As the velocity of a train increases,the corresponding air pumping power consumption of the brake discs increases proportionally.In the present experimental study,a standard axle-mounted brake disc with circumferentia...As the velocity of a train increases,the corresponding air pumping power consumption of the brake discs increases proportionally.In the present experimental study,a standard axle-mounted brake disc with circumferential pillars was analyzed using a 1:1 scale model and a test rig in a wind tunnel.In particular,three upstream velocities were selected on the basis of earlier investigations of trains operating at 160,250,and 400 km/h,respectively.Moreover,3D steady computational fluid dynamics(CFD)simulations of the flow field were conducted to compare with the wind tunnel test outcomes.The results for a 3-car train at 180 km/h demonstrated:(1)good agreement between the air resistance torques obtained from the wind tunnel tests and the related numerical results,with differences ranging from 0.95%to 5.88%;(2)discrepancies ranging from 3.2 to 3.8 N·m;(3)cooling ribs contributing more than 60%of the air resistance torque;(4)the fast rotation of brake discs causing a significantly different flow field near the bogie area,resulting in 25 times more air pumping power loss than that obtained in the stationary brake-disc case.展开更多
背景与目的目前在单孔胸腔镜肺手术中需留置双根胸腔引流管时常联合使用细管与粗管,且粗管多置于切口内,增加了术后疼痛感及切口愈合不良风险。本研究将评估单孔胸腔镜肺部术后采用双根10 F超细猪尾巴管引流的疗效及安全性。方法回顾苏...背景与目的目前在单孔胸腔镜肺手术中需留置双根胸腔引流管时常联合使用细管与粗管,且粗管多置于切口内,增加了术后疼痛感及切口愈合不良风险。本研究将评估单孔胸腔镜肺部术后采用双根10 F超细猪尾巴管引流的疗效及安全性。方法回顾苏州大学附属第二医院胸心外科同一治疗组2018年6月-2020年6月的单孔胸腔镜肺手术病历资料,对比在不同时期分别采用“10 F超细猪尾巴管+24 F粗管”及“双根10 F超细猪尾巴管”两种胸腔引流方案的效果。结果2019年6月及以后采用“双根10 F超细猪尾巴管”方案的A组共有106例,2019年6月及以前采用10 F超细猪尾巴管+24 F粗管的B组共有183例。术后A、B两组胸腔引流液量(mL)(1^(st):199.54±126.56 vs 203.59±139.32,P=0.84;2^(nd):340.30±205.47 vs 349.74±230.92,P=0.76;3^(rd):435.19±311.51 vs 451.37±317.03,P=0.70;4^(th):492.58±377.33 vs 512.57±382.94,P=0.69;共计:604.57±547.24 vs 614.64±546.08,P=0.88)、引流管留置时间(d)(上管:2.54±2.20 vs 3.40±2.07,P=0.21;下管:2.24±2.43 vs 3.82±2.12,P=0.10)、术后住院时间(d)(6.87±3.17 vs 7.06±3.21,P=0.63)、切口愈合不良情况(0 vs 3.28%,P=0.09)、术后调整下胸腔引流管情况(0.94%vs 2.19%,P=0.66)、术后第一次视觉模拟量表(visual analogue score,VAS)(3.00±0.24 vs 2.99±0.15,P=0.63)在两组之间均无统计学差异。但A组术后VAS2(2.28±0.63 vs 2.92±0.59,P<0.01)、VAS3(2.50±1.58 vs 2.79±1.53,P=0.02)、术后追加镇痛药物频次(25.47%vs 38.25%,P=0.03)及术后调整上胸腔引流管的频次(0 vs 4.37%,P=0.03)均较B组显著偏低。结论在部分高选择的单孔胸腔镜肺手术过程中采用双根10 F超细猪尾巴管引流安全有效,可减少术后疼痛,降低术后胸腔引流管重置发生率。展开更多
目的 通过实验动物小肠结肠炎耶尔森菌(Yersinia enterocolitica)检出能力验证,了解实验动物检测机构的检验能力,提高实验动物质量检测水平。方法 按照中国合格评定国家认可委员会(China National Accreditation Service for Conformity...目的 通过实验动物小肠结肠炎耶尔森菌(Yersinia enterocolitica)检出能力验证,了解实验动物检测机构的检验能力,提高实验动物质量检测水平。方法 按照中国合格评定国家认可委员会(China National Accreditation Service for Conformity, CNAS)批准的能力验证方案,低温冷冻干燥制备样品;稳定性和均匀性检验合格后,通过CNAS平台随机分组编号,发放给参加单位,并附作业指导书。要求在规定时限提交检验报告和原始记录,其结果与样品设置一致的判为满意结果,不一致或未按时提交的判为不满意结果。结果 共有24个实验室参加本项能力验证;其中获得满意结果的实验室为22个,占总参加机构的91.7%;得到不满意结果的实验室有2个,占8.3%。结论 实验动物质量检测机构对小肠结肠炎耶尔森菌的检测能力较高。展开更多
基金supported by the National Key Research and Development Program of China(2020YFA0710901)the National Natural Science Foundation of China(12002395)Natural Science Foundation of Hunan Province(Grant No.2023JJ30643).
