The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic perf...The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic performance of Ni-Al2O3 catalyst for hydrogenation of 1,4-butynediol to produce 1,4-butenediol were investigated.The catalysts were characterized by PSD,EDX,XRD,H2-TPR,BET,TEM,and NH3-TPD methods.Results showed that the MCt2.5 catalyst treated at a ball milling time of 2.5 h could form a smallest particle size of 191.0 nm.The evaluation experiments revealed that the activity of the prepared catalyst increased at first and then reached a constant value with the extension of ballmilling time.The BYD conversion,BED selectivity and yield on the MCt2.5 catalyst reached 35.63%,33.48%and 32.46%,respectively,which were higher than those obtained by other samples.The excellent performance of MCt2.5 sample is mainly related to the following three reasons from characterization results.Firstly,it has a smallest particle size of 191.0 nm;and then,the surface acidity(in terms of strong acids)of the catalyst was weaker than other catalysts;and eventually,the loading amount(23.84%)of the active component Ni exceeded the theoretical value(20%).展开更多
目的观察卵巢-附件报告和数据系统超声2022版(O-RADS US v2022)及其联合恶性风险指数4(RMI4)鉴别附件良、恶性肿瘤的价值。方法回顾性分析126例手术病理诊断为附件肿瘤患者,根据O-RADS US v2022将1~3类归为良性病变、4~5类归为恶性病变,...目的观察卵巢-附件报告和数据系统超声2022版(O-RADS US v2022)及其联合恶性风险指数4(RMI4)鉴别附件良、恶性肿瘤的价值。方法回顾性分析126例手术病理诊断为附件肿瘤患者,根据O-RADS US v2022将1~3类归为良性病变、4~5类归为恶性病变,以450为RMI4分类的临界值,基于二者进行联合分类。以病理结果为金标准,绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评估单一O-RADS US v2022、RMI4及其联合鉴别附件良、恶性肿瘤的效能。结果126例附件肿瘤中,良性94例、恶性32例。O-RADS US v2022鉴别附件良、恶性肿瘤的敏感度、特异度、准确率及AUC分别为78.13%、80.85%和80.16%、0.795,RMI4分别为71.88%、84.04%和80.95%、0.780;二者联合的特异度及准确率(93.62%、92.06%)均高于单一O-RADS US v2022(χ^(2)=7.322、5.967,P=0.007、0.015)或RMI4(χ^(2)=4.625、5.331,P=0.032、0.021),而敏感度及AUC(87.50%、0.906)差异均无统计学意义(P均>0.05)。结论O-RADS US v2022能有效鉴别附件良、恶性肿瘤,联合RMI4可提高鉴别特异度及准确率。展开更多
基金This work has been supported by the Xinjiang Uygur Autonomous Region Key R&D Program(2017B02012)the Xinjiang University Natural Science Foundation Project(BS160221).
文摘The Ni-Al2O3 catalyst was prepared by the mechanochemical method in combination with a planetary ballmilling machine.Effect of milling time on the crystal structure,the reduction characteristics and the catalytic performance of Ni-Al2O3 catalyst for hydrogenation of 1,4-butynediol to produce 1,4-butenediol were investigated.The catalysts were characterized by PSD,EDX,XRD,H2-TPR,BET,TEM,and NH3-TPD methods.Results showed that the MCt2.5 catalyst treated at a ball milling time of 2.5 h could form a smallest particle size of 191.0 nm.The evaluation experiments revealed that the activity of the prepared catalyst increased at first and then reached a constant value with the extension of ballmilling time.The BYD conversion,BED selectivity and yield on the MCt2.5 catalyst reached 35.63%,33.48%and 32.46%,respectively,which were higher than those obtained by other samples.The excellent performance of MCt2.5 sample is mainly related to the following three reasons from characterization results.Firstly,it has a smallest particle size of 191.0 nm;and then,the surface acidity(in terms of strong acids)of the catalyst was weaker than other catalysts;and eventually,the loading amount(23.84%)of the active component Ni exceeded the theoretical value(20%).
文摘目的观察卵巢-附件报告和数据系统超声2022版(O-RADS US v2022)及其联合恶性风险指数4(RMI4)鉴别附件良、恶性肿瘤的价值。方法回顾性分析126例手术病理诊断为附件肿瘤患者,根据O-RADS US v2022将1~3类归为良性病变、4~5类归为恶性病变,以450为RMI4分类的临界值,基于二者进行联合分类。以病理结果为金标准,绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评估单一O-RADS US v2022、RMI4及其联合鉴别附件良、恶性肿瘤的效能。结果126例附件肿瘤中,良性94例、恶性32例。O-RADS US v2022鉴别附件良、恶性肿瘤的敏感度、特异度、准确率及AUC分别为78.13%、80.85%和80.16%、0.795,RMI4分别为71.88%、84.04%和80.95%、0.780;二者联合的特异度及准确率(93.62%、92.06%)均高于单一O-RADS US v2022(χ^(2)=7.322、5.967,P=0.007、0.015)或RMI4(χ^(2)=4.625、5.331,P=0.032、0.021),而敏感度及AUC(87.50%、0.906)差异均无统计学意义(P均>0.05)。结论O-RADS US v2022能有效鉴别附件良、恶性肿瘤,联合RMI4可提高鉴别特异度及准确率。