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Robust UKF orbit determination method with timevarying forgetting factor for angle/range-based integrated navigation system

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Chinese Journal of Aeronautics 2024年第11期37卷 420-434页

作者： Qichang QIANG Baojun lin Yingchun LIU xia lin Shen WANG Innovation Academy for Microsatellites of Chinese Academy of Sciences Shanghai 201203China School of Electronic Electrical and Communication EngineeringUniversity of Chinese Academy of SciencesBeijing 100049China Shanghai Engineering Center for Microsatellites Shanghai 201203China School of Information Science and Technology Shanghai Tech UniversityShanghai 201210China

The angle/range-based integrated navigation system is a favorable navigation solution for deep space ***,the statistical characteristics of the measurement noise are time-varying,leading to inaccuracies in the derived measurement covariance even causing filter *** reduce the gap between theoretical and actual covariances,some adaptive methods use empirically determined and unchanged forgetting factors to scale innovations within the sliding ***,the constant weighting sequence cannot accurately adapt to the time-varying measurement noise in dynamic ***,this paper proposes an Adaptive Robust Unscented Kalman Filter with Time-varying forgetting factors(TFF-ARUKF)for the angle/range integrated navigation ***,based on a statistically linear regression model approximating the nonlinear measurement model,the M-estimator is adopted to suppress the interference of ***,the covariance matching method is combined with the Huber linear regression problem to adaptively adjust the measurement noise covariance used in the ***,to capture the time-varying characteristics of the measurement noise in each estimation,a new timevarying forgetting factors selection strategy is designed to dynamically adjust the adaptive matrix used in the covariance matching *** and experimental analysis compared with EKF,AMUKF,ARUKF,and Student's t-based methods have validated the effectiveness and robustness of the proposed algorithm.

关键词： Autonomous navigation Integrated navigation system State estimation Kalman filter Adaptive filter

The effects of ion screening on neutrino-nucleus interactions in core-collapse supernova explosions

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Research in Astronomy and Astrophysics 2010年第7期10卷 689-695页

作者： Xiong-Ping xia lin Yi Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

The effects of ion screening in stellar core collapses are investigated based on a new progenitor star model. Simulation results show that ion screening slightly affects the leptons and decreases explosion energy, which is a negative factor for energy transfer supernova explosions. We also investigate the effect on type Ⅱ-supernova explosions of neutrino-nucleus elastic scattering based on the new progenitor star model. It is shown that, compared with the previously calculated results, neutrinos-nucleus elastic scattering in stellar core collapses is more severe, leading to an obvious reduction of the neutrino leakage energy loss and an increase of supernova explosion energy.

关键词： stars supernovae general -- neutrino-nucleus

Exclusive Semileptonic Rare Decays B→K()(?)+(?)^- in a Top Quark Two-Higgs-Doublet Model

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Communications in Theoretical Physics 2008年第7期50卷 149-160页

作者： LV lin-xia xiaO Zhen-Jun Department of Physics Nanyang Teacher＇s College Nanyang 473061 China Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210097 China

Employing improved calculations of the decay form factors from light-cone sum rules, we evaluate the invariant mass spectrum, forward-backward asymmetry, and lepton polarizations of the exclusive processes B → K^（＊）e＋e- in the SM and T2HDM. From the recent measurements of their branching ratios, we find that these processes do provide additional bounds on the new parameters in the model considered here. After the inclusion of the new physics contributions, the large enhancement of FBA, which is unobservably small within the SM and of the lepton polarization at large tan β, may precisely test the SM or reveal new physics in forthcoming accurate experiments.

关键词： semileptonic decay two-Higgs-doublet model polarization forward-backward asymmetry

Travel Patterns Analysis of Urban Residents Using Automated Fare Collection System

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Chinese Journal of Electronics 2016年第1期25卷 40-47页

作者： WANG Ya DU Bowen RONG Qiannan lin xia State Key Laboratory of Software Development Environment Beihang University School of Software Beihang University

As one of the essential information, passenger Origin-destination(OD) matrix is crucial for transit system planning. Automated fare collection(AFC) system is widely used in big cities all around the world, OD data not only can be collected in dynamic way but also through citywide. It is only a byproduct of AFC and have the imperfection. This paper proposes a novel method to infer trip chain information of each commuter’s OD matrix based on travel pattern identify, and then the relationship between lines which have the character of the geographical proximity is used to calibrate the result of inferring. A serious of experiment results based on the real data show that the method has relatively high accuracy and can be use to practical application.

