In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric s...In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.展开更多
目的:采用Meta分析综合相关随机对照试验(RCT),探讨智能手机技术对学龄前儿童、学龄儿童及青少年静坐行为与屏幕时间可能存在的干预效果。方法:通过检索PubMed、Web of Science、EBSCO和中国知网(核心期刊)数据库,获取智能手机技术干预...目的:采用Meta分析综合相关随机对照试验(RCT),探讨智能手机技术对学龄前儿童、学龄儿童及青少年静坐行为与屏幕时间可能存在的干预效果。方法:通过检索PubMed、Web of Science、EBSCO和中国知网(核心期刊)数据库,获取智能手机技术干预儿童青少年静坐行为及屏幕时间的RCT;采用Cochrane偏倚风险评估工具进行文献质量评价,STATA 15.1软件进行合并效应量分析和亚组分析。结果:共纳入文献15篇,其中应用程序(App)干预3篇、短信(SMS)干预10篇、App+SMS干预2篇。Meta分析发现,与对照组相比,智能手机技术对静坐行为时间的减少无显著干预效果(SMD=0.04;95%CI:-0.06,0.14;P=0.41),但可显著降低屏幕时间(SMD=-0.24;95%CI:-0.35,-0.13;P<0.001)。亚组分析发现,基于SMS技术、SMS+其他、>12岁、>12周、频率<3次/周均可显著降低屏幕时间,但各亚组均未见对静坐行为时间具有显著减少作用。结论:基于智能手机技术干预可有效改善儿童青少年屏幕时间,但对静坐行为无明显干预效果;基于SMS技术干预能有效改善屏幕时间;智能手机技术改善屏幕时间的作用对青少年较适宜,长周期与低频率干预更能体现干预效果。展开更多
目的:探讨冠状病毒对感染患者心肺适能与肌肉适能的影响,为新型冠状病毒肺炎患者的后期运动康复提供依据。方法:通过PubMed、Web of Science、CNKI等数据库检索现有发表的国内外有关人类致命冠状病毒与患者心肺适能、肌肉适能等关系的...目的:探讨冠状病毒对感染患者心肺适能与肌肉适能的影响,为新型冠状病毒肺炎患者的后期运动康复提供依据。方法:通过PubMed、Web of Science、CNKI等数据库检索现有发表的国内外有关人类致命冠状病毒与患者心肺适能、肌肉适能等关系的相关文献,根据纽卡斯尔-渥太华量表(NOS)对纳入文献进行质量评价,提取文献相关信息进行系统评价综合分析。结果:共纳入23篇文献,22篇非随机化研究NOS质量评分平均分为6.9分,1篇随机对照研究为低偏倚风险。患者出院后心肺适能和肌肉适能指标均低于健康人群。患者心肺适能在出院后3年内逐渐恢复,但最大摄氧量(VO2 max)3年内未完全康复,6分钟步行距离(6MWD)1年内未完全康复。患者肌肉适能指标握力、仰卧起坐、俯卧撑出院2周后差于健康人群。运动干预可使患者VO2 max、6MWD、握力、仰卧起坐、俯卧撑水平显著提升。患者感染程度、确诊天数、住院天数等分别与握力、6MWD等显著相关。结论:冠状病毒可导致感染患者心肺适能和肌肉适能受损。患者出院后心肺适能和肌肉适能呈好转趋势,但仍需较长时间才能完全康复。患者心肺适能与肌肉适能的变化受感染程度、确诊天数、住院天数等因素的影响。展开更多
基金supported by National Natural Science Foundation of China(Nos.52202460,52177128)National Key R&D Program of China(Nos.2020YFC2201100,2021YFC2202804)+2 种基金China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036)Science Foundation for Youth Scholars of the Beijing Institute of TechnologyAdvanced Space Propulsion Laboratory of BICE and the Beijing Engineering Research Centre of Efficient and Green Aerospace Propulsion Technology(No.LabASP-2021-04)。
文摘In the present work,the turbulent mixing process of a polydisperse quartz particle flow with a plasma stream generated by a radio-frequency(RF)inductively coupled plasma torch was numerically studied.The thermobaric stress in the quartz particles under dynamic heating in a heterogeneous plasma flow was determined by a two-stage approximation approach.The effect of the presence of vacuoles in natural quartz on the particle thermobaric destruction conditions was studied.It was found that the equivalent thermal and baric stresses in quartz particles may significantly increase in the presence of vacuoles within a small gas volume fraction.The influence of the regime and energetic working conditions of an RF inductively coupled plasma torch system on the particle thermobaric destruction conditions was examined,and a recommendation was given to promote the degree of thermobaric destruction of quartz particles,which is of substantial importance for improving the overall enrichment efficiency of quartz concentrates.
文摘目的:采用Meta分析综合相关随机对照试验(RCT),探讨智能手机技术对学龄前儿童、学龄儿童及青少年静坐行为与屏幕时间可能存在的干预效果。方法:通过检索PubMed、Web of Science、EBSCO和中国知网(核心期刊)数据库,获取智能手机技术干预儿童青少年静坐行为及屏幕时间的RCT;采用Cochrane偏倚风险评估工具进行文献质量评价,STATA 15.1软件进行合并效应量分析和亚组分析。结果:共纳入文献15篇,其中应用程序(App)干预3篇、短信(SMS)干预10篇、App+SMS干预2篇。Meta分析发现,与对照组相比,智能手机技术对静坐行为时间的减少无显著干预效果(SMD=0.04;95%CI:-0.06,0.14;P=0.41),但可显著降低屏幕时间(SMD=-0.24;95%CI:-0.35,-0.13;P<0.001)。亚组分析发现,基于SMS技术、SMS+其他、>12岁、>12周、频率<3次/周均可显著降低屏幕时间,但各亚组均未见对静坐行为时间具有显著减少作用。结论:基于智能手机技术干预可有效改善儿童青少年屏幕时间,但对静坐行为无明显干预效果;基于SMS技术干预能有效改善屏幕时间;智能手机技术改善屏幕时间的作用对青少年较适宜,长周期与低频率干预更能体现干预效果。
文摘目的:探讨冠状病毒对感染患者心肺适能与肌肉适能的影响,为新型冠状病毒肺炎患者的后期运动康复提供依据。方法:通过PubMed、Web of Science、CNKI等数据库检索现有发表的国内外有关人类致命冠状病毒与患者心肺适能、肌肉适能等关系的相关文献,根据纽卡斯尔-渥太华量表(NOS)对纳入文献进行质量评价,提取文献相关信息进行系统评价综合分析。结果:共纳入23篇文献,22篇非随机化研究NOS质量评分平均分为6.9分,1篇随机对照研究为低偏倚风险。患者出院后心肺适能和肌肉适能指标均低于健康人群。患者心肺适能在出院后3年内逐渐恢复,但最大摄氧量(VO2 max)3年内未完全康复,6分钟步行距离(6MWD)1年内未完全康复。患者肌肉适能指标握力、仰卧起坐、俯卧撑出院2周后差于健康人群。运动干预可使患者VO2 max、6MWD、握力、仰卧起坐、俯卧撑水平显著提升。患者感染程度、确诊天数、住院天数等分别与握力、6MWD等显著相关。结论:冠状病毒可导致感染患者心肺适能和肌肉适能受损。患者出院后心肺适能和肌肉适能呈好转趋势,但仍需较长时间才能完全康复。患者心肺适能与肌肉适能的变化受感染程度、确诊天数、住院天数等因素的影响。