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Determination of global geodetic parameters using satellite laser ranging to Galileo,GLONASS,and BeiDou satellites

Satellite Navigation 2024年第1期5卷 240-257页

作者： Xingxing Li Jiaqing Lou yongqiang yuan Jiaqi Wu Keke Zhang School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079HubeiChina

The new Global Navigation Satellite System(GNSS)satellites,including GLONASS,Galileo,and BeiDou system,are equipped with Laser Retroreflector Arrays(LRA)to support Satellite Laser Ranging(SLR)tracking,which contributes to the estimation of global geodetic *** this study,we estimate the global geodetic parameters using the SLR observations to GNSS satellites and also investigate the effects of different data processing strategies on the estimated Earth Rotation Parameters(ERP),geocenter motion,and terrestrial *** results indicate that setting range bias parameters for each satellite-station pair can effectively account for the satellite-specific biases induced by LRAs,leading to smaller Root Mean Square Errors(RMSE)of the post-fit SLR ***,estimating the range biases for each satellite-station pair improves the accuracy of the estimated station coordinates and *** also examine the impact of different arc lengths on the estimates of ERP,geocenter motion,and terrestrial *** results show that extending arc length can significantly reduce the formal error of *** 7-day strategy produces the smallest RMSEs of 473 microarcseconds and 495 microarcseconds for the estimated X-and Y-component of pole coordinates,and 52 microseconds for length-of-day,***,the estimated geocenter motion is less affected by the arc length,even the shortest 1-day arc strategy can capture the seasonal variations of geocenter motion in Z *** scale estimation,extending the arc length notably improves the accuracy of the estimated station coordinates and scale,but this advantage becomes less noticeable in longer *** 7-day solution also obtains the closet scale results compared to ITRF2014,with the RMSE of 2.10×10^(–9).

关键词： Satellite laser ranging GNSS Geodetic parameters Earth rotation parameters Geocenter motion Terrestrial scale

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Orbit and clock products for quad-system satellites with undifferenced ambiguity fixing approach

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Satellite Navigation 2024年第1期5卷 125-139页

作者： Jiaqi Wu Xingxing Li yongqiang yuan Keke Zhang Xin Li Jiaqing Lou Yun Xiong School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China Hubei Luojia Laboratory 129 Luoyu RoadWuhan430079China German Research Centre for Geosciences GFZ Telegrafenberg14473PotsdamGermany Technische Universitat Berlin(TUB) Straße Des 17.Juni10623BerlinGermany

Integer Ambiguity Resolution(IAR)can significantly improve the accuracy of GNSS Precise Orbit Determination(POD).Traditionally,the IAR in POD is achieved at the Double Differenced(DD)*** this contribution,we develop an Un-Differenced(UD)IAR method for Global Positioning System(GPS)+BeiDou Navigation Satellite System(BDS)+Galileo navigation satellite system(Galileo)+Global'naya Navigatsionnaya Sputnikovaya Sistema(GLONASS)quad-system POD by calibrating UD ambiguities in the raw carrier phase and generating the so-called carrier *** on this method,we generate the UD ambiguity-fixed orbit and clock products for the Wuhan Innovation Application Center(IAC)of the International GNSS Monitoring and Assessment System(iGMAS).One-year observations in 2020 from 150 stations are employed to investigate performance of orbit and clock ***,the UD Ambiguity Resolution(AR)yields more resolved integer ambiguities than the traditional DD AR,scaling up to 9%,attributable to its avoidance of station baseline *** from the removal of ambiguity parameters,the computational efficiency of parameter estimation undergoes a substantial 70%*** with the float solution,the orbit consistencies of UD AR solution achieve the accuracy of 1.9,5.2,2.8,2.1,and 2.7 cm for GPS,BeiDou-2 Navigation Satellite System(BDS-2),BeiDou-3 Navigation Satellite System(BDS-3),Galileo,and GLONASS satellites respectively,reflecting enhancements of 40%,24%,54%,34%,and 42%.Moreover,the standard deviations of Satellite Laser Ranging(SLR)residuals are spanning 2.5–3.5 cm,underscoring a comparable accuracy to the DD AR solution,with discrepancies below 5%.A notable advantage of UD AR lies in its capability to produce the Integer Recovered Clock(IRC),facilitating Precise Point Positioning(PPP)AR without requiring additional Uncalibrated Phase Delay(UPD)*** assess the performance of quad-system kinematic PPP based on IRC,a network comprising 120 stations is uti

