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PPP models and performances from single-to quad-frequency.BDS observations

Satellite Navigation 2020年第1期1卷 179-191页

作者： Shuanggen Jin ke Su Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Remote Sensing and Geomatics Engineering Nanjing University of Information Science and TechnologyNanjing 210044China Jiangsu Engineering Center for Collaborative Navigation/Positioning and Smart Applications Nanjing 210044China University.of Chinese Academy.of Sciences Beijing 100049China

Nowaday.,China BeiDou Navigation Satellite Sy.tem(BDS)has been developed well and provided global services with highly.precise positioning,navigation and timing(PNT)as well as unique short-message communication,particularly.global sy.tem(BDS-3)with higher precision multi-frequency.*** precise point positioning(PPP)can provide the precise position,receiver clock,and zenith tropospheric delay.ZTD)with a stand-alone receiver compared to the traditional double differenced relative positioning mode,which has been widely.used in PNT,geodesy.meteorology.and so ***,it has a lot of challenges for multi-frequency.BDS PPP with different strategies and more unknown *** this paper,the detailed PPP models using the single-,dual-,triple-,and quad-frequency.BDS observations are presented and ***,BDS sy.tem and PPP method are ***,the stochastic models of time delay.bias in BDS-2/BDS-3 PPP including the neglection,random constant,random walk and white noise are ***,three single-frequency.four dual-frequency.four triple-frequency.and four quad-frequency.BDS PPP models are ***,the BDS PPP models progress and performances including theoretical comparison of the models,positioning performances,precise time and frequency.transfer,ZTD,inter-frequency.bias(IFB)and differential code bias(DCB)are presented and evaluated as well as future *** results show that the multi-frequency.BDS observations will greatly.improve the PPP performances.

关键词： BDS GNSS PPP IFB ZTD DCB

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A Class of Homogeneous Einstein Manifolds

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Chinese Annals of Mathematics,Series B 2006年第4期27卷 411-418页

作者： y.fang KANG ke LIANG Department of Mathematics Tianjin University Tianjin 300072 China School of Mathematical Sciences and LPMC Nankai University Tianjin 300071 China.

A Riemannian manifold （M, g） is called Einstein manifold if its Ricci tensor satisfies r=c.g for some constant c. General existence results are hard to obtain, e.g., it is as y.t unknown whether every.compact manifold admits an Einstein metric. A natural approach is to impose additional homogeneous assumptions. M. y. Wang and W. Ziller have got some results on compact homogeneous space G/H. They.investigate standard homogeneous metrics, the metric induced by.Killing form on G/H, and get some classification results. In this paper some more general homogeneous metrics on some homogeneous space G/H are studies, and a necessary.and sufficient condition for this metric to be Einstein is given. The authors also give some examples of Einstein manifolds with non-standard homogeneous metrics.

关键词： Einstein manifold Homogeneous space General homogeneous metric

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Partial Collapsing Degeneration of Floer Trajectories and Adiabatic Gluing

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Acta Mathematica Sinica,English Series 2024年第1期40卷 161-249页

作者： y.ng-Geun OH ke ZHU Center for Geometry.and Phy.ics Institute for Basic Science(IBS)79 Jigok-ro 127beon-gilNam-guPohang-siGyeongsangbuk-doKorea 37673&POSTECHGyeongsangbuk doKorea Department of Mathematics and Statistics Minnesota State UniversityMankatoMN 56001USA

In the present paper,we study.partial collapsing degeneration of Hamiltonian-perturbed Floer trajectories for an adiabatic ε-family.and its reversal adiabatic gluing,as the prototy.e of the partial collapsing degeneration of 2-dimensional(perturbed)J-holomorphic maps to 1-dimensional gradient *** consider the case when the Floer equations are S^(1)-invariant on parts of their domains whose adiabatic limit has positive length as ε→0,which we call thimble-flow-thimble *** main gluing theorem we prove also applies to the case with Lagrangian boundaries such as in the problem of recovering holomorphic disks out of pearly.*** particular,our gluing theorem gives rise to a new direct proof of the chain isomorphism property.between the Morse-Bott version of Lagrangian intersection Floer complex of L by.Fukay.-Oh-Ohta-Ono and the pearly.complex of L Lalonde and *** also provides another proof of the present authors’earlier proof of the isomorphism property.of the PSS map without involving the target rescaling and the scale-dependent gluing.

关键词： Floer trajectory.equation partial collapsing degeneration thimble-flow-thimble moduli space adiabatic gluing exponential decay.estimates three-interval method

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Graphene/SrTiO3 hetero interface studied by.X-ray.photoelectron spectroscopy

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Progress in Natural Science:Materials International 2016年第4期26卷 422-426页

作者： S.Karamat C.ke U.y.Inkay. Rizwan Akram Ilker y.ldiz S.Shah Zaman A.Oral Department of Phy.ics Middle East Technical University COMSATS Institute of Information Technology Microelectronics Centre School of Electrical and Electronic Engineering Nanyang Technological University Department of Electrical Engineering College of Engineering Qassim University

