Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to deteriorate.In a bid to enhance the turbocharger’s acceleration capabilities,this study ...Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to deteriorate.In a bid to enhance the turbocharger’s acceleration capabilities,this study scrutinizes various factors impacting its performance.Based on the operational principles and transient response process of the turbocharger,three types of in-ertiadnamely,aerodynamic inertia(ADI),thermal inertia(TI),and mechanical inertia(MI)d are identified and addressed for design.To begin,this paper pioneers the innovative definition of a method for evaluating the transient response performance of the turbocharger.This method incor-porates the introduction of an ADI parameter,inspired by the definition of MI.Subsequently,a thin-walled volute design with a low Biot number and a lightweight turbine impeller is introduced to reduce the turbocharger’s TI and MI.The simulation results of theflowfield distribution within the volute and diffuser demonstrate the comprehensive design method’s effectiveness in improving gas pressure and temperature distributions in these components.Notably,the pressure distributionfluctuation in the constant moment-of-momentum volute(CMV)is 62.8%lower than that in the constant velocity moment volute(CVMV).The low-TI thin-walled volute not only en-hances the turbocharger’s response speed but also reduces its weight by approximately 40%.The impact of three types of inertia on the engine’s response speed is quantified as follows:ADI(94%)>MI(5%)>TI(1%).This conclusion has been verified through test results of both the turbocharger and the engine.This design method not only significantly improves the turbo-charger’s response performance but also offers valuable insights for the optimal design of other blade mechanical systems.展开更多
Methicillin-resistant Staphylococcus aureus (MRSA), the most common pathogen in hospital and community environments, can cause serious and even fatal infections. The antibiotics currently used for clinical treatment o...Methicillin-resistant Staphylococcus aureus (MRSA), the most common pathogen in hospital and community environments, can cause serious and even fatal infections. The antibiotics currently used for clinical treatment of MRSA have developed resistance, and there is an urgent need to develop new antimicrobials to treat infections caused by MRSA strains. Quinoline analogues play an important role in the development of antimicrobials. Herein, we discussed the current development of antibacterial activities of quinoline analogues, mainly for anti-MRSA activity, and their structure-activity relationships (SARs) from the perspective of using the quinoline nucleus to search for novel potential anti-MRSA candidates. Additionally, the mechanisms of some representative quinoline analogues against MRSA were clarified. Altogether, this review could provide further insights for the rational development of quinoline-based antibacterial drugs, especially against MRSA.展开更多
Unlike adult mammalian heart,zebrafish heart has a remarkable capacity to regenerate after injury.Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium ...Unlike adult mammalian heart,zebrafish heart has a remarkable capacity to regenerate after injury.Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium and this activation is mediated by hemodynamic alteration after injury,however,the molecular mechanism has not been fully explored.In this study we demonstrated that blood flow change could be perceived and transmitted in a primary cilia dependent manner to control the hemodynamic responsive klf2 gene expression and subsequent activation of Notch signaling in the endocardium.First we showed that both homologues of human gene KLF2 in zebrafish,klf2a and klf2b,could respond to hemodynamic alteration and both were required for Notch signaling activation and heart regeneration.Further experiments indicated that the upregulation of klf2 gene expression was mediated by endocardial primary cilia.Overall,our findings reveal a novel aspect of mechanical shear stress signal in activating Notch pathway and regulating cardiac regeneration.展开更多
As a highly conserved signaling pathway in metazoans,the Notch pathway plays important roles in embryonic development and tissue regeneration.Recently,cardiac injury and regeneration have become an increasingly popula...As a highly conserved signaling pathway in metazoans,the Notch pathway plays important roles in embryonic development and tissue regeneration.Recently,cardiac injury and regeneration have become an increasingly popular topic for biomedical research,and Notch signaling has been shown to exert crucial functions during heart regeneration as well.In this review,we briefly summarize the molecular functions of the endocardial Notch pathway in several cardiac injury and stress models.Although there is an increase in appreciating the importance of endocardial Notch signaling in heart regeneration,the mechanism of its activation is not fully understood.This review highlights recent findings on the activation of the endocardial Notch pathway by hemodynamic blood flow change in larval zebrafish ventricle after partial ablation,a process involving primary cilia,mechanosensitive ion channel Trpv4 and mechanosensitive transcription factor Klf2.展开更多
