Given their numerous functional and architectural benefits,such as improved bearing capacity and increased resistance to elastic instability modes,cold-formed steel(CFS)built-up sections have become increasingly devel...Given their numerous functional and architectural benefits,such as improved bearing capacity and increased resistance to elastic instability modes,cold-formed steel(CFS)built-up sections have become increasingly developed and used in recent years,particularly in the construction industry.This paper presents an analytical and numerical study of assembled CFS two single channel-shaped columns with different slenderness and configurations(backto-back,face-to-face,and box).These columns were joined by double-row rivets for the back-to-back and box configurations,whereas they were welded together for the face-to-face design.The built-up columns were filled with ordinary concrete of good strength.Finite element models were applied,using ABAQUS software,to assess mechanical performance and study the influence of assembly techniques on the behavior of cold-formed columns under axial compression.Analytical approaches based on Eurocode 3 and Eurocode 4 recommendations for un-filled and concrete-filled columns respectively were followed for the numerical analysis,and concrete confinement effects were also considered per American Concrete Institute(ACI)standards for face-to-face and box configurations.The obtained results indicated a good correlation between the numerical results and the proposed analytical methodology which did not exceed 8%.The failure modes showed that the columns failed due to instabilities such as local and global buckling.展开更多
目的:探讨产科剖宫产患者腰硬联合麻醉后发生的肢体幻像现象对患者焦虑情绪的影响。方法:选取腰硬联合麻醉下行剖宫产的患者100例,入室前5 min对患者进行医院焦虑抑郁量表(HADS)评分,HADS评分≥11分者剔除。患者入室后自确定麻醉体位开...目的:探讨产科剖宫产患者腰硬联合麻醉后发生的肢体幻像现象对患者焦虑情绪的影响。方法:选取腰硬联合麻醉下行剖宫产的患者100例,入室前5 min对患者进行医院焦虑抑郁量表(HADS)评分,HADS评分≥11分者剔除。患者入室后自确定麻醉体位开始进行观察,对肢体幻像现象发生情况进行记录。对发生肢体幻像患者的焦虑发生情况进行HADS评分并记录、分析。探讨文化程度、初产妇或经产妇、首次和非首次剖宫产对发生肢体幻像现象患者焦虑情绪的影响。当肢体幻像现象消失后,再次对患者进行HADS评分。结果:100例剖宫产患者中,入室前5 min HADS评分≥11分者6例,予以剔除。HADS评分<11分者94例,其中72例发生肢体幻像现象,发生率高达76.60%。在72例发生肢体幻像现象患者中,焦虑情绪发生率高达68.06%。在22例未发生肢体幻像现象患者中,焦虑情绪发生率为4.55%。发生肢体幻像现象组与未发生肢体幻像现象组比较有统计学差异(P<0.05)。不同文化程度对发生肢体幻像现象患者的焦虑情绪有一定影响(P<0.05)。发生肢体幻像现象的患者中初产妇较经产妇更易产生焦虑情绪,首次剖宫产较非首次剖宫产患者更易产生焦虑情绪(P<0.05)。当肢体幻像现象消失后,发生肢体幻像现象患者与未发生肢体幻像患者焦虑情绪发生率比较无统计学差异(P>0.05)。结论:腰硬联合麻醉后发生肢体幻像现象患者较未发生肢体幻像现象患者更易产生焦虑情绪,文化程度、是否初产妇和首次剖宫产对发生肢体幻像现象患者焦虑情绪的产生有一定影响。展开更多
文摘Given their numerous functional and architectural benefits,such as improved bearing capacity and increased resistance to elastic instability modes,cold-formed steel(CFS)built-up sections have become increasingly developed and used in recent years,particularly in the construction industry.This paper presents an analytical and numerical study of assembled CFS two single channel-shaped columns with different slenderness and configurations(backto-back,face-to-face,and box).These columns were joined by double-row rivets for the back-to-back and box configurations,whereas they were welded together for the face-to-face design.The built-up columns were filled with ordinary concrete of good strength.Finite element models were applied,using ABAQUS software,to assess mechanical performance and study the influence of assembly techniques on the behavior of cold-formed columns under axial compression.Analytical approaches based on Eurocode 3 and Eurocode 4 recommendations for un-filled and concrete-filled columns respectively were followed for the numerical analysis,and concrete confinement effects were also considered per American Concrete Institute(ACI)standards for face-to-face and box configurations.The obtained results indicated a good correlation between the numerical results and the proposed analytical methodology which did not exceed 8%.The failure modes showed that the columns failed due to instabilities such as local and global buckling.
文摘目的:探讨产科剖宫产患者腰硬联合麻醉后发生的肢体幻像现象对患者焦虑情绪的影响。方法:选取腰硬联合麻醉下行剖宫产的患者100例,入室前5 min对患者进行医院焦虑抑郁量表(HADS)评分,HADS评分≥11分者剔除。患者入室后自确定麻醉体位开始进行观察,对肢体幻像现象发生情况进行记录。对发生肢体幻像患者的焦虑发生情况进行HADS评分并记录、分析。探讨文化程度、初产妇或经产妇、首次和非首次剖宫产对发生肢体幻像现象患者焦虑情绪的影响。当肢体幻像现象消失后,再次对患者进行HADS评分。结果:100例剖宫产患者中,入室前5 min HADS评分≥11分者6例,予以剔除。HADS评分<11分者94例,其中72例发生肢体幻像现象,发生率高达76.60%。在72例发生肢体幻像现象患者中,焦虑情绪发生率高达68.06%。在22例未发生肢体幻像现象患者中,焦虑情绪发生率为4.55%。发生肢体幻像现象组与未发生肢体幻像现象组比较有统计学差异(P<0.05)。不同文化程度对发生肢体幻像现象患者的焦虑情绪有一定影响(P<0.05)。发生肢体幻像现象的患者中初产妇较经产妇更易产生焦虑情绪,首次剖宫产较非首次剖宫产患者更易产生焦虑情绪(P<0.05)。当肢体幻像现象消失后,发生肢体幻像现象患者与未发生肢体幻像患者焦虑情绪发生率比较无统计学差异(P>0.05)。结论:腰硬联合麻醉后发生肢体幻像现象患者较未发生肢体幻像现象患者更易产生焦虑情绪,文化程度、是否初产妇和首次剖宫产对发生肢体幻像现象患者焦虑情绪的产生有一定影响。
基金Sponsored by Scientific Innovation Program of SHMEC(09YZ173)Scientific research funds of Shanghai Normal University(SK201133)Shanghai Undergraduate Innovation Program(B900110003049)
