目的:采用真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO)预测制何首乌中大黄素在不同溶剂中的提取情况,筛选最佳提取溶剂并对提取机理进行解释。方法:利用COSMO模型预测了1,3-丙二醇-乳酸(1∶3)制...目的:采用真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO)预测制何首乌中大黄素在不同溶剂中的提取情况,筛选最佳提取溶剂并对提取机理进行解释。方法:利用COSMO模型预测了1,3-丙二醇-乳酸(1∶3)制备的天然低共熔溶剂(natural deep eutectic solvents,NADESs)与传统低共熔溶剂(traditional deep eutectic solvents,DESs)对制何首乌中大黄素的提取情况,并通过试验验证该模型预测结果的准确性,进一步解释提取机理。结果:经COSMO模型预测,大黄素与1,3-丙二醇-乳酸(1∶3)组成的NADES间的相互作用能为-762.8972 kJ/mol,显著高于大黄素与甲醇和水间的相互作用能。相互作用能越大,提取效率越高。最终预测大黄素提取效率由高到低依次为1,3-丙二醇-乳酸(1∶3)、甲醇、水。经试验进一步验证,NADES对大黄素的提取率为1.1266 mg/g,提取效率是水的16.07倍,甲醇的1.19倍,整体趋势与COSMO模型预测结果一致。结论:COSMO模型不仅可以准确预测大黄素在不同溶剂中的溶解规律,还可以从微观角度解释提取机理,可为各类天然产物高效提取溶剂的选择提供一定借鉴。展开更多
在化工、能源、环境、食品和药物等工业设计过程中,真实混合物的可靠溶解度数据非常重要,不仅能丰富相平衡数据库,还能指导工艺设备设计和产品质量控制。本文介绍了烃-水体系相互溶解度的模型化研究,包括状态方程法、活度系数法和经验...在化工、能源、环境、食品和药物等工业设计过程中,真实混合物的可靠溶解度数据非常重要,不仅能丰富相平衡数据库,还能指导工艺设备设计和产品质量控制。本文介绍了烃-水体系相互溶解度的模型化研究,包括状态方程法、活度系数法和经验关联式,以及近年来发展起来的真实溶剂似导体屏蔽模型法(conductor-like screening model for real solvents,COSMO-RS)。状态方程法和活度系数法主要是通过选择非对称的混合规则以及引进描述水分子极性作用的参数,来改善对烃-水体系相互溶解度的计算精度。经验关联式主要是对实验数据的拟合,每种烃的参数不同。COSMO-RS模型根据密度泛函理论(即建立极化电荷密度的简单经验式)计算单个分子嵌入虚拟导体产生的作用,通过准确描述界面统计相互作用获得体系的热力学性质。因此,该方法对各种体系具有普适性。分析表明,COSMO-RS模型对烃-水体系相互溶解度的预测值与实验值吻合良好,可以补充某些难以通过实验获得的烃-水体系互溶度数据。最后总结和展望了烃-水体系相互溶解度模型化的未来发展方向。展开更多
The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based earl...The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.展开更多
文摘目的:采用真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO)预测制何首乌中大黄素在不同溶剂中的提取情况,筛选最佳提取溶剂并对提取机理进行解释。方法:利用COSMO模型预测了1,3-丙二醇-乳酸(1∶3)制备的天然低共熔溶剂(natural deep eutectic solvents,NADESs)与传统低共熔溶剂(traditional deep eutectic solvents,DESs)对制何首乌中大黄素的提取情况,并通过试验验证该模型预测结果的准确性,进一步解释提取机理。结果:经COSMO模型预测,大黄素与1,3-丙二醇-乳酸(1∶3)组成的NADES间的相互作用能为-762.8972 kJ/mol,显著高于大黄素与甲醇和水间的相互作用能。相互作用能越大,提取效率越高。最终预测大黄素提取效率由高到低依次为1,3-丙二醇-乳酸(1∶3)、甲醇、水。经试验进一步验证,NADES对大黄素的提取率为1.1266 mg/g,提取效率是水的16.07倍,甲醇的1.19倍,整体趋势与COSMO模型预测结果一致。结论:COSMO模型不仅可以准确预测大黄素在不同溶剂中的溶解规律,还可以从微观角度解释提取机理,可为各类天然产物高效提取溶剂的选择提供一定借鉴。
文摘在化工、能源、环境、食品和药物等工业设计过程中,真实混合物的可靠溶解度数据非常重要,不仅能丰富相平衡数据库,还能指导工艺设备设计和产品质量控制。本文介绍了烃-水体系相互溶解度的模型化研究,包括状态方程法、活度系数法和经验关联式,以及近年来发展起来的真实溶剂似导体屏蔽模型法(conductor-like screening model for real solvents,COSMO-RS)。状态方程法和活度系数法主要是通过选择非对称的混合规则以及引进描述水分子极性作用的参数,来改善对烃-水体系相互溶解度的计算精度。经验关联式主要是对实验数据的拟合,每种烃的参数不同。COSMO-RS模型根据密度泛函理论(即建立极化电荷密度的简单经验式)计算单个分子嵌入虚拟导体产生的作用,通过准确描述界面统计相互作用获得体系的热力学性质。因此,该方法对各种体系具有普适性。分析表明,COSMO-RS模型对烃-水体系相互溶解度的预测值与实验值吻合良好,可以补充某些难以通过实验获得的烃-水体系互溶度数据。最后总结和展望了烃-水体系相互溶解度模型化的未来发展方向。
基金the joint research project Early Dike–Sensor and Risk based Early Warning Systems for Coastal Dikes(No.03G0847C)funded by the German Ministry of Education and Research(BMBF)
文摘The knowledge of the wave-induced hydrodynamic loads on coastal dikes including their temporal and spatial resolution on the dike in combination with actual water levels is of crucial importance of any risk-based early warning system. As a basis for the assessment of the wave-induced hydrodynamic loads, an operational wave now-and forecast system is set up that consists of i) available field measurements from the federal and local authorities and ii) data from numerical simulation of waves in the German Bight using the SWAN wave model. In this study, results of the hindcast of deep water wave conditions during the winter storm on 5–6 December, 2013(German name ‘Xaver') are shown and compared with available measurements. Moreover field measurements of wave run-up from the local authorities at a sea dike on the German North Sea Island of Pellworm are presented and compared against calculated wave run-up using the Eur Otop(2016) approach.
