以努塞尔数Nu最大,摩擦系数f最小,综合传热性能η最大为目标,对凹凸板换热器进行多目标优化。运用Workbench软件分析板片结构参数对其传热阻力性能的影响,并对各因素进行敏感性分析。结果表明:凹坑凸胞直径D对传热性能影响较大,凹坑深度...以努塞尔数Nu最大,摩擦系数f最小,综合传热性能η最大为目标,对凹凸板换热器进行多目标优化。运用Workbench软件分析板片结构参数对其传热阻力性能的影响,并对各因素进行敏感性分析。结果表明:凹坑凸胞直径D对传热性能影响较大,凹坑深度(凸胞高度)H对板的阻力性能和综合传热性能影响较大;在给定的输入参数范围内,得到三组较优的结构组合,分别是组合1(D=9 mm, H=1.5 mm, T=23.5 mm),组合2(D=9 mm, H=1.5 mm, T=32 mm),组合3(D=9.1485 mm,H=1.6429 mm,T=25.083 mm)。展开更多
We demonstrate the synthesis of C-Cl-codoped titania/attapulgite（TiO2/ATT） composites containing a mixture of TiO2 phases by a facile sol-gel method at 70 ℃ using titanium tetraisopropoxide as the TiO2 precursor an...We demonstrate the synthesis of C-Cl-codoped titania/attapulgite（TiO2/ATT） composites containing a mixture of TiO2 phases by a facile sol-gel method at 70 ℃ using titanium tetraisopropoxide as the TiO2 precursor and ATT as a support for the TiO2 nanoparticles.The photocatalytic activity of the C-Cl-codoped TiO2/ATT composites with mixed anatase/brookite/rutile phases obtained at pH= 3.0 was much higher than that of commercially available Degussa P25 for the photocatalytic degradation of acid red G under visible-light irradiation.The excellent photocatalytic activity of the developed composite originates from the nonmetal codoping,which extends the absorption edge of TiO2 into visible region,and the presence of multiple phases,which slow the recombination of photoexcited electron/hole pairs.The formation of hydroxyl radicals during the photocatalytic degradation process was detected by photoluminescence probing using terephthalic acid.A mechanism for photocatalysis over the C-Cl-codoped TiO2/ATT composites was proposed.展开更多
The static test of 13 square hollow section(SHS) X-joints with different β and different types of plate reinforcement under in-plane moment in brace was carried out. Experimental test schemes, failure modes of specim...The static test of 13 square hollow section(SHS) X-joints with different β and different types of plate reinforcement under in-plane moment in brace was carried out. Experimental test schemes, failure modes of specimens, moment-vertical displacement curves, moment-deformation of the chord, and strain strength distribution curves were presented. The effect of β and plate reinforcement types on in-plane flexural property of SHS X-joints was studied. Results show that punching shear of chord face disappears, brace material fracture appears and concave and convex deformation of chord decrease when either collar plates or doubler plates were welded on chord face. Moment-vertical displacement curves of all specimens have obvious elastic, elastic-plastic and plastic stages. As β increases, the in-plane flexural ultimate capacity and initial stiffness of joints of the same plate reinforcement type increase, but ductility of joints decreases. With the same β, the in-plane flexural initial stiffness and ultimate capacity of doubler plate reinforced joints, collar plate reinforced joints, and unreinforced joints decrease progressively. Thickness of reinforcement plate has no obvious effect on in-plane flexural initial stiffness and ultimate capacity of joints. As thickness of reinforcement plate increases, the ductility of reinforced X-joints decreases. The concave and convex deformation of every specimen has good symmetry;as β increases, the yield and ultimate deformation of chord decrease.展开更多
文摘以努塞尔数Nu最大,摩擦系数f最小,综合传热性能η最大为目标,对凹凸板换热器进行多目标优化。运用Workbench软件分析板片结构参数对其传热阻力性能的影响,并对各因素进行敏感性分析。结果表明:凹坑凸胞直径D对传热性能影响较大,凹坑深度(凸胞高度)H对板的阻力性能和综合传热性能影响较大;在给定的输入参数范围内,得到三组较优的结构组合,分别是组合1(D=9 mm, H=1.5 mm, T=23.5 mm),组合2(D=9 mm, H=1.5 mm, T=32 mm),组合3(D=9.1485 mm,H=1.6429 mm,T=25.083 mm)。
基金supported by the National Basic Research Program of China (973 Program, 2007CB613302)the Natural Science Foundation of Hubei Province (2016CFA078)~~
文摘We demonstrate the synthesis of C-Cl-codoped titania/attapulgite（TiO2/ATT） composites containing a mixture of TiO2 phases by a facile sol-gel method at 70 ℃ using titanium tetraisopropoxide as the TiO2 precursor and ATT as a support for the TiO2 nanoparticles.The photocatalytic activity of the C-Cl-codoped TiO2/ATT composites with mixed anatase/brookite/rutile phases obtained at pH= 3.0 was much higher than that of commercially available Degussa P25 for the photocatalytic degradation of acid red G under visible-light irradiation.The excellent photocatalytic activity of the developed composite originates from the nonmetal codoping,which extends the absorption edge of TiO2 into visible region,and the presence of multiple phases,which slow the recombination of photoexcited electron/hole pairs.The formation of hydroxyl radicals during the photocatalytic degradation process was detected by photoluminescence probing using terephthalic acid.A mechanism for photocatalysis over the C-Cl-codoped TiO2/ATT composites was proposed.
基金Projects(51278209 and 51478047) supported by the National Natural Science Foundation of ChinaProject(ZQN-PY110) supported by Promotion Program for Young and Middle-aged Teacher in Science and Technology Research of Huaqiao University,China+1 种基金Project(2014FJ-NCET-ZR03) supported by Program for New Century Excellent Talents in Fujian Province University,ChinaProject(JA13005) supported by Incubation Programme for Excellent Young Science and Technology Talents in Fujian Province Universities,China
文摘The static test of 13 square hollow section(SHS) X-joints with different β and different types of plate reinforcement under in-plane moment in brace was carried out. Experimental test schemes, failure modes of specimens, moment-vertical displacement curves, moment-deformation of the chord, and strain strength distribution curves were presented. The effect of β and plate reinforcement types on in-plane flexural property of SHS X-joints was studied. Results show that punching shear of chord face disappears, brace material fracture appears and concave and convex deformation of chord decrease when either collar plates or doubler plates were welded on chord face. Moment-vertical displacement curves of all specimens have obvious elastic, elastic-plastic and plastic stages. As β increases, the in-plane flexural ultimate capacity and initial stiffness of joints of the same plate reinforcement type increase, but ductility of joints decreases. With the same β, the in-plane flexural initial stiffness and ultimate capacity of doubler plate reinforced joints, collar plate reinforced joints, and unreinforced joints decrease progressively. Thickness of reinforcement plate has no obvious effect on in-plane flexural initial stiffness and ultimate capacity of joints. As thickness of reinforcement plate increases, the ductility of reinforced X-joints decreases. The concave and convex deformation of every specimen has good symmetry;as β increases, the yield and ultimate deformation of chord decrease.