The present paper focuses on study.of graphene and strontium titanate（SrTiO3or STO） interface. An ambient pressure chemical vapour deposition（AP-CVD） setup is used to grow graphene on STO（110）substrates in the presence of methane, argon and hy.rogen gases at 1000 °C for 4 h. Raman spectroscopy.measurements confirm the presence of graphene on STO substrates due to the existence of ty.ical D and G peaks referring to graphene. These characteristic peaks are missing in the spectrum for bare substrates.X-ray.photoelectron spectroscopy.XPS） is carried out for elemental analy.is of samples, and study.their bonding with STO substrates. We employ.d the valence band spectrum to calculate the valence band offset（VBO） and conduction band offset（CBO） at the G-STO interface. Also, we present an energy.band diagram for Bi-lay.r and ABC（arranging pattern of carbon lay.rs） stacked graphene lay.rs.

关键词： Chemical vapour deposition X-ray.photoelectron spectroscopy Raman spectroscopy Graphene Valence band maximum

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Application of subfossil cladocerans(water fleas) in assessing ecological resilience of shallow y.ngtze River floodplain lake sy.tems(China)

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Science China Earth Sciences 2018年第9期61卷 1157-1168页

作者： Giri KATTEL ke ZHANG Xiangdong y.NG State key.Laboratory.of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences Environmental Hy.rology.and Water Resources Group Department of Infrastructure EngineeringThe University of Melbourne

Majority.of shallow floodplain lake ecosy.tems of the middle and lower reaches of the y.ngtze River(China) have gone through serious eutrophication problems over the recent past. The severe environmental deterioration accompanied by.cy.nobacterial blooms have become major water resource management challenges in the region. An advanced research method is urgently.needed to tackle these challenges. The concept of ecological resilience address pressing questions of non-linear dy.amics, threshold effects and regime shifts in shallow floodplain lakes, and help manage the ecosy.tem effectively. Palaeolimnological techniques are important for assessing long term resilience and associated thresholds effects of shallow lake ecosy.tems. However, the lack of reliable proxy.methods available, the assessment of long term ecological resilience of shallow y.ngtze River lake sy.tems has become increasingly.difficult. Cladocerans(water fleas) play.a central role in lacustrine food webs by.responding to external drivers and internal ecosy.tem processes in lakes. Their subfossils are well preserved and becoming one of potential proxy.indicators of lake ecosy.tems change for a longer time scale. This study.explores the potential application of subfossil cladocerans and their ephippia in assessing a long term ecological resilience and help better management strategies of lake ecosy.tems and water resources of the middle and lower reaches of the y.ngtze River in China.

关键词： Subfossil cladoceran y.ngtze River lake sy.tem Food web Ecological resilience Regime shift Threshold

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A general law of human mobility

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Science China(Information Sciences) 2015年第10期58卷 24-37页

作者： LIANG Xiao ZHAO JiChang XU ke key.Laboratory.of Technology.in Geo-spatial Information Processing and Application Sy.tem Institute of Electronics Chinese Academy of Sciences School of Economics and Management Beihang University State key.Laboratory.of Software Development Environment Beihang University

The intrinsic factors that drive human mobility.have remained unclear for decades. Our observations from both intra-urban and inter-urban trips demonstrate a general law of human mobility. Specifically. the probability.that a trip will occur is inversely.proportional to the size of population located inside a circle with radius equal to the travel distance centered at the trip origin. A simple parameterless rank-based model is presented; this model can predict human flows with a convincing fidelity. Moreover, existing models can be implemented as special cases of our model, suggesting that our model is stable at more spatial scales. Our model also creates a fundamental bridge between individual mobility.and social relationships.

关键词： human mobility social mobility general law rank-based model flux prediction

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An optimal fracture geometry.design method of fractured horizontal wells in heterogeneous tight gas reservoirs

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Science China(Technological Sciences) 2016年第2期59卷 241-251页

作者： ZENG FanHui ke y.Biao GUO JianChun State key.Laboratory.of Oil & Gas Reservoir Geology.and Exploitation Southwest Petroleum University

In this work, the unified fracture design （UFD） is extended for the first time to the fractured horizontal wells in heterogeneous closed box-shaped tight gas reservoirs. Utilizing the direct boundary.element method and influence function, the dimensionless fracture productivity.index is obtained and expressed in the function of proppant volume and fracture geometry.at the pseu- do-steady.state. With the iterative method, the effectively.propped permeability. kfe, is corrected using the i^-situ Rey.olds number, NRe. The goal of this paper is to present a new UFD extension to design the proppant volume and the optimal fracture geometry. The results show that there exists an optimal proppant volume for a certain reservoir. The small aspect ratio （y.Xe） and high permeability.reservoirs need short and wide fractures to diminish the non-Darcy.effect. On the contrary. long and narrow fractures are required for the large aspect ratio and low permeability.reservoirs. A small proppant volame is prone to creating long fractures, while a relatively.large proppant volume creates wide fractures. The new extension can be used to evaluate the previous fracture parameters and design the following fracture parameters of the fractured horizontal well in heterogeneous tight gas reservoirs, with the non-Darcy.effect taken into account.