关键词： Multi-GNSS Precise orbit determination Integer recover clock Undifferenced ambiguity resolution iGMAS innovation application center

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Identification and characterization of FpRco1 in regulating vegetative growth and pathogenicity based on T-DNA insertion in Fusarium pseudograminearum

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Journal of Integrative Agriculture 2024年第9期23卷 3055-3065页

作者： Haiyang Li yuan Zhang Cancan Qin Zhifang Wang Lingjun Hao Panpan Zhang yongqiang yuan Chaopu Ding Mengxuan Wang Feifei Zan Jiaxing Meng Xunyu Zhuang Zheran Liu Limin Wang Haifeng Zhou Linlin Chen Min Wang Xiaoping Xing Hongxia yuan Honglian Li Shengli Ding College of Plant Protection Henan Agricultural UniversityZhengzhou 450046China National Key Laboratory of Wheat and Maize Crop Science Zhengzhou 450046China Henan Plant Health Protection Technology Engineering Research Center Zhenzhou 450046China

Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and ***,the mechanism by which *** infects wheat remains *** this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of *** screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley *** these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in *** further investigate the role of FpRCO1 in ***,we employed a split-marker approach to knock out FpRCO1 in *** ***1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these ***,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type ***-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)*** summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of *** study provides valuable insights into the molecular mechanisms underlying *** infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.

关键词： Fusarium pseudograminearum T-DNA insertion Rpd3S complex FpRCO1 pathogenicity DON production

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基于TOEPLITZ重构的压缩感知嵌套阵列DOA估计

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雷达科学与技术 2024年第3期22卷 334-340页

作者：李荣禄汤建龙袁永强西安电子科技大学电子工程学院陕西西安710071

针对传统稀疏阵列波达方向(DOA)估计算法在小快拍数、低信噪比和多信源数等条件下的估计精度不高的问题,提出了一种基于TOEPLITZ重构的压缩感知嵌套阵列DOA估计方法。首先利用TOEPLITZ重构方法将虚拟阵列的输出信号向量构建成满秩协方... 详细信息

针对传统稀疏阵列波达方向(DOA)估计算法在小快拍数、低信噪比和多信源数等条件下的估计精度不高的问题,提出了一种基于TOEPLITZ重构的压缩感知嵌套阵列DOA估计方法。首先利用TOEPLITZ重构方法将虚拟阵列的输出信号向量构建成满秩协方差矩阵,然后利用信号在空间域的稀疏性,将阵列协方差矩阵进行稀疏表示,通过噪声子空间和信号子空间的正交关系构建权值向量,对稀疏向量进行加权约束,最后通过求解最优化方程获取入射信源的DOA估计。仿真结果表明,本文方法比传统稀疏阵列DOA估计算法在低信噪比、小快拍数和多信源数下具有更好的DOA估计性能。

关键词： DOA估计 TOEPLITZ重构嵌套阵列稀疏表示加权约束

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星基并置轨道配置对地球自转参数解算的影响

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导航定位学报 2024年第2期12卷 13-22页

作者：陈子超李星星张柯柯张伟黄适袁勇强武汉大学测绘学院武汉430079

为了进一步研究全球卫星导航系统(GNSS)和卫星激光测距(SLR)低轨卫星(LEO)星基并置对于地球自转参数(ERP)解算的贡献,综合评估星基并置轨道配置和空间连接误差对地球自转参数解算的影响:通过仿真实验,联合地面全球定位系统(GPS)、低轨... 详细信息

