Corrosion caused by sulfate-reducing prokaryotes(SRP)is an important cause of magnesium alloy anode failure in oil pipeline.In this study,the effects of Desulfovibrio sp.HQM3 on the corrosion behavior of AZ31B magnesi...Corrosion caused by sulfate-reducing prokaryotes(SRP)is an important cause of magnesium alloy anode failure in oil pipeline.In this study,the effects of Desulfovibrio sp.HQM3 on the corrosion behavior of AZ31B magnesium alloy anode in organic carbon sources with different contents in simulated tidal flat environment were analyzed using weight loss test,surface analysis and electrochemical analysis technologies.The results showed that the weight loss rate of coupons in low carbon sources contents(0%,1%,10%)was higher than that in 100%carbon sources.Electrochemical analyses showed that the corrosion current density(J_(corr))under low carbon sources contents was larger,while the charge transfer resistance(R_(ct))was lower,leading to a higher corrosion rate compared to those under 100%carbon sources content.Observations from scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM)revealed more severe pitting corrosion on the alloy surface in the absence of carbon sources.In addition,a large number of nanowires were observed between bacteria on the alloy surface using SEM.Combined with thermodynamic calculations,it was demonstrated that the corrosion of coupons by Desulfovibrio sp.HQM3 in the absence of carbon sources was achieved through extracellular electron transfer.展开更多
Transport is a major component of energy consumption and 002 emissions in travelling. Understanding changes in the energy efficiency of tourism transport （EETT） and factors affecting this is important to the promoti...Transport is a major component of energy consumption and 002 emissions in travelling. Understanding changes in the energy efficiency of tourism transport （EETT） and factors affecting this is important to the promotion of low-carbon tourism. This paper established a new method following the top to bottom principle and analyzed EETT variation characteristics and influencing factors from 1994 to 2013 in China. We found that the energy consumption of tourism transport （ECTT） increased from 178.21 PJ in 1994 to 565.82 PJ in 2013 at an average annual growth rate of 6.27%; CO2 emissions of tourism transport （CETT） went up from 14.96×10^6t to 47.94×10^6 t due to person-trip and trip distance growth. EETT went from 3.22×10^6 person-trips PJ^-1 in 1994 to 5.99×10^6 person-trips PJ^-1 in 2013 at an average annual growth rate of 4.90%, and the CO2 emissions of tourism transport unit person-trips （CETTU） shifted from 26.07 kg person-trips^-1 in 1994 to 14.01 kg person-trips^-1 in 2013. Energy intensity decline, scale effects and policy promotion were key factors that enhanced EETT. Meanwhile, trip mode changes and enjoyment-oriented transport hindered EETT. Based on our analysis, we suggest methods to decrease ECTT and CETT. and enhance EETT.展开更多
基金Project(42076043) supported by the National Natural Science Foundation of ChinaProject(ZR2023ZD31) supported by the Major Basic Research Project of Natural Science Foundation of Shandong Province,ChinaProject(2023VEA0007) supported by the Chinese Academy of Sciences President’s International Fellowship Initiative。
文摘Corrosion caused by sulfate-reducing prokaryotes(SRP)is an important cause of magnesium alloy anode failure in oil pipeline.In this study,the effects of Desulfovibrio sp.HQM3 on the corrosion behavior of AZ31B magnesium alloy anode in organic carbon sources with different contents in simulated tidal flat environment were analyzed using weight loss test,surface analysis and electrochemical analysis technologies.The results showed that the weight loss rate of coupons in low carbon sources contents(0%,1%,10%)was higher than that in 100%carbon sources.Electrochemical analyses showed that the corrosion current density(J_(corr))under low carbon sources contents was larger,while the charge transfer resistance(R_(ct))was lower,leading to a higher corrosion rate compared to those under 100%carbon sources content.Observations from scanning electron microscopy(SEM)and confocal laser scanning microscopy(CLSM)revealed more severe pitting corrosion on the alloy surface in the absence of carbon sources.In addition,a large number of nanowires were observed between bacteria on the alloy surface using SEM.Combined with thermodynamic calculations,it was demonstrated that the corrosion of coupons by Desulfovibrio sp.HQM3 in the absence of carbon sources was achieved through extracellular electron transfer.
基金National Natural Science Foundation of China(41501159)Key Research of Hebei Education Department Foundation(SD151019)China Postdoctoral Science Foundation(2014M560731)
文摘Transport is a major component of energy consumption and 002 emissions in travelling. Understanding changes in the energy efficiency of tourism transport （EETT） and factors affecting this is important to the promotion of low-carbon tourism. This paper established a new method following the top to bottom principle and analyzed EETT variation characteristics and influencing factors from 1994 to 2013 in China. We found that the energy consumption of tourism transport （ECTT） increased from 178.21 PJ in 1994 to 565.82 PJ in 2013 at an average annual growth rate of 6.27%; CO2 emissions of tourism transport （CETT） went up from 14.96×10^6t to 47.94×10^6 t due to person-trip and trip distance growth. EETT went from 3.22×10^6 person-trips PJ^-1 in 1994 to 5.99×10^6 person-trips PJ^-1 in 2013 at an average annual growth rate of 4.90%, and the CO2 emissions of tourism transport unit person-trips （CETTU） shifted from 26.07 kg person-trips^-1 in 1994 to 14.01 kg person-trips^-1 in 2013. Energy intensity decline, scale effects and policy promotion were key factors that enhanced EETT. Meanwhile, trip mode changes and enjoyment-oriented transport hindered EETT. Based on our analysis, we suggest methods to decrease ECTT and CETT. and enhance EETT.