The in-cylinder gas exchange process is crucial to the power performance of two-stroke aircraft piston engines,which is easily influenced by complex factors such as high-altitude performance variation and in-cylinder ...The in-cylinder gas exchange process is crucial to the power performance of two-stroke aircraft piston engines,which is easily influenced by complex factors such as high-altitude performance variation and in-cylinder flow characteristics.This paper reviews the development history and characteristics of gas exchange types,as well as the current state of theory and the validation methods of gas exchange technology,while also discusses the trends of cutting-edge technologies in the field.This paper provides a theoretical foundation for the optimization and engineering design of gas exchange systems and,more importantly,points out that the innovation of gas exchange types,the modification of theoretical models,and the technology of variable airflow organization are the key future research directions in this field.展开更多
The poppet valves two-stroke(PV2S)aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio,uniform t...The poppet valves two-stroke(PV2S)aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio,uniform torque output,and flexible valve timings.However,its high-altitude gas exchange performance remains unexplored,presenting new opportunities for optimization through artificial intelligence(AI)technology.This study uses validated 1D+3D models to evaluate the high-altitude gas exchange performance of PV2S aircraft engines.The valve timings of the PV2S engine exhibit considerable flexibility,thus the Latin hypercube design of experiments(DoE)methodology is employed to fit a response surface model.A genetic algorithm(GA)is applied to iteratively optimize valve timings for varying altitudes.The optimization process reveals that increasing the intake duration while decreasing the exhaust duration and valve overlap angles can significantly enhance high-altitude gas exchange performance.The optimal valve overlap angle emerged as 93°CA at sea level and 82°CA at 4000 m altitude.The effects of operating parameters,including engine speed,load,and exhaust back pressure,on the gas exchange process at varying altitudes are further investigated.The higher engine speed increases trapping efficiency but decreases the delivery ratio and charging efficiency at various altitudes.This effect is especially pronounced at elevated altitudes.The increase in exhaust back pressure will significantly reduce the delivery ratio and increase the trapping efficiency.This study demonstrates that integrating DoE with AI algorithms can enhance the high-altitude performance of aircraft engines,serving as a valuable reference for further optimization efforts.展开更多
Sarcasm detection in Natural Language Processing(NLP)has become increasingly important,partic-ularly with the rise of social media and non-textual emotional expressions,such as images.Existing methods often rely on se...Sarcasm detection in Natural Language Processing(NLP)has become increasingly important,partic-ularly with the rise of social media and non-textual emotional expressions,such as images.Existing methods often rely on separate image and text modalities,which may not fully utilize the information available from both sources.To address this limitation,we propose a novel multimodal large model,i.e.,the PKME-MLM(Prior Knowledge and Multi-label Emotion analysis based Multimodal Large Model for sarcasm detection).The PKME-MLM aims to enhance sarcasm detection by integrating prior knowledge to extract useful textual information from images,which is then combined with text data for deeper analysis.This method improves the integration of image and text data,addressing the limitation of previous models that process these modalities separately.Additionally,we incorporate multi-label sentiment analysis,refining sentiment labels to improve sarcasm recognition accuracy.This design overcomes the limitations of prior models that treated sentiment classification as a single-label problem,thereby improving sarcasm recognition by distinguishing subtle emotional cues from the text.Experimental results demonstrate that our approach achieves significant performance improvements in multimodal sarcasm detection tasks,with an accuracy(Acc.)of 94.35%,and Macro-Average Precision and Recall reaching 93.92%and 94.21%,respectively.These results highlight the potential of multimodal models in improving sarcasm detection and suggest that further integration of modalities could advance future research.This work also paves the way for incorporating multimodal sentiment analysis into sarcasm detection.展开更多
基金funded by the Basic Research Program of the National Nature Science Foundation of China (Grant number[52206131],[U2233213],[51775025]and[U2333217])National Key R&D Program of China,grant number[2022YFB2602002]and[2018YFB0104100]+1 种基金Zhejiang Provincial Natural Science Foundation of China,grant number[LQ22E060004]Science Center of Gas Turbine Project[P2022-A-I-001-001].
