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Kinetic Analysis of Vectored Electric Propulsion System for Stratosphere Airship

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Transactions of Nanjing University of Aeronautics and Astronautics 2016年第5期33卷 559-565页

作者： Nie Ying zhou jianghua Yang Yanchu Wang Sheng Wang Xuwei Academy of Opto-electronics Chinese Academy of Sciences Beijing 100094 P. R. China University of Chinese Academy of Sciences Beijing 100094 P.R. China

To enhance the controllability of stratosphere airship,a vectored electric propulsion system is *** using the Lagrangian method,a kinetic model of the vectored electric propulsion system is established and validated through ground *** fake gyroscopic torque is first proposed,which the vector mechanism should overcome besides the inertial torque and the gravitational *** fake gyroscopic torque is caused by the difference between inertial moments about two principal inertial axes of the propeller in the rotating plane,appears only when the propeller is rotating and is proportional with the rotation *** is a sinusoidal pulse,with a frequency that is twice of the rotation *** the fake gyroscope torque pulse and aerodynamic efficiency,three blade propeller is recommended for the vectored propulsion system used for stratosphere airship.

关键词： stratosphere airship vectored electric propulsion system kinetic model vector torque fake gyroscopic torque blade number

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Innovation and Development Policy 2022年第2期 150-167页

作者： jianghua zhou Zixu Liu Jizhen Li Business School Beijing Normal UniversityBeijing 100875China School of Economics and Management Tsinghua UniversityBeijing 100084China

As the strategic alliance between firms is becoming increasingly popular, and collaborative innovation is becoming an important management issue, the lack of a holistic framework of different collaborative partners’ characteristics and their different effects on firms’ innovation is becoming a critical research gap. Another intension of our study is to explore the moderating factors that affect the market dissimilarity/technology complementarity—innovation performance relationships. Using the data of collaboration between innovative firms, we tested our hypotheses using partial least squares(PLS). The results show that both market dissimilarity and technology complementarity between collaborative partners relate positively to focal firms’ innovation performance, in terms of both novelty and efficiency,while technology complementarity is more effective. Our results also indicate that IT adoption negatively moderates the relationship between market dissimilarity and collaborative innovation novelty/efficiency,and the relationship between technology complementarity and innovation efficiency, while in terms of the relationship between technology complementarity and innovation novelty, the moderating effect becomes significantly positive. This study extends previous research on collaborative innovation.

关键词： market dissimilarity technology complementarity IT adoption collaborative innovation

Analysis on the Optimal Transfer of the Stratospheric Airship in Wind Field

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Analysis on the Optimal Transfer of the Stratospheric Airshi...

第37届中国控制会议

作者： Miao Yuhong zhou jianghua Research Institute of Hi-Tech No.3Xibeiwang North Rd.BeijingChina Academy of Opto-Electronics Chinese Academy of Sciences

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关键词： stratospheric airship reachable criterion track angle transfer trajectory

来源： cnki会议评论

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基于可观测度分析的稳定姿态滤波器

航空学报 2010年第1期31卷 165-171页

作者：苗育红周江华第二炮兵工程学院603教研室陕西西安710025 清华大学自动化系北京100084 中国科学院光电研究院北京100190

提出一种适用于惯性/天文组合航天飞行器的稳定姿态滤波器,可以在不降低系统可观测度的前提下解决滤波计算中的奇异问题。对于奇异问题的传统解决方案是删除观测方程的一行,通过对比删除前后系统可观测度的变化,证明此解决方案会导致系... 详细信息

提出一种适用于惯性/天文组合航天飞行器的稳定姿态滤波器,可以在不降低系统可观测度的前提下解决滤波计算中的奇异问题。对于奇异问题的传统解决方案是删除观测方程的一行,通过对比删除前后系统可观测度的变化,证明此解决方案会导致系统可观测度下降,并指出如何选择最优删除方案以使系统可观测度下降最小。根据对传统解决方案的分析结果,提出了不降低系统可观测度的投影算法。理论分析和仿真试验证明,应用了投影算法的姿态滤波器更为稳定,估计效率更高。

