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Dynamics and FNTSM Control of Spacecraft with a Film Capture Pocket System
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作者 zhuoran huang Chao Tang +2 位作者 Qiang Yu Mohamed Shehata Saleh Khaliel Cheng Wei 《Space(Science & Technology)》 EI 2023年第1期547-559,共13页
To solve the problem of space debris,a film capture pocket system is designed in this paper.The film capture pocket is more flexible and reliable,compared with the space rope net.The film capture pocket system contain... To solve the problem of space debris,a film capture pocket system is designed in this paper.The film capture pocket is more flexible and reliable,compared with the space rope net.The film capture pocket system contains many flexible structures that are prone to large deformation and vibration during movement.The deformation causes large disturbances to the service spacecraft.It is necessary to establish an accurate rigid-flexible coupling dynamic model for quantitative analysis of disturbances.First,a film dynamic model is developed using high-order absolute nodal coordinate formulation.Second,an attitude tracking control law is designed by using the fast nonsingular terminal sliding mode controller and fixed time dilation observer(FxESO).Finally,combining dynamics and control principles,a virtual prototype of spacecraft with film capture pocket system is established.The simulation results show that higher-order absolute nodal coordinate formulation elements have better convergence,compared to ABAQUS finite element analysis.Meanwhile,the dynamic model simulates the deformation and vibration states of large flexible structures,during the spacecraft maneuver.The FxESO can estimate and compensate the complex disturbance.The error under fast nonsingular terminal sliding mode+FxESO control law converge more rapidly than the nonsingular terminal sliding mode+expansion observer control law.The final spacecraft attitude tracking error is about 10−4,indicating the effectiveness of the controller. 展开更多
关键词 FILM ABSOLUTE FORMULATION
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短期重复口服鸡α干扰素体内抑制H9N2亚型流感病毒复制 被引量:5
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作者 王萌 宋洁 +6 位作者 范文辉 刘丽蓉 黄卓然 杨成程 吴昊 刘文军 李晶 《生物工程学报》 CAS CSCD 北大核心 2019年第6期1029-1040,共12页
为研究口服鸡α干扰素最佳的给药频率及与灭活病毒联合使用对鸡群的影响,文中将构建的原核表达质粒pET-22b-ChIFN-α转入大肠杆菌Escherichia coli BL21 (DE3),宿主菌经诱导表达收获重组包涵体蛋白,经变性、纯化、复性后获得重组鸡α干... 为研究口服鸡α干扰素最佳的给药频率及与灭活病毒联合使用对鸡群的影响,文中将构建的原核表达质粒pET-22b-ChIFN-α转入大肠杆菌Escherichia coli BL21 (DE3),宿主菌经诱导表达收获重组包涵体蛋白,经变性、纯化、复性后获得重组鸡α干扰素。SDS-PAGE结果分析显示,目的蛋白可在原核表达载体中高效表达,发酵液上清中目的蛋白浓度高达0.2 mg/mL,分子量约为20 kDa。将鸡α干扰素稀释至活性为2.5×10~4 U/羽份,与灭活H9N2亚型流感病毒联用以口服的方式免疫无特定病原(SPF)鸡群,试验结果表明,短期(96 h)重复免疫3次,鸡α干扰素具有较好的安全性,可诱导鸡群的外周血、脾脏及胸腺产生较高水平的抗病毒相关的诱导基因,攻毒结果显示鸡α干扰素使用次数为连续使用3–5 d鸡群排毒率最低,体现出较好的抗流感病毒能力。本研究结果获得了鸡α干扰素的最佳免疫频率及免疫时间,为干扰素的最佳临床应用方法提供理论支撑。 展开更多
关键词 鸡α干扰素 H9N2亚型流感病毒 口服 短期重复
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