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A Performance Evaluation Platform for Mega Satellite Constellation Network

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Journal of Computer and Communications 2023年第6期11卷 122-130页

作者： Yifei Jiang Wanxia He Shufan Wu Lili Zuo Weixin Zhang qiankun mo School of Aeronautics and Astronautics Shanghai Jiao Tong University Shanghai China Shanghai Aerospace Computer Technology Institute Shanghai China

With the rapid development of satellite technology, mega satellite constellations have become a research hotspot. A large number of related techniques have been developed on orbit topology, network routing, energy balance and resource control. However, it is difficult to accurately compare the performance of similar studies due to differences in the means of validation. Especially for invulnerability studies in many military applications, a unified evaluation system is essential. This paper proposes a network evaluation system for mega satellite constellations. Evaluation parameters include orbit topology, communication network, energy balance and invulnerability. Different application algorithms and traffic models were used to validate the specific system. .

关键词： Mega Constellation Satellite Communication Network Evaluation

基于最大条件熵的射频隐身数据链猝发通信模型

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航空学报 2014年第5期35卷 1385-1393页

作者：杨宇晓周建江陈军莫乾坤南京航空航天大学高新技术研究院江苏南京210016 南京航空航天大学电子信息工程学院江苏南京210016 上海微小卫星工程中心上海201203

为提高数据链的低被截获性能,以数据链发射时刻的不确定性为对象,提出了一种基于最大条件熵的射频隐身数据链猝发通信模型。该模型以先验数据为训练样本空间,以拉格朗日乘子为优化粒子,将最大条件熵的对偶规划问题作为目标,利用混合混... 详细信息

为提高数据链的低被截获性能,以数据链发射时刻的不确定性为对象,提出了一种基于最大条件熵的射频隐身数据链猝发通信模型。该模型以先验数据为训练样本空间,以拉格朗日乘子为优化粒子,将最大条件熵的对偶规划问题作为目标,利用混合混沌粒子群优化(HCPSO)算法进行优化计算,最终确定最大条件熵概率分布模型。与单阈值方法 (STM)和双阈值方法(DTM)的对比仿真结果表明:利用最大熵方法(MEM)自适应生成的发射规划,不仅具有最大的发射时刻条件熵,射频隐身性能最好,而且MEM的通信总时间、通信占空比也最大,对环境约束特征的适应性最好,因此,MEM具有最优的综合性能。

关键词：隐身技术最大熵猝发通信数据链混合混沌粒子群优化算法

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立方体卫星质量矩姿态控制建模与布局优化

系统工程与电子技术 2017年第3期39卷 599-605页

作者：陆正亮张翔于永军莫乾坤廖文和南京理工大学机械工程学院江苏南京210094

针对使用固体火箭发动机进行立方体卫星快速变轨机动过程中存在的姿态翻转问题,创新性地提出应用质量矩控制技术实现其姿态稳定。首先推导了完整的八自由度动力学模型,并深入分析了质量矩控制机理;然后利用仿真手段对质量块移动产生的... 详细信息

针对使用固体火箭发动机进行立方体卫星快速变轨机动过程中存在的姿态翻转问题,创新性地提出应用质量矩控制技术实现其姿态稳定。首先推导了完整的八自由度动力学模型,并深入分析了质量矩控制机理;然后利用仿真手段对质量块移动产生的附加扰动力矩以及系统耦合进行了研究,并指导了执行机构的布局优化设计;最后提出的双对称执行机构保证了附加扰动小的同时还大幅降低了通道间耦合。仿真表明该系统具有良好的操纵性。

关键词：快速机动立方体卫星质量矩姿态控制

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纳卫星变轨段质量矩姿态控制系统设计

航空学报 2017年第6期38卷 237-247页

作者：陆正亮张翔于永军莫乾坤廖文和南京理工大学机械工程学院南京210094

提出应用质量矩控制技术实现纳卫星轨道机动过程中的姿态稳定控制。在设计出质量矩滑块构型后,利用动量和动量矩定理推导了八自由度(DOF)动力学模型,并根据动力学分析结果建立了简化控制模型。以此为基础,基于全局滑模控制理论设计了俯... 详细信息

提出应用质量矩控制技术实现纳卫星轨道机动过程中的姿态稳定控制。在设计出质量矩滑块构型后,利用动量和动量矩定理推导了八自由度(DOF)动力学模型,并根据动力学分析结果建立了简化控制模型。以此为基础,基于全局滑模控制理论设计了俯仰偏航通道姿态稳定和滑块位置跟踪的鲁棒控制器,并在参数不确定性条件下对控制系统进行了仿真,结果表明:所设计的二维质量矩控制系统能快速控制卫星姿态,并对系统扰动具有较强的鲁棒性,可以应用于纳卫星变轨段的姿态控制。