关键词：姿态估计天文导航卡尔曼滤波可观测度系统稳定性

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一种基于地转风模型的平流层风场插值方法

北京航空航天大学学报 2022年第4期48卷 639-646页

作者：胡康周江华张晓军中国科学院空天信息创新研究院北京100094 中国科学院大学光电学院北京100049

平流层风场水平分量的数据精度和密度对高空气球实验的轨迹预测精度和飞行控制精度有着直接的影响。面向平流层风场,提出一种基于地转风模型的插值方法。该方法通过改进科里奥利频率公式,并用二维卷积计算地转风模型,提升了地转风模型... 详细信息

平流层风场水平分量的数据精度和密度对高空气球实验的轨迹预测精度和飞行控制精度有着直接的影响。面向平流层风场,提出一种基于地转风模型的插值方法。该方法通过改进科里奥利频率公式,并用二维卷积计算地转风模型,提升了地转风模型的计算效率和低纬度地区风场精度,再用迭代二元线性回归和改进的自适应观测场偏差权重矩阵减小了观测误差对插值结果的影响。实验结果表明:所提插值方法能有效提升平流层风场插值计算速度,并对平流层风场水平分量的插值精度有显著提升。

关键词：风场插值平流层风场地转风二元线性回归二维卷积

Association Analysis of Hyperlipidemia with the 28-Day All-Cause Mortality of COVID-19 in Hospitalized Patients

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Chinese Medical Sciences Journal 2021年第1期36卷 17-26页

作者： Bin Wu jianghua zhou Wenxin Wang Huilin Yang Meng Xia Binghong Zhang Zhigang She Hongliang Li Department of Cardiology Renmin Hospital of Wuhan UniversityWuhan 430071China Institute of Model Animal Wuhan UniversityWuhan 430071China Basic Medical School Wuhan UniversityWuhan 430071China Department of Neonatology Renmin Hospital of Wuhan UniversityWuhan 430072China Medical Science Research Center Zhongnan Hospital of Wuhan UniversityWuhan 430071China

Objective This study aimed to determine the association of hyperlipidemia with clinical endpoints among hospitalized patients with COVID-19,especially those with pre-existing cardiovascular diseases(CVDs)and *** This multicenter retrospective cohort study included all patients who were hospitalized due to COVID-19 from 21 hospitals in Hubei province,China between December 31,2019 and April 21,*** who were aged<18 or≥85 years old,in pregnancy,with acute lethal organ injury(e.g.,acute myocardial infarction,severe acute pancreatitis,acute stroke),hypothyroidism,malignant diseases,severe malnutrition,and those with normal lipid profile under lipid-lowering medicines(e.g,statin,niacin,fenofibrate,gemfibrozil,and ezetimibe)were *** score matching(PSM)analysis at 1:1 ratio was performed to minimize baseline differences between patient groups of hyperlipidemia and *** analyses with the same strategies were further conducted for the parameters of hyperlipidemia in patients with increased triglyceride(TG),increased low・density lipoprotein cholesterol(LDL-C),and decreased high-density lipoprotein cholesterol(HDL-C).Mixed-effect Cox model analysis was performed to investigate the associations of the 28-days all-cause deaths of COVID-19 patients with hyperlipidemia and the abnormalities of lipid *** results were verified in male,female patients,and in patients with pre-existing CVDs and type 2 *** Of 1094S inpatients confirmed as COVID-19,there were 9822 inpatients included in the study,comprising 3513(35.8%)cases without hyperlipidemia and 6309(64.2%)cases with *** on a mixed-effect Cox model after PSM at 1:1 ratio,hyperlipidemia was not associated with increased or decreased 28-day all-cause death[adjusted hazard ratio(HR),1.17(95%C/,0.95-1.44),P二0.151].Wb found that the parameters of hyperlipidemia were not associated with the risk of 28-day all-cause mortality[adjusted HR,1.23(

关键词： coronavirus disease 2019(COVID-19) lipid disorder mortality cardiovascular diseases diabetes

