Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios （Ce-Mn/GF） were prepared by an impregnation method and tested for low-temperature （80 180 ℃） selective cataly...Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios （Ce-Mn/GF） were prepared by an impregnation method and tested for low-temperature （80 180 ℃） selective catalytic reduction （SCR） of NO with ammonia. This brand-new technology could remove NO and particles matter from coal-fired flue gas. The surface properties of the catalysts were examined by means of Bmnauer-Emmett-Teller （BET）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and scanning electron microscopy （SEM）. The experimental results showed that the catalyst with a Ce/Mn molar ratio of 0.2 obtained high activity of 87.4% NO conversion at 150 ℃ under a high space velocity of 50000 h1. Deactivation poisoned by SO2 still occurred, but the Ce-Mn/GF（0.2） catalyst performed desirable tolerance to SO2 with decreasing 50% in 40 min and then maintaining at about 30% NO conversion. Characterization results indicated that the excellent low-temperature catalytic activity was related to the high specific surface area, pore structure, and amorphous phase.展开更多
The use of a glass-fiber reinforced composite in marine structures is becoming more common, particularly due to the potential weight savings. The mechanical response of the joint between a glass-fiber reinforced polym...The use of a glass-fiber reinforced composite in marine structures is becoming more common, particularly due to the potential weight savings. The mechanical response of the joint between a glass-fiber reinforced polymer （GRP） superstructure and a steel hull formed is examined and subsequently modified to improve performance through a combined program of modeling and testing. A finite-element model is developed to predict the response of the joint. The model takes into account the contact at the interface between different materials, progressive damage, large deformation theory, and a non-linear stress-strain relationship. To predict the progressive failure, the analysis combines Hashin failure criteria and maximum stress failure criteria. The results show stress response has a great influence on the strength and bearing of the joint. The Balsawood-steel interface is proved to be critical to the mechanical behavior of the joint. Good agreement between experimental results and numerical predictions is observed.展开更多
The effects of Ethylene-Vinyl Acetate copolymer （EVA） latex as an additive or a glass fiber surface modifier on the properties of Glass-Fiber （ GF ）/ Magnesium Oxychloride Cement （MOC） composites was studied. Th...The effects of Ethylene-Vinyl Acetate copolymer （EVA） latex as an additive or a glass fiber surface modifier on the properties of Glass-Fiber （ GF ）/ Magnesium Oxychloride Cement （MOC） composites was studied. The mechanical properties, water resistance aud aging resistance of the cured GF/ MOC composites were estimated and chemical ingredients analysis and morphological study of the GF/ MOC composites were also performed. It is found that EVA added to the MOC matrix could substantially improve the interfacial adhesion, water resistance aud aging resistance of GF/ MOC composites. EVA treatment on glass fibers resulted in decreasing initial flexural strength of GF/ MOC composites while enhancing the soft coefficients. In addition, the drying time and dilution of the EVA treatment on glass fibers also had an otwioas effect on the properties of GF/ MOC composites. However, excessive EVA interfered with the growth of the 5 Mg（ OH）2· MgCl2 ·8H2O crystal and the properties of GF / MOC composites.展开更多
采用三维编织技术和真空辅助树脂灌注成型工艺制备了碳/玻混杂三维五向编织复合材料工字梁,对不同混杂比例和不同混杂部位的复合材料工字梁进行四点弯曲测试,结合三维数字图像相关(3D Digital Image Correlation,3D-DIC)技术分析其应变...采用三维编织技术和真空辅助树脂灌注成型工艺制备了碳/玻混杂三维五向编织复合材料工字梁,对不同混杂比例和不同混杂部位的复合材料工字梁进行四点弯曲测试,结合三维数字图像相关(3D Digital Image Correlation,3D-DIC)技术分析其应变分布和损伤过程。结果表明:采用不同混杂比例时,1/3碳纤维轴纱和2/3碳纤维轴纱相比纯玻璃纤维试样的强度提升了4.5%和11.5%,随着碳纤维占比的增加,复合材料的强度逐渐提升,但提升幅度较小;而碳纤维分布位置不同时,工字梁弯曲失效形式也不同,纯玻璃纤维和碳纤维在下翼缘的2种试样属于下压头附近边缘断裂的失效形式,碳纤维在腹板、腹板和下翼缘的2种试样属于腹板前后错位倾斜的失效形式,碳纤维在上翼缘、上翼缘和下翼缘、上翼缘和腹板的3种试样都属于腹板中心纵向断裂的失效形式;结合位移-载荷曲线及失效形式分析可知,1/3碳纤维分布于上翼缘,2/3碳纤维分布于上翼缘和下翼缘时,工字梁强度及抵抗变形的能力更佳,碳纤维更适合混杂于上翼缘。展开更多
