The seismic ductility of reinforced very-high-strength-concrete （VHSC） short columns was studied by combinatively applying axial load and low cyclic lateral load on specimens to simulate seismic impact. Twelve speci...The seismic ductility of reinforced very-high-strength-concrete （VHSC） short columns was studied by combinatively applying axial load and low cyclic lateral load on specimens to simulate seismic impact. Twelve specimens with concrete compressive strength ranging from 95.6 MPa to 118.6 MPa and a shear-span ratio of 2.0 were tested for shear failure pattern and fear force-displacement hysteretic responses. Combinative application of axial load and low cyclic lateral load to VHSC short columns incurs shear failure. The displacement ductility is much smaller when the axial load ratio is larger; whereas a larger stirrup ratio is accompanied with a better displacement ductility. The relationship of displacement ductility factor,μ△, with stirrup characteristic value, λv, and test axial load ratio, nt, is μ△=（1＋8λv）/（0.33＋nt）. By this relationship and relevant codes for aseismatic design, the axial load ratio limits for aseismatic design of reinforced VHSC （C95 to C100） short columns for frame construction are respectively 0.5, 0.6, and 0.7 for seismic classes Ⅰ, Ⅱ, and Ⅲ; corresponding minimum characteristic values of stirrups are calculated according to the required characteristic values of at least 1.273 times of experimental results. These data are very useful to aseismatic engineering.展开更多
目的:建立PRIME HLB Plus Short柱-液质质法测定畜肉产品中瘦肉精残留量的分析方法。方法:采用PRIME HLB Plus Short柱和QuEChERS试剂2种方式分别对猪肉、牛肉、羊肉进行净化的同时优化了方法的取样量、质谱条件等,并与国标GB/T 22286—...目的:建立PRIME HLB Plus Short柱-液质质法测定畜肉产品中瘦肉精残留量的分析方法。方法:采用PRIME HLB Plus Short柱和QuEChERS试剂2种方式分别对猪肉、牛肉、羊肉进行净化的同时优化了方法的取样量、质谱条件等,并与国标GB/T 22286—2008的基质种类、净化效率及回收率等进行比较。结果:PRIME HLB Plus Short柱的提取效率和净化效果均良好,平均提取及净化时间为0.5h/样品,与GB/T 22286—2008方法相比,提取及净化时间缩短了近10倍,进一步净化了本底,回收率也有所提高。结论:该方法极大的缩短了前处理的时间,最大限度的提高了检测的工作效率,莱克多巴胺、沙丁胺醇、克伦特罗的线性关系良好,方法的检出限、回收率、精密度等均满足实际检测的需求,可实现畜肉产品中β-受体激动剂残留量的快速测定。展开更多
基金the key project of the National Natural Science Foundation of China (No.50438010)
文摘The seismic ductility of reinforced very-high-strength-concrete （VHSC） short columns was studied by combinatively applying axial load and low cyclic lateral load on specimens to simulate seismic impact. Twelve specimens with concrete compressive strength ranging from 95.6 MPa to 118.6 MPa and a shear-span ratio of 2.0 were tested for shear failure pattern and fear force-displacement hysteretic responses. Combinative application of axial load and low cyclic lateral load to VHSC short columns incurs shear failure. The displacement ductility is much smaller when the axial load ratio is larger; whereas a larger stirrup ratio is accompanied with a better displacement ductility. The relationship of displacement ductility factor,μ△, with stirrup characteristic value, λv, and test axial load ratio, nt, is μ△=（1＋8λv）/（0.33＋nt）. By this relationship and relevant codes for aseismatic design, the axial load ratio limits for aseismatic design of reinforced VHSC （C95 to C100） short columns for frame construction are respectively 0.5, 0.6, and 0.7 for seismic classes Ⅰ, Ⅱ, and Ⅲ; corresponding minimum characteristic values of stirrups are calculated according to the required characteristic values of at least 1.273 times of experimental results. These data are very useful to aseismatic engineering.
文摘目的:建立PRIME HLB Plus Short柱-液质质法测定畜肉产品中瘦肉精残留量的分析方法。方法:采用PRIME HLB Plus Short柱和QuEChERS试剂2种方式分别对猪肉、牛肉、羊肉进行净化的同时优化了方法的取样量、质谱条件等,并与国标GB/T 22286—2008的基质种类、净化效率及回收率等进行比较。结果:PRIME HLB Plus Short柱的提取效率和净化效果均良好,平均提取及净化时间为0.5h/样品,与GB/T 22286—2008方法相比,提取及净化时间缩短了近10倍,进一步净化了本底,回收率也有所提高。结论:该方法极大的缩短了前处理的时间,最大限度的提高了检测的工作效率,莱克多巴胺、沙丁胺醇、克伦特罗的线性关系良好,方法的检出限、回收率、精密度等均满足实际检测的需求,可实现畜肉产品中β-受体激动剂残留量的快速测定。