为了进一步研究全球卫星导航系统(GNSS)和卫星激光测距(SLR)低轨卫星(LEO)星基并置对于地球自转参数(ERP)解算的贡献,综合评估星基并置轨道配置和空间连接误差对地球自转参数解算的影响:通过仿真实验,联合地面全球定位系统(GPS)、低轨卫星星载GPS,以及低轨卫星激光测距观测数据,分析低轨卫星轨道配置、空间连接误差对地球自转参数解算精度的影响。结果表明,ERP的估计精度受低轨星基并置站的轨道高度和倾角影响较为明显;相比于低轨道、低倾角卫星,高轨道、高倾角卫星对于极移参数的解算精度提升效果更为显著,这主要是得益于该轨道配置可提供更多的SLR观测数据;此外,空间连接误差分析结果表明,ERP对于低轨卫星SLR棱镜质心改正的误差更加敏感,特别是在Z向,2 cm的Z向SLR棱镜质心改正误差可使得极移X分量和Y分量的估计精度分别下降24%和14%。

关键词：低轨卫星(LEO) 星基并置站地球自转参数(ERP) 轨道配置空间连接误差

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Heat Transfer Analysis During "One-Step" Directional Solidification Process for Giant Magnetostrictive Materials

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Journal of Rare Earths 2004年第z2期22卷 183-185页

作者： Li Kuoshe Yang Hongchuan Xu Jing yuan yongqiang Yu Dunbo Li Hongwei Grirem Advanced Materials Co. LtdGeneral Research Institute for Nonferrous MetalsBeijing 100088China

By theoretical analysis of heat transfer during the "one-step" directional solidification process, the functional relation between the temperature in solid-liquid interface and its effect factor was studied. The thermal gradient in solid liquid interface and heat transfer coefficient between the samples and surroundings were also calculated. On the basis of the above analysis, some suggestions for improving the thermal gradient in solid-liquid interface were put forward. It will provide a theoretical instruction for preparing high performance giant magnetostrictive materials (GMM).

关键词： directional solidification "one-step"process heat transfer solid-liquid interface thermal gradient

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Biomineralization of Se Nanoshpere by Bacillus Licheniformis

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Journal of Earth Science 2015年第2期26卷 246-250页

作者： yongqiang yuan Jianming Zhu Congqiang Liu Shen Yu Lei Lei State Key Laboratory of Environmental Geochemistry Institute of Geochemistry Chinese Academy of Sciences Research Center for Urban Ecological Health and Environmental Safety Institute of Urban EnvironmentChinese Academy of Sciences Insititute of Earth Sciences China University of GeosciencesBeijing

Biological dissimilatory reduction of selenite （SeO3^2-） to elemental selenium （Se^0） is common, but the mineral formation and the biogenic process remain uncertain. In this study, we examined the Se^0 formation during the selenite bioreduction by Bacillus licheniformis SeRB-1 through transmission electron microscope （TEM）, energy-dispersive spectrometry （EDS） and X-ray absorption fine structure （XAFS） techniques. Results showed that the reduction process occurred mostly during the exponential phase and early stationary phase, whilst the elemental selenium was produced in these periods. From the TEM images and polyaerylamide gel eleetropheresis, it is known that the Se^0 granule formation is a biologically-induced type, and the cell envelopes are the main biomineralization positions, and particles may go through a process from nucleation to crystallization, under the control of microbes. In fact, the minerals are spherical nanoparticles, occurring as a microcrystal or amorphous form. It is vital to recognize which kinds of proteins and/or polysaccharides act as a template to direct nanoparticle nucleation and growth？ This should focus for further studies. This study may shed light on the process of formation of Se（0） nanosphere.

关键词： biomineralization genesis selenite reduction selenium nanosphere.

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Multi-GNSS products and services at iGMAS Wuhan Innovation Application Center:strategy and evaluation

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Satellite Navigation 2022年第3期3卷 106-124,I0004页

作者： Xingxing Li Qingyun Wang Jiaqi Wu yongqiang yuan Yun Xiong Xuewen Gong Zhilu Wu School of Geodesy and Geomatics Wuhan University129 Luoyu RoadWuhan430079China