文摘As the velocity of a train increases,the corresponding air pumping power consumption of the brake discs increases proportionally.In the present experimental study,a standard axle-mounted brake disc with circumferential pillars was analyzed using a 1:1 scale model and a test rig in a wind tunnel.In particular,three upstream velocities were selected on the basis of earlier investigations of trains operating at 160,250,and 400 km/h,respectively.Moreover,3D steady computational fluid dynamics(CFD)simulations of the flow field were conducted to compare with the wind tunnel test outcomes.The results for a 3-car train at 180 km/h demonstrated:(1)good agreement between the air resistance torques obtained from the wind tunnel tests and the related numerical results,with differences ranging from 0.95%to 5.88%;(2)discrepancies ranging from 3.2 to 3.8 N·m;(3)cooling ribs contributing more than 60%of the air resistance torque;(4)the fast rotation of brake discs causing a significantly different flow field near the bogie area,resulting in 25 times more air pumping power loss than that obtained in the stationary brake-disc case.
文摘背景与目的目前在单孔胸腔镜肺手术中需留置双根胸腔引流管时常联合使用细管与粗管,且粗管多置于切口内,增加了术后疼痛感及切口愈合不良风险。本研究将评估单孔胸腔镜肺部术后采用双根10 F超细猪尾巴管引流的疗效及安全性。方法回顾苏州大学附属第二医院胸心外科同一治疗组2018年6月-2020年6月的单孔胸腔镜肺手术病历资料,对比在不同时期分别采用“10 F超细猪尾巴管+24 F粗管”及“双根10 F超细猪尾巴管”两种胸腔引流方案的效果。结果2019年6月及以后采用“双根10 F超细猪尾巴管”方案的A组共有106例,2019年6月及以前采用10 F超细猪尾巴管+24 F粗管的B组共有183例。术后A、B两组胸腔引流液量(mL)(1^(st):199.54±126.56 vs 203.59±139.32,P=0.84;2^(nd):340.30±205.47 vs 349.74±230.92,P=0.76;3^(rd):435.19±311.51 vs 451.37±317.03,P=0.70;4^(th):492.58±377.33 vs 512.57±382.94,P=0.69;共计:604.57±547.24 vs 614.64±546.08,P=0.88)、引流管留置时间(d)(上管:2.54±2.20 vs 3.40±2.07,P=0.21;下管:2.24±2.43 vs 3.82±2.12,P=0.10)、术后住院时间(d)(6.87±3.17 vs 7.06±3.21,P=0.63)、切口愈合不良情况(0 vs 3.28%,P=0.09)、术后调整下胸腔引流管情况(0.94%vs 2.19%,P=0.66)、术后第一次视觉模拟量表(visual analogue score,VAS)(3.00±0.24 vs 2.99±0.15,P=0.63)在两组之间均无统计学差异。但A组术后VAS2(2.28±0.63 vs 2.92±0.59,P<0.01)、VAS3(2.50±1.58 vs 2.79±1.53,P=0.02)、术后追加镇痛药物频次(25.47%vs 38.25%,P=0.03)及术后调整上胸腔引流管的频次(0 vs 4.37%,P=0.03)均较B组显著偏低。结论在部分高选择的单孔胸腔镜肺手术过程中采用双根10 F超细猪尾巴管引流安全有效,可减少术后疼痛,降低术后胸腔引流管重置发生率。
文摘目的 通过实验动物小肠结肠炎耶尔森菌(Yersinia enterocolitica)检出能力验证,了解实验动物检测机构的检验能力,提高实验动物质量检测水平。方法 按照中国合格评定国家认可委员会(China National Accreditation Service for Conformity, CNAS)批准的能力验证方案,低温冷冻干燥制备样品;稳定性和均匀性检验合格后,通过CNAS平台随机分组编号,发放给参加单位,并附作业指导书。要求在规定时限提交检验报告和原始记录,其结果与样品设置一致的判为满意结果,不一致或未按时提交的判为不满意结果。结果 共有24个实验室参加本项能力验证;其中获得满意结果的实验室为22个,占总参加机构的91.7%;得到不满意结果的实验室有2个,占8.3%。结论 实验动物质量检测机构对小肠结肠炎耶尔森菌的检测能力较高。
