A new direct-lift control carrier landing mode is advanced, and it is proved to be very effective to keep the attitude angle and path angle constant when the aircraft is in the blind area of tracking radar and the gui...A new direct-lift control carrier landing mode is advanced, and it is proved to be very effective to keep the attitude angle and path angle constant when the aircraft is in the blind area of tracking radar and the guidance system is shut off. The direct-lift control mode is achieved with the symmetric deflection of the flaps and dynamic decoupling for minor disturbance of the angle of attack. This mode changes an aircraft' s model from a short-period oscillation model to a non-oscillation one, which could evidently increase the gust-rejection capability of the aircraft.展开更多
Silicon carbide (SiC) composites were prepared by hot-press sintering from α-SiC starting powders with BaAl2Si2O8 (BAS). The effects of additives on densification, microstructure, flexural strength, and fracture beha...Silicon carbide (SiC) composites were prepared by hot-press sintering from α-SiC starting powders with BaAl2Si2O8 (BAS). The effects of additives on densification, microstructure, flexural strength, and fracture behavior of the liquid phase sintered (LPS) SiC composites were investigated. The results show that the served BAS effectively promotes the densification of SiC composites. The flexural strength and fracture toughness of the SiC composites can reach a maximum value of 454 MPa and 5.1 MPa·m1/2, respectively, for 40% (w/w) BAS/SiC composites. SiC grain pullout, crack deflection, and crack bridging were main toughening mechanisms for the sintered composites.展开更多
基金Sponsored by the Aviation Science Foundation(Grant No. 01E52028)the National S-863 Plan-study of the AeronauticsAstronautics Foundational Techniques
文摘A new direct-lift control carrier landing mode is advanced, and it is proved to be very effective to keep the attitude angle and path angle constant when the aircraft is in the blind area of tracking radar and the guidance system is shut off. The direct-lift control mode is achieved with the symmetric deflection of the flaps and dynamic decoupling for minor disturbance of the angle of attack. This mode changes an aircraft' s model from a short-period oscillation model to a non-oscillation one, which could evidently increase the gust-rejection capability of the aircraft.
文摘Silicon carbide (SiC) composites were prepared by hot-press sintering from α-SiC starting powders with BaAl2Si2O8 (BAS). The effects of additives on densification, microstructure, flexural strength, and fracture behavior of the liquid phase sintered (LPS) SiC composites were investigated. The results show that the served BAS effectively promotes the densification of SiC composites. The flexural strength and fracture toughness of the SiC composites can reach a maximum value of 454 MPa and 5.1 MPa·m1/2, respectively, for 40% (w/w) BAS/SiC composites. SiC grain pullout, crack deflection, and crack bridging were main toughening mechanisms for the sintered composites.
