Utilizing sunlight to convert CO_(2) into chemical fuels could address the greenhouse effect and fossil fuel crisis,Heterojunction structure catalysts with oxygen vacancy are attractive in the field of photocatalytic ...Utilizing sunlight to convert CO_(2) into chemical fuels could address the greenhouse effect and fossil fuel crisis,Heterojunction structure catalysts with oxygen vacancy are attractive in the field of photocatalytic CO_(2) conversion.Herein,a modified TiO_(2)/In_(2)O_(3)(R-P2 5/In_(2)O_(3-x)) type Ⅱ heterojunction composite with oxygen vacancies is designed for photocatalytic CO_(2) reduction,which exhibits excellent CO_(2) reduction activity,with a C_(2) selectivity of 56.66%(in terms of R_(electron)).In situ Fourier-transform infrared spectroscopy(DRIFTS) and time-resolved photoluminescence(TR-PL) spectroscopy are used to reveal the intermediate formation of the photocatalytic mechanism and photogenerated electron lifetime,respectively.The experimental characterizations reveal that the R-P25/In_(2)O_(3-x) composite shows a remarkable behavior for coupling C-C bonds.Besides,efficient charge separation contributes to the improved CO_(2) conversion performance of photocatalysts.This work introduces a type Ⅱ heterojunction composite photocatalyst,which promotes understanding the CO_(2) reduction mechanisms on heterojunction composites and is valuable for the development of photocatalysts.展开更多
A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice ...A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9CO0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.展开更多
Baosteel＇s 60000 m^3/h air separation unit （ASU） is the largest oxygen generating system in China. The operational cost of such a giant system is very high. How to reduce the operational cost is a critical issue. T...Baosteel＇s 60000 m^3/h air separation unit （ASU） is the largest oxygen generating system in China. The operational cost of such a giant system is very high. How to reduce the operational cost is a critical issue. This paper discusses the system＇s characteristics,the current operational status and the difficulties in reducing the cost,and analyzes relevant indicators, such as the technical and economical indicators of individual units and systems as well as the indicators concerning the costs. The relationship between the cost and each economical indicator and measures to optimize an economical operation of the oxygen generating system are also discussed in this paper.展开更多
水分利用效率(WUE)是农田生态系统碳水循环的重要指标,对指导农业灌溉和提高水分生产力有重要意义。宁夏灌区是我国地处干旱气候带的大型灌区,其中,玉米种植面积最大。在涡度通量观测农田生态系统实际蒸散发(ET)的基础上,利用氢氧稳定...水分利用效率(WUE)是农田生态系统碳水循环的重要指标,对指导农业灌溉和提高水分生产力有重要意义。宁夏灌区是我国地处干旱气候带的大型灌区,其中,玉米种植面积最大。在涡度通量观测农田生态系统实际蒸散发(ET)的基础上,利用氢氧稳定同位素法将蒸散发分割为土壤蒸发(evaporation,E)、植物蒸腾(transpiration,T),并通过光能利用模型估算宁夏引黄灌区典型玉米农田生态系统的总初级生产力(GPP),计算群体水分利用效率WUET=GPP/T、生态系统水分利用效率WUEET=GPP/ET以及固有水分利用效率(Intrinsic Water Use Efficiency)IWUEVPD=(GPP·VPD)/ET三种水分利用效率,进而从函数响应关系、相关性以及敏感性三个方面分析不同水分利用效率与气温、饱和水汽压差(VPD)、CO_(2)浓度、光合有效辐射以及土壤含水量等环境因子之间的关系。结果表明:宁夏引黄灌区玉米农田生态系统生长季的实际蒸散发变化呈单驼峰型,作物蒸腾与实际蒸散发的变化趋势相一致。WUET在生育期内呈“W型”变化,WUEET与IWUEVPD在生育期内呈“单峰型”变化,三种WUE的峰值出现在抽雄期,分别达到5.90 kg C·m^(-3)·H2O、5.02 kg C·m^(-3)·H2O和32.90 kg C·hPa·m^(-3)·H2O,灌浆后期三种水分利用效率开始降低,玉米成熟晚期由于蒸腾微弱所以WUET略有增加。WUET、WUEET和IWUEVPD与土壤含水量显著正相关,相关度和敏感性最强;VPD与三种WUE显著负相关,相关度和敏感性最强次之;气温、光合有效辐射以及CO_(2)浓度与三种WUE的负相关性但不是敏感因素。因此,在宁夏引黄灌区土壤水分和VPD是影响玉米农田生态系统WUE的关键因素。展开更多