文摘Limited by the poor transient response performance of turbochargers,the dynamic performance of aviation piston engines tends to deteriorate.In a bid to enhance the turbocharger’s acceleration capabilities,this study scrutinizes various factors impacting its performance.Based on the operational principles and transient response process of the turbocharger,three types of in-ertiadnamely,aerodynamic inertia(ADI),thermal inertia(TI),and mechanical inertia(MI)d are identified and addressed for design.To begin,this paper pioneers the innovative definition of a method for evaluating the transient response performance of the turbocharger.This method incor-porates the introduction of an ADI parameter,inspired by the definition of MI.Subsequently,a thin-walled volute design with a low Biot number and a lightweight turbine impeller is introduced to reduce the turbocharger’s TI and MI.The simulation results of theflowfield distribution within the volute and diffuser demonstrate the comprehensive design method’s effectiveness in improving gas pressure and temperature distributions in these components.Notably,the pressure distributionfluctuation in the constant moment-of-momentum volute(CMV)is 62.8%lower than that in the constant velocity moment volute(CVMV).The low-TI thin-walled volute not only en-hances the turbocharger’s response speed but also reduces its weight by approximately 40%.The impact of three types of inertia on the engine’s response speed is quantified as follows:ADI(94%)>MI(5%)>TI(1%).This conclusion has been verified through test results of both the turbocharger and the engine.This design method not only significantly improves the turbo-charger’s response performance but also offers valuable insights for the optimal design of other blade mechanical systems.
基金the National Natural Science Foundation of China(No.32272575)National College Student Innovation and Entrepreneurship Training Program(No.202210459164)for financial support.
文摘Methicillin-resistant Staphylococcus aureus (MRSA), the most common pathogen in hospital and community environments, can cause serious and even fatal infections. The antibiotics currently used for clinical treatment of MRSA have developed resistance, and there is an urgent need to develop new antimicrobials to treat infections caused by MRSA strains. Quinoline analogues play an important role in the development of antimicrobials. Herein, we discussed the current development of antibacterial activities of quinoline analogues, mainly for anti-MRSA activity, and their structure-activity relationships (SARs) from the perspective of using the quinoline nucleus to search for novel potential anti-MRSA candidates. Additionally, the mechanisms of some representative quinoline analogues against MRSA were clarified. Altogether, this review could provide further insights for the rational development of quinoline-based antibacterial drugs, especially against MRSA.
基金We thank Haitao Zhou and Lifeng Li for fish care,Kaa Seng Lai,Yabo Fang and Wenyan Li for technical support and other lab members for in depth discussion.We thank Dr Tao Zhong for providing reagents.This study was supported by National Key R&D Program of China grant 2018YFA0801004 and NSFC grant 31571492 to R.Z.
文摘Unlike adult mammalian heart,zebrafish heart has a remarkable capacity to regenerate after injury.Previous study has shown Notch signaling activation in the endocardium is essential for regeneration of the myocardium and this activation is mediated by hemodynamic alteration after injury,however,the molecular mechanism has not been fully explored.In this study we demonstrated that blood flow change could be perceived and transmitted in a primary cilia dependent manner to control the hemodynamic responsive klf2 gene expression and subsequent activation of Notch signaling in the endocardium.First we showed that both homologues of human gene KLF2 in zebrafish,klf2a and klf2b,could respond to hemodynamic alteration and both were required for Notch signaling activation and heart regeneration.Further experiments indicated that the upregulation of klf2 gene expression was mediated by endocardial primary cilia.Overall,our findings reveal a novel aspect of mechanical shear stress signal in activating Notch pathway and regulating cardiac regeneration.
基金This study was supported by National Key R&D Program of China grant 2018YFA0801000 and NSFC grant 31571492 to R.
文摘As a highly conserved signaling pathway in metazoans,the Notch pathway plays important roles in embryonic development and tissue regeneration.Recently,cardiac injury and regeneration have become an increasingly popular topic for biomedical research,and Notch signaling has been shown to exert crucial functions during heart regeneration as well.In this review,we briefly summarize the molecular functions of the endocardial Notch pathway in several cardiac injury and stress models.Although there is an increase in appreciating the importance of endocardial Notch signaling in heart regeneration,the mechanism of its activation is not fully understood.This review highlights recent findings on the activation of the endocardial Notch pathway by hemodynamic blood flow change in larval zebrafish ventricle after partial ablation,a process involving primary cilia,mechanosensitive ion channel Trpv4 and mechanosensitive transcription factor Klf2.
