This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly a...This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation mechanism.The effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive microcalorimetry.The results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and could effectively delay the setting time of ACCM,but the mechanical properties were slightly decreased.The setting time of ACCM increased with the increase in SG content,but the mechanical properties of ACCM decreased with the increase in SG content.C1_(2)H_(22)O_(11)(CHO)could effectively delay the hydration reaction of ACCM and weakly enhanced the compressive strength.H_(3)PO_(4)(HP)at a concentration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a concentration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.展开更多
China is setting to roll out more strict emissions rule of CHINA Ⅵ Emission Standard which poses huge challenge to automotive catalytic technology.Rare earth elements are the key compositions of the catalysts coating...China is setting to roll out more strict emissions rule of CHINA Ⅵ Emission Standard which poses huge challenge to automotive catalytic technology.Rare earth elements are the key compositions of the catalysts coating.To develop multiple-component rare earth materials is an important way to improve the performance of the catalyst.The study concluded that quaternary or quinary rare earth materials for CHINA Ⅵ Emission Standard,can improve substantially the oxygen storage capacity and high thermal stability of the catalyst,after the modification by Pr/NdAT elements.It improved the utilization efficiency of precious metal.展开更多
目的通过评估我国公开发表的医保预算影响分析(BIA)研究文献,探讨我国医保BIA研究预测的准确性,并分析其影响因素,以期为我国医保决策提供参考。方法通过PubMed、Web of Science、CNKI、万方和维普等数据库检索BIA研究的相关文献,使用...目的通过评估我国公开发表的医保预算影响分析(BIA)研究文献,探讨我国医保BIA研究预测的准确性,并分析其影响因素,以期为我国医保决策提供参考。方法通过PubMed、Web of Science、CNKI、万方和维普等数据库检索BIA研究的相关文献,使用医保预算影响分析质量评估量表对纳入研究的文献质量进行定量评估,准确性分析指标为药品销售金额预测值与其实际值的比值,使用t检验进行单因素分析、多重线性回归进行多因素分析。结果最终纳入11篇文献,文献评估得分为0.7503±0.0309。共有24项数据纳入分析,单因素分析结果显示文献评分对BIA预测准确性差异有统计学意义(P<0.05),多因素分析显示BIA预测准确性受到文献评分、年均/疗程药品成本的影响(F=7.844,P<0.05)。结论我国医保BIA相关文献质量总体较好,但在数据引用、分析内容与结果呈现等方面仍存在一定问题;研究预测结果的准确性存在欠缺,预测值普遍高于实际值。建议提高对医保BIA研究质量的重视程度,加强医保BIA准确性的相关研究。展开更多
基金Funded by Key Laboratory for Comprehensive Energy Saving of Cold Regions Architecture of Ministry of Education(No.JLJZHDKF202204)。
文摘This paper studied the effects of different retarders on the performance of the"one-step"alkali-activated composite cementitious material(ACCM)which is composed of ground granulated blast slag(GGBS)and fly ash(FA),and analyzed its mechanical properties,hydration mechanism,and retardation mechanism.The effects of retarders on the hydration products,mechanical properties,and hydration kinetics of ACCM were investigated using XRD,SEM,FTIR,EDS,and thermoactive microcalorimetry.The results showed that Na_(2)B_(4)O_(7)·10H_(2)O(B)delayed the exotherm during the alkali activation process and could effectively delay the setting time of ACCM,but the mechanical properties were slightly decreased.The setting time of ACCM increased with the increase in SG content,but the mechanical properties of ACCM decreased with the increase in SG content.C1_(2)H_(22)O_(11)(CHO)could effectively delay the hydration reaction of ACCM and weakly enhanced the compressive strength.H_(3)PO_(4)(HP)at a concentration of 0.05 mol/L had a certain effect on ACCM retardation,but HP at a concentration of 0.07 and 0.09 mol/L had an effect of promoting the setting and hardening time of ACCM.
文摘China is setting to roll out more strict emissions rule of CHINA Ⅵ Emission Standard which poses huge challenge to automotive catalytic technology.Rare earth elements are the key compositions of the catalysts coating.To develop multiple-component rare earth materials is an important way to improve the performance of the catalyst.The study concluded that quaternary or quinary rare earth materials for CHINA Ⅵ Emission Standard,can improve substantially the oxygen storage capacity and high thermal stability of the catalyst,after the modification by Pr/NdAT elements.It improved the utilization efficiency of precious metal.
文摘目的通过评估我国公开发表的医保预算影响分析(BIA)研究文献,探讨我国医保BIA研究预测的准确性,并分析其影响因素,以期为我国医保决策提供参考。方法通过PubMed、Web of Science、CNKI、万方和维普等数据库检索BIA研究的相关文献,使用医保预算影响分析质量评估量表对纳入研究的文献质量进行定量评估,准确性分析指标为药品销售金额预测值与其实际值的比值,使用t检验进行单因素分析、多重线性回归进行多因素分析。结果最终纳入11篇文献,文献评估得分为0.7503±0.0309。共有24项数据纳入分析,单因素分析结果显示文献评分对BIA预测准确性差异有统计学意义(P<0.05),多因素分析显示BIA预测准确性受到文献评分、年均/疗程药品成本的影响(F=7.844,P<0.05)。结论我国医保BIA相关文献质量总体较好,但在数据引用、分析内容与结果呈现等方面仍存在一定问题;研究预测结果的准确性存在欠缺,预测值普遍高于实际值。建议提高对医保BIA研究质量的重视程度,加强医保BIA准确性的相关研究。