基金Project supported by the National High Technology Research and Development Program of China(863 Program)(2008AA05Z305)the Scientific Research Foundation for the Returned Overseas Chinese Scholars,State Education Ministry(201109)+2 种基金the Master Dissertation Innovation Funded Projects(EG2013015)the Fundamental Research Funds for the Central Universities Special Fund Project(11D11315)Program of Shanghai Subject Chief Scientist(14XD1424700)
文摘Samples of cerium-manganese oxides supported on modified glass-fiber with different Ce/Mn molar ratios （Ce-Mn/GF） were prepared by an impregnation method and tested for low-temperature （80 180 ℃） selective catalytic reduction （SCR） of NO with ammonia. This brand-new technology could remove NO and particles matter from coal-fired flue gas. The surface properties of the catalysts were examined by means of Bmnauer-Emmett-Teller （BET）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, and scanning electron microscopy （SEM）. The experimental results showed that the catalyst with a Ce/Mn molar ratio of 0.2 obtained high activity of 87.4% NO conversion at 150 ℃ under a high space velocity of 50000 h1. Deactivation poisoned by SO2 still occurred, but the Ce-Mn/GF（0.2） catalyst performed desirable tolerance to SO2 with decreasing 50% in 40 min and then maintaining at about 30% NO conversion. Characterization results indicated that the excellent low-temperature catalytic activity was related to the high specific surface area, pore structure, and amorphous phase.
基金Foundation item： Supported by the National Natural Science Foundation of China （Grant No 61004008）, the Central Universities under Grant HEUCFR1001 and LBH-10138 Higher Sliding Mode Control for Underactuated Surface Ship.
文摘The use of a glass-fiber reinforced composite in marine structures is becoming more common, particularly due to the potential weight savings. The mechanical response of the joint between a glass-fiber reinforced polymer （GRP） superstructure and a steel hull formed is examined and subsequently modified to improve performance through a combined program of modeling and testing. A finite-element model is developed to predict the response of the joint. The model takes into account the contact at the interface between different materials, progressive damage, large deformation theory, and a non-linear stress-strain relationship. To predict the progressive failure, the analysis combines Hashin failure criteria and maximum stress failure criteria. The results show stress response has a great influence on the strength and bearing of the joint. The Balsawood-steel interface is proved to be critical to the mechanical behavior of the joint. Good agreement between experimental results and numerical predictions is observed.
文摘The effects of Ethylene-Vinyl Acetate copolymer （EVA） latex as an additive or a glass fiber surface modifier on the properties of Glass-Fiber （ GF ）/ Magnesium Oxychloride Cement （MOC） composites was studied. The mechanical properties, water resistance aud aging resistance of the cured GF/ MOC composites were estimated and chemical ingredients analysis and morphological study of the GF/ MOC composites were also performed. It is found that EVA added to the MOC matrix could substantially improve the interfacial adhesion, water resistance aud aging resistance of GF/ MOC composites. EVA treatment on glass fibers resulted in decreasing initial flexural strength of GF/ MOC composites while enhancing the soft coefficients. In addition, the drying time and dilution of the EVA treatment on glass fibers also had an otwioas effect on the properties of GF/ MOC composites. However, excessive EVA interfered with the growth of the 5 Mg（ OH）2· MgCl2 ·8H2O crystal and the properties of GF / MOC composites.
文摘采用三维编织技术和真空辅助树脂灌注成型工艺制备了碳/玻混杂三维五向编织复合材料工字梁,对不同混杂比例和不同混杂部位的复合材料工字梁进行四点弯曲测试,结合三维数字图像相关(3D Digital Image Correlation,3D-DIC)技术分析其应变分布和损伤过程。结果表明:采用不同混杂比例时,1/3碳纤维轴纱和2/3碳纤维轴纱相比纯玻璃纤维试样的强度提升了4.5%和11.5%,随着碳纤维占比的增加,复合材料的强度逐渐提升,但提升幅度较小;而碳纤维分布位置不同时,工字梁弯曲失效形式也不同,纯玻璃纤维和碳纤维在下翼缘的2种试样属于下压头附近边缘断裂的失效形式,碳纤维在腹板、腹板和下翼缘的2种试样属于腹板前后错位倾斜的失效形式,碳纤维在上翼缘、上翼缘和下翼缘、上翼缘和腹板的3种试样都属于腹板中心纵向断裂的失效形式;结合位移-载荷曲线及失效形式分析可知,1/3碳纤维分布于上翼缘,2/3碳纤维分布于上翼缘和下翼缘时,工字梁强度及抵抗变形的能力更佳,碳纤维更适合混杂于上翼缘。
