Direct Lyapunov-based control law design for spacecraft attitude maneuvers

A direct Lyapunov-based control law is presented to perform on-orbit stability for spacecraft attitude maneuvers. Spacecraft attitude kinematic equations and dynamic equations are coupled, nonlinear, multi-input multi-output(MIMO), which baffles controller design. Orbit angular rates are taken into account in kinematic equations and influence of gravity gradient moments and disturbance moments on the spacecraft attitude in dynamic equations is considered to approach the practical environment, which enhance the problem complexity to some extent. Based on attitude tracking errors and angular rates, a Lyapunov function is constructed, through which the stabilizing feedback control law is deduced via Lie derivation of the Lyapunov function. The proposed method can deal with the case that the spacecraft is subjected to mass property variations or centroidal inertia matrix variations due to fuel assumption or flexibility, and disturbance moments, which shows the proposed controller is robust for spacecraft attitude maneuvers. The unlimited controller and the limited controller are taken into account respectively in simulations. Simulation results are demonstrated to validate effectiveness and feasibility of the proposed method.     

航天器内仪器安装板的热分析计算

以航天器内安装有仪器及仪器盒的安装板为对象,建立热分析数学模型,计算安装板内温度分布并提供了不同的仪器安装位置及仪器发热量条件下安装板的温度状况。由此,可确定加剧温度不均匀分布的源处,得到仪器工作的热环境状况,可作为航天器热控制设计的重要依据,并可为进一步热分析计算时合理划分节点提供参考。     

带挠性轴太阳帆板航天器姿态动力学研究

建立了带挠性轴太阳帆板航天器的物理模型 ,利用保守系统的 Lagrange方程 ,导出了带挠性轴太阳帆板航天器动力学方程 ,在小姿态角速率情况下 ,推出了航天器挠性轴扭转运动、航天器姿态运动的运动学方程 ,给出了数值结果 ,分析了太阳帆板转动惯量、挠性轴的扭转刚度对航天器姿态运动的影响。     

带挠性轴太阳帆板与航天器中心刚体耦合动力学研究

建立了带挠性轴太阳帆板航天器的物理模型, 利用保守系统的Lagrange方程, 导出 了带挠性轴太阳帆板航天器系统动力学方程. 通过变换, 给出太阳帆板、 航天器中心刚体 耦合运动微分方程组. 应用Runge-Kutta积分法得出数值结果. 并分析了太阳帆板转动惯量 、 挠性轴的扭转刚度、 太阳帆板的初始扰动对航天器姿势运动的影响.     

可卡因与其降解抗体15A10的分子对接及分子动力学研究

可卡因是一种精神依赖性药物．它首先作用于大脑皮层使之兴奋,然后由过度兴奋转为抑制,可卡因最重要的作用是对中枢系统的刺激作用,可卡因中毒后,先是感到欣快,随后会出现情绪不安、恶心、呕吐等症状．严重者出现脉搏增快、血压增高和呼吸加快,可引起高血压及其各种合并症,导致室性纤颤、呼吸和循环系统衰竭而死亡。显然,发展一种合适的抑制剂去治疗可卡因的滥用和上瘾是十分困难的,因为可卡因本身就是一个抑制剂,这意味着要用一个毒性更高的抑制剂去抑制可卡因的作用,既然很难在中枢神经系统中设置一个阻碍可卡因的小分子,我们可以考虑在可卡因到达中枢神经系统之前将之降解,     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Deployable boom for Mars Orbiter Magnetometer onboard Tianwen-1

A more than 3 m-long deployable boom is an essential component of the Mars Orbiter Magnetometer (MOMAG) onboard the orbiter of Tianwen-1. The boom was developed to place fluxgate magnetometer (FGM) sensors away from the satellite to reduce the influence of the satellite magnetic field. It was designed as an articulated spring-driven deployable mechanism for single-shot deployment. Functionality, reliability and system constraints are fully considered in the boom design. Mechanical analyses and proof tests show that the boom has sufficient safety margin to withstand environmental conditions, even in the worst cases. After a long voyage from Earth to Mars, the boom was deployed successfully on May 25, 2021. A full deployment was performed in about 4.6 s, sending the two sensors to distances of 3.19 m and 2.29 m respectively, away from the orbiter. After deployment, the field from the orbiter decreased from 1250 nT to less than 6 nT at the sensor mounted at the tip of the boom. The MOMAG boom provides valuable engineering experience for the development of deployable structures stowed for long periods in cold temperatures in space missions.     

嗜热酯酶EstTs1的远源三维结构模建及分子对接

利用Phyre网络服务器,构建嗜热酯酶EstTs1的三维结构,并通过分子动力学优化构型,得到了可靠的构型.分子对接研究表明,p-硝基苯基丁酸酯是EstTs1的最适底物,其大小正适合EstTs1的活性口袋.Thr111是底物与酶结合的重要残基,与底物形成了氢键; Ser85是重要的催化残基.     

基于网络药理学和分子对接探究威灵仙治疗类风湿性关节炎的作用机制

运用网络药理学和分子对接方法探究威灵仙治疗类风湿性关节炎的作用机制。中药系统药理学数据库与分析平台、PubChem、SwissTargetPrediction数据库筛选威灵仙的活性成分及其作用靶点;OMIM、GeneCards数据库预测类风湿性关节炎的靶点;Venn图获取威灵仙-类风湿性关节炎的交集靶点;STRING数据库构建蛋白质-蛋白质相互作用网络后导入Cytoscape3.7.1获取核心靶点;DAVID数据库进行基因本体和京都基因与基因组百科全书富集分析; AutoDock Vina1.5.6对关键活性成分和核心靶点进行分子对接验证。威灵仙中的关键活性成分齐墩果酸、β-谷甾醇、豆甾醇、3-表齐墩果酸作用于MAPK3、PTGS2、CYP19A1等核心靶点,通过调控花生四烯酸代谢通路、卵巢类固醇生成等发挥治疗类风湿性关节炎的作用,分子对接结果显示关键活性成分与核心靶点具有较好的结合活性。该研究初步探讨了威灵仙治疗类风湿性关节炎的关键活性成分、核心作用靶点及其相关通路,为威灵仙的临床应用提供参考。     

基于网络药理学探讨玫瑰花抗抑郁物质基础及作用机制

利用网络药理学和分子对接方法探究玫瑰花抗抑郁的物质基础及作用机制。通过中国知网收集抗抑郁单体和玫瑰花的化学成分,借助PubChem、SwissTargetPrediction数据库预测玫瑰花的抗抑郁活性成分及作用靶点,通过DAVID数据库进行通路富集分析,运用Discovery Studio 2017软件对关键成分和靶点进行分子对接。收集抗抑郁单体117个,玫瑰花成分127个,筛选出玫瑰花与抗抑郁相关的核心成分17个,分子对接显示玫瑰花所含芹菜素、槲皮素、山柰酚、异丁香酚、异槲皮苷、矢车菊素-3-O-葡萄糖苷6个活性成分,可较好地与AKT1、PTGS2、ESR1 3个抑郁相关靶点结合。结果表明玫瑰花抗抑郁的物质基础为芹菜素、槲皮素、山柰酚等黄酮类化合物,主要通过影响HIF-1信号通路、神经活性配体-受体相互作用信号通路、催乳激素信号通路、多巴胺能神经突触信号通路发挥抗抑郁作用。该研究为抗抑郁新药研发提供了理论依据及新的研究思路。