This study presents a fragility curve to assess explosively induced damage to military vehicle tires based on shock tube experiments.To replicate lateral damage scenarios that may occur in real battlefield environment...This study presents a fragility curve to assess explosively induced damage to military vehicle tires based on shock tube experiments.To replicate lateral damage scenarios that may occur in real battlefield environments involving missile or bomb detonations,extreme overpressure conditions were generated using a shock tube.The influence of explosive charge mass on tire damage was quantitatively evaluated.Experimental results identified two critical failure thresholds:for loss of pressure,the threshold was 354 kPa peak overpressure and 3052 kPa·ms impulse;for rupture,the values were 485 kPa and 4237 kPa-ms,respectively.The same damage profile was reproduced through finite element analysis(FEA),verifying the reliability of the simulation.A Single Degree of Freedom(SDOF)model and Kingery-Bulmash(K-B)chart were employed to generate pressure-impulse data as a function of standoff distance.These data were applied to a finite element tire model using the BLAST ENHANCED keyword in LS-DYNA.The applied peak overpressures were identical to the experimental values with a 24%-27%difference in impulse.The simulation also captured recurring bead rim separation phenomenon,leading to internal pressure loss consistent with high-speed camera observations from the experiments.The resulting fragility curve clearly defines the threshold conditions for tire damage and provides a standardized damage assessment model applicable to various explosive charge masses and stand-off distances.The proposed model offers a quantitative basis for evaluating tire vulnerability,providing foundational reference data for defense applications.Specifically,the findings are expected to serve as a reliable source for weapon effects analysis and target vulnerability assessments involving wheeled military vehicles.展开更多
The performance-based passive control analysis of the Maxwell dampers between one 10-story and one 6-story adjacent RC frames is conducted in this work.Not only the optimal parameters but also the optimal arrangements...The performance-based passive control analysis of the Maxwell dampers between one 10-story and one 6-story adjacent RC frames is conducted in this work.Not only the optimal parameters but also the optimal arrangements of the Maxwell dampers are proposed based on the optimal target of making the total exceeding probability of the adjacent structures to be minimal.The applicability of the analytical expressions of the Maxwell damper damping parameters under different seismic performance targets are firstly examined and then the preferable damping parameters of the Maxwell dampers are proposed through the extensive parametric studies.Furthermore,the optimal arranging positions and optimal arranging numbers of the Maxwell dampers between the adjacent buildings are derived based on a large number of seismic fragility analyses,as well.The general arranging laws of the Maxwell dampers between the adjacent buildings are generated based on the discussion of the theoretical method through the simplified plane model.The optimal parameters and optimal arrangement of the Maxwell dampers presented make both the adjacent structures have preferable controlled effects under each seismic performance target which can satisfy the requirements of multi-performance seismic resistance of the modern seismic codes.展开更多
Variations between earthquakes result in many factors that influence post-earthquake building damage(e.g.,ground motion parameters,building structure,site information,and quality of construction).Consequently,it is ne...Variations between earthquakes result in many factors that influence post-earthquake building damage(e.g.,ground motion parameters,building structure,site information,and quality of construction).Consequently,it is necessary to develop an appropriate building damage-rate estimation model.The building damage survey data were recorded and constructed into files by the Architecture and Building Research Institute(ABRI),Taiwan for the 1999 Chi-Chi earthquake in the Nantou region as a basis for developing a building damage rate estimation model by applying fuzzy theory to express the fragility curves of buildings as a membership function.Empirical verification was performed using post-earthquake building damage data in the Taichung city that suffered relatively severe damage.Results indicate that fuzzy theory can be applied to predict building damage rates and that the estimated results are similar to actual disaster figures.Prediction of disaster damage using building damage rates can provide a reference for immediate disaster response during earthquakes and for regular disaster prevention and rescue planning.展开更多
Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which l...Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which leads to intellectual disability and social impairment. γ-aminobutyric acid （GABA） is the major inhibitory neuro- transmitter of the mammalian central nervous system, and its metabotropic GABAB receptor has been implicated in various mental disorders. The GABAB receptor agonist baclofen has been shown to improve FXS symptoms in a mouse model and in human patients, suggesting the role of GABAB receptor on FMRP regulation. Here we investi- gated the signaling events linking the GABAB receptor and FMRP. Methods Western blot was used in this study to detect protein expression and kinase phosphorylation in cerebellar granule neurons. For key molecules in signal- ling pathway, RNAi was used in MEFs to confirm the results in neurons. Results GABAB receptor activation up- regulated cAMP response element binding protein-dependent Fmrp expression in cultured mouse cerebellar granule neurons via two distinct mechanisms： the transactivation of insulin-like growth factor-1 receptor and activation of protein kinase C. In addition, a positive allosteric modulator of the GABAB receptor, CGP7930, stimulated Fmrp expression in neurons. Conclusion These results suggest a role for GABAB receptor in Fmrp regulation and a po- tential interest of GABAB receptor signaling in FXS improvement.展开更多
Fragile X syndrome(FXS)is the most prevalent inherited intellectual disability,resulting from a loss of fragile X mental retardation protein(FMRP).Patients with FXS suffer lifelong cognitive disabilities,but the funct...Fragile X syndrome(FXS)is the most prevalent inherited intellectual disability,resulting from a loss of fragile X mental retardation protein(FMRP).Patients with FXS suffer lifelong cognitive disabilities,but the function of FMRP in the adult brain and the mechanism underlying age-related cognitive decline in FXS is not fully understood.Here,we report that a loss of FMRP results in increased protein synthesis of histone acetyltransferase EP300 and ubiquitinationmediated degradation of histone deacetylase HDAC1 in adult hippocampal neural stem cells(NSCs).Consequently,FMRPdeficient NSCs exhibit elevated histone acetylation and age-related NSC depletion,leading to cognitive impairment in mature adult mice.Reducing histone acetylation rescues both neurogenesis and cognitive deficits in mature adult FMRPdeficient mice.Our work reveals a role for FMRP and histone acetylation in cognition and presents a potential novel ther⁃apeutic strategy for treating adult FXS patients.展开更多
基金part of the Agency for Defense Development(ADD)research project on Weapon lethality/effectiveness analysis technology for material targets and grant funded by the korean goverment(511225-912A03301)。
文摘This study presents a fragility curve to assess explosively induced damage to military vehicle tires based on shock tube experiments.To replicate lateral damage scenarios that may occur in real battlefield environments involving missile or bomb detonations,extreme overpressure conditions were generated using a shock tube.The influence of explosive charge mass on tire damage was quantitatively evaluated.Experimental results identified two critical failure thresholds:for loss of pressure,the threshold was 354 kPa peak overpressure and 3052 kPa·ms impulse;for rupture,the values were 485 kPa and 4237 kPa-ms,respectively.The same damage profile was reproduced through finite element analysis(FEA),verifying the reliability of the simulation.A Single Degree of Freedom(SDOF)model and Kingery-Bulmash(K-B)chart were employed to generate pressure-impulse data as a function of standoff distance.These data were applied to a finite element tire model using the BLAST ENHANCED keyword in LS-DYNA.The applied peak overpressures were identical to the experimental values with a 24%-27%difference in impulse.The simulation also captured recurring bead rim separation phenomenon,leading to internal pressure loss consistent with high-speed camera observations from the experiments.The resulting fragility curve clearly defines the threshold conditions for tire damage and provides a standardized damage assessment model applicable to various explosive charge masses and stand-off distances.The proposed model offers a quantitative basis for evaluating tire vulnerability,providing foundational reference data for defense applications.Specifically,the findings are expected to serve as a reliable source for weapon effects analysis and target vulnerability assessments involving wheeled military vehicles.
