Mild thermal treatment is an important partial upgrading technique to enable bitumen pipeline transportation,but no attention has been paid to the impact of mild thermal treatment on the emulsification behavior of eme...Mild thermal treatment is an important partial upgrading technique to enable bitumen pipeline transportation,but no attention has been paid to the impact of mild thermal treatment on the emulsification behavior of emerging partially upgraded bitumen.Asphaltene compounds are active emulsion stabilizers in bitumen oil.The emulsion stabilizing capacity of bitumen asphaltenes was investigated,before and after a mild thermal treatment at 400℃.The structural morphology and mechanical property of the asphaltene interfacial films were analyzed by using a combination of cryo-SEM,Langmuir trough,and Brewster angle microscopy.The thermal treatment significantly enhanced the emulsion stabilizing capacity of bitumen asphaltenes;the interfacial films formed by the thermally treated asphaltene samples appeared to be rougher and thicker with more abundant micron-scale wrinkle structures.The interfacial corrugation may intensify the mechanical stability/flexibility of the asphaltene films and consequently strengthen the stability of emulsion droplet.展开更多
Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buil...Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃ to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.展开更多
Thermal and photothermal catalytic selec-tive oxidation of isobutane to methacrylic acid(MAA)are comparatively studied over a keggin-type Cs2.9Cu0.34V0.49PMo12O40 het-eropolyacid acid.An introduction of light was obse...Thermal and photothermal catalytic selec-tive oxidation of isobutane to methacrylic acid(MAA)are comparatively studied over a keggin-type Cs2.9Cu0.34V0.49PMo12O40 het-eropolyacid acid.An introduction of light was observed to enhance both the i-C4H10 conversion and the MAA selectivity,and consequently the MAA formate rate,particularly at low temperatures.Characterization re-sults show that oxidation of methacrolein(MAL)to MAA is the rate-limiting step while UV light illumination promotes the oxidation ofσ-bonded MAL with OH groups toσ-bonded MAA on the catalyst surface.These results demonstrate a synergistic effect of thermal cataly-sis and photocatalysis in selective oxidation of isobutane to MAA,which suggests photother-mal catalysis as a promising strategy to catalyze the selective oxidation of higher hydrocar-bons at relative mild reaction conditions.展开更多
为探究气候温和地区高校教室内的热舒适性,且修正预测热感觉和不满意度模型(predicted mean vote-predicted percentage of dissatisfaction,PMV-PPD模型)与实际热感觉投票值存在偏差情况,本文以昆明某高校大学生受试者为试验对象,分别...为探究气候温和地区高校教室内的热舒适性,且修正预测热感觉和不满意度模型(predicted mean vote-predicted percentage of dissatisfaction,PMV-PPD模型)与实际热感觉投票值存在偏差情况,本文以昆明某高校大学生受试者为试验对象,分别测试室内环境参数、人员评估环境温度(t_(1))以及受试者主观评价等,共获得2229份有效数据。结果表明:在自然通风教室中,超过80%的大学生可以接受当前的热湿环境,PMV与实际平均热感觉投票(mean thermal sensation,MTS)模型相关较弱,PMV模型高估了受试者的实际热感觉,实测人员不满意百分比普遍大于预测不满意百分比。鉴于PMV模型预测准确性较低,综合考虑温度变化、主观反应等影响因素,提出人员评估环境温度(t_(1))作为修正性指标。人员评估环境温度与实际环境温度存在较强相关性,且在不同场景中两者温差值小于1.5℃。将t_(1)与热感觉投票进行回归分析,该参数与热感觉投票高度相关。在PMV计算中使用t_(1)代替空气温度对PMV模型进行修正得到tPMV,修正后的tPMV更接近于MTS模型,对PMV起到显著有效的修正作用。展开更多
基金supported by National Natural Science Foundation of China(52004266)the Opening Fund of State Key Laboratory of Heavy Oil Processing(SKLOP202001001)+1 种基金the Key R&D Program of Shandong,China(2019JZZY020502)independent innovation project of China University of Petroleum(21CX06008A)
文摘Mild thermal treatment is an important partial upgrading technique to enable bitumen pipeline transportation,but no attention has been paid to the impact of mild thermal treatment on the emulsification behavior of emerging partially upgraded bitumen.Asphaltene compounds are active emulsion stabilizers in bitumen oil.The emulsion stabilizing capacity of bitumen asphaltenes was investigated,before and after a mild thermal treatment at 400℃.The structural morphology and mechanical property of the asphaltene interfacial films were analyzed by using a combination of cryo-SEM,Langmuir trough,and Brewster angle microscopy.The thermal treatment significantly enhanced the emulsion stabilizing capacity of bitumen asphaltenes;the interfacial films formed by the thermally treated asphaltene samples appeared to be rougher and thicker with more abundant micron-scale wrinkle structures.The interfacial corrugation may intensify the mechanical stability/flexibility of the asphaltene films and consequently strengthen the stability of emulsion droplet.
