Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in aero-engines.This study aims to investigate the complex heat transfer mechanisms of a rot...Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in aero-engines.This study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various factors.Specifically,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical analyses.In particular,a novel combined solution method is proposed to simplify the complex heat transfer problem.The results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature ratio.The heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds number.Analysis reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine disk.Thus,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.展开更多
Sexual dimorphism has been reported in various human diseases including autoimmune diseases,neurological diseases,pulmonary arterial hypertension,and some types of cancers,although the underlying mechanisms remain poo...Sexual dimorphism has been reported in various human diseases including autoimmune diseases,neurological diseases,pulmonary arterial hypertension,and some types of cancers,although the underlying mechanisms remain poorly understood.The long noncoding RNA(lncRNA)X-inactive specific transcript(XIST)is involved in X chromosome inactivation(XCI)in female placental mammals,a process that ensures the balanced expression dosage of X-linked genes between sexes.XIST is abnormally expressed in many sex-biased diseases.In addition,escape from XIST-mediated XCI and skewed XCI also contribute to sex-biased diseases.Therefore,its expression or modification can be regarded as a biomarker for the diagnosis and prognosis of many sex-biased diseases.Genetic manipulation of XIST expression can inhibit the progression of some of these diseases in animal models,and therefore XIST has been proposed as a potential therapeutic target.In this manuscript,we summarize the current knowledge about the mechanisms for XIST-mediated XCI and the roles of XIST in sex-biased diseases,and discuss potential therapeutic strategies targeting XIST.展开更多
Two pure hydrocarbon molecules of l,3,5-tris(9-phenyl-9H-fluoren-9-yl)benzene(mTPFB)and l,3,5-tris(2-tert-butyl-9-phenyl-9H-fluoren-9-yl)benzene(tBu-mTPFB)were synthesized.Due to the conjugation blocked connection mod...Two pure hydrocarbon molecules of l,3,5-tris(9-phenyl-9H-fluoren-9-yl)benzene(mTPFB)and l,3,5-tris(2-tert-butyl-9-phenyl-9H-fluoren-9-yl)benzene(tBu-mTPFB)were synthesized.Due to the conjugation blocked connection mode and rigid/bulky substitutions,these two materials possess high triplet energy,enabling them as good hosts for blue phosphor in PhOLEDs.By studying their thermal,electrochemical,electronic absorption and photoluminescent properties,it was found that the influence of the inert tert-butyl group on material photoelectrical properties is negligible.For instance,mTPFB and tBu-mTPFB showed very similar absorption and emission profiles,with almost the same bandgap,triplet energy and energy levels.However,the encapsulation of tert-butyl on the 2-position of 9-phenylfluorene enhanced material thermal stability.Most importantly,carrier transport properties were improved dramatically,as proved by the mono carrier device.Blue phosphorescent OLEDs hosted by tBu-mTPFB showed external quantum efficiency of 15.2%and current efficiency of 23.0 cd/A,which were much higher than that of the OLEDs based on mTPFB with the analogous structure.展开更多
基金supported by the National Science and Technology Major Project of China(2017-II-0011-0037)In addition,special thanks are addressed to the support of China Postdoctoral Science Foundation(2023M742834)Guangdong Basic and Applied Basic Research Foundation,China(2023A1515011597).
文摘Thermal boundary conditions of the turbine disk cavity system are of great importance in the design of secondary air systems in aero-engines.This study aims to investigate the complex heat transfer mechanisms of a rotating turbine disk under high-speed conditions.A high-speed rotating free-disk model with Dorfman empirical solutions is developed to evaluate the heat transfer performance considering various factors.Specifically,the influence of compressibility,variable properties,and heat dissipation is determined using theoretical and numerical analyses.In particular,a novel combined solution method is proposed to simplify the complex heat transfer problem.The results indicate that the heat transfer performance of a free disk is primarily influenced by the rotating Mach number,rotating Reynolds number,Rossby number,and wall temperature ratio.The heat transfer temperature and Nusselt number of the free disk are strongly correlated with the rotating Mach number and rotating Reynolds number.Analysis reveals that heat dissipation is a critical factor affecting the accurate evaluation of the heat transfer performance of the turbine disk.Thus,the combined solution method can serve as a reference for future investigations of flow and heat transfer in high-speed rotating turbine disk cavity systems in aero-engines.
基金This work was supported by the National Natural Science Foundation of China(No.32070870)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515010758)+2 种基金Guangdong Provincial Key Laboratory of Synthetic Genomics,Shenzhen Key Laboratory of Synthetic Genomics(No.ZDSYS201802061806209)Shenzhen Institute of Synthetic Biology Scientific Research Program(No.ZTXM20200008 and DWKF20210003)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDPB18).
文摘Sexual dimorphism has been reported in various human diseases including autoimmune diseases,neurological diseases,pulmonary arterial hypertension,and some types of cancers,although the underlying mechanisms remain poorly understood.The long noncoding RNA(lncRNA)X-inactive specific transcript(XIST)is involved in X chromosome inactivation(XCI)in female placental mammals,a process that ensures the balanced expression dosage of X-linked genes between sexes.XIST is abnormally expressed in many sex-biased diseases.In addition,escape from XIST-mediated XCI and skewed XCI also contribute to sex-biased diseases.Therefore,its expression or modification can be regarded as a biomarker for the diagnosis and prognosis of many sex-biased diseases.Genetic manipulation of XIST expression can inhibit the progression of some of these diseases in animal models,and therefore XIST has been proposed as a potential therapeutic target.In this manuscript,we summarize the current knowledge about the mechanisms for XIST-mediated XCI and the roles of XIST in sex-biased diseases,and discuss potential therapeutic strategies targeting XIST.
基金supported by the National Natural Science Foundation of China(61474064,61504063)funding from Nanjing University of Posts and Telecommunications (NY214085,NY214177)+5 种基金the Natural Science Foundation of Jiangsu Province(BK20150836)the National Basic Research Program of China (2015CB932200)the National Synergistic Innovation Center for Advanced Materials(SICAM)Synergistic Innovation Center for Organic Electronics and Information DisplaysPriority Academic Program Development of Jiangsu Higher Education Institutions(PAPD,YX03001)funding from Key Laboratory for Organic Electronics & Information Displays
文摘Two pure hydrocarbon molecules of l,3,5-tris(9-phenyl-9H-fluoren-9-yl)benzene(mTPFB)and l,3,5-tris(2-tert-butyl-9-phenyl-9H-fluoren-9-yl)benzene(tBu-mTPFB)were synthesized.Due to the conjugation blocked connection mode and rigid/bulky substitutions,these two materials possess high triplet energy,enabling them as good hosts for blue phosphor in PhOLEDs.By studying their thermal,electrochemical,electronic absorption and photoluminescent properties,it was found that the influence of the inert tert-butyl group on material photoelectrical properties is negligible.For instance,mTPFB and tBu-mTPFB showed very similar absorption and emission profiles,with almost the same bandgap,triplet energy and energy levels.However,the encapsulation of tert-butyl on the 2-position of 9-phenylfluorene enhanced material thermal stability.Most importantly,carrier transport properties were improved dramatically,as proved by the mono carrier device.Blue phosphorescent OLEDs hosted by tBu-mTPFB showed external quantum efficiency of 15.2%and current efficiency of 23.0 cd/A,which were much higher than that of the OLEDs based on mTPFB with the analogous structure.