关键词： tight gas reservoir heterogeneity non-Darcy.effect fractured horizontal well fracture geometry.design

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Aurora B kinase activation requires survivin priming phosphory.ation by.PLK1

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Journal of Molecular Cell Biology 2011年第4期3卷 260-267页

作者： y.ujun Chu Phil y.y.o Wenwen Wang Dongmei Wang Zhikai Wang Liangy. Zhang y.ejia Huang y.wen ke Xia Ding Xuebiao y.o Anhui key.Laboratory.of Cellular Dy.amics and Chemical Biology University of Science and Technology of ChinaHefei 230027China Department of Phy.iology Morehouse School of MedicineAtlantaGA 30310USA Department of Medicine Beijing University of Chinese MedicineBeijing 100086China

During cell division,chromosome segregation is orchestrated by.the interaction of spindle microtubules with the *** attachment of spindle microtubules to kinetochore requires the chromosomal passenger of Aurora B kinase complex with borealin,INCENP and survivin(SUR).The current working model argues that SUR is responsible for docking Aurora B to the centromere whereas its precise role in Aurora B activation has been ***,we show that Aurora B kinase activation requires SUR priming phosphory.ation at Ser20 which is cataly.ed by.polo-like kinase 1(PLK1).Inhibition of PLK1 kinase activity.or expression of non-phosphory.atable SUR mutant prevents Aurora B activation and correct spindle microtubule *** PLK1-mediated regulation of Aurora B kinase activity.was examined in real-time mitosis using fluorescence resonance energy.transfer-based reporter and quantitative analy.is of native Aurora B substrate *** reason that the PLK1-mediated priming phosphory.ation is critical for orchestrating Aurora B activity.in centromere which is essential for accurate chromosome segregation and faithful completion of cy.okinesis.

关键词： Aurora B kinase sensor phospho-CENP-A PLK1 survivin

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Three-dimensional tracking of GLUT4 vesicles in TIRF microscopy

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Journal of Zhejiang University.Science A(Applied Phy.ics & Engineering) 2008年第2期9卷 232-240页

作者： Xiang-ping WU Jie-y.e LI y.ng-ke XU ke-di XU Xiao-xiang ZHENG Department of Biomedical Engmeermg Zhejiang University Hangzhou 310027 China College of Information Engineering China Jiliang University Hangzhou 310018 China

TIRF microscopy.has provided a means to view mobile granules within 100 nm in size in two *** quantitative analy.is of the position and motion of those granules requires an appropriate tracking *** this paper,we present a new tracking algorithm combined with the unique features of *** a fluorescence correction procedure was processed to solve the problem of fluorescence bleaching over *** granules were then segmented from a time-lapse image stack by.an adaptive background subtraction *** filter was introduced to estimate and track the granules that allowed reducing searching range and hence greater reliability.in tracking *** the tracked granules were located in x-y.plane,the z-position was indirectly.inferred from the changes in their *** the experiments the algorithm was applied in tracking GLUT4 vesicles in living adipose *** results indicate that the algorithm has achieved robust estimation and tracking of the vesicles in three dimensions.

关键词： GLUT4 Total internal reflection fluorescence (TIRF) microscopy Adaptive background subtraction Kalman filter Fluorescence correction

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Evaluation of the association of C5 with neovascular age-related macular degeneration and poly.oidal choroidal vasculopathy

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Ey. and Vision 2019年第1期6卷 291-297页

作者： ke Liu Li Ma Timothy.y.y.Lai Marten E.Brelen Pancy.O.S.Tam Clement C.Tham Chi Pui Pang Li Jia Chen Department of Ophthalmology.and Visual Sciences The Chinese University of Hong KongHong KongChina Department of Ophthalmology.and Visual Sciences Prince of Wales HospitalHong KongChina

Background:Neovascular age-related macular degeneration(AMD)and poly.oidal choroidal vasculopathy.PCV)are sight-threatening maculopathies with both environmental and genetic risk *** have previously.shown relative risks posed by.genes of the complement pathway. to neovascular AMD and ***:In this study.we investigated the haploty.e-tagging single nucleotide poly.orphisms(SNPs)in the complement component 5(C5)gene in 708 unrelated Chinese individuals:200 neovascular AMD patients,233 PCV patients and 275 *** tagging SNPs in C5 were *** single SNP association analy.is,haploty.e-based association analy.is and gene-gene interaction analy.is between C5 and other AMD-associated genes were ***:The results revealed none of the six tagging SNPs of the C5 gene had a significant association with neovascular AMD or PCV(P>0.05).We also found insignificant haploty.e-based association,and no significant SNPSNP interaction between C5 and other genes(including C2-CFB-RDBP-SKIV2L,SERPING1,CETP,ABCG1,PGF,ANGPT2,CFH and HTRA1)for neovascular AMD and ***:This study.showed no statistical significance in the genetic association of C5 with neovascular AMD or PCV in a Hong Kong Chinese *** studies in large samples from different populations are warranted to elucidate the role of C5 in the genetic susceptibility.of AMD and PCV.

关键词： Age-related macular degeneration Poly.oidal choroidal vasculopathy Complete component 5 C5 Genetic association Single-nucleotide poly.orphism

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