Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prep...Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol.展开更多
目的开发与验证基于主动脉周围脂肪组织(PVAT)影像组学特征及其联合临床、CTA特征的预测模型,评估其对A型主动脉夹层(TAAD)术后短期不良事件(AE)的预测效能。方法本研究采用纳入2015年1月至2024年12月收治的116例TAAD手术患者。通过随...目的开发与验证基于主动脉周围脂肪组织(PVAT)影像组学特征及其联合临床、CTA特征的预测模型,评估其对A型主动脉夹层(TAAD)术后短期不良事件(AE)的预测效能。方法本研究采用纳入2015年1月至2024年12月收治的116例TAAD手术患者。通过随机分配将患者划分为训练集和验证集。患者根据术后是否发生AE分为AE组和非AE组。使用3D Slicer软件对术前CTA影像中主动脉破口PVAT进行三维分割,经影像组学特提取、降维后构建影像组学模型。筛选临床及CTA特征,建立临床-CTA预测模型。整合组学预测参数与临床-CTA特征构建联合模型。通过受试者工作特征曲线(ROC)、Delong检验评估模型的区分度。结果联合模型的预测效能优于临床-CTA模型(AUC=0.939 vs 0.775,P=0.043),但与组学模型无显著差异(AUC=0.939 vs 0.881,P=0.138)。结论基于PVAT影像组学特征联合临床CTA特征构建的预测模型能有效预测TAAD术后AE高危患者。展开更多
基金Supported by National Key R&D Program of China(2022YFA1503400)。
文摘Aiming at the problems of insufficient activity and selectivity of Cu-based catalysts in CO_(2)hydrogenation to methanol,Al_(2)O_(3),ZrO_(2)and CeO_(2)modified Cu-ZnO catalysts by the co-precipitation method were prepared,and the influence mechanism of additives on the structure-performance relationship of the catalysts was systematically explored.Through a variety of characterization methods such as XRD,N2 physical adsorption-desorption,TEM,H_(2)-TPR,CO_(2)-TPD and XPS,combined with catalytic performance evaluation experiments,the correlation between the microstructure of catalysts and the reaction performance of CO_(2)hydrogenation to methanol was analyzed in depth.The results show that metal additives significantly improve the performance of catalysts.After the introduction of additives,the specific surface area and pore volume of the catalysts increase,the grain size of Cu decreases,and its dispersion improves.The Ce-modified CZC catalyst exhibited the best performance,with the grain size of CuO as small as 11.41 nm,and the surface oxygen vacancy concentration(OⅡ/OⅠ=3.15)was significantly higher than that of other samples.The reaction performance test shows that under the conditions of 2.8 MPa,8000 h−1 and 280℃,the CO_(2)conversion of the CZC catalyst reached 18.83%,the methanol selectivity was 68.40%,and the methanol yield was 12.88%,all of which are superior to other catalysts.Its excellent performance can be attributed to the fact that CeO_(2)enhances the metal-support interaction,increases the surface basicity,promotes the adsorption and activation of CO_(2),and simultaneously inhibits the reverse water-gas shift side reaction.This study clarifies the structure-activity regulation mechanism of additive modification on Cu-ZnO catalysts,providing a theoretical basis and technical reference for the development of efficient catalysts for CO_(2)hydrogenation to methanol.
文摘目的开发与验证基于主动脉周围脂肪组织(PVAT)影像组学特征及其联合临床、CTA特征的预测模型,评估其对A型主动脉夹层(TAAD)术后短期不良事件(AE)的预测效能。方法本研究采用纳入2015年1月至2024年12月收治的116例TAAD手术患者。通过随机分配将患者划分为训练集和验证集。患者根据术后是否发生AE分为AE组和非AE组。使用3D Slicer软件对术前CTA影像中主动脉破口PVAT进行三维分割,经影像组学特提取、降维后构建影像组学模型。筛选临床及CTA特征,建立临床-CTA预测模型。整合组学预测参数与临床-CTA特征构建联合模型。通过受试者工作特征曲线(ROC)、Delong检验评估模型的区分度。结果联合模型的预测效能优于临床-CTA模型(AUC=0.939 vs 0.775,P=0.043),但与组学模型无显著差异(AUC=0.939 vs 0.881,P=0.138)。结论基于PVAT影像组学特征联合临床CTA特征构建的预测模型能有效预测TAAD术后AE高危患者。
