Propane dehydrogenation(PDH)on Ga/H-ZSM-5 catalysts is a promising reaction for propylene production,while the detail mechanism remains debatable.Ga_(2)O_(2)^(2+) stabilized by framework Al pairs have been identified ...Propane dehydrogenation(PDH)on Ga/H-ZSM-5 catalysts is a promising reaction for propylene production,while the detail mechanism remains debatable.Ga_(2)O_(2)^(2+) stabilized by framework Al pairs have been identified as the most active species in Ga/H-ZSM-5 for PDH in our recent work.Here we demonstrate a strong correlation between the PDH activity and a fraction of Ga_(2)O_(2)^(2+) species corresponding to the infrared GaH band of higher wavenumber(GaHHW)in reduced Ga/H-ZSM-5,instead of the overall Ga_(2)O_(2)^(2+) species,by employing five H-ZSM-5 supports sourced differently with comparable Si/Al ratio.This disparity in Ga_(2)O_(2)^(2+) species stems from their differing capacity in completing the catalytic cycle.Spectroscopic results suggest that PDH proceeds via a two-step mechanism:(1)C-H bond activation of propane on H-Ga_(2)O_(2)^(2+) species(rate determining step);(2)β-hydride elimination of adsorbed propyl group,which only occurs on active Ga_(2)O_(2)^(2+) species corresponding to GaHHW.展开更多
Two unusual one-dimensional（1-D） compounds,viz.[Co（Medpq）（QUI）·H2O]2n· 2.4nH2O 1 and [Cd（Medpq）（QUI）·H2O]n·nH2O 2,were synthesized by the combination of two different metallic salts and o...Two unusual one-dimensional（1-D） compounds,viz.[Co（Medpq）（QUI）·H2O]2n· 2.4nH2O 1 and [Cd（Medpq）（QUI）·H2O]n·nH2O 2,were synthesized by the combination of two different metallic salts and organic ligands,namely 2,3-pyridinedicarboxylic acid（H2QUI） and 2-methyldipyrido[3,2-f：2＇,3＇-h]quinoxaline（Medpq） ligand.The compounds were characterized by elemental analyses,TG,fluorescent emission and single-crystal X-ray diffraction analyses.展开更多
The dehydration of 2-（4＇-ethylbenzoyl） benzoic acid （BE acid） to 2-ethylanthraquinone （2-EAQ） was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 ...The dehydration of 2-（4＇-ethylbenzoyl） benzoic acid （BE acid） to 2-ethylanthraquinone （2-EAQ） was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 solution exhibited an excellent performance. In our study, the conversion of BE acid can reach 96.7%, and the selectivity to 2-EAQ is up to 99.6%.展开更多
目的探究西格列汀治疗2型糖尿病的临床疗效及对患者糖化血红蛋白(HbA_(1)c)、餐后2 h血糖(2 h PBG)水平的影响。方法选取2018年5月至2019年10月于本院就诊的100例2型糖尿病患者作为研究对象,随机分为两组,每组50例。观察组采用西格列汀...目的探究西格列汀治疗2型糖尿病的临床疗效及对患者糖化血红蛋白(HbA_(1)c)、餐后2 h血糖(2 h PBG)水平的影响。方法选取2018年5月至2019年10月于本院就诊的100例2型糖尿病患者作为研究对象,随机分为两组,每组50例。观察组采用西格列汀治疗,对照组采用阿卡波糖治疗,比较两组血糖[空腹血糖(FPG)、2 h PBG、HbA_(1)c]水平、不良反应发生情况、氧化应激指标[丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-PX)、超氧化物歧化酶(SOD)]及临床疗效。结果治疗前,两组FPG、2 h PBG、HbA_(1)c水平比较差异无统计学意义;治疗后,两组FPG、2 h PBG、HbA_(1)c水平均低于治疗前,且观察组低于对照组,差异有统计学意义(P<0.05)。观察组不良反应发生率为2.00%,低于对照组的20.00%,差异有统计学意义(P<0.05)。治疗前,两组MDA、SOD、GSH-PX水平比较差异无统计学意义;治疗后,两组MDA水平均低于治疗前,SOD、GSH-PX水平均高于治疗前,且观察组MDA水平低于对照组,SOD、GSH-PX水平均高于对照组,差异有统计学意义(P<0.05)。结论西格列汀治疗2型糖尿病效果显著,能降低FPG和2 h PBG水平,值得临床推广应用。展开更多
