Earthquake may cause severe damage to all kinds of bridge such as the falling down of the girder; therefore,effective measures should be employed to control the seismic displacement. In this paper,the method of compre...Earthquake may cause severe damage to all kinds of bridge such as the falling down of the girder; therefore,effective measures should be employed to control the seismic displacement. In this paper,the method of comprehensive optimal control,com-bined with analytic hierarchy process,is employed to investigate the seismic response control of the Nanjing Jiangxinzhou Bridge,which is a single-tower self-anchored suspension bridge （SSSB）. Also,3-dimensional nonlinear seismic response analyses are con-ducted. Three types of practical connection measures for seismic response control of SSSB are investigated,and the optimal pa-rameters of the connection devices are achieved by this method. Results show that both the elastic connection devices and the damp-ers with rational parameters can reduce the seismic displacement of the bridge effectively,but the elastic connection devices will in-crease the seismic force of the tower. When all factors are consid-ered,the optimal measure is by using the elastic connection devices and the dampers together. These results can provide references for seismic response control of SSSBs.展开更多
In Korea construction industry, the increase of tower crane’s usage continuously and the accidents of tower crane are increasing simultaneously. But research on tower crane is insufficient for reducing the tower cran...In Korea construction industry, the increase of tower crane’s usage continuously and the accidents of tower crane are increasing simultaneously. But research on tower crane is insufficient for reducing the tower crane accident. This study aims to derive the importance ranking of accident factors of cab-control tower crane by AHP analysis. AHP survey was conducted on experts such as construction engineer, construction manager, safety engineer, and tower crane operator, who have more than 10-year career. The results of AHP analysis reveal that top ranking factor of cab-control tower crane’s accident is erection work. Therefore, the derived factors should be managed, and the priority measures taken for reducing the tower crane accidents according to the ranking of accident factors.展开更多
利用Aspen Plus V14流程模拟软件,对炼厂气分馏工艺进行模拟,验证模拟流程的准确性;对丙烯精馏单元建立了常规单塔精馏、顺流双效精馏和逆流双效精馏模型,经过模拟对比,确定逆流双效精馏为最佳方案,其精丙烯产品纯度达到99.76%,冷凝器...利用Aspen Plus V14流程模拟软件,对炼厂气分馏工艺进行模拟,验证模拟流程的准确性;对丙烯精馏单元建立了常规单塔精馏、顺流双效精馏和逆流双效精馏模型,经过模拟对比,确定逆流双效精馏为最佳方案,其精丙烯产品纯度达到99.76%,冷凝器热负荷和再沸器热负荷分别比单塔精馏降低52.7%和53.4%。利用灵敏度分析工具,对逆流双效精馏进行了初步优化;在此基础上,采用正交试验进行进一步优化,得到逆流双效精馏的最优参数:低压塔塔顶采出量为62 kmol h,低压塔进料塔板编号为46(自上而下),高压塔进料塔板编号为42(自上而下),高压塔回流摩尔比为14。展开更多
基金Supported by the National Natural Science Foundation of China for Distinguished Young Scientists (50725828)the National Natural Science Foundation of China (50908046)the Specialized Research Fund for the Doctoral Program of Higher Education (200802861012)
文摘Earthquake may cause severe damage to all kinds of bridge such as the falling down of the girder; therefore,effective measures should be employed to control the seismic displacement. In this paper,the method of comprehensive optimal control,com-bined with analytic hierarchy process,is employed to investigate the seismic response control of the Nanjing Jiangxinzhou Bridge,which is a single-tower self-anchored suspension bridge （SSSB）. Also,3-dimensional nonlinear seismic response analyses are con-ducted. Three types of practical connection measures for seismic response control of SSSB are investigated,and the optimal pa-rameters of the connection devices are achieved by this method. Results show that both the elastic connection devices and the damp-ers with rational parameters can reduce the seismic displacement of the bridge effectively,but the elastic connection devices will in-crease the seismic force of the tower. When all factors are consid-ered,the optimal measure is by using the elastic connection devices and the dampers together. These results can provide references for seismic response control of SSSBs.
文摘In Korea construction industry, the increase of tower crane’s usage continuously and the accidents of tower crane are increasing simultaneously. But research on tower crane is insufficient for reducing the tower crane accident. This study aims to derive the importance ranking of accident factors of cab-control tower crane by AHP analysis. AHP survey was conducted on experts such as construction engineer, construction manager, safety engineer, and tower crane operator, who have more than 10-year career. The results of AHP analysis reveal that top ranking factor of cab-control tower crane’s accident is erection work. Therefore, the derived factors should be managed, and the priority measures taken for reducing the tower crane accidents according to the ranking of accident factors.
文摘利用Aspen Plus V14流程模拟软件,对炼厂气分馏工艺进行模拟,验证模拟流程的准确性;对丙烯精馏单元建立了常规单塔精馏、顺流双效精馏和逆流双效精馏模型,经过模拟对比,确定逆流双效精馏为最佳方案,其精丙烯产品纯度达到99.76%,冷凝器热负荷和再沸器热负荷分别比单塔精馏降低52.7%和53.4%。利用灵敏度分析工具,对逆流双效精馏进行了初步优化;在此基础上,采用正交试验进行进一步优化,得到逆流双效精馏的最优参数:低压塔塔顶采出量为62 kmol h,低压塔进料塔板编号为46(自上而下),高压塔进料塔板编号为42(自上而下),高压塔回流摩尔比为14。