关键词：变轨纳卫星质量矩姿态控制滑模控制

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VHF/UHF立方星地面站系统设计及应用

南京理工大学学报 2016年第2期40卷 177-182,189页

作者：于小康张翔莫乾坤于永军廖文和南京理工大学机械工程学院江苏南京210094

该文根据"南理工一号"卫星发射任务,设计甚高频/特高频(VHF/UHF)卫星地面站系统,并成功实现信号的上下行功能。在分析立方体纳卫星通信特性的基础上,提出了适用于VHF/UHF频段的卫星地面站系统设计方案。针对卫星任务提出了音频频移键控(... 详细信息

该文根据"南理工一号"卫星发射任务,设计甚高频/特高频(VHF/UHF)卫星地面站系统,并成功实现信号的上下行功能。在分析立方体纳卫星通信特性的基础上,提出了适用于VHF/UHF频段的卫星地面站系统设计方案。针对卫星任务提出了音频频移键控(AFSK)调制与二进制相移键控(BPSK)解调实现方式,地面站系统采用硬件方式实现AFSK调制,利用基于Costas环的软件方式实现BPSK解调。实际测试表明,地面站上行功能良好,BPSK接收灵敏度达-120 d Bm,该系统可成功解调QB50P1和QB50P2等其他卫星信号。

关键词：立方体纳卫星卫星地面站音频频移键控调制二进制相移键控解调

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立方体卫星制动帆装置离轨时间分析

航天器工程 2016年第3期25卷 26-31页

作者：梁振华曾玉堂张翔莫乾坤于永军廖文和南京理工大学机械工程学院南京210094

为了避免立方体卫星(CubeSat)失效后成为空间碎片,在立方体卫星寿命末期应采用低成本制动帆装置使其快速脱离轨道,从而减少对低地球轨道(LEO)航天器碰撞和损坏的威胁。文章建立了立方体卫星离轨的数学模型,得到立方体卫星离轨时间的影... 详细信息

为了避免立方体卫星(CubeSat)失效后成为空间碎片,在立方体卫星寿命末期应采用低成本制动帆装置使其快速脱离轨道,从而减少对低地球轨道(LEO)航天器碰撞和损坏的威胁。文章建立了立方体卫星离轨的数学模型,得到立方体卫星离轨时间的影响因素分别为立方体卫星面质比、轨道高度和发射日期。应用实例仿真分析上述3种影响因素对离轨时间的影响,结果表明:随着立方体卫星面质比的增加,离轨时间不断减少;轨道高度越高,离轨时间越长;发射日期不同,离轨时间也存在较大的差异,在太阳活动峰年时离轨时间短,在太阳活动低年时离轨时间长。根据分析结果,对于3U立方体卫星而言,制动帆面积可设计为4m^2。

关键词：立方体卫星制动帆装置离轨时间面质比轨道高度发射日期

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立方星电源系统设计与实验

机械制造与自动化 2017年第5期46卷 198-201页

作者：高海振莫乾坤张翔廖文和南京理工大学机械工程学院江苏南京210094

针对立方星体积小、成本低、能源有限等特点,设计了基于最大功率点跟踪的立方星电源系统。该系统采用三结砷化镓太阳能电池和比容量高的锂离子电池构成太阳能电池阵联合供电系统,电源转换和功率分配电路采用商用集成器件,在降低成本的... 详细信息

针对立方星体积小、成本低、能源有限等特点,设计了基于最大功率点跟踪的立方星电源系统。该系统采用三结砷化镓太阳能电池和比容量高的锂离子电池构成太阳能电池阵联合供电系统,电源转换和功率分配电路采用商用集成器件,在降低成本的同时能够提升功率转换与传输效率,降低系统功耗,提高负载供电可靠性。利用变步长扰动观察法实现了MPPT功能,试验表明该电源系统MPPT模块功率跟踪误差在2%以内,动态响应速度和稳定性较高。

关键词：立方星电源系统 MPPT

Transcriptional landscape of cotton roots in response to salt stress at single-cell resolution

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Plant Communications 2024年第2期5卷 46-66页

