The escalating production of industrial solid waste,combined with the dwindling availability of natural resources,has intensified the focus on waste recycling.However,the heterogeneity and complexity of waste pose sig...The escalating production of industrial solid waste,combined with the dwindling availability of natural resources,has intensified the focus on waste recycling.However,the heterogeneity and complexity of waste pose significant challenges to determining process parameters.In this study,burnt coal cinder(BCC),granite powder(GP),and high-calcium fly ash(Class-C FA)were used as raw materials,and the response surface methodology(RSM)and single-factor experiments were applied to optimize the process parameters for geopolymer preparation.The optimized precursor powder composition was determined to be a mass ratio of 1.6:0.9:7.3 for BCC,GP,and Class-C FA.The NaOH-precursor powder ratio and liquid-solid ratio were adjusted to 0.084 and 0.222,respectively.The curing condition was set at 80℃ for 24 h.The resulting 28 d-aged multi-solid wastes-based geopolymer exhibited a high compressive strength of61.34 MPa.The microstructure,mineral phase,and atomic bonding of geopolymers were investigated using X-ray diffraction(XRD),thermal analysis(TA),Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS).Findings indicate that the compressive strength of geopolymer is most significantly influenced by the Class-C FA,followed by BCC.Furthermore,a minor addition of GP can optimize the structural density of the geopolymer.The Ca present in the Class-C FA participates in the geopolymerization,forming a hybrid N-(C)-A-S-H gel.RSM optimization facilitates the synergistic utilization of multi-solid wastes,ensuring an even distribution of gel and filler.This research establishes a theoretical framework for optimizing the preparation parameters of multi-solid wastes-based geopolymer and its subsequent applications;it holds significant scientific implications for the circular economy,resource transformation,and environmental conservation.展开更多
本文基于Web of Science核心数据库检索多脉冲/双脉冲发动机主题的英文文献,使用文献可视化分析软件VOSviewer构建并绘制检索结果的研究关键词以及来源国家/地区的共现网络图,来分析该主题研究的现状、热点和发展趋势。在对国外专业技...本文基于Web of Science核心数据库检索多脉冲/双脉冲发动机主题的英文文献,使用文献可视化分析软件VOSviewer构建并绘制检索结果的研究关键词以及来源国家/地区的共现网络图,来分析该主题研究的现状、热点和发展趋势。在对国外专业技术文献进行数据分析的基础上,阐述了国外多脉冲固体火箭发动机的研制和应用情况,主要梳理了美国、俄罗斯、德国等国家多脉冲固体火箭发动机在导弹型号和原型机的应用情况,同时总结了多脉冲固体火箭发动机的关键技术。展开更多
基金supported by the Fundamental Research Funds for the Central Universities,China(No.104972025RSCrc0005)the Science and Technology Project of Shaanxi Yanchang Petroleum(Group)Co.,LTD,China(No.yc-whlg-2023ky-03)。
文摘The escalating production of industrial solid waste,combined with the dwindling availability of natural resources,has intensified the focus on waste recycling.However,the heterogeneity and complexity of waste pose significant challenges to determining process parameters.In this study,burnt coal cinder(BCC),granite powder(GP),and high-calcium fly ash(Class-C FA)were used as raw materials,and the response surface methodology(RSM)and single-factor experiments were applied to optimize the process parameters for geopolymer preparation.The optimized precursor powder composition was determined to be a mass ratio of 1.6:0.9:7.3 for BCC,GP,and Class-C FA.The NaOH-precursor powder ratio and liquid-solid ratio were adjusted to 0.084 and 0.222,respectively.The curing condition was set at 80℃ for 24 h.The resulting 28 d-aged multi-solid wastes-based geopolymer exhibited a high compressive strength of61.34 MPa.The microstructure,mineral phase,and atomic bonding of geopolymers were investigated using X-ray diffraction(XRD),thermal analysis(TA),Fourier transform infrared spectroscopy(FTIR),and scanning electron microscopy with energy dispersive spectroscopy(SEM-EDS).Findings indicate that the compressive strength of geopolymer is most significantly influenced by the Class-C FA,followed by BCC.Furthermore,a minor addition of GP can optimize the structural density of the geopolymer.The Ca present in the Class-C FA participates in the geopolymerization,forming a hybrid N-(C)-A-S-H gel.RSM optimization facilitates the synergistic utilization of multi-solid wastes,ensuring an even distribution of gel and filler.This research establishes a theoretical framework for optimizing the preparation parameters of multi-solid wastes-based geopolymer and its subsequent applications;it holds significant scientific implications for the circular economy,resource transformation,and environmental conservation.
文摘本文基于Web of Science核心数据库检索多脉冲/双脉冲发动机主题的英文文献,使用文献可视化分析软件VOSviewer构建并绘制检索结果的研究关键词以及来源国家/地区的共现网络图,来分析该主题研究的现状、热点和发展趋势。在对国外专业技术文献进行数据分析的基础上,阐述了国外多脉冲固体火箭发动机的研制和应用情况,主要梳理了美国、俄罗斯、德国等国家多脉冲固体火箭发动机在导弹型号和原型机的应用情况,同时总结了多脉冲固体火箭发动机的关键技术。