Over the past years the International Global Navigation Satellite System(GNSS)Monitoring and Assessment System(iGMAS)Wuhan Innovation Application Center(IAC)dedicated to exploring the potential of multi-GNSS signals and providing a set of products and *** contribution summarizes the strategies,achievements,and innovations of multi-GNSS orbit/clock/bias determination in iGMAS Wuhan *** the precise products and Real-Time Services(RTS)are evaluated and *** precise orbit and clock products have comparable accuracy with the precise products of the International GNSS Service(IGS)and *** multi-frequency code and phase bias products for Global Positioning System(GPS),BeiDou Navigation Satellite System(BDS),Galileo navigation satellite system(Galileo),and GLObal NAvigation Satellite System(GLONASS)are provided to support multi-GNSS and multi-frequency Precise Point Positioning(PPP)Ambiguity Resolution(AR).Compared with dual-frequency PPP AR,the time to first fix of triple-frequency solution is improved by 30%.For RTS,the proposed orbit prediction strategy improves the three dimensional accuracy of predicted orbit by 1 *** multi-thread strategy and high-performance matrix library are employed to accelerate the real-time orbit and clock *** results with respect to the IGS precise products show the high accuracy of RTS orbits and clocks,4–9 cm and 0.1–0.2 ns,*** real-time satellite corrections,real-time PPP solutions achieve satisfactory performance with horizontal and vertical positioning errors within 2 and 4 cm,respectively,and convergence time of 16.97 min.

关键词： iGMAS Wuhan Innovation Application Center GREAT software Precise orbit determination Precise clock estimation Observation-specific bias Precise point positioning Real-time service

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左卡尼汀联合人促红细胞生成素治疗维持性血液透析肾性贫血患者的效果

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中国民康医学 2024年第7期36卷 55-58页

作者：袁永强胡端凤罗正辉叶贞发上犹县人民医院肾内内分泌科江西赣州341200 上犹县人民医院心血管内科江西赣州341200

目的:观察左卡尼汀联合人促红细胞生成素治疗维持性血液透析肾性贫血患者的效果。方法:选取2021年1月至2023年5月该院收治的80例维持性血液透析肾性贫血患者进行前瞻性研究,根据随机数字表法将其分为对照组和观察组各40例。对照组给予... 详细信息

目的:观察左卡尼汀联合人促红细胞生成素治疗维持性血液透析肾性贫血患者的效果。方法:选取2021年1月至2023年5月该院收治的80例维持性血液透析肾性贫血患者进行前瞻性研究,根据随机数字表法将其分为对照组和观察组各40例。对照组给予人促红细胞生成素治疗,观察组在对照组基础上联合左卡尼汀治疗。比较两组临床疗效、治疗前后贫血指标[血红蛋白(Hb)、前白蛋白(PA)、血钙、血磷]水平、肾功能指标[血肌酐(Scr)、β2微球蛋白(β2-MG)、转化生长因子-β1(TGF-β1)、胱抑素C(Cys-C)]水平和不良反应发生率。结果:观察组治疗总有效率为97.50%(39/40),高于对照组的80.00%(32/40),差异有统计学意义(P0.05)。结论:左卡尼汀联合人促红细胞生成素治疗维持性血液透析肾性贫血患者可提高治疗总有效率,改善贫血指标水平,降低肾功能指标水平,其效果优于单纯人促红细胞生成素治疗。

关键词：左卡尼汀维持性血液透析肾性贫血肾功能不良反应

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Magnetism in Mn and Co doped ZnO bulk samples

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Chinese Science Bulletin 2007年第8期52卷 1019-1023页

作者： WANG yongqiang yuan SongLiu SONG YunXing LIU Li TIAN ZhaoMing LI Pai ZHOU yuanMing LI YunLong YIN ShiYan Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

Bulk samples with nominal composition Zn0.95Co0.05O and Zn0.92Co0.05Mn0.03O were fabricated by a solid-state reaction method at 600℃.X-ray diffraction experiment showed that the peaks of secondary phase Co3O4 with a cubic structure were visible in both samples,besides the main peaks of wurtzite structure as *** measurement indicated that doping Co alone can induce ferromag- netism in ZnO itself,while the introduction of Mn significantly enhances ***, both samples showed different magnetic behavior at temperatures below 50 *** was also noted that ferromagnetic coupling interaction was weakened due to the presence of antiferromagnetic Co3O4.

关键词：锰钴掺杂氧化锌块磁性铁磁现象

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