To satisfy the requirements of substantial green development,it is urgent to explore an innovative eco‐friendly semiconductor photocatalyst to efficiently achieve visible‐light‐driven photocatalytic H 2 evolution(P...To satisfy the requirements of substantial green development,it is urgent to explore an innovative eco‐friendly semiconductor photocatalyst to efficiently achieve visible‐light‐driven photocatalytic H 2 evolution(PHE).The strategy of promoting the spatial separation efficiency of photoinduced carriers can essentially enhance the PHE performance of a photocatalyst.Herein,a graphitic carbon nitride(g‐C 3 N 4)‐based donor–acceptor(D‐A)copolymer(CNDM x)is constructed by simple one‐pot thermal polycondensation,using urea and 5,8‐DibroMoquinoxaline(as an electron donor)as precursors.The electron D-A modulation consequently creates an internal electric field to facilitate the intramolecular charge transfer within the copolymer.A series of experimental characterizations and density functional theory calculations are applied to elucidate the variation and correlation of the structure and PHE performance of the as-prepared catalysts.It is found that the best average PHE rate of 3012.5μmolg^(−1) h^(−1) can be achieved over the optimal D-A copolymer under visible‐light(400<λ<800nm)irradiation,which is~3.3 times that of pure urea-derived g-C_(3)N_(4).The corresponding apparent quantum efficiency is 1.3% at 420nm.This study provides a protocol for designing effective visible-light photocatalysts via D-A modulation of polymeric semiconductors.展开更多
Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally pre...Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally present in the 5' untranslated regions of a few m RNAs, constitute a powerful tool to co-express several genes of interest. IRESs are translational enhancers allowing the translational machinery to start protein synthesis by internal initiation. This feature allowed the design of multi-cistronic vectors expressing several genes from a single m RNA. IRESs exhibit tissue specificity, and drive translation in stress conditions when the global cell translation is blocked, which renders them useful for gene transfer in hypoxic conditions occurring in ischemic diseases and cancer. IRES-based viral and non viral vectors have been used successfully in preclinical and clinical assays of combined gene therapy and resulted in therapeutic benefits for various pathologies including cancers, cardiovascular diseases and degenerative diseases.展开更多
This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The in...This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The investigations focus on the heat transfer and aerodynamic measurements in the channel, which is an accurate representation of the configuration used in aeroengines. Correlations foi： the heat transfer coefficient and the pressure drop used in the design of internal cooling passages are often developed from simplified models. It is important to note that real engine passages do not have perfect rectangular cross sections, but include a comer fillets, ribs with fillet radii and a special orientation. Therefore, this work provides detailed fluid flow and heat transfer data for a model of radial cooling geometry which has very realistic features.展开更多
基金This study was financially supported by the National Key Research and Development Program of China(2018YFB1502001)the National Natural Science Foundation of China(51922081,51961135303,51932007,and U1705251).
文摘To satisfy the requirements of substantial green development,it is urgent to explore an innovative eco‐friendly semiconductor photocatalyst to efficiently achieve visible‐light‐driven photocatalytic H 2 evolution(PHE).The strategy of promoting the spatial separation efficiency of photoinduced carriers can essentially enhance the PHE performance of a photocatalyst.Herein,a graphitic carbon nitride(g‐C 3 N 4)‐based donor–acceptor(D‐A)copolymer(CNDM x)is constructed by simple one‐pot thermal polycondensation,using urea and 5,8‐DibroMoquinoxaline(as an electron donor)as precursors.The electron D-A modulation consequently creates an internal electric field to facilitate the intramolecular charge transfer within the copolymer.A series of experimental characterizations and density functional theory calculations are applied to elucidate the variation and correlation of the structure and PHE performance of the as-prepared catalysts.It is found that the best average PHE rate of 3012.5μmolg^(−1) h^(−1) can be achieved over the optimal D-A copolymer under visible‐light(400<λ<800nm)irradiation,which is~3.3 times that of pure urea-derived g-C_(3)N_(4).The corresponding apparent quantum efficiency is 1.3% at 420nm.This study provides a protocol for designing effective visible-light photocatalysts via D-A modulation of polymeric semiconductors.
文摘Gene therapy appears as a promising strategy to treatincurable diseases. In particular, combined gene therapy has shown improved therapeutic efficiency. Internal ribosome entry sites(IRESs), RNA elements naturally present in the 5' untranslated regions of a few m RNAs, constitute a powerful tool to co-express several genes of interest. IRESs are translational enhancers allowing the translational machinery to start protein synthesis by internal initiation. This feature allowed the design of multi-cistronic vectors expressing several genes from a single m RNA. IRESs exhibit tissue specificity, and drive translation in stress conditions when the global cell translation is blocked, which renders them useful for gene transfer in hypoxic conditions occurring in ischemic diseases and cancer. IRES-based viral and non viral vectors have been used successfully in preclinical and clinical assays of combined gene therapy and resulted in therapeutic benefits for various pathologies including cancers, cardiovascular diseases and degenerative diseases.
基金funding from the European Union Seventh Framework Programme(FP7/2007-2013)under Grant Agreement No.233799(ERICKA)
文摘This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The investigations focus on the heat transfer and aerodynamic measurements in the channel, which is an accurate representation of the configuration used in aeroengines. Correlations foi： the heat transfer coefficient and the pressure drop used in the design of internal cooling passages are often developed from simplified models. It is important to note that real engine passages do not have perfect rectangular cross sections, but include a comer fillets, ribs with fillet radii and a special orientation. Therefore, this work provides detailed fluid flow and heat transfer data for a model of radial cooling geometry which has very realistic features.
