针对传统评价方法对长序列且样本分布在不同功能分区的水质评价的不足,提出MSA(Markov-SFI-AHP)水质评价模型,并结合混匀浓度法(Well-mixed model calculation)在南水北调中线焦作段地下水水质评价中加以应用。首先,利用马尔科夫动态评...针对传统评价方法对长序列且样本分布在不同功能分区的水质评价的不足,提出MSA(Markov-SFI-AHP)水质评价模型,并结合混匀浓度法(Well-mixed model calculation)在南水北调中线焦作段地下水水质评价中加以应用。首先,利用马尔科夫动态评价法(M)对干渠周边浅层地下水水质作评价,确定水质变差时段;然后,利用单因子指数法(S)和层次分析法(A)对该时段水质进行分析,确定水质变差的主控因素;最后,利用混匀浓度法(W)评价干渠周边浅层地下水对干渠水质的影响。结果显示:虽然2015-2022年浅层地下水水质整体变好,但各时段内水质变差的情况时有发生,2019年和2021年水质变差,主要污染指标为总硬度、TDS、Cl^(-)和NO_(3)^(-);水质变差的浅层地下水进入干渠后,干渠各项水质指标评价等级并未下降。MSA模型为长序列水质监测数据的评价提供了新的方法。展开更多
Starch acetate with high DS was prepared by glacial acetic acid and acetic anhydride using methyl sulfonic acid as a catalyst. The influences of reaction temperature, reaction time, ratios of reactants on the esterifi...Starch acetate with high DS was prepared by glacial acetic acid and acetic anhydride using methyl sulfonic acid as a catalyst. The influences of reaction temperature, reaction time, ratios of reactants on the esterification have been examined. The product is characterized by chemical analysis, infrared analysis, intrinsic viscosity and solubility measurements. High linear amylose was found easier to be esterized.展开更多
文摘针对传统评价方法对长序列且样本分布在不同功能分区的水质评价的不足,提出MSA(Markov-SFI-AHP)水质评价模型,并结合混匀浓度法(Well-mixed model calculation)在南水北调中线焦作段地下水水质评价中加以应用。首先,利用马尔科夫动态评价法(M)对干渠周边浅层地下水水质作评价,确定水质变差时段;然后,利用单因子指数法(S)和层次分析法(A)对该时段水质进行分析,确定水质变差的主控因素;最后,利用混匀浓度法(W)评价干渠周边浅层地下水对干渠水质的影响。结果显示:虽然2015-2022年浅层地下水水质整体变好,但各时段内水质变差的情况时有发生,2019年和2021年水质变差,主要污染指标为总硬度、TDS、Cl^(-)和NO_(3)^(-);水质变差的浅层地下水进入干渠后,干渠各项水质指标评价等级并未下降。MSA模型为长序列水质监测数据的评价提供了新的方法。
文摘Starch acetate with high DS was prepared by glacial acetic acid and acetic anhydride using methyl sulfonic acid as a catalyst. The influences of reaction temperature, reaction time, ratios of reactants on the esterification have been examined. The product is characterized by chemical analysis, infrared analysis, intrinsic viscosity and solubility measurements. High linear amylose was found easier to be esterized.