作者： Pengtao Li qiankun Liu Yangyang Wei Chaozhu Xing Zhongping Xu Fang Ding Yuling Liu Quanwei Lu Nan Hu Tao Wang Xiangqian Zhu Shuang Cheng Zhaoguo Li Zilin Zhao Yanfang Li Jiangping Han Xiaoyan Cai Zhongli Zhou Kunbo Wang Baohong Zhang Fang Liu Shuangxia Jin Renhai Peng College of Biology and Food Engineering Anyang Institute of TechnologyAnyangHenan 455000China State Key Laboratory of Cotton Biology Institute of Cotton ResearchChinese Academy of Agricultural SciencesAnyangHenan 455000China Research Base Anyang Institute of TechnologyState Key Laboratory of Cotton BiologyAnyang 455000HenanChina School of Life Sciences Zhengzhou UniversityZhengzhouHenan 450001China Hubei Hongshan Laboratory National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural UniversityWuhanHubeiChina Hubei Key Laboratory of Plant Pathology Huazhong Agricultural UniversityWuhanHubei 430070China Department of Biology East Carolina UniversityGreenvilleNC 27858USA

Increasing soil salinization has led to severe reductions in plant yield and quality,and investigating the mo-lecular mechanism of salt stress response is therefore an urgent *** this study,we systematically analyzed the response of cotton roots to salt stress using single-cell transcriptomics technology;56281 high-quality cells were obtained from 5-day-old lateral root tips of Gossypium arboreum under natural growth conditions and different salt *** cell types with an array of novel marker genes were identified and confirmed by in situ RNA hybridization,and pseudotime analysis of some specific cell types revealed their potential differentiation *** changes in cell numbers under salt stress were observed for outer epidermal and inner endodermal cells,which were significantly enriched in response to stress,amide biosynthetic process,glutathione metabolism,and glycolysis/*** of differentially expressed genes identified in multiple comparisons revealed other functional ag-gregations concentrated on plant-type primary cell wall biogenesis,defense response,phenylpropanoid biosynthesis,and metabolic *** candidate differentially expressed genes encoding transcrip-tion factors or associated with plant hormones also responsive to salt stress were identified,and the func-tion of Ga03G2153,annotated as auxin-responsive GH3.6,was confirmed by virus-induced gene *** GaGH3.6-silenced plants showed a severe stress-susceptible phenotype,and physiological and biochemical measurements indicated that they suffered more significant oxidative *** results suggest that GaGH3.6 might participate in cotton salt tolerance by regulating redox *** thus construct a transcriptional atlas of salt-stressed cotton roots at single-cell resolution,enabling us to explore cellular heterogeneity and differentiation trajectories and providing valuable insights into the mo-lecular mechanisms that underlie plan

关键词： cotton salt stress scRNA-seq root cell types virus-induced gene silencing

A multiplexed time-resolved fluorescence resonance energy transfer ultrahigh-throughput screening assay for targeting the SMAD4–SMAD3–DNA complex

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Journal of molecular Cell Biology 2023年第11期15卷 21-32页

作者： Wukun Ouyang Qianjin Li qiankun Niu Min Qui Haian Fu Yuhong Du Xiulei mo Department of Pharmacology and Chemical Biology Emory University School of MedicineAtlantaGA 30322USA Emory Chemical Biology Discovery Center Emory University School of MedicineAtlantaGA 30322USA Department of Hematology and Medical Oncology and Winship Cancer Institute Emory UniversityAtlantaGA 30322USA

The transforming growth factor-beta(TGFβ)signaling pathway plays crucial roles in the establishment of an immunosuppressive tumor microenvironment,making anti-TGFβagents a significant area of interest in cancer ***,the clinical translation of current anti-TGFβagents that target upstream cytokines and receptors remains ***,the development of small-molecule inhibitors specifically targeting SMAD4,the downstream master regulator of the TGFβpathway,would offer an alternative approach with significant therapeutic potential for anti-TGFβ*** this study,we present the development of a cell lysate-based multiplexed time-resolved fluorescence resonance energy transfer(TR-FRET)assay in an ultrahigh-throughput screening(uHTS)1536-well plate *** assay enables simultaneous monitoring of the protein–protein interaction between SMAD4 and SMAD3,as well as the protein–DNA interaction between SMADs and their consensus DNA-binding *** multiplexed TR-FRET assay exhibits high sensitivity,allowing the dynamic analysis of the SMAD4–SMAD3–DNA complex at single-amino acid ***,the multiplexed uHTS assay demonstrates robustness for screening small-molecule *** a pilot screening of an FDA-approved bioactive compound library,we identified gambogic acid and gambogenic acid as potential hit *** proof-of-concept findings underscore the utility of our optimized multiplexed TR-FRET platform for large-scale screening to discover small-molecule inhibitors that target the SMAD4–SMAD3–DNA complex as novel antiTGFβsignaling agents.

关键词： TGFβ/SMAD4 signaling high-throughput screening TR-FRET