Graphene nanoplatelets(GNPs)are considered to be one of the most promising new reinforcements due to their unique two-dimensional structure and remarkable mechanical properties.In addition,their impressive electrical ...Graphene nanoplatelets(GNPs)are considered to be one of the most promising new reinforcements due to their unique two-dimensional structure and remarkable mechanical properties.In addition,their impressive electrical and thermal properties make them attractive fillers for producing multifunctional ceramics with a wide range of applications.This paper reviews the current status of the research and development of graphene-reinforced ceramic matrix composite(CMC)materials.Firstly,we focused on the processing methods for effective dispersion of GNPs throughout ceramic matrices and the reduction of the porosity of CMC products.Then,the microstructure and mechanical properties are provided,together with an emphasis on the possible toughening mechanisms that may operate.Additionally,the unique functional properties endowed by GNPs,such as enhanced electrical/thermal conductivity,are discussed,with a comprehensive comparison in different ceramic matrices as oxide and nonoxide composites.Finally,the prospects and problems needed to be solved in GNPs-reinforced CMCs are discussed.展开更多
Owing to their high performance and earth abundance,copper sulfides(Cu_(2-x)S)have attracted wide attention as a promising medium-temperature thermoelectric material.Nanostructure and grain-boundary engineering are ex...Owing to their high performance and earth abundance,copper sulfides(Cu_(2-x)S)have attracted wide attention as a promising medium-temperature thermoelectric material.Nanostructure and grain-boundary engineering are explored to tune the electrical transport and phonon scattering of Cu_(2-x)S based on the liquid-like copper ion.Here multiscale architecture-engineered Cu_(2-x)S are fabricated by a room-temperature wet chemical synthesis combining mechanical mixing and spark plasma sintering.The observed electrical conductivity in the multiscale architecture-engineered Cu_(2-x)S is four times as much as that of the Cu_(2-x)S sample at 800 K,which is attributed to the potential energy filtering effect at the new grain boundaries.Moreover,the multiscale architecture in the sintered Cu_(2-x)S increases phonon scattering and results in a reduced lattice thermal conductivity of 0.2 W·m^(-1)·K^(-1) and figure of merit(zT)of 1.0 at 800 K.Such a zT value is one of the record values in copper sulfide produced by chemical synthesis.These results suggest that the introduction of nanostructure and formation of new interface are effective strategies for the enhancement of thermoelectric material properties.展开更多
Objective:Metabolic syndrome is a complex medical condition that has become an alarming epidemic,but an effective therapy for this disease is still lacking.The use of the herbal formula Huangqisan(HQS)to treat diabete...Objective:Metabolic syndrome is a complex medical condition that has become an alarming epidemic,but an effective therapy for this disease is still lacking.The use of the herbal formula Huangqisan(HQS)to treat diabetes is documented in the Chinese medical literature as early as 1117 A.D.;however,its therapeutic effects and underlying mechanisms remain elusive.Methods:To investigate the beneficial effects of HQS on metabolic disorders,high-fat diet-induced obesity(DIO),leptin receptor dysfunction(db/db)and low-density lipoprotein receptor-knockout(LDLR^(-/-))mice were used.Obese mice were treated with either HQS or vehicle.Blood,liver tissue,white fat tissue and brown adipose tissue were harvested at the end of the treatment.Metabolic disease-related parameters were evaluated to test effects of HQS against diabetes,obesity and hyperlipidemia.Aortic arches from LDLR^(-/-)mice were analyzed to investigate the effects of HQS on atherosclerosis.RNA-sequence,quantitative real-time polymerase chain reaction and Western blot were performed to investigate the mechanisms of HQS against metabolic disorder.Results:HQS lowered body weight,fasting blood glucose and serum lipid levels and improved glucose tolerance and insulin sensitivity in DIO mice and db/db mice(P<0.05).HQS also blocked atherosclerotic plaque formation in LDLR^(^(-/-)) mice.HQS suppressed de novo lipid synthesis by reducing the expression of messenger RNA for sterol regulatory element-binding factor 1,stearyl coenzyme A desaturase 1 and fatty acid synthase,and enhancing adenosine 5’-monophosphate-activated protein kinase signaling in both in vivo and in vitro experiments,indicating potential mechanisms for HQS’s activity against diabetes.Conclusion:HQS is effective for reversing metabolic disorder and has the potential to be used as therapy for metabolic syndrome.展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.51432004 and 51672041)the Fundamental Research Funds for the Central Universities(No.2232018G-07)+2 种基金the Innovation Program of Shanghai Municipal Education Commission(No.2017-01-07-00-03-E00025)the Program for Innovative Research Team in University of Ministry of Education of China(No.IRT_16R13)Shanghai Sailing Program(No.17YF1400400)。
