将化工热力学溶液理论和化工流程模拟有机结合,设计了正己烷-甲基环戊烷萃取精馏计算型实验。通过类导体屏蔽电荷真实溶液模型(conductor-like screening model for real solvents,COSMO-RS)计算,基于溶解性、选择性指标筛选离子液体溶...将化工热力学溶液理论和化工流程模拟有机结合,设计了正己烷-甲基环戊烷萃取精馏计算型实验。通过类导体屏蔽电荷真实溶液模型(conductor-like screening model for real solvents,COSMO-RS)计算,基于溶解性、选择性指标筛选离子液体溶剂;通过量子化学计算及屏蔽电荷密度曲线分析溶剂和溶质分子相互作用,探究离子液体促进分离过程的机理;基于筛选的溶剂,利用Aspen Plus软件计算优化萃取分离工艺。该综合实验融合了化工热力学、化工原理和过程系统工程等专业课程内容,同时将学科理论知识与工程实践应用有机结合,强化了专业基本功训练,激发了研究兴趣,提升了创新能力。展开更多
Floods are phenomenon with significant socio-economic implications mainly for human loss, agriculture, livestock, soil loss and land degradation, for which many researchers try to identify the most appropriate methodo...Floods are phenomenon with significant socio-economic implications mainly for human loss, agriculture, livestock, soil loss and land degradation, for which many researchers try to identify the most appropriate methodologies by analyzing their temporal and spatial development. This study therefore attempts to employ the GIS-based multi-criteria decision analysis and analytical hierarchy process techniques to derive the flood risks management on rice productivity in the Gishari Agricultural Marshland in Rwamagana district, Rwanda. Here, six influencing potential factors to flooding, including river slope, soil texture, Land Use Land Cover through Land Sat 8, rainfall, river distance and Digital Elevation Model are considered for the delineation of flood risk zones. Data acquisition like Landsat 8 images, DEM, land use land cover, slope, and soil class in the study area were considered. Results showed that if the DEM is outdated or inaccurate due to changes in the terrain, such as construction, excavation, or erosion, the predicted flood patterns might not reflect the actual water flow. This could result unexpected flood extents and depths, potentially inundating rice fields that were not previously at risk and this, expectedly explained that the increase 1 m in elevation would reduce the rice productivity by 0.17% due to unplanned flood risks in marshland. It was found that the change in rainfall distribution in Gishari agricultural marshland would also decrease the rice productivity by 0.0018%, which is a sign that rainfall is a major factor of flooding in rice scheme. Rainfall distribution plays a crucial role in flooding analysis and can directly impact rice productivity. Oppositely, another causal factor was Land Use Land Cover (LULC), where the Multivariate Logistic Regression Model Analysis findings showed that the increase of one unit in Land Use Land Cover would increase rice productivity by 0.17% of the total rice productivity from the Gishari Agricultural Marshland. Based on findings from these techniques, the Gishari Agricultural Marshlands having steeped land with grassland is classified into five classes of flooding namely very low, low, moderate, high, and very high which include 430%, 361%, 292%, 223%, and 154%. Government of Rwanda and other implementing agencies and major key actors have to contribute on soil and water conservation strategies to reduce the runoff and soil erosion as major contributors of flooding.展开更多
文摘将化工热力学溶液理论和化工流程模拟有机结合,设计了正己烷-甲基环戊烷萃取精馏计算型实验。通过类导体屏蔽电荷真实溶液模型(conductor-like screening model for real solvents,COSMO-RS)计算,基于溶解性、选择性指标筛选离子液体溶剂;通过量子化学计算及屏蔽电荷密度曲线分析溶剂和溶质分子相互作用,探究离子液体促进分离过程的机理;基于筛选的溶剂,利用Aspen Plus软件计算优化萃取分离工艺。该综合实验融合了化工热力学、化工原理和过程系统工程等专业课程内容,同时将学科理论知识与工程实践应用有机结合,强化了专业基本功训练,激发了研究兴趣,提升了创新能力。
文摘Floods are phenomenon with significant socio-economic implications mainly for human loss, agriculture, livestock, soil loss and land degradation, for which many researchers try to identify the most appropriate methodologies by analyzing their temporal and spatial development. This study therefore attempts to employ the GIS-based multi-criteria decision analysis and analytical hierarchy process techniques to derive the flood risks management on rice productivity in the Gishari Agricultural Marshland in Rwamagana district, Rwanda. Here, six influencing potential factors to flooding, including river slope, soil texture, Land Use Land Cover through Land Sat 8, rainfall, river distance and Digital Elevation Model are considered for the delineation of flood risk zones. Data acquisition like Landsat 8 images, DEM, land use land cover, slope, and soil class in the study area were considered. Results showed that if the DEM is outdated or inaccurate due to changes in the terrain, such as construction, excavation, or erosion, the predicted flood patterns might not reflect the actual water flow. This could result unexpected flood extents and depths, potentially inundating rice fields that were not previously at risk and this, expectedly explained that the increase 1 m in elevation would reduce the rice productivity by 0.17% due to unplanned flood risks in marshland. It was found that the change in rainfall distribution in Gishari agricultural marshland would also decrease the rice productivity by 0.0018%, which is a sign that rainfall is a major factor of flooding in rice scheme. Rainfall distribution plays a crucial role in flooding analysis and can directly impact rice productivity. Oppositely, another causal factor was Land Use Land Cover (LULC), where the Multivariate Logistic Regression Model Analysis findings showed that the increase of one unit in Land Use Land Cover would increase rice productivity by 0.17% of the total rice productivity from the Gishari Agricultural Marshland. Based on findings from these techniques, the Gishari Agricultural Marshlands having steeped land with grassland is classified into five classes of flooding namely very low, low, moderate, high, and very high which include 430%, 361%, 292%, 223%, and 154%. Government of Rwanda and other implementing agencies and major key actors have to contribute on soil and water conservation strategies to reduce the runoff and soil erosion as major contributors of flooding.
