanding the emission sources of volatile organic compounds(VOCs)is critical for air pollution mitigation.Continuous measurements of atmospheric VOCs were conducted from January to February in Hangzhou in 2021.The average measured concentration of total VOCs(TVOCs)was 38.2±20.9 ppb,>42% lower than that reported by previous studies at the urban center in Hangzhou.The VOC concentrations and proportions were similar between weekdays and weekends.During the long holidays of the Spring Festival in China,the concentrations of TVOCs were∼50% lower than those during the regular days,but their profiles showed no significant difference(p>0.05).Further,we deduced that aromatics and alkenes were the most crucial chemicals promoting the formation of O3 and secondary organic aerosol(SOA)in Hangzhou.According to interspecies correlations,combustion processes and solvent use were inferred as major VOC emission sources.This study provides implications for air quality improvements before and during the upcoming Asian Games that will be hosted in Hangzhou in 2022.展开更多
文摘Unilateral power supply system has been used because of the management status of the power grid system, while, bilateral power supply system is adopted in the Soviet Union and France. The feasibility that whether bilateral system can be put applied in China is discussed. Compared with unilateral power supply system, bilateral system has better reliability and better capability of supply power system, which gives bilateral system more advantages over unilateral system on both engineering investment and operating efficiency. In this paper, voltage losses under the two different systems are calculated and also compared, the advantages of bilateral system is explored and then conclusion is drawn by referring to the practical data of passenger transport lines.
基金support by the National Natural Science Foundation of China (No. 22106134)the National Key Research and Development Program of China (No. 2019YFC0214503)+1 种基金the Ecological Civilization Research Plan of Zhejiang Universitythe Key R&D Program of Zhejiang Province (No. 2022C03154)
文摘Understanding the emission sources of volatile organic compounds(VOCs)is critical for air pollution mitigation.Continuous measurements of atmospheric VOCs were conducted from January to February in Hangzhou in 2021.The average measured concentration of total VOCs(TVOCs)was 38.2±20.9 ppb,>42% lower than that reported by previous studies at the urban center in Hangzhou.The VOC concentrations and proportions were similar between weekdays and weekends.During the long holidays of the Spring Festival in China,the concentrations of TVOCs were∼50% lower than those during the regular days,but their profiles showed no significant difference(p>0.05).Further,we deduced that aromatics and alkenes were the most crucial chemicals promoting the formation of O3 and secondary organic aerosol(SOA)in Hangzhou.According to interspecies correlations,combustion processes and solvent use were inferred as major VOC emission sources.This study provides implications for air quality improvements before and during the upcoming Asian Games that will be hosted in Hangzhou in 2022.