基金funded by the National Natural Science Foundation of China(Nos.52206131,U2233213and 51775025)the National Key R&D Program of China(2022YFB2602002,2018YFB0104100)+1 种基金the Zhejiang Provincial Natural Science Foundation of China(LQ22E060004)the Science Center of Gas Turbine Project,China(No.P2022-A-I-001-001)。
文摘The in-cylinder gas exchange process is crucial to the power performance of two-stroke aircraft piston engines,which is easily influenced by complex factors such as high-altitude performance variation and in-cylinder flow characteristics.This paper reviews the development history and characteristics of gas exchange types,as well as the current state of theory and the validation methods of gas exchange technology,while also discusses the trends of cutting-edge technologies in the field.This paper provides a theoretical foundation for the optimization and engineering design of gas exchange systems and,more importantly,points out that the innovation of gas exchange types,the modification of theoretical models,and the technology of variable airflow organization are the key future research directions in this field.
基金funded by the Basic Research Program of the National Natural Science Foundation of China[grant numbers 52206131,U2333217,U2233213,and 51775025]National Key R&D Program of China[grant number 2022YFB2602002 and 2018YFB0104100]+1 种基金Zhejiang Provincial Natural Science Foundation of China[grant number LQ22E060004]Science Center of Gas Turbine Project[grant number P2022-A-I-001-001].
文摘The poppet valves two-stroke(PV2S)aircraft engine fueled with sustainable aviation fuel is a promising option for general aviation and unmanned aerial vehicle propulsion due to its high power-to-weight ratio,uniform torque output,and flexible valve timings.However,its high-altitude gas exchange performance remains unexplored,presenting new opportunities for optimization through artificial intelligence(AI)technology.This study uses validated 1D+3D models to evaluate the high-altitude gas exchange performance of PV2S aircraft engines.The valve timings of the PV2S engine exhibit considerable flexibility,thus the Latin hypercube design of experiments(DoE)methodology is employed to fit a response surface model.A genetic algorithm(GA)is applied to iteratively optimize valve timings for varying altitudes.The optimization process reveals that increasing the intake duration while decreasing the exhaust duration and valve overlap angles can significantly enhance high-altitude gas exchange performance.The optimal valve overlap angle emerged as 93°CA at sea level and 82°CA at 4000 m altitude.The effects of operating parameters,including engine speed,load,and exhaust back pressure,on the gas exchange process at varying altitudes are further investigated.The higher engine speed increases trapping efficiency but decreases the delivery ratio and charging efficiency at various altitudes.This effect is especially pronounced at elevated altitudes.The increase in exhaust back pressure will significantly reduce the delivery ratio and increase the trapping efficiency.This study demonstrates that integrating DoE with AI algorithms can enhance the high-altitude performance of aircraft engines,serving as a valuable reference for further optimization efforts.
基金funding partly by the National Natural Science Foundation of China under grant number 61701179.
文摘Sarcasm detection in Natural Language Processing(NLP)has become increasingly important,partic-ularly with the rise of social media and non-textual emotional expressions,such as images.Existing methods often rely on separate image and text modalities,which may not fully utilize the information available from both sources.To address this limitation,we propose a novel multimodal large model,i.e.,the PKME-MLM(Prior Knowledge and Multi-label Emotion analysis based Multimodal Large Model for sarcasm detection).The PKME-MLM aims to enhance sarcasm detection by integrating prior knowledge to extract useful textual information from images,which is then combined with text data for deeper analysis.This method improves the integration of image and text data,addressing the limitation of previous models that process these modalities separately.Additionally,we incorporate multi-label sentiment analysis,refining sentiment labels to improve sarcasm recognition accuracy.This design overcomes the limitations of prior models that treated sentiment classification as a single-label problem,thereby improving sarcasm recognition by distinguishing subtle emotional cues from the text.Experimental results demonstrate that our approach achieves significant performance improvements in multimodal sarcasm detection tasks,with an accuracy(Acc.)of 94.35%,and Macro-Average Precision and Recall reaching 93.92%and 94.21%,respectively.These results highlight the potential of multimodal models in improving sarcasm detection and suggest that further integration of modalities could advance future research.This work also paves the way for incorporating multimodal sentiment analysis into sarcasm detection.
