In this study,ceramics was prepared by slip casting(no pressure was used during shaping step)and atmospheric pressure sintering with low-melting point glass(LPG)powder as the binding material to facilitate the transfo...In this study,ceramics was prepared by slip casting(no pressure was used during shaping step)and atmospheric pressure sintering with low-melting point glass(LPG)powder as the binding material to facilitate the transformation of spodumene flotation tailings(SFTs)into ceramics at lower temperatures.The influence of sintering temperature and mass ratio of LPG on the mechanical properties(flexural strength and compressive strength)of ceramic materials was studied by orthogonal test.The results showed that when the mass ratio of LPG powder was higher than or equal to 20 wt%and the sintering temperature was higher than or equal to 550℃,mutual adhesion between the sample particles was realised and consequently the ceramic materials could be prepared with good mechanical properties(the maximum flexural strength=19.55 MPa,the maximum compressive strength=42.25 MPa,average porosity=24.52%,average apparent density=1.66 g/cm^(3),and average water absorption=14.79%).The sintered ceramics were characterized by XRF,XRD,optical microscopy analysis,SEM,TGA-DSC and FT-IR.The formation of liquid phase at high temperature may lead to the mutual bonding between particles,which might be the main reason for the improvement of mechanical properties of ceramic materials.Overall,SFTs were successfully sintered at low temperature to prepare ceramic materials with good mechanical properties,which are crucial for energy conservation and environmental preservation.展开更多
目的探究晚期早产儿肺部感染病原菌分布特点及预测风险模型的建立和早期诊断价值。方法回顾性选取温州医科大学附属第二医院2018年1月-2020年12月晚期早产儿肺部感染患儿63例作为研究组,另按照1∶2的匹配原则选择同期无肺部感染的晚期...目的探究晚期早产儿肺部感染病原菌分布特点及预测风险模型的建立和早期诊断价值。方法回顾性选取温州医科大学附属第二医院2018年1月-2020年12月晚期早产儿肺部感染患儿63例作为研究组,另按照1∶2的匹配原则选择同期无肺部感染的晚期早产儿126例作为对照组。分析肺部感染患儿病原菌分布特点及其影响因素,并建立Logistic多因素回归预测模型,采用受试者工作特征(ROC)曲线评价模型早期诊断价值。结果63例肺部感染患儿中,病毒感染14例,细菌感染49例;Logistic回归显示,出生5 min Apgar评分是晚期早产儿肺部感染的独立保护因素,胎膜早破、气管插管操作史、PCT、CRP、Lac是晚期早产儿肺部感染的独立危险因素(P<0.05);ROC曲线分析,Logistic多因素回归模型诊断晚期早产儿肺部感染的AUC为0.983,敏感度为92.06%,特异度为96.03%。结论晚期早产儿肺部感染以细菌感染为主,出生5 min Apgar评分、胎膜早破、气管插管操作史、PCT、CRP、Lac均是其独立影响因素,根据上述因素构建Logistic回归模型能有效诊断肺部感染,为临床防控提供指导。展开更多
基金Projects(51674207,51922091)supported by the National Natural Science Foundation of ChinaProject(2018QNRC001)supported by the Young Elite Scientists Sponsorship Program by CAST,ChinaProjects(2019YFS0453,2018JY0148)supported by the Sichuan Science and Technology Program,China。
文摘In this study,ceramics was prepared by slip casting(no pressure was used during shaping step)and atmospheric pressure sintering with low-melting point glass(LPG)powder as the binding material to facilitate the transformation of spodumene flotation tailings(SFTs)into ceramics at lower temperatures.The influence of sintering temperature and mass ratio of LPG on the mechanical properties(flexural strength and compressive strength)of ceramic materials was studied by orthogonal test.The results showed that when the mass ratio of LPG powder was higher than or equal to 20 wt%and the sintering temperature was higher than or equal to 550℃,mutual adhesion between the sample particles was realised and consequently the ceramic materials could be prepared with good mechanical properties(the maximum flexural strength=19.55 MPa,the maximum compressive strength=42.25 MPa,average porosity=24.52%,average apparent density=1.66 g/cm^(3),and average water absorption=14.79%).The sintered ceramics were characterized by XRF,XRD,optical microscopy analysis,SEM,TGA-DSC and FT-IR.The formation of liquid phase at high temperature may lead to the mutual bonding between particles,which might be the main reason for the improvement of mechanical properties of ceramic materials.Overall,SFTs were successfully sintered at low temperature to prepare ceramic materials with good mechanical properties,which are crucial for energy conservation and environmental preservation.
文摘目的探究晚期早产儿肺部感染病原菌分布特点及预测风险模型的建立和早期诊断价值。方法回顾性选取温州医科大学附属第二医院2018年1月-2020年12月晚期早产儿肺部感染患儿63例作为研究组,另按照1∶2的匹配原则选择同期无肺部感染的晚期早产儿126例作为对照组。分析肺部感染患儿病原菌分布特点及其影响因素,并建立Logistic多因素回归预测模型,采用受试者工作特征(ROC)曲线评价模型早期诊断价值。结果63例肺部感染患儿中,病毒感染14例,细菌感染49例;Logistic回归显示,出生5 min Apgar评分是晚期早产儿肺部感染的独立保护因素,胎膜早破、气管插管操作史、PCT、CRP、Lac是晚期早产儿肺部感染的独立危险因素(P<0.05);ROC曲线分析,Logistic多因素回归模型诊断晚期早产儿肺部感染的AUC为0.983,敏感度为92.06%,特异度为96.03%。结论晚期早产儿肺部感染以细菌感染为主,出生5 min Apgar评分、胎膜早破、气管插管操作史、PCT、CRP、Lac均是其独立影响因素,根据上述因素构建Logistic回归模型能有效诊断肺部感染,为临床防控提供指导。
