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Hybrid TDOA/FDOA and track optimization of UAV swarm based on A-optimality

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Journal of Systems Engineering and Electronics 2023年第1期34卷 149-159页

作者： LI Hao sun hemin ZHOU Ronghua ZHANG Huainian Department of Intelligence Air Force Early Warning AcademyWuhan 430019China

The source location based on the hybrid time difference of arrival(TDOA)/frequency difference of arrival(FDOA) is a basic problem in wireless sensor networks, and the layout of sensors in the hybrid TDOA/FDOA positioning will greatly affect the accuracy of positioning. Using unmanned aerial vehicle(UAV) as base stations, by optimizing the trajectory of the UAV swarm, an optimal positioning configuration is formed to improve the accuracy of the target position and velocity estimation. In this paper, a hybrid TDOA/FDOA positioning model is first established, and the positioning accuracy of the hybrid TDOA/FDOA under different positioning configurations and different measurement errors is simulated by the geometric dilution of precision(GDOP) factor. Second, the Cramer-Rao lower bound(CRLB) matrix of hybrid TDOA/FDOA location under different moving states of the target is derived theoretically, the objective function of the track optimization is obtained, and the track of the UAV swarm is optimized in real time. The simulation results show that the track optimization effectively improves the accuracy of the target position and velocity estimation.

关键词： unmanned aerial vehicle(UAV)swarm time difference of arrival(TDOA) frequency difference of arrival(FDOA) A-optimality track optimization

Regional Frequency Analysis of Observed Sub-Daily Rainfall Maxima over Eastern China

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Advances in Atmospheric Sciences 2017年第2期34卷 209-225页

作者： hemin sun Guojie WANG Xiucang LI Jing CHEN Buda SU Tong JIANG Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Institute of Geography and Remote SensingNanjing University of Information Science and TechnologyNanjing 210044China State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesOriimqi 830011China National Climate Center China MeteorologicaI AdministrationBeijing 100081China

Based on hourly rainfall observational data from 442 stations during 1960-2014, a regional frequency analysis of the annual maxima （AM） sub-daily rainfall series （1-, 2-, 3-, 6-, 12-, and 24-h rainfall, using a moving window approach） for eastern China was conducted. Eastern China was divided into 13 homogeneous regions： Northeast （NE1, NE2）, Central （C）, Central North （CN1, CN2）, Central East （CE1, CE2, CE3）, Southeast （SE1, SE2, SE3, SE4）, and Southwest （SW）. The generalized extreme value performed best for the AM series in regions NE, C, CN2, CE1, CE2, SE2, and SW, and the generalized logistic distribution was appropriate in the other regions. Maximum return levels were in the SE4 region, with value ranges of 80-270 mm （1-h to 24-h rainfall） and 108-390 mm （1-h to 24-h rainfall） for 20- and 100 yr, respectively. Minimum return levels were in the CN1 and NE1 regions, with values of 37-104 mm and 53-140 mm for 20 and 100 yr, respectively. Comparing return levels using the optimal and commonly used Pearson-III distribution, the mean return-level differences in eastern China for 1-24-h rainfall varied from -3-4 mm to -23-11 mm （- 10%-10%） for 20-yr events, reaching -6-26 mm （-10%-30%） and -10-133 mm （-10%-90%） for 100-yr events. In view of the large differences in estimated return levels, more attention should be given to frequency analysis of sub-daily rainfall over China, for improved water management and disaster reduction.

关键词： sub-daily rainfall annual maxima regional frequency analysis return level eastern China

Changes in Extreme Maximum Temperature Events and Population Exposure in China under Global Warming Scenarios of 1.5 and 2.0°C: Analysis Using the Regional Climate Model COSMO-CLM

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Journal of Meteorological Research 2018年第1期32卷 99-112页

作者： Mingjin ZHAN Xiucang LI hemin sun Jianqing ZHAI Tong JIANG Yanjun WANG Chinese Academy of Meteorological Sciences Beijing 100081 University of ChineseAcademy of Sciences Beijing 100049 Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/School of Geography and Remote Sensing Nanjing University of Information Science & Technology Nanjing 210044 National Climate Center China Meteorological Administration Beijing 100081 Jiangxi Provincial Climate Center Nanchang 330046

