Hip-hop granny rolls back the years to prove that with passion,anything is possible Who says hip hop belongs to the teenagers? In China,more and more seniors are choosing this trendy dance style as a way to keep fit,r...Hip-hop granny rolls back the years to prove that with passion,anything is possible Who says hip hop belongs to the teenagers? In China,more and more seniors are choosing this trendy dance style as a way to keep fit,rather than the more serene move- ments of taiji or ballroom dancing in the parks. Wu Ying is one of them.The 71-year- old Wu is the founder of a granny hip-hop dance team in Beijing,whose participants are in their 60s.Wu is the oldest in the team.In their loose modern outfits and hair wrapped in bandanas,these old ladies展开更多
Promotional videos tell why and how China can develop so fast China has just released a 17-minute long video promoting the country’s national image. On February 3,the video titled China on the Way began airing on tel...Promotional videos tell why and how China can develop so fast China has just released a 17-minute long video promoting the country’s national image. On February 3,the video titled China on the Way began airing on television stations in Asia,Europe and America.展开更多
The titanium alloy strut serves as a key load-bearing component of aircraft landing gear,typically manufactured via forging.The friction condition has important influence on material flow and cavity filling during the...The titanium alloy strut serves as a key load-bearing component of aircraft landing gear,typically manufactured via forging.The friction condition has important influence on material flow and cavity filling during the forging process.Using the previously optimized shape and initial position of preform,the influence of the friction condition(friction factor m=0.1–0.3)on material flow and cavity filling was studied by numerical method with a shear friction model.A novel filling index was defined to reflect material flow into left and right flashes and zoom in on friction-induced results.The results indicate that the workpiece moves rigidly to the right direction,with the displacement decreasing as m increases.When m<0.18,the underfilling defect will occur in the left side of strut forging,while overflow occurs in the right forging die cavity.By combining the filling index and analyses of material flow and filling status,a reasonable friction factor interval of m=0.21–0.24 can be determined.Within this interval,the cavity filling behavior demonstrates robustness,with friction fluctuations exerting minimal influence.展开更多
The increasing performance demands of modern aero engines necessitate the integrated design of compressor transition ducts with upstream components to reduce the axial length of the engine.However,this design approach...The increasing performance demands of modern aero engines necessitate the integrated design of compressor transition ducts with upstream components to reduce the axial length of the engine.However,this design approach narrows the spacing between the stator and the strut,making traditional research on transition ducts only with struts unsuitable.The numerical results and experimental oil flow visualization results were utilized to reconstruct the three-dimensional flow structures in the stator passages under various operating conditions.Additionally,numerical methods were employed to analyze the mechanisms of the strut's effect on the upstream stator in an aggressive transition duct.The results show that the strut potential field increases the load on the upstream stator,leading to severe blade surface separation and corner separation/stall,and redistributes the inflow angle of the upstream stators circumferentially,resulting in significant differences in the flow structures within the stator passages on both sides.The separation flows within the stator passages mainly manifest in five types:pressure surface separation vortex,suction surface concentrated shedding vortex,suction surface separation vortex,suction surface-corner stall separation vortex,and suction surface separation vortex pair.Under different operating conditions,the separation flows within the stator passages are always composed of a part of these five types or a transitional state between two of them.展开更多
The alternating wedge strut,serving as both an injector and a vortex generator,has great potential for application in the scramjet combustor.The expansive trailing edge structure can further enhance the mixing perform...The alternating wedge strut,serving as both an injector and a vortex generator,has great potential for application in the scramjet combustor.The expansive trailing edge structure can further enhance the mixing performance of the alternating wedge strut.To enhance the performance of scramjet engines,it is essential to investigate the fuel/air mixing characteristics and mechanism downstream of alternating wedge struts with expansive trailing edges.The research focused on the impact of two different fuel injection schemes on the air/fuel mixing process and plume morphology.The optical diagnostic technique,particle laser-induced fluorescence,was employed to measure fuel plume morphology at various downstream locations under ambient temperature conditions.The results show that the expansive trailing edge significantly enhances the vertical diffusion of the fuel,leading to distinct plume characteristics.Compared to the strut injecting fuel into the edge of the streamwise vortex,the strut injecting fuel into the core of the streamwise vortex results in a larger fuel plume area with a more uniform distribution.Additionally,a streamwise vortex model was established to investigate the vortex dynamics and mixing mechanisms behind the strut from a mechanistic perspective.The simulation results indicate that the model demonstrates good performance in forecasting the dynamics of streamwise vortices and the evolution of fuel plume morphology.展开更多
Agile Web Development Framework(AWDF)开发框架是作者提出的一种新型的Web开发框架,它基于MVC模型2,用于Web应用的开发。通过与struts的比较提出了AWDF的优势所在,并对AWDF的设计思想、框架模式、各个组成部分的定义功能及责任作了详...Agile Web Development Framework(AWDF)开发框架是作者提出的一种新型的Web开发框架,它基于MVC模型2,用于Web应用的开发。通过与struts的比较提出了AWDF的优势所在,并对AWDF的设计思想、框架模式、各个组成部分的定义功能及责任作了详细的描述。此构架的优势在于与其它框架相比,它的简单易用使得降低系统的复杂度和系统的开发成本成为可能;并且AWDF框架采用可复用的数据验证的机制来提高系统的可复用性,从而使得在大型系统的开发中使用此构架成为可能。展开更多
文摘Hip-hop granny rolls back the years to prove that with passion,anything is possible Who says hip hop belongs to the teenagers? In China,more and more seniors are choosing this trendy dance style as a way to keep fit,rather than the more serene move- ments of taiji or ballroom dancing in the parks. Wu Ying is one of them.The 71-year- old Wu is the founder of a granny hip-hop dance team in Beijing,whose participants are in their 60s.Wu is the oldest in the team.In their loose modern outfits and hair wrapped in bandanas,these old ladies
文摘Promotional videos tell why and how China can develop so fast China has just released a 17-minute long video promoting the country’s national image. On February 3,the video titled China on the Way began airing on television stations in Asia,Europe and America.