文摘Propane dehydrogenation(PDH)on Ga/H-ZSM-5 catalysts is a promising reaction for propylene production,while the detail mechanism remains debatable.Ga_(2)O_(2)^(2+) stabilized by framework Al pairs have been identified as the most active species in Ga/H-ZSM-5 for PDH in our recent work.Here we demonstrate a strong correlation between the PDH activity and a fraction of Ga_(2)O_(2)^(2+) species corresponding to the infrared GaH band of higher wavenumber(GaHHW)in reduced Ga/H-ZSM-5,instead of the overall Ga_(2)O_(2)^(2+) species,by employing five H-ZSM-5 supports sourced differently with comparable Si/Al ratio.This disparity in Ga_(2)O_(2)^(2+) species stems from their differing capacity in completing the catalytic cycle.Spectroscopic results suggest that PDH proceeds via a two-step mechanism:(1)C-H bond activation of propane on H-Ga_(2)O_(2)^(2+) species(rate determining step);(2)β-hydride elimination of adsorbed propyl group,which only occurs on active Ga_(2)O_(2)^(2+) species corresponding to GaHHW.
文摘Two unusual one-dimensional（1-D） compounds,viz.[Co（Medpq）（QUI）·H2O]2n· 2.4nH2O 1 and [Cd（Medpq）（QUI）·H2O]n·nH2O 2,were synthesized by the combination of two different metallic salts and organic ligands,namely 2,3-pyridinedicarboxylic acid（H2QUI） and 2-methyldipyrido[3,2-f：2＇,3＇-h]quinoxaline（Medpq） ligand.The compounds were characterized by elemental analyses,TG,fluorescent emission and single-crystal X-ray diffraction analyses.
文摘The dehydration of 2-（4＇-ethylbenzoyl） benzoic acid （BE acid） to 2-ethylanthraquinone （2-EAQ） was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 solution exhibited an excellent performance. In our study, the conversion of BE acid can reach 96.7%, and the selectivity to 2-EAQ is up to 99.6%.
文摘目的探究西格列汀治疗2型糖尿病的临床疗效及对患者糖化血红蛋白(HbA_(1)c)、餐后2 h血糖(2 h PBG)水平的影响。方法选取2018年5月至2019年10月于本院就诊的100例2型糖尿病患者作为研究对象,随机分为两组,每组50例。观察组采用西格列汀治疗,对照组采用阿卡波糖治疗,比较两组血糖[空腹血糖(FPG)、2 h PBG、HbA_(1)c]水平、不良反应发生情况、氧化应激指标[丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-PX)、超氧化物歧化酶(SOD)]及临床疗效。结果治疗前,两组FPG、2 h PBG、HbA_(1)c水平比较差异无统计学意义;治疗后,两组FPG、2 h PBG、HbA_(1)c水平均低于治疗前,且观察组低于对照组,差异有统计学意义(P<0.05)。观察组不良反应发生率为2.00%,低于对照组的20.00%,差异有统计学意义(P<0.05)。治疗前,两组MDA、SOD、GSH-PX水平比较差异无统计学意义;治疗后,两组MDA水平均低于治疗前,SOD、GSH-PX水平均高于治疗前,且观察组MDA水平低于对照组,SOD、GSH-PX水平均高于对照组,差异有统计学意义(P<0.05)。结论西格列汀治疗2型糖尿病效果显著,能降低FPG和2 h PBG水平,值得临床推广应用。
