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超交联多孔材料的合成及吸附氨基酸特性 被引量:1
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作者 闫慧君 高飞翔 +5 位作者 王爽 李思龙 高锦鹏 李姗姗 王楷淞 白建伟 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2023年第6期1-7,14,共8页
以苯为反应单体、二甲氧基甲烷(FDA)为交联剂,通过Friedel-Crafts烷基化反应,改变单体与交联剂之间的摩尔比来调控聚合物的孔隙结构,合成了一系列具有高比表面积的多孔芳香交联聚合物HCP-PhH-(1-3)。通过氮气吸附脱附、热失重和红外光... 以苯为反应单体、二甲氧基甲烷(FDA)为交联剂,通过Friedel-Crafts烷基化反应,改变单体与交联剂之间的摩尔比来调控聚合物的孔隙结构,合成了一系列具有高比表面积的多孔芳香交联聚合物HCP-PhH-(1-3)。通过氮气吸附脱附、热失重和红外光谱对其进行表征,聚合物表现出丰富的孔径结构与良好的稳定性。将其对色氨酸(Trp)、苯丙氨酸(Phe)以及苯甘氨酸(Phg)进行了吸附行为研究,结果表明,单体苯与交联剂FDA的摩尔比为1:5时,合成的聚合物HCP-PhH-3具有相对较大的比表面积901.498 m^(2)/g,在25℃时对pH=7、浓度1.5 mmol/L的氨基酸溶液具有较大的吸附能力,吸附量分别为色氨酸(0.199 mmol/g)、苯丙氨酸(0.140mmol/g)、苯甘氨酸(0.034 mmol/g),显示出明显的吸附效果。对HCP-PhH-3吸附氨基酸的过程进行动力学拟合,线性拟合相关度(R2)符合准二级动力学模型。 展开更多
关键词 超交联 外交联编织 多孔材料 氨基酸吸附
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含磷六元醇的制备及改性水性聚氨酯的结构与性能 被引量:3
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作者 王双 谢敏 +3 位作者 王海波 成煦 刘源森 杜宗良 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2018年第2期32-36,共5页
以三氯氧磷、丙烯酸羟乙酯和二乙醇胺为原料,合成了一种含磷六羟基多元醇(NP6),将NP6作为内交联剂,异氟尔酮二异氰酸酯、聚丙二醇及二羟甲基丙酸等原料,合成了一系列NP6含量不同的聚氨酯乳液(WPU)。采用红外光谱、核磁共振对NP6和WPU的... 以三氯氧磷、丙烯酸羟乙酯和二乙醇胺为原料,合成了一种含磷六羟基多元醇(NP6),将NP6作为内交联剂,异氟尔酮二异氰酸酯、聚丙二醇及二羟甲基丙酸等原料,合成了一系列NP6含量不同的聚氨酯乳液(WPU)。采用红外光谱、核磁共振对NP6和WPU的结构进行了表征,测试了乳液粒径、乳液稳定性和胶膜力学性能,采用热失重分析对乳胶膜的耐热性能进行了分析。结果表明,合成了与设计结构相符的NP6,制备的WPU具有良好的储存稳定性;乳液粒径随NP6含量增加先减小后增大,NP6的加入使乳胶膜的初始模量显著增加;加入NP6后乳胶膜的起始分解温度降低,分解后的残渣量增加。 展开更多
关键词 水性聚氨酯 含磷六元醇 改性 结构 性能
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Fabrication of electrostatic safety copper azide film with in situ growing MOF
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作者 shuang wang Li Yang +3 位作者 Zhenzhan Yan Jimin Han Xiaoting Ren Wei Li 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第9期93-100,共8页
Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared ... Due to its extremely low electrostatic sensitivity,copper azide primary explosive is greatly limited in practical applications.In this study,a composite film with Cu-MOF in-situ growth on carbon nanofilm was prepared by electrospinning and solvothermal methods,and CNF@Cu-N3film with electrostatic safety was obtained by carbonization and azide later.Its electrostatic sensitivity(E50)was greatly increased from 0.05 mJ of raw materials to 4.06 mJ,and still maintained a good detonation performance which could successfully detonate the CL-20 secondary explosive.This is mainly due to the synergistic effect of the carbon film and the MOF structure,which greatly improves the conductivity of the entire system and the uniform distribution of copper particles,providing a new preparation strategy for metal azide film that is suitable for the micro-initiator device. 展开更多
关键词 Carbon nanofilm Metal-organic framework Copper azide(CA) Electrostatic sensitivity ELECTROSPINNING
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An empirical study on the effect of user engagement on personalized free-content promotion based on a causal machine learning model
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作者 shuang wang Hanbing Xue Lizheng wang 《中国科学技术大学学报》 CSCD 北大核心 2024年第10期51-62,I0007,共13页
Many digital platforms have employed free-content promotion strategies to deal with the high uncertainty levels regarding digital content products.However,the diversity of digital content products and user heterogenei... Many digital platforms have employed free-content promotion strategies to deal with the high uncertainty levels regarding digital content products.However,the diversity of digital content products and user heterogeneity in content preference may blur the impact of platform promotions across users and products.Therefore,free-content promotion strategies should be adapted to allocate marketing resources optimally and increase revenue.This study develops personal-ized free-content promotion strategies based on individual-level heterogeneous treatment effects and explores the causes of their heterogeneity,focusing on the moderating effect of user engagement-related variables.To this end,we utilize ran-dom field experimental data provided by a top Chinese e-book platform.We employ a framework that combines machine learning with econometric causal inference methods to estimate individual treatment effects and analyze their potential mechanisms.The analysis shows that,on average,free-content promotions lead to a significant increase in consumer pay-ments.However,the higher the level of user engagement,the lower the payment lift caused by promotions,as more-engaged users are more strongly affected by the cannibalization effect of free-content promotion.This study introduces a novel causal research design to help platforms improve their marketing strategies. 展开更多
关键词 free-content promotion user engagement random experiment causal machine learning individual-level treat-ment effect
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