We used daily maximum temperature data（1986–2100） from the COSMO-CLM（COnsortium for Small-scale MOdeling in CLimate Mode） regional climate model and the population statistics for China in 2010 to determine the frequency, intensity, coverage, and population exposure of extreme maximum temperature events（EMTEs） with the intensity–area–duration method. Between 1986 and 2005（reference period）, the frequency, intensity, and coverage of EMTEs are 1330–1680 times yr^–1, 31.4–33.3℃, and 1.76–3.88 million km^2, respectively. The center of the most severe EMTEs is located in central China and 179.5–392.8 million people are exposed to EMTEs annually. Relative to 1986–2005, the frequency, intensity, and coverage of EMTEs increase by 1.13–6.84, 0.32–1.50, and15.98%–30.68%, respectively, under 1.5℃ warming; under 2.0℃ warming, the increases are 1.73–12.48, 0.64–2.76,and 31.96%–50.00%, respectively. It is possible that both the intensity and coverage of future EMTEs could exceed the most severe EMTEs currently observed. Two new centers of EMTEs are projected to develop under 1.5℃ warming, one in North China and the other in Southwest China. Under 2.0℃ warming, a fourth EMTE center is projected to develop in Northwest China. Under 1.5 and 2.0℃ warming, population exposure is projected to increase by 23.2%–39.2% and 26.6%–48%, respectively. From a regional perspective, population exposure is expected to increase most rapidly in Southwest China. A greater proportion of the population in North, Northeast, and Northwest China will be exposed to EMTEs under 2.0℃ warming. The results show that a warming world will lead to increases in the intensity, frequency, and coverage of EMTEs. Warming of 2.0℃ will lead to both more severe EMTEs and the exposure of more people to EMTEs. Given the probability of the increased occurrence of more severe EMTEs than in the past, it is vitally important to China that the global temperature increase is limited within 1.5℃.

关键词： extreme maximum temperature events population exposure 1.5 and 2.0℃ global warming COSMO-CLM regional climate model China

Synchronous Characteristics of Precipitation Extremes in the Yangtze and Murray–Darling River Basins and the Role of ENSO

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Journal of Meteorological Research 2021年第2期35卷 282-294页

作者： Yu GONG Tong JIANG Buda SU Jinlong HUANG Zbigniew WKUNDZEWICZ Cheng JING hemin sun State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi 830011China Institute for Disaster Risk Management/School of Geographical Science Nanjing University of Information Science&Technologyy Nanjing 210044China National Climate Center China Meteorological AdministrationBeijing 100081China Beijing Meteorological Observation Center(Beijing Observatory) Beijing 100089China National Meteorological Center China Meteorological AdministrationBeijing 100081China University of Chinese Academy of Sciences Beijing 100049China Institute of Agricultural and Forest Environment Polish Academy of Sciences y Bukowska 1960-809PoznanPoland

The floods caused by the extreme precipitation in the Yangtze River basin(YRB)and Murray–Darling River basin(MDRB),the largest basins in China and Australia,have significant impacts on the society and regional *** on the spatial–temporal analysis of the daily precipitation extremes(DPEs)during 1982–2016,we found that for both basins,the whole-basin-type DPEs have the highest proportion and a synchronous DPE interannual variation characteristic exists in the two basins,with the 3-yr running correlation coefficient of the annual DPE days(DPEDs)reaching almost 0.7(significant at the 0.01 level).The El Ni?o–Southern Oscillation(ENSO),which is one of the most significant climate disturbance factors in the world,plays an important role in modulating the variability of the DPEs in the two *** value decomposition(SVD)analysis revealed that both the YRB and the MDRB’s whole-basin-type DPEs are closely coupled with the procedure that the preceding winter eastern Pacific(EP)-type El Ni?o faded to a central Pacific(CP)-type La *** means that the DPEs in the YRB and MDRB may synchronously occur more frequently when the above process *** to the atmosphere–ocean interaction from the east–west dipole sea surface temperature(SST)anomaly pattern,the atmospheric circulation disturbance exhibits a pattern in which the equatorial eastern Pacific region is a mass source anomaly with a higher pressure,drier air,and weaker convection,while the equatorial western Pacific region is a mass sink anomaly with a lower pressure,wetter air,and stronger ***,two wave trains that originated from the tropical western Pacific were found to extend to the YRB and *** interaction between the wave train’s interphase dynamics and water vapor transport disturbance results in the ascent conditions and enhanced water vapor transport,which leads to the synchronous occurrence of DPEs in the YRB and MDRB on an interannual scale.

