In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spat...In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spatial model of the bridge and a biaxial vehicle model of the vehicle are established,and then a vehicle-bridge coupling vibration system is constructed on the basis of the Nemak-βmethod,and the impact coefficients of each part of the bridge are obtained under different bridge deck unevenness and vehicle speed.The simulation results show that the bridge deck unevenness has the greatest influence on the vibration response of the bridge,and the bridge impact coefficient increases along with the increase in the level of bridge deck unevenness,and the impact coefficient of the main longitudinal girder and the secondary longitudinal girder achieves the maximum value when the level 4 unevenness is 0.328 and 0.314,respectively;when the vehicle speed is increased,the vibration response of the bridge increases and then decreases,and the impact coefficient of the bridge in the middle of the bridge at a speed of 60 km/h achieves the maximum value of 0.192.展开更多
目的观察黄芪注射液治疗早期糖尿病肾病(DN)患者的临床疗效及对尿白蛋白及相关细胞因子水平的影响。方法将80例早期DN患者随机分为治疗组与对照组各40例,2组均给予西医基础治疗+贝那普利口服,治疗组在此基础上加用中药黄芪注射液50 m L...目的观察黄芪注射液治疗早期糖尿病肾病(DN)患者的临床疗效及对尿白蛋白及相关细胞因子水平的影响。方法将80例早期DN患者随机分为治疗组与对照组各40例,2组均给予西医基础治疗+贝那普利口服,治疗组在此基础上加用中药黄芪注射液50 m L+生理盐水250 m L静脉滴注,1次/d。2组疗程均为4周,观察2组临床疗效,比较2组治疗前后尿微量白蛋白(m Alb)、24 h尿蛋白定量、尿白蛋白排泄率(UAER)和β2-微球蛋白(β2-MG)、IL-6、TNF-α及VEGF水平的变化。结果治疗组总有效率明显高于对照组(P<0.05);2组治疗4周后m Alb、24h尿蛋白定量、UAER、β2-MG、IL-6、TNF-α及VEGF水平均较治疗前明显降低(P均<0.05),且治疗组较对照组降低更明显(P均<0.05)。结论黄芪注射液治疗早期DN可提高临床疗效,降低尿白蛋白水平,而减轻患者随机体内相关微炎症状态可能为其发挥治疗作用的重要机制之一。展开更多
基金National Natural Science Foundation of China(11572001,51478004)2021 Undergraduate Course Ideological and Political Demonstration Course-Theoretical Mechanics(108051360022XN569)2022 Great Innovation Project-Frame Bridge Structural Engineering Research(108051360022XN388)。
文摘In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spatial model of the bridge and a biaxial vehicle model of the vehicle are established,and then a vehicle-bridge coupling vibration system is constructed on the basis of the Nemak-βmethod,and the impact coefficients of each part of the bridge are obtained under different bridge deck unevenness and vehicle speed.The simulation results show that the bridge deck unevenness has the greatest influence on the vibration response of the bridge,and the bridge impact coefficient increases along with the increase in the level of bridge deck unevenness,and the impact coefficient of the main longitudinal girder and the secondary longitudinal girder achieves the maximum value when the level 4 unevenness is 0.328 and 0.314,respectively;when the vehicle speed is increased,the vibration response of the bridge increases and then decreases,and the impact coefficient of the bridge in the middle of the bridge at a speed of 60 km/h achieves the maximum value of 0.192.
文摘目的观察黄芪注射液治疗早期糖尿病肾病(DN)患者的临床疗效及对尿白蛋白及相关细胞因子水平的影响。方法将80例早期DN患者随机分为治疗组与对照组各40例,2组均给予西医基础治疗+贝那普利口服,治疗组在此基础上加用中药黄芪注射液50 m L+生理盐水250 m L静脉滴注,1次/d。2组疗程均为4周,观察2组临床疗效,比较2组治疗前后尿微量白蛋白(m Alb)、24 h尿蛋白定量、尿白蛋白排泄率(UAER)和β2-微球蛋白(β2-MG)、IL-6、TNF-α及VEGF水平的变化。结果治疗组总有效率明显高于对照组(P<0.05);2组治疗4周后m Alb、24h尿蛋白定量、UAER、β2-MG、IL-6、TNF-α及VEGF水平均较治疗前明显降低(P均<0.05),且治疗组较对照组降低更明显(P均<0.05)。结论黄芪注射液治疗早期DN可提高临床疗效,降低尿白蛋白水平,而减轻患者随机体内相关微炎症状态可能为其发挥治疗作用的重要机制之一。