The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H...The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-per fluorooctyltrichlorosilane or 1H,1H,2H,2H-per fluorodecyltriethoxysilane and followed by ultraviolet irradiation.The surface water contact angle was improved from 46° of original ceramic membrane to 159°,which exhibited a stable and excellent superhydrophobic effect.The modi fied membranes showed a high flux of 27.28 kg·m^(-2)·h^(-1) and simultaneously maintained an excellent retention rate of 99.99%,when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl(75 °C) aqueous solution.These results suggested that superhydrophobic modi fication of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance.The superhydrophobically-modi fied ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.展开更多
This paper empirically investigates the effect of mandatory pension contributions on firm innovation. We find that firms with mandatory contributions experience a decline in their innovation output. This effect is str...This paper empirically investigates the effect of mandatory pension contributions on firm innovation. We find that firms with mandatory contributions experience a decline in their innovation output. This effect is stronger for firms with financial constraints, more shortterm institutional investors, higher levels of managerial short-termism. We also document that mandatory pension contributions result in a reduction in firm research and development expenditures and an increase in firm debt-to-asset ratio. Moreover, we report that firms with mandatory contributions increase their alliance activities to pursue innovation with external partners.展开更多
基金Supported by the National Natural Science Foundation of China(51473013)
文摘The hydrophobically modi fied ceramic membranes have great potential for energy-ef ficient membrane distillation.In this work,flat-sheet ceramic membranes with a superhydrophobic surface were fabricated by grafting 1H,1H,2H,2H-per fluorooctyltrichlorosilane or 1H,1H,2H,2H-per fluorodecyltriethoxysilane and followed by ultraviolet irradiation.The surface water contact angle was improved from 46° of original ceramic membrane to 159°,which exhibited a stable and excellent superhydrophobic effect.The modi fied membranes showed a high flux of 27.28 kg·m^(-2)·h^(-1) and simultaneously maintained an excellent retention rate of 99.99%,when used in vacuum membrane distillation process for treatment of a 1 wt% NaCl(75 °C) aqueous solution.These results suggested that superhydrophobic modi fication of ceramic surface is a facile and cost-effective way to achieve higher membrane distillation performance.The superhydrophobically-modi fied ceramic membrane with an excellent desalination capacity would show considerable potential in practical membrane distillation utilizations.
文摘This paper empirically investigates the effect of mandatory pension contributions on firm innovation. We find that firms with mandatory contributions experience a decline in their innovation output. This effect is stronger for firms with financial constraints, more shortterm institutional investors, higher levels of managerial short-termism. We also document that mandatory pension contributions result in a reduction in firm research and development expenditures and an increase in firm debt-to-asset ratio. Moreover, we report that firms with mandatory contributions increase their alliance activities to pursue innovation with external partners.