基金National Natural Science Foundation of China(52375378)National Key Laboratory of Metal Forming Technology and Heavy Equipment(S2308100.W12)Huxiang High-Level Talent Gathering Project of Hunan Province(2021RC5001)。
文摘The titanium alloy strut serves as a key load-bearing component of aircraft landing gear,typically manufactured via forging.The friction condition has important influence on material flow and cavity filling during the forging process.Using the previously optimized shape and initial position of preform,the influence of the friction condition(friction factor m=0.1–0.3)on material flow and cavity filling was studied by numerical method with a shear friction model.A novel filling index was defined to reflect material flow into left and right flashes and zoom in on friction-induced results.The results indicate that the workpiece moves rigidly to the right direction,with the displacement decreasing as m increases.When m<0.18,the underfilling defect will occur in the left side of strut forging,while overflow occurs in the right forging die cavity.By combining the filling index and analyses of material flow and filling status,a reasonable friction factor interval of m=0.21–0.24 can be determined.Within this interval,the cavity filling behavior demonstrates robustness,with friction fluctuations exerting minimal influence.
基金supported by the National Natural Science Foundation of China(No.52276025)the Science Center for Gas Turbine Project of China(Nos.P2022-A-Ⅱ-001-001,P2022-A-Ⅱ-002-001 and P2022-B-Ⅱ-002-001)。
文摘The increasing performance demands of modern aero engines necessitate the integrated design of compressor transition ducts with upstream components to reduce the axial length of the engine.However,this design approach narrows the spacing between the stator and the strut,making traditional research on transition ducts only with struts unsuitable.The numerical results and experimental oil flow visualization results were utilized to reconstruct the three-dimensional flow structures in the stator passages under various operating conditions.Additionally,numerical methods were employed to analyze the mechanisms of the strut's effect on the upstream stator in an aggressive transition duct.The results show that the strut potential field increases the load on the upstream stator,leading to severe blade surface separation and corner separation/stall,and redistributes the inflow angle of the upstream stators circumferentially,resulting in significant differences in the flow structures within the stator passages on both sides.The separation flows within the stator passages mainly manifest in five types:pressure surface separation vortex,suction surface concentrated shedding vortex,suction surface separation vortex,suction surface-corner stall separation vortex,and suction surface separation vortex pair.Under different operating conditions,the separation flows within the stator passages are always composed of a part of these five types or a transitional state between two of them.
文摘The alternating wedge strut,serving as both an injector and a vortex generator,has great potential for application in the scramjet combustor.The expansive trailing edge structure can further enhance the mixing performance of the alternating wedge strut.To enhance the performance of scramjet engines,it is essential to investigate the fuel/air mixing characteristics and mechanism downstream of alternating wedge struts with expansive trailing edges.The research focused on the impact of two different fuel injection schemes on the air/fuel mixing process and plume morphology.The optical diagnostic technique,particle laser-induced fluorescence,was employed to measure fuel plume morphology at various downstream locations under ambient temperature conditions.The results show that the expansive trailing edge significantly enhances the vertical diffusion of the fuel,leading to distinct plume characteristics.Compared to the strut injecting fuel into the edge of the streamwise vortex,the strut injecting fuel into the core of the streamwise vortex results in a larger fuel plume area with a more uniform distribution.Additionally,a streamwise vortex model was established to investigate the vortex dynamics and mixing mechanisms behind the strut from a mechanistic perspective.The simulation results indicate that the model demonstrates good performance in forecasting the dynamics of streamwise vortices and the evolution of fuel plume morphology.
文摘Agile Web Development Framework(AWDF)开发框架是作者提出的一种新型的Web开发框架,它基于MVC模型2,用于Web应用的开发。通过与struts的比较提出了AWDF的优势所在,并对AWDF的设计思想、框架模式、各个组成部分的定义功能及责任作了详细的描述。此构架的优势在于与其它框架相比,它的简单易用使得降低系统的复杂度和系统的开发成本成为可能;并且AWDF框架采用可复用的数据验证的机制来提高系统的可复用性,从而使得在大型系统的开发中使用此构架成为可能。