关键词： precipitation extreme El Ni?o–Southern Oscillation(ENSO) Yangtze River basin(YRB) Murray–Darling River basin(MDRB)

测风激光雷达与风廓线雷达的探测性能评估及数据融合

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气象科技 2024年第2期52卷 151-162页

作者：夏芸洁韦涛李林赖悦孙雪琪张治国孙赫敏北京市气象探测中心北京100176

测风激光雷达和风廓线雷达作为L波段探空测风的有效补充,均可以提供高时空分辨率的大气风场信息,然而由于工作原理和适用条件存在明显差异,在探测性能上各有优缺点,单一设备的探测数据已不能满足精细化预报的要求。本研究使用2020年1—... 详细信息

测风激光雷达和风廓线雷达作为L波段探空测风的有效补充,均可以提供高时空分辨率的大气风场信息,然而由于工作原理和适用条件存在明显差异,在探测性能上各有优缺点,单一设备的探测数据已不能满足精细化预报的要求。本研究使用2020年1—5月北京南郊观象台的L波段探空资料对同址观测的测风激光雷达和风廓线雷达进行了数据质量评估,结果表明测风激光雷达与探空的一致性较高,U、V分量的相关系数分别为0.97和0.98,均方根误差分别为1.1和0.95 m·s^(-1),然而在2 km以上数据获取率较低且偏差较大;风廓线雷达与探空相比,U、V分量的相关系数分别为0.94和0.93,均方根误差分别为2.94和2.91 m·s^(-1),风廓线雷达的探测距离虽然更远,但在0.5 km以下和6 km以上的测量偏差较大。考虑到两种测风雷达在不同探测高度上的性能优缺点,提出分段曲面拟合法对两者的水平风资料进行融合处理,并选取个例对融合效果进行验证,结果表明,融合后的风廓线与融合前相比,风向和风速的一致性均得到明显提升。

关键词：测风激光雷达风廓线雷达探空数据融合风向风速

4-Hydroxy-2-Oxoglutaric Acid,A KeyMetabolite Involved in Trypsin-Regulation of Arginine Metabolism in Hylocereus undatus during Storage

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 885-900页

作者： Bairu Li Jingyu Jia hemin Wang Jiaju sun Enyan Chen Xin Li College of Food and Bioengineering Henan University of Science and TechnologyLuoyang471023China Henan Engineering Research Center of Food Microbiology Luoyang471023China National Demonstration Center for Experimental Food Processing and Safety Education Luoyang471000China

Trypsin,a novel superoxide scavenger,significantly enhances the storage quality of Hylocereus undatus(***).To elucidate the preservation mechanism of trypsin on ***,a widely targeted metabolomic analysis,and transcriptomics analysis were ***,a total of 453 metabolites were identified,with organic acids and their derivatives constituting the largest proportion(25%).Amino acids and their metabolites,prominent among organic acids,were further *** them,73 metabolites were associated with amino acids,and 37 exhibited significant *** most enriched Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway was arginine biosynthesis(map00220),with polyamine metabolites showing the most pronounced differences,particularly spermine(FC=1.7594).Compared with the control group,4-hydroxy-2-oxoglutaric acid was significantly upregulated(FC=2.117)in the process of spermine ***,the results of Gene Ontology(GO)and KEGG enrichment analysis of the *** transcriptome profile revealed that trypsin treatment led to 187 differentially expressed genes associated with *** GO and KEGG analyses exhibited significant enrichment in the spermine biosynthetic process(GO:0006597)(map:00220)within the arginine biosynthesis ***,most enzymes and metabolites within the spermine biosynthesis pathway in *** were *** results of the PPI network highlighted that ADC,SPDS,and SAMDC,among others,were pivotal proteins involved in trypsin-regulated arginine metabolism and spermine *** study revealed that trypsin could significantly delay postharvest senescence of *** at room *** effect might be attributed to trypsin triggering the synthesis of 4-hydroxy-2-oxoglutaric acid in the fruit peel,thereby promoting the biosynthesis of spermine and other polyamines.

关键词： Trypsin arginine transcriptomics widely targeted metabolomics

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频率编码脉冲信号性能分析

系统工程与电子技术 2001年第5期23卷 102-104,F003页

作者：谭贤四武文孙合敏王红空军雷达学院雷达装备研究所武汉430010

使用大时宽带宽信号是提高雷达距离、速度及其联合分辨性能的最常用方法之一。频率编码脉冲是一种大时宽带信号 ,具有良好的距离分辨性能和较窄的瞬时带宽。推导了频率编码脉冲信号及步进频率脉冲信号的模糊函数 ,分析了其距离、速度分... 详细信息

