甲醇缸内直喷点燃技术在提高燃油经济性和降低排放方面有着显著优势,但存在中低负荷工况下燃烧不稳定及容易失火等问题,为此以MAN公司L23/30H型柴油机作为目标机型构建三维仿真模型,通过Converge软件建立原柴油机的缸内燃烧仿真模型,并...甲醇缸内直喷点燃技术在提高燃油经济性和降低排放方面有着显著优势,但存在中低负荷工况下燃烧不稳定及容易失火等问题,为此以MAN公司L23/30H型柴油机作为目标机型构建三维仿真模型,通过Converge软件建立原柴油机的缸内燃烧仿真模型,并结合甲醇的理化性质和甲醇燃烧反应机理建立甲醇缸内直喷发动机燃烧仿真模型,分析火花塞位置、火花塞数量以及甲醇喷射时刻和点火时刻对缸内燃烧特性的影响。研究发现:当火花塞安装在位置1(距燃烧室壁面40 mm)时,缸内压力峰值和燃烧放热率峰值较大;根据对燃烧效率、指示热效率和燃烧相位的分析,喷射时刻对应的上止点前曲轴转角(crank angle before top dead center,CA BTDC)为30°、点火时刻对应的CA BTDC为15°的喷射策略最有利于甲醇的缸内燃烧;使用多点点火策略会促进其余(未通过火花塞引燃)雾束的着火,但同时需要喷射时刻与点火时刻的优化匹配,不然会导致燃烧速率加快,燃烧相位提前,使热能转化成指示功的有效程度降低,指示热效率下降,不利于发动机高效工作。展开更多
Objective:To compare the efficacy of transoral robotic surgery(TORS)and non-robotic surgery(NRS)in the treatment of tongue base tumors.Methods:A total of 45 patients with tongue base tumors treated in our hospital wer...Objective:To compare the efficacy of transoral robotic surgery(TORS)and non-robotic surgery(NRS)in the treatment of tongue base tumors.Methods:A total of 45 patients with tongue base tumors treated in our hospital were selected,and they were divided into the TORS group and NRS group according to different surgical methods.The surgical indicators and postoperative complications of patients in the two groups were compared and analyzed.Results:Compared with the NRS group,the operative time,bleeding volume and length of hospital stay were less in the TORS group,and the postoperative recurrence rate was less in the TORS group than that in the NRS group.The incidence rate of dysphagia and restricted mouth opening in the TORS group was lower than that in the NRS group within 30 d after surgery,and the difference was statistically significant(P<0.05).Conclusion:TORS has better minimally invasive advantages in the treatment of tongue base tumors,including less intraoperative bleeding,smaller trauma,shorter length of hospital stay and faster recovery.展开更多
目的:施行我院第一例经口入路机器人手术(transoral robotic surgery TORS),为将来颌面外科机器人的应用提供经验。方法:解放军总医院口腔科应用达芬奇机器人手术系统对1例软腭肿瘤患者行TORS,总结手术体会。结果:患者顺利完成手术,术...目的:施行我院第一例经口入路机器人手术(transoral robotic surgery TORS),为将来颌面外科机器人的应用提供经验。方法:解放军总医院口腔科应用达芬奇机器人手术系统对1例软腭肿瘤患者行TORS,总结手术体会。结果:患者顺利完成手术,术区暴露用时30min,手术时间20min,患者术后2d顺利出院。结论:达芬奇机器人手术系统可以独立完成口腔深部肿瘤,在口腔颌面外科领域有较大的临床应用潜力。展开更多
文摘甲醇缸内直喷点燃技术在提高燃油经济性和降低排放方面有着显著优势,但存在中低负荷工况下燃烧不稳定及容易失火等问题,为此以MAN公司L23/30H型柴油机作为目标机型构建三维仿真模型,通过Converge软件建立原柴油机的缸内燃烧仿真模型,并结合甲醇的理化性质和甲醇燃烧反应机理建立甲醇缸内直喷发动机燃烧仿真模型,分析火花塞位置、火花塞数量以及甲醇喷射时刻和点火时刻对缸内燃烧特性的影响。研究发现:当火花塞安装在位置1(距燃烧室壁面40 mm)时,缸内压力峰值和燃烧放热率峰值较大;根据对燃烧效率、指示热效率和燃烧相位的分析,喷射时刻对应的上止点前曲轴转角(crank angle before top dead center,CA BTDC)为30°、点火时刻对应的CA BTDC为15°的喷射策略最有利于甲醇的缸内燃烧;使用多点点火策略会促进其余(未通过火花塞引燃)雾束的着火,但同时需要喷射时刻与点火时刻的优化匹配,不然会导致燃烧速率加快,燃烧相位提前,使热能转化成指示功的有效程度降低,指示热效率下降,不利于发动机高效工作。
文摘Objective:To compare the efficacy of transoral robotic surgery(TORS)and non-robotic surgery(NRS)in the treatment of tongue base tumors.Methods:A total of 45 patients with tongue base tumors treated in our hospital were selected,and they were divided into the TORS group and NRS group according to different surgical methods.The surgical indicators and postoperative complications of patients in the two groups were compared and analyzed.Results:Compared with the NRS group,the operative time,bleeding volume and length of hospital stay were less in the TORS group,and the postoperative recurrence rate was less in the TORS group than that in the NRS group.The incidence rate of dysphagia and restricted mouth opening in the TORS group was lower than that in the NRS group within 30 d after surgery,and the difference was statistically significant(P<0.05).Conclusion:TORS has better minimally invasive advantages in the treatment of tongue base tumors,including less intraoperative bleeding,smaller trauma,shorter length of hospital stay and faster recovery.
文摘目的:施行我院第一例经口入路机器人手术(transoral robotic surgery TORS),为将来颌面外科机器人的应用提供经验。方法:解放军总医院口腔科应用达芬奇机器人手术系统对1例软腭肿瘤患者行TORS,总结手术体会。结果:患者顺利完成手术,术区暴露用时30min,手术时间20min,患者术后2d顺利出院。结论:达芬奇机器人手术系统可以独立完成口腔深部肿瘤,在口腔颌面外科领域有较大的临床应用潜力。