基金Project(2018YFC0704500)supported by the National Key R&D Program of ChinaProjects(51838007,52130803)supported by the National Natural Science Foundation of China。
文摘Kunming,a city in southwest China,has a climate that is different from most of the other places in the world because of its unique geographical characteristics.Due to its temperate climate,most of the residential buildings in this region are naturally ventilated.Accordingly,a winter thermal comfort study was conducted in Kunming to reveal the thermal response of residents.Indoor and outdoor environmental parameters were measured,and participants were investigated about their clothing,thermal sensations,thermal preferences,and thermal acceptance using online questionnaires.Data from 162 valid questionnaires were collected in the survey.Although the climate is referred to as“mild”,the survey showed that the indoor temperature during winter was lower than the typical comfort range.Nevertheless,the participants responded that most of them felt neutral and comfortable.The neutral temperature of participants living in Kunming was determined to be 16.96℃.The acceptable thermal sensation vote(TSV)range of the residents is-0.72 to 1.52.The acceptable indoor air temperature range is 15.03℃ to 19.55℃,and the optimum indoor air temperature is 17.2℃.According to this study,the existing thermal comfort evaluation models can hardly predict residents’thermal responses in Kunming well.
基金supported by the Shaanxi Yancheng Petroleum(Group)Co.,Ltd.,the National Natural Science Foundation of China(No.22202189)the Changjiang Scholars Program of the Ministry of Education of China.
文摘Thermal and photothermal catalytic selec-tive oxidation of isobutane to methacrylic acid(MAA)are comparatively studied over a keggin-type Cs2.9Cu0.34V0.49PMo12O40 het-eropolyacid acid.An introduction of light was observed to enhance both the i-C4H10 conversion and the MAA selectivity,and consequently the MAA formate rate,particularly at low temperatures.Characterization re-sults show that oxidation of methacrolein(MAL)to MAA is the rate-limiting step while UV light illumination promotes the oxidation ofσ-bonded MAL with OH groups toσ-bonded MAA on the catalyst surface.These results demonstrate a synergistic effect of thermal cataly-sis and photocatalysis in selective oxidation of isobutane to MAA,which suggests photother-mal catalysis as a promising strategy to catalyze the selective oxidation of higher hydrocar-bons at relative mild reaction conditions.
文摘为探究气候温和地区高校教室内的热舒适性,且修正预测热感觉和不满意度模型(predicted mean vote-predicted percentage of dissatisfaction,PMV-PPD模型)与实际热感觉投票值存在偏差情况,本文以昆明某高校大学生受试者为试验对象,分别测试室内环境参数、人员评估环境温度(t_(1))以及受试者主观评价等,共获得2229份有效数据。结果表明:在自然通风教室中,超过80%的大学生可以接受当前的热湿环境,PMV与实际平均热感觉投票(mean thermal sensation,MTS)模型相关较弱,PMV模型高估了受试者的实际热感觉,实测人员不满意百分比普遍大于预测不满意百分比。鉴于PMV模型预测准确性较低,综合考虑温度变化、主观反应等影响因素,提出人员评估环境温度(t_(1))作为修正性指标。人员评估环境温度与实际环境温度存在较强相关性,且在不同场景中两者温差值小于1.5℃。将t_(1)与热感觉投票进行回归分析,该参数与热感觉投票高度相关。在PMV计算中使用t_(1)代替空气温度对PMV模型进行修正得到tPMV,修正后的tPMV更接近于MTS模型,对PMV起到显著有效的修正作用。