使用大时宽带宽信号是提高雷达距离、速度及其联合分辨性能的最常用方法之一。频率编码脉冲是一种大时宽带信号 ,具有良好的距离分辨性能和较窄的瞬时带宽。推导了频率编码脉冲信号及步进频率脉冲信号的模糊函数 ,分析了其距离、速度分辨性能及其相应关系 ,并就有效解决其距离 -速度联合测量问题进行了讨论。

关键词：编码脉冲干扰模糊函数信号分析分辨率雷达

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大型望远镜拼接弧线永磁电机电流谐波抑制

红外与激光工程 2021年第S2期50卷 114-121页

作者：宋晓莉孙何敏汪达兴张驰中国科学院国家天文台南京天文光学技术研究所江苏南京210042 中国科学院天文光学技术重点实验室(南京天文光学技术研究所) 江苏南京210042 中国科学院大学北京100049 南京信息工程大学江苏南京210044

望远镜口径的增加使得其轴系驱动电机越来越大,近年来拼接电机成为国际上研究的热点。拼接弧线永磁电机的电流谐波影响大型天文望远镜目标观测轴系跟踪精度,文中根据拼接弧线电机的数学模型及谐波分析,提出了一种基于准比例-谐振控制器... 详细信息

望远镜口径的增加使得其轴系驱动电机越来越大,近年来拼接电机成为国际上研究的热点。拼接弧线永磁电机的电流谐波影响大型天文望远镜目标观测轴系跟踪精度,文中根据拼接弧线电机的数学模型及谐波分析,提出了一种基于准比例-谐振控制器的电流谐波抑制算法,并设计了单元拼接弧线电机相应的电流控制器。仿真和实验分别对比了PI和准比例谐振控制器对电流谐波的影响。实验结果表明,采用准比例谐振控制器时,拼接弧线电机定子电流中的5次谐波分量削弱了63.3%,7次谐波分量削弱了34.4%,11次谐波分量削弱了51%,13次谐波分量削弱了59.2%,大大降低了拼接弧线电机电流谐波,有助于提高望远镜跟踪精度。

关键词：电流谐波抑制拼接弧线永磁电机准比例谐振控制器 PI控制器望远镜

Genetic lineage tracing identifies adaptive mechanisms of pancreatic islet β cells in various mouse models of diabetes with distinct age of initiation

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Science China(Life Sciences) 2024年第3期67卷 504-517页

作者： Qi Fu Yu Qian hemin Jiang Yunqiang He Hao Dai Yang Chen Zhiqing Xia Yucheng Liang Yuncai Zhou Rui Gao Shuai Zheng Hui Lv Min sun Kuanfeng Xu Tao Yang Department of Endocrinology the First Affiliated Hospital of Nanjing Medical UniversityNanjing 210029China

During the pathogenesis of type 1 diabetes(T1D) and type 2 diabetes(T2D), pancreatic islets, especially the β cells, face significant challenges. These insulin-producing cells adopt a regeneration strategy to compensate for the shortage of insulin, but the exact mechanism needs to be defined. High-fat diet(HFD) and streptozotocin(STZ) treatment are well-established models to study islet damage in T2D and T1D respectively. Therefore, we applied these two diabetic mouse models, triggered at different ages, to pursue the cell fate transition of isletβ cells. Cre-LoxP systems were used to generate islet cell type-specific(α, β, or δ) green fluorescent protein(GFP)-labeled mice for genetic lineage tracing, thereinto β-cell GFP-labeled mice were tamoxifen induced. Single-cell RNA sequencing(scRNA-seq) was used to investigate the evolutionary trajectories and molecular mechanisms of the GFP-labeled β cells in STZ-treated mice. STZ-induced diabetes caused extensive dedifferentiation of β cells and some of which transdifferentiated into α or δ cells in both youth-and adulthood-initiated mice while this phenomenon was barely observed in HFD models. β cells in HFD mice were expanded via self-replication rather than via transdifferentiation from α or δ cells, in contrast, α or δ cells were induced to transdifferentiate into β cells in STZ-treated mice(both youthand adulthood-initiated). In addition to the re-dedifferentiation of β cells, it is also highly likely that these “α or δ” cells transdifferentiated from pre-existing β cells could also re-trans-differentiate into insulin-producing β cells and be beneficial to islet recovery. The analysis of ScRNA-seq revealed that several pathways including mitochondrial function, chromatin modification, and remodeling are crucial in the dynamic transition of β cells. Our findings shed light on how islet β cells overcome the deficit of insulin and the molecular mechanism of islet recovery in T1D and T2D pathogenesis.

关键词： islet regeneration lineage tracing high fat diet(HFD) streptozotocin(STZ)