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高空气球外形计算及通用算法设计

国防科技大学学报 2021年第4期43卷 17-23页

作者：周江华金伟城李智斌中国科学院空天信息创新研究院北京100094 中国科学院大学北京100049 山东科技大学电气与自动化工程学院山东青岛266590

高空气球为临近空间中的研究提供了可靠的低成本平台。目前高空气球球形一般直接采用"自然形"或以"自然形"为基础,但通用、简捷地求解"自然形"外形方程一直是个难点。将"自然形"气球外形求解问题转化为最优控制问题,利用最优控制领域成... 详细信息

高空气球为临近空间中的研究提供了可靠的低成本平台。目前高空气球球形一般直接采用"自然形"或以"自然形"为基础,但通用、简捷地求解"自然形"外形方程一直是个难点。将"自然形"气球外形求解问题转化为最优控制问题,利用最优控制领域成熟的求解工具——高斯伪谱法最优化软件包计算气球外形。此外,通过分析外形数据得到外形变化规律,设计通用算法求解任意球形控制因子、任意高度的"自然形"气球外形。结果显示,该算法无须调参便可计算所需的"自然形"球形,便于科研人员快速获得大量所需球形数据.

关键词：高空气球 “自然形”气球球形设计高斯伪谱法

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球舱方位通道动力学建模及参数辨识

北京航空航天大学学报 2024年第6期50卷 2001-2008页

作者：李一健周江华张晓军中国科学院空天信息创新研究院北京100094 中国科学院大学航空宇航学院北京100049

用于天文观测的高空气球姿态控制系统是一种软联结控制系统,其控制稳定性与气球吊舱的运动特性有重要关系。使用拉格朗日方程对球舱方位通道的运动学特性进行建模,并使用基于最小递推二乘的算法对球舱方位通道模型中的扭转刚度和阻尼系... 详细信息

用于天文观测的高空气球姿态控制系统是一种软联结控制系统,其控制稳定性与气球吊舱的运动特性有重要关系。使用拉格朗日方程对球舱方位通道的运动学特性进行建模,并使用基于最小递推二乘的算法对球舱方位通道模型中的扭转刚度和阻尼系数进行离线辨识。与传统的稳定性分析方法相比,所提方法进一步揭示了系统控制稳定性与系统的关系和球舱方位控制运动特性,为高空气球吊舱姿控系统的设计及优化提供了重要参考。

关键词：高空气球方位控制拉格朗日建模递推最小二乘参数辨识

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基于参数闭环控制的配电网柔性接地消弧方法

高电压技术 2020年第4期46卷 1189-1197页

作者：周江华万山明张勇华中科技大学强电磁工程与新技术国家重点实验室武汉430074

针对配电网小电流接地系统在发生单相接地故障之后故障点残余电流无法实现全补偿从而影响消弧性能的问题,在中性点柔性接地的技术基础上提出了基于零序导纳参数闭环控制的有源消弧方法。分析了开环电流补偿指令将受到参数测量误差的影响... 详细信息

针对配电网小电流接地系统在发生单相接地故障之后故障点残余电流无法实现全补偿从而影响消弧性能的问题,在中性点柔性接地的技术基础上提出了基于零序导纳参数闭环控制的有源消弧方法。分析了开环电流补偿指令将受到参数测量误差的影响,理论推导了柔性接地系统故障前后零序导纳参数的变化规律,并以此作为参数闭环控制的依据,通过参数闭环控制策略提高了故障点电流补偿的准确性。在考虑高斯白噪声(50 dB)干扰的仿真算例中,采用参数闭环控制的结果(接地电流为0.25 A)优于参数开环控制的结果(接地电流为1.35 A);在金属性接地的仿真算例中,采用参数闭环控制的结果(接地电流为0.38 A)优于电压闭环控制的结果(接地电流为4.51 A)。仿真与实验结果表明了所提方法能够准确补偿故障点接地电流的有功分量和无功分量,降低了系统对零序互感器测量精度的要求,且适用于不同接地过渡电阻的故障情况,实现了接地故障的快速处理与可靠消弧。

关键词：配电网有源消弧中性点柔性接地单相接地故障闭环控制