基金Projects(51408443,51178203)supported by the National Natural Science Foundation of ChinaProject(K201511)supported by the Science Foundation of Wuhan Institute of Technology,China
文摘The performance-based passive control analysis of the Maxwell dampers between one 10-story and one 6-story adjacent RC frames is conducted in this work.Not only the optimal parameters but also the optimal arrangements of the Maxwell dampers are proposed based on the optimal target of making the total exceeding probability of the adjacent structures to be minimal.The applicability of the analytical expressions of the Maxwell damper damping parameters under different seismic performance targets are firstly examined and then the preferable damping parameters of the Maxwell dampers are proposed through the extensive parametric studies.Furthermore,the optimal arranging positions and optimal arranging numbers of the Maxwell dampers between the adjacent buildings are derived based on a large number of seismic fragility analyses,as well.The general arranging laws of the Maxwell dampers between the adjacent buildings are generated based on the discussion of the theoretical method through the simplified plane model.The optimal parameters and optimal arrangement of the Maxwell dampers presented make both the adjacent structures have preferable controlled effects under each seismic performance target which can satisfy the requirements of multi-performance seismic resistance of the modern seismic codes.
基金Project(93-2625-Z-027-006)supported by the National Science Council of Taipei,China
文摘Variations between earthquakes result in many factors that influence post-earthquake building damage(e.g.,ground motion parameters,building structure,site information,and quality of construction).Consequently,it is necessary to develop an appropriate building damage-rate estimation model.The building damage survey data were recorded and constructed into files by the Architecture and Building Research Institute(ABRI),Taiwan for the 1999 Chi-Chi earthquake in the Nantou region as a basis for developing a building damage rate estimation model by applying fuzzy theory to express the fragility curves of buildings as a membership function.Empirical verification was performed using post-earthquake building damage data in the Taichung city that suffered relatively severe damage.Results indicate that fuzzy theory can be applied to predict building damage rates and that the estimated results are similar to actual disaster figures.Prediction of disaster damage using building damage rates can provide a reference for immediate disaster response during earthquakes and for regular disaster prevention and rescue planning.
文摘Aim Fragile X mental retardation protein （FMRP） is an RNA-binding protein important for the control of translation and synaptic function. The mutation or silencing of FMRP causes Fragile X syndrome （FXS） , which leads to intellectual disability and social impairment. γ-aminobutyric acid （GABA） is the major inhibitory neuro- transmitter of the mammalian central nervous system, and its metabotropic GABAB receptor has been implicated in various mental disorders. The GABAB receptor agonist baclofen has been shown to improve FXS symptoms in a mouse model and in human patients, suggesting the role of GABAB receptor on FMRP regulation. Here we investi- gated the signaling events linking the GABAB receptor and FMRP. Methods Western blot was used in this study to detect protein expression and kinase phosphorylation in cerebellar granule neurons. For key molecules in signal- ling pathway, RNAi was used in MEFs to confirm the results in neurons. Results GABAB receptor activation up- regulated cAMP response element binding protein-dependent Fmrp expression in cultured mouse cerebellar granule neurons via two distinct mechanisms： the transactivation of insulin-like growth factor-1 receptor and activation of protein kinase C. In addition, a positive allosteric modulator of the GABAB receptor, CGP7930, stimulated Fmrp expression in neurons. Conclusion These results suggest a role for GABAB receptor in Fmrp regulation and a po- tential interest of GABAB receptor signaling in FXS improvement.
文摘Fragile X syndrome(FXS)is the most prevalent inherited intellectual disability,resulting from a loss of fragile X mental retardation protein(FMRP).Patients with FXS suffer lifelong cognitive disabilities,but the function of FMRP in the adult brain and the mechanism underlying age-related cognitive decline in FXS is not fully understood.Here,we report that a loss of FMRP results in increased protein synthesis of histone acetyltransferase EP300 and ubiquitinationmediated degradation of histone deacetylase HDAC1 in adult hippocampal neural stem cells(NSCs).Consequently,FMRPdeficient NSCs exhibit elevated histone acetylation and age-related NSC depletion,leading to cognitive impairment in mature adult mice.Reducing histone acetylation rescues both neurogenesis and cognitive deficits in mature adult FMRPdeficient mice.Our work reveals a role for FMRP and histone acetylation in cognition and presents a potential novel ther⁃apeutic strategy for treating adult FXS patients.
