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
Awell-anticipated wide-field X-ray focusing imager,the Einstein Probe(EP,also named“Tianguan”in Chinese)has caught the eye of astronomers since its launch in January 2024.Initiated and sponsored by the Chinese Acade...Awell-anticipated wide-field X-ray focusing imager,the Einstein Probe(EP,also named“Tianguan”in Chinese)has caught the eye of astronomers since its launch in January 2024.Initiated and sponsored by the Chinese Academy of Sciences(CAS),and developed in cooperation with the European Space Agency(ESA).展开更多
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
After more than 18 months of nearly flawless operation,the James Webb Space Telescope(JWST)continues to deliver amazement,making unexpected discoveries,adding new wrinkles to known phenomena,and calling into question ...After more than 18 months of nearly flawless operation,the James Webb Space Telescope(JWST)continues to deliver amazement,making unexpected discoveries,adding new wrinkles to known phenomena,and calling into question long-held theories of how the universe works.“The instruments are working amazingly well,in essentially all cases better than expected,”said Garth Illingworth,professor emeritus of astronomy and astrophysics at the University of California,Santa Cruz(CA,USA),and one of the three originators of the mission over three decades ago.“It has exceeded every one of its performance requirements,which is truly amazing when you think about how complex it is.”That complexity has included three decades of planning,design,and construction,followed by launch and maneuvering 1.5106 km from Earth to its second Lagrange(L2)orbit,unfolding and locking into position the 18 segments of its 6.5 m diameter main mirror,and deploying 8 motors,90 cables,and some 400 pulleys to unfurl its fragile sunshield[1,2].展开更多
离子液体(ionic liquids,ILs)具有许多独特的理化性质,可作为传统有机溶剂吸收分离气体的优良替代物。预测型分子热力学模型,真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO-RS)能够有效模拟“气体+...离子液体(ionic liquids,ILs)具有许多独特的理化性质,可作为传统有机溶剂吸收分离气体的优良替代物。预测型分子热力学模型,真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO-RS)能够有效模拟“气体+离子液体”体系,预测气体在离子液体中的溶解度及选择性。介绍了COSMO-RS模型中重要的理论参数,阐释了COSMO-RS模型计算离子液体性质时的类三元体系,总结了COSMO-RS方法模拟离子液体吸收分离CO_(2)、SO_(2)、芳香族VOCs(volatile organic compounds)、脂肪族VOCs、水蒸气等气体的研究进展,讨论了COSMO-RS模型针对离子液体体系的校正和优化,展望了COSMO-RS模型筛选离子液体用于气体捕集和分离的未来研究方向。展开更多
真实溶剂似导体屏蔽模型(COSMO-RS,Conductor-likescreening model for real solvents)是Klamt等在连续介质溶剂化模式COSMO的基础上,结合统计力学方法发展起来的定量计算溶剂化现象的新方法。本文简单介绍了COSMO-RS的基本原理、概念,...真实溶剂似导体屏蔽模型(COSMO-RS,Conductor-likescreening model for real solvents)是Klamt等在连续介质溶剂化模式COSMO的基础上,结合统计力学方法发展起来的定量计算溶剂化现象的新方法。本文简单介绍了COSMO-RS的基本原理、概念,以及应用该模式的基本步骤。综述了COSMO-RS应用于离子性化合物、聚合物溶液体系、高温高压体系以及预测复杂生物体系的分配系数和药物设计的进展。评述了简化分子表面屏蔽电荷分布计算的COSMOfrag和GC-COSMO(group contribution COSMO)方法,对不同版本的COSMO-RS之间以及其与基团贡献方法的对比研究也作了详细的讨论,并指出了COSMO-RS的不足之处和进一步发展该模式的建议。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Awell-anticipated wide-field X-ray focusing imager,the Einstein Probe(EP,also named“Tianguan”in Chinese)has caught the eye of astronomers since its launch in January 2024.Initiated and sponsored by the Chinese Academy of Sciences(CAS),and developed in cooperation with the European Space Agency(ESA).
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After more than 18 months of nearly flawless operation,the James Webb Space Telescope(JWST)continues to deliver amazement,making unexpected discoveries,adding new wrinkles to known phenomena,and calling into question long-held theories of how the universe works.“The instruments are working amazingly well,in essentially all cases better than expected,”said Garth Illingworth,professor emeritus of astronomy and astrophysics at the University of California,Santa Cruz(CA,USA),and one of the three originators of the mission over three decades ago.“It has exceeded every one of its performance requirements,which is truly amazing when you think about how complex it is.”That complexity has included three decades of planning,design,and construction,followed by launch and maneuvering 1.5106 km from Earth to its second Lagrange(L2)orbit,unfolding and locking into position the 18 segments of its 6.5 m diameter main mirror,and deploying 8 motors,90 cables,and some 400 pulleys to unfurl its fragile sunshield[1,2].
文摘离子液体(ionic liquids,ILs)具有许多独特的理化性质,可作为传统有机溶剂吸收分离气体的优良替代物。预测型分子热力学模型,真实溶剂似导体屏蔽模型(conductor-like screening model for real solvents,COSMO-RS)能够有效模拟“气体+离子液体”体系,预测气体在离子液体中的溶解度及选择性。介绍了COSMO-RS模型中重要的理论参数,阐释了COSMO-RS模型计算离子液体性质时的类三元体系,总结了COSMO-RS方法模拟离子液体吸收分离CO_(2)、SO_(2)、芳香族VOCs(volatile organic compounds)、脂肪族VOCs、水蒸气等气体的研究进展,讨论了COSMO-RS模型针对离子液体体系的校正和优化,展望了COSMO-RS模型筛选离子液体用于气体捕集和分离的未来研究方向。
文摘真实溶剂似导体屏蔽模型(COSMO-RS,Conductor-likescreening model for real solvents)是Klamt等在连续介质溶剂化模式COSMO的基础上,结合统计力学方法发展起来的定量计算溶剂化现象的新方法。本文简单介绍了COSMO-RS的基本原理、概念,以及应用该模式的基本步骤。综述了COSMO-RS应用于离子性化合物、聚合物溶液体系、高温高压体系以及预测复杂生物体系的分配系数和药物设计的进展。评述了简化分子表面屏蔽电荷分布计算的COSMOfrag和GC-COSMO(group contribution COSMO)方法,对不同版本的COSMO-RS之间以及其与基团贡献方法的对比研究也作了详细的讨论,并指出了COSMO-RS的不足之处和进一步发展该模式的建议。
