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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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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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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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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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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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Electrogenic sulfur oxidation mediated by cable bacteria and its ecological effects

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Environmental Science and Ecotechnology 2024年第4期20卷 34-41页

作者： Zhenyu Wang Leonid Digel yongqiang yuan Hui Lu Yonggang Yang Carsten Vogt Hans-Hermann Richnow Lars Peter Nielsen Department of Isotope Biogeochemistry Helmholtz Centre for Environmental Research e UFZPermoserstraße 1504318LeipzigGermany Center for Electromicrobiology Department of BiologyAarhus UniversityDK-8000AarhusDenmark Key Laboratory of Karst Georesources and Environment Ministry of EducationCollege of Resources and Environmental EngineeringGuizhou UniversityGuiyang550025China School of Environmental Science and Engineering Sun Yat-Sen UniversityGuangzhou510006China School of Life Science and Engineering Foshan UniversityFoshan528225China State Key Laboratory of Applied Microbiology Southern China Institute of MicrobiologyGuangdong Academy of SciencesGuangzhou510007China

At the sediment-water interfaces,filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron *** multicellular bacteria belonging to the family Desulfobulbaceae thus form a biogeobattery that mediates redox processes between multiple *** bacteria were first reported in *** the past years,cable bacteria have been found to be widely distributed across the *** potential in shaping the surface water environments has been extensively studied but is not fully *** this review,the biogeochemical characteristics,conduction mechanisms,and geographical distribution of cable bacteria,as well as their ecological effects,are systematically reviewed and *** insights for understanding and applying the role of cable bacteria in aquatic ecology are summarized.

关键词： Cable bacteria Electrogenic sulfur oxidation Long-distance electron transfer Aquatic ecology

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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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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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硅酸盐掺杂对AgO正极材料影响的研究

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材料导报 2016年第10期30卷 23-26页

作者：原勇强崔益秀冯秀丽中国工程物理研究院电子工程研究所绵阳621900

利用液相沉淀法制备高纯度片状结构的AgO正极材料,通过物理掺杂的方法制备不同硅酸盐含量的AgO材料,并对其进行物性表征及电化学性能测试。利用碘量法分析样品的纯度,XRD研究表明随着含量的增加,硅酸盐的图谱更加明显。热重分析掺杂后... 详细信息

利用液相沉淀法制备高纯度片状结构的AgO正极材料,通过物理掺杂的方法制备不同硅酸盐含量的AgO材料,并对其进行物性表征及电化学性能测试。利用碘量法分析样品的纯度,XRD研究表明随着含量的增加,硅酸盐的图谱更加明显。热重分析掺杂后的样品热分解温度无变化,第一个分解温度仍在210℃左右。在常温下测试其电化学性能,在4C恒流放电下,掺杂硅酸盐都有一个压降过程,其中质量分数约为12%的AgO样品的电压降低到0.2V。同时,老化试验测试表明,掺杂一定量的硅酸盐可以降低AgO材料的分解速率。

关键词： AgO 掺杂正极材料

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第Ⅱ类尾矿库环保防渗系统设计探讨

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金属矿山 2016年第5期45卷 178-182页

作者：袁永强中国瑞林工程技术有限公司江西南昌330002

尾矿库是堆存矿山工业固体废物的场所,根据国家新环保法和新尾矿设施设计规范,第Ⅱ类尾矿库必须进行环保防渗系统设计,且防渗性能必须满足规范要求。防渗系统是Ⅱ类尾矿库的极其关键的部分,它能有效地将尾矿库内的尾矿及矿浆水与外界隔... 详细信息

尾矿库是堆存矿山工业固体废物的场所,根据国家新环保法和新尾矿设施设计规范,第Ⅱ类尾矿库必须进行环保防渗系统设计,且防渗性能必须满足规范要求。防渗系统是Ⅱ类尾矿库的极其关键的部分,它能有效地将尾矿库内的尾矿及矿浆水与外界隔离,防止尾矿水对环境的污染。重点探讨了环保防渗系统中HDPE膜及膨润土垫的主要技术特点、防渗层的结构设计、锚固平台及锚固沟的主要技术要求。指出了HDPE膜使用时,应该注意膜材中添加再生料问题、高寒地区温差问题、膜的厚度问题;膨润土应选择钠基膨润土,在含高浓度电解质溶液的防水、防渗工程中,不宜采用膨润土防水毯。针对尾矿库所在地场地基础层渗透系数等因素综合确定防渗结构层,并根据国内外防渗工程实际效果推广单层人工复合防渗结构层。

关键词：尾矿库工业固体废物第Ⅱ类尾矿库环保防渗 HDPE膜膨润土垫

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