To design the optimum acceleration control schedule for the Adaptive Cycle Engine(ACE)in the full flight envelope,this paper establishes a direct simulation model of the ACE transient state.In this model,geometric par...To design the optimum acceleration control schedule for the Adaptive Cycle Engine(ACE)in the full flight envelope,this paper establishes a direct simulation model of the ACE transient state.In this model,geometric parameters are used to replace the component state parameters.The corresponding relationship between geometric parameters and component state parameters is determined by sensitivity analysis.The geometric variables are controlled when the geometric adjustment speed exceeds the limit,and at the same time the corresponding component state parameters are iterated.The gradient optimization algorism is used to optimize the ground acceleration process of ACE,and the control schedule in terms of operating point of compression components and corrected acceleration rate is used as the full-envelope acceleration control schedule based on the similarity principle.The acceleration control schedules of the triple-bypass mode and the double-bypass mode are designed in this paper.The acceleration processes under various flight conditions are simulated using the acceleration control schedules.Compared with the acceleration process with the linear geometric adjustment schedule,the acceleration performance of ACE is improved by the acceleration control schedule,with the impulse of the acceleration process of the triple-bypass mode being increased by 8.7%-12.3% and the impulse of the double-bypass mode acceleration process being increased by 11.8%-14.1%.展开更多
Spinal cord injury(SCI)often results in an inhibitory environment at the injury site.In our previous studies,transplantation of a scaffold combined with stem cells was proven to induce neural regeneration in animal mo...Spinal cord injury(SCI)often results in an inhibitory environment at the injury site.In our previous studies,transplantation of a scaffold combined with stem cells was proven to induce neural regeneration in animal models of complete SCI.Based on these preclinical studies,collagen scaffolds loaded with the patients’own bone marrow mononuclear cells or human umbilical cord mesenchymal stem cells were transplanted into SCI patients.Fifteen patients with acute complete SCI and 51 patients with chronic complete SCI were enrolled and followed up for 2 to 5 years.No serious adverse events related to functional scaffold transplantation were observed.Among the patients with acute SCI,five patients achieved expansion of their sensory positions and six patients recovered sensation in the bowel or bladder.Additionally,four patients regained voluntary walking ability accompanied by reconnection of neural signal transduction.Among patients with chronic SCI,16 patients achieved expansion of their sensation level and 30 patients experienced enhanced reflexive defecation sensation or increased skin sweating below the injury site.Nearly half of the patients with chronic cervical SCI developed enhanced finger activity.These long-term follow-up results suggest that functional scaffold transplantation may represent a feasible treatment for patients with complete SCI.展开更多
基金co-supported by the National Science and Technology Major Project,China(No.J2019-I-0015-0014)the National Natural Science Foundation of China(No.52372397).
文摘To design the optimum acceleration control schedule for the Adaptive Cycle Engine(ACE)in the full flight envelope,this paper establishes a direct simulation model of the ACE transient state.In this model,geometric parameters are used to replace the component state parameters.The corresponding relationship between geometric parameters and component state parameters is determined by sensitivity analysis.The geometric variables are controlled when the geometric adjustment speed exceeds the limit,and at the same time the corresponding component state parameters are iterated.The gradient optimization algorism is used to optimize the ground acceleration process of ACE,and the control schedule in terms of operating point of compression components and corrected acceleration rate is used as the full-envelope acceleration control schedule based on the similarity principle.The acceleration control schedules of the triple-bypass mode and the double-bypass mode are designed in this paper.The acceleration processes under various flight conditions are simulated using the acceleration control schedules.Compared with the acceleration process with the linear geometric adjustment schedule,the acceleration performance of ACE is improved by the acceleration control schedule,with the impulse of the acceleration process of the triple-bypass mode being increased by 8.7%-12.3% and the impulse of the double-bypass mode acceleration process being increased by 11.8%-14.1%.
基金supported by grants from the National Natural Science Foundation of China(81891000)the National Key Research and Development Program of China(2016YFC1101504 and2016YFC1101505)。
文摘Spinal cord injury(SCI)often results in an inhibitory environment at the injury site.In our previous studies,transplantation of a scaffold combined with stem cells was proven to induce neural regeneration in animal models of complete SCI.Based on these preclinical studies,collagen scaffolds loaded with the patients’own bone marrow mononuclear cells or human umbilical cord mesenchymal stem cells were transplanted into SCI patients.Fifteen patients with acute complete SCI and 51 patients with chronic complete SCI were enrolled and followed up for 2 to 5 years.No serious adverse events related to functional scaffold transplantation were observed.Among the patients with acute SCI,five patients achieved expansion of their sensory positions and six patients recovered sensation in the bowel or bladder.Additionally,four patients regained voluntary walking ability accompanied by reconnection of neural signal transduction.Among patients with chronic SCI,16 patients achieved expansion of their sensation level and 30 patients experienced enhanced reflexive defecation sensation or increased skin sweating below the injury site.Nearly half of the patients with chronic cervical SCI developed enhanced finger activity.These long-term follow-up results suggest that functional scaffold transplantation may represent a feasible treatment for patients with complete SCI.