文摘Graphene nanoplatelets(GNPs)are considered to be one of the most promising new reinforcements due to their unique two-dimensional structure and remarkable mechanical properties.In addition,their impressive electrical and thermal properties make them attractive fillers for producing multifunctional ceramics with a wide range of applications.This paper reviews the current status of the research and development of graphene-reinforced ceramic matrix composite(CMC)materials.Firstly,we focused on the processing methods for effective dispersion of GNPs throughout ceramic matrices and the reduction of the porosity of CMC products.Then,the microstructure and mechanical properties are provided,together with an emphasis on the possible toughening mechanisms that may operate.Additionally,the unique functional properties endowed by GNPs,such as enhanced electrical/thermal conductivity,are discussed,with a comprehensive comparison in different ceramic matrices as oxide and nonoxide composites.Finally,the prospects and problems needed to be solved in GNPs-reinforced CMCs are discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.51702091 and 51702046)the College Outstanding Young Scientific and Technological Innovation Team of Hubei province(No.T201922)+2 种基金the Special Funding of Preventing the Spread of COVID-19,Hubei University of Education(No.20XGZX20)Fok Ying-Tong Education Foundation of China(No.171041)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University。
文摘Owing to their high performance and earth abundance,copper sulfides(Cu_(2-x)S)have attracted wide attention as a promising medium-temperature thermoelectric material.Nanostructure and grain-boundary engineering are explored to tune the electrical transport and phonon scattering of Cu_(2-x)S based on the liquid-like copper ion.Here multiscale architecture-engineered Cu_(2-x)S are fabricated by a room-temperature wet chemical synthesis combining mechanical mixing and spark plasma sintering.The observed electrical conductivity in the multiscale architecture-engineered Cu_(2-x)S is four times as much as that of the Cu_(2-x)S sample at 800 K,which is attributed to the potential energy filtering effect at the new grain boundaries.Moreover,the multiscale architecture in the sintered Cu_(2-x)S increases phonon scattering and results in a reduced lattice thermal conductivity of 0.2 W·m^(-1)·K^(-1) and figure of merit(zT)of 1.0 at 800 K.Such a zT value is one of the record values in copper sulfide produced by chemical synthesis.These results suggest that the introduction of nanostructure and formation of new interface are effective strategies for the enhancement of thermoelectric material properties.
基金supported by Shanghai Municipal Planning Commission of Science and Research Fund(Shanghai,China,No.20174Y0164)to SF。
文摘Objective:Metabolic syndrome is a complex medical condition that has become an alarming epidemic,but an effective therapy for this disease is still lacking.The use of the herbal formula Huangqisan(HQS)to treat diabetes is documented in the Chinese medical literature as early as 1117 A.D.;however,its therapeutic effects and underlying mechanisms remain elusive.Methods:To investigate the beneficial effects of HQS on metabolic disorders,high-fat diet-induced obesity(DIO),leptin receptor dysfunction(db/db)and low-density lipoprotein receptor-knockout(LDLR^(-/-))mice were used.Obese mice were treated with either HQS or vehicle.Blood,liver tissue,white fat tissue and brown adipose tissue were harvested at the end of the treatment.Metabolic disease-related parameters were evaluated to test effects of HQS against diabetes,obesity and hyperlipidemia.Aortic arches from LDLR^(-/-)mice were analyzed to investigate the effects of HQS on atherosclerosis.RNA-sequence,quantitative real-time polymerase chain reaction and Western blot were performed to investigate the mechanisms of HQS against metabolic disorder.Results:HQS lowered body weight,fasting blood glucose and serum lipid levels and improved glucose tolerance and insulin sensitivity in DIO mice and db/db mice(P<0.05).HQS also blocked atherosclerotic plaque formation in LDLR^(^(-/-)) mice.HQS suppressed de novo lipid synthesis by reducing the expression of messenger RNA for sterol regulatory element-binding factor 1,stearyl coenzyme A desaturase 1 and fatty acid synthase,and enhancing adenosine 5’-monophosphate-activated protein kinase signaling in both in vivo and in vitro experiments,indicating potential mechanisms for HQS’s activity against diabetes.Conclusion:HQS is effective for reversing metabolic disorder and has the potential to be used as therapy for metabolic syndrome.