基金National Research Foundation (NRF) of Korea grant funded by the Korea Government (MSIT) (NRF-2022R1A2C2093415)partially funding from the Circle Foundation (Republic of Korea) (Grant Number: 2023 TCF Innovative Science Project-03))partially Korea Basic Science Institute (National Research Facilities and Equipment Center) grant funded by the Ministry of Education (2022R1A6C101A751)。
文摘Utilizing sunlight to convert CO_(2) into chemical fuels could address the greenhouse effect and fossil fuel crisis,Heterojunction structure catalysts with oxygen vacancy are attractive in the field of photocatalytic CO_(2) conversion.Herein,a modified TiO_(2)/In_(2)O_(3)(R-P2 5/In_(2)O_(3-x)) type Ⅱ heterojunction composite with oxygen vacancies is designed for photocatalytic CO_(2) reduction,which exhibits excellent CO_(2) reduction activity,with a C_(2) selectivity of 56.66%(in terms of R_(electron)).In situ Fourier-transform infrared spectroscopy(DRIFTS) and time-resolved photoluminescence(TR-PL) spectroscopy are used to reveal the intermediate formation of the photocatalytic mechanism and photogenerated electron lifetime,respectively.The experimental characterizations reveal that the R-P25/In_(2)O_(3-x) composite shows a remarkable behavior for coupling C-C bonds.Besides,efficient charge separation contributes to the improved CO_(2) conversion performance of photocatalysts.This work introduces a type Ⅱ heterojunction composite photocatalyst,which promotes understanding the CO_(2) reduction mechanisms on heterojunction composites and is valuable for the development of photocatalysts.
基金Project supported by the National Natural Science Foundation of China (20306016, 20322201)
文摘A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9CO0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.
文摘Baosteel＇s 60000 m^3/h air separation unit （ASU） is the largest oxygen generating system in China. The operational cost of such a giant system is very high. How to reduce the operational cost is a critical issue. This paper discusses the system＇s characteristics,the current operational status and the difficulties in reducing the cost,and analyzes relevant indicators, such as the technical and economical indicators of individual units and systems as well as the indicators concerning the costs. The relationship between the cost and each economical indicator and measures to optimize an economical operation of the oxygen generating system are also discussed in this paper.
文摘水分利用效率(WUE)是农田生态系统碳水循环的重要指标,对指导农业灌溉和提高水分生产力有重要意义。宁夏灌区是我国地处干旱气候带的大型灌区,其中,玉米种植面积最大。在涡度通量观测农田生态系统实际蒸散发(ET)的基础上,利用氢氧稳定同位素法将蒸散发分割为土壤蒸发(evaporation,E)、植物蒸腾(transpiration,T),并通过光能利用模型估算宁夏引黄灌区典型玉米农田生态系统的总初级生产力(GPP),计算群体水分利用效率WUET=GPP/T、生态系统水分利用效率WUEET=GPP/ET以及固有水分利用效率(Intrinsic Water Use Efficiency)IWUEVPD=(GPP·VPD)/ET三种水分利用效率,进而从函数响应关系、相关性以及敏感性三个方面分析不同水分利用效率与气温、饱和水汽压差(VPD)、CO_(2)浓度、光合有效辐射以及土壤含水量等环境因子之间的关系。结果表明:宁夏引黄灌区玉米农田生态系统生长季的实际蒸散发变化呈单驼峰型,作物蒸腾与实际蒸散发的变化趋势相一致。WUET在生育期内呈“W型”变化,WUEET与IWUEVPD在生育期内呈“单峰型”变化,三种WUE的峰值出现在抽雄期,分别达到5.90 kg C·m^(-3)·H2O、5.02 kg C·m^(-3)·H2O和32.90 kg C·hPa·m^(-3)·H2O,灌浆后期三种水分利用效率开始降低,玉米成熟晚期由于蒸腾微弱所以WUET略有增加。WUET、WUEET和IWUEVPD与土壤含水量显著正相关,相关度和敏感性最强;VPD与三种WUE显著负相关,相关度和敏感性最强次之;气温、光合有效辐射以及CO_(2)浓度与三种WUE的负相关性但不是敏感因素。因此,在宁夏引黄灌区土壤水分和VPD是影响玉米农田生态系统WUE的关键因素。
