Actuation system is a vital system in an aircraft, providing the force necessary to move flight control surfaces. The system has a significant influence on the overall aircraft performance and its safety. In order to ...Actuation system is a vital system in an aircraft, providing the force necessary to move flight control surfaces. The system has a significant influence on the overall aircraft performance and its safety. In order to further increase already high reliability and safety, Airbus has imple- mented a dissimilar redundancy actuation system （DRAS） in its aircraft. The DRAS consists of a hydraulic actuation system （HAS） and an electro-hydrostatic actuation system （EHAS）, in which the HAS utilizes a hydraulic source （HS） to move the control surface and the EHAS utilizes an elec- trical supply （ES） to provide the motion force. This paper focuses on the performance degradation processes and fault monitoring strategies of the DRAS, establishes its reliability model based on the generalized stochastic Petri nets （GSPN）, and carries out a reliability assessment considering the fault monitoring coverage rate and the false alarm rate. The results indicate that the proposed reli- ability model of the DRAS, considering the fault and redundancy degradation process and identify monitoring, can express its fault logical relation potential safety hazards.展开更多
Natural muscle provides excellent motilities for animals.As the basic unit of the muscle system,the skeletal muscle fibers function as a soft linear actuator.Inspired by the muscle fibers,researchers have developed va...Natural muscle provides excellent motilities for animals.As the basic unit of the muscle system,the skeletal muscle fibers function as a soft linear actuator.Inspired by the muscle fibers,researchers have developed various soft active devices with linear actuation.This paper reviews several soft linear actu ators,such as the dielec trie elastomer,t hermal responsive hydrogels,pneumatic artificial muscle,and conducting polymers.The actuation mechanisms and performances of these soft linear actuators are summarized.Based on the dielectric elastomer,we propose a design of a hybrid system with linear actuation,driven by both the electric motor and dielectric elasto mer cone.The elec tromechanical behaviors of the dielec trie elastomer cone have been investigated in both experiment and finite element analysis.This work may guide the further design of soft actuators and robots.展开更多
目的探讨PI3K/Akt信号通路对急性肺损伤(ALI)大鼠肺泡上皮钠通道(ENaC)α、β和γ亚基表达的影响。方法成年SD大鼠随机分为对照组、ALI组(脂多糖)、胰岛素组及渥曼青霉素组,每组5只。观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),测...目的探讨PI3K/Akt信号通路对急性肺损伤(ALI)大鼠肺泡上皮钠通道(ENaC)α、β和γ亚基表达的影响。方法成年SD大鼠随机分为对照组、ALI组(脂多糖)、胰岛素组及渥曼青霉素组,每组5只。观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),测量总肺水含量,RT-PCR和Western blot测定ENaC mRNA和蛋白、p-Akt表达。结果胰岛素组BALF蛋白含量、髓过氧化物酶(MPO)活性、总肺水含量较ALI组显著减少(P<0.05),渥曼青霉素组BALF蛋白含量、MPO活性及总肺水含量较胰岛素组显著增加(P<0.05)。ALI组α-、β-和γ-ENaC蛋白表达显著低于对照组(0.33±0.06 vs 1.27±0.07,0.18±0.04 vs 0.72±0.04,0.37±0.04 vs 0.69±0.05)(P<0.05)。胰岛素组蛋白表达α-ENaC(2.19±0.04)、β-ENaC(1.18±0.07)和γ-ENaC(1.18±0.08)显著高于ALI组(P<0.05)。渥曼青霉素组蛋白表达α-ENaC(0.86±0.09)、β-ENaC(0.58±0.05)和γ-ENaC(0.59±0.02)显著低于胰岛素组(P<0.05)。胰岛素组ENaC mRNA和p-Akt较ALI组显著升高(P<0.05)。渥曼青霉素组ENaC mRNA和p-Akt较胰岛素组显著降低(P<0.05)。结论激活PI3K/Akt通路上调3种ENaC亚基表达,从而清除肺水肿液。展开更多
基金supported by the National Basic Research and Development Program of China(No.2014CB046402)the National Natural Science Foundation of China(No.51175014)‘‘111" Program of China
文摘Actuation system is a vital system in an aircraft, providing the force necessary to move flight control surfaces. The system has a significant influence on the overall aircraft performance and its safety. In order to further increase already high reliability and safety, Airbus has imple- mented a dissimilar redundancy actuation system （DRAS） in its aircraft. The DRAS consists of a hydraulic actuation system （HAS） and an electro-hydrostatic actuation system （EHAS）, in which the HAS utilizes a hydraulic source （HS） to move the control surface and the EHAS utilizes an elec- trical supply （ES） to provide the motion force. This paper focuses on the performance degradation processes and fault monitoring strategies of the DRAS, establishes its reliability model based on the generalized stochastic Petri nets （GSPN）, and carries out a reliability assessment considering the fault monitoring coverage rate and the false alarm rate. The results indicate that the proposed reli- ability model of the DRAS, considering the fault and redundancy degradation process and identify monitoring, can express its fault logical relation potential safety hazards.
基金This work acknowledges the supports from the following programs:National Key R&D Program of China(2017YFA0701100)National Natural Science Foundation of China(11572280,11822207,U161320211321202 and 11432012)+3 种基金National Basic Research Program of China(Grant No.2015CB057301)China Association for Science and Technology(Young Elite Scientist Sponsorship Program No.YESS20150004)Zhejiang Provincial Natural Science Foundation of China(R18A020004)Fund of State Key Laboratory of Fluid Power and Mechatronic Systems,Zhejiang University,and Dr.Li Dak Sum&Yip Yio Chin Fund for Stem Cell and Regenerative Medicine.
文摘Natural muscle provides excellent motilities for animals.As the basic unit of the muscle system,the skeletal muscle fibers function as a soft linear actuator.Inspired by the muscle fibers,researchers have developed various soft active devices with linear actuation.This paper reviews several soft linear actu ators,such as the dielec trie elastomer,t hermal responsive hydrogels,pneumatic artificial muscle,and conducting polymers.The actuation mechanisms and performances of these soft linear actuators are summarized.Based on the dielectric elastomer,we propose a design of a hybrid system with linear actuation,driven by both the electric motor and dielectric elasto mer cone.The elec tromechanical behaviors of the dielec trie elastomer cone have been investigated in both experiment and finite element analysis.This work may guide the further design of soft actuators and robots.
文摘目的探讨PI3K/Akt信号通路对急性肺损伤(ALI)大鼠肺泡上皮钠通道(ENaC)α、β和γ亚基表达的影响。方法成年SD大鼠随机分为对照组、ALI组(脂多糖)、胰岛素组及渥曼青霉素组,每组5只。观察肺组织病理改变,收集支气管肺泡灌洗液(BALF),测量总肺水含量,RT-PCR和Western blot测定ENaC mRNA和蛋白、p-Akt表达。结果胰岛素组BALF蛋白含量、髓过氧化物酶(MPO)活性、总肺水含量较ALI组显著减少(P<0.05),渥曼青霉素组BALF蛋白含量、MPO活性及总肺水含量较胰岛素组显著增加(P<0.05)。ALI组α-、β-和γ-ENaC蛋白表达显著低于对照组(0.33±0.06 vs 1.27±0.07,0.18±0.04 vs 0.72±0.04,0.37±0.04 vs 0.69±0.05)(P<0.05)。胰岛素组蛋白表达α-ENaC(2.19±0.04)、β-ENaC(1.18±0.07)和γ-ENaC(1.18±0.08)显著高于ALI组(P<0.05)。渥曼青霉素组蛋白表达α-ENaC(0.86±0.09)、β-ENaC(0.58±0.05)和γ-ENaC(0.59±0.02)显著低于胰岛素组(P<0.05)。胰岛素组ENaC mRNA和p-Akt较ALI组显著升高(P<0.05)。渥曼青霉素组ENaC mRNA和p-Akt较胰岛素组显著降低(P<0.05)。结论激活PI3K/Akt通路上调3种ENaC亚基表达,从而清除肺水肿液。