关键词： Smart card Public transportation Travel patterns

Hydrothermal Synthesis and Crystal Structure of a Heterometallic Cu/Cd Complex with H_2dipic(Pyridine-2,6-dicarboxylic Acid)

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Chinese Journal of Structural Chemistry 2006年第10期25卷 1250-1254页

作者： XUE lin CHE Yun-xia ZHENG Ji-Min Department of Chemistry Nankai University Tianjin 300071 China

A new heterometallic complex {[Cu（pic）2（H2O）2][Cd2（Hdipic）2（H2O）2Cl2]}n （Mr = 1007.73） has been synthesized under hydrothermal condition and characterized by single-crystal X-ray diffraction. It crystallizes in triclinic, space group PI^- with a = 5.8397（4）, b = 9.8664（7）, c = 14.1739（10） °A, α= 82.0150（10）, β = 80.4540（10）, γ= 82.3570（10）°, Z= 1, V= 792.47（10）°A^3, Dc = 2.112 g/cm^3,μ（MoKα） = 2.247 mm^-1, F（000） = 495, the final R = 0.0232 and wR = 0.0644 for 2748 observed reflections （I〉 2σ（I））. In the complex, seven-coordinated·Cd ions form a zigzag chain based on the alternated dinuclear Cd units. The neutral [Cu（pic）2（H2O）2] units are located at the centers of the inter space and fasten to the 1-D chain by hydrogen bonds.

关键词： copper cadmium heterometallic dinuclear hydrothermal coordination polymer

Impacts of High-Frequency Atmospheric Forcing on Southern OceanCirculation and Antarctic Sea Ice

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Advances in Atmospheric Sciences 2020年第5期37卷 515-531页

作者： Yang WU Zhaomin WANG Chengyan LIU and xia lin College of Oceanography Hohai UniversityNanjing 210098China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China International Polar Environment Research Laboratory Hohai UniversityNanjing 210098China University Corporation for Polar Research Beijing 100875China

The relative contributions of atmospheric fluctuations on 6 h?2 d,2?8 d,and 8 d?1 month time scales to the changes in the air?sea fluxes,the SO circulation,and Antarctic sea ice are *** was found that the imposed forcing variability on the three time scales creates a significant increase in wind power input,and hence an increase of about 50%,97%,and 5%of eddy kinetic energy relative to the simulation driven by monthly forcing,***,SO circulation and the strength of the upper cell of meridional overturning circulation become *** results indicate more dominant effects of atmospheric variability on the 2?8 d time scale on the SO ***,the 6 h?2 d(2?8 d)atmospheric variability causes an increase in the total sea-ice extent,area,and volume,by about 33%,30%,and 19%(17%,20%,and 25%),respectively,relative to those in the experiment forced by monthly atmospheric *** significant sea-ice increases are caused by a cooler ocean surface and stronger sea-ice transports owing to the enhanced heat losses and air-ice stresses induced by the atmospheric variability at 6 h?2 d and 2?8 d,while the effects of the variability at 8 d?1 month are rather *** influences of atmospheric variability found here mainly result from wind *** findings in this study indicate the importance of properly resolving high-frequency atmospheric variability in modeling studies.

关键词： high-frequency atmospheric variability momentum fluxes buoyancy fluxes Southern Ocean circula tion Antarctic sea ice MITgcm-ECCO2

One-dimensional atom laser in microgravity

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Chinese Physics B 2021年第11期30卷 223-227页

作者： Yi Qin xiaoyang Shen lin xia Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China

Using coupled Gross–Pitaevksii(GP)equations,we simulate the output of one-dimensional pulsed atom laser in space *** get two atom laser pulses propagating in opposite directions with one pulsed RF *** with atom laser under gravity,the laser pulse in microgravity shows much slower moving speed,which is suitable to be used for long-term *** also simulate the output flux at different coupling strengths.

关键词： microgravity atom laser Bose-Einstein condensation

Distribution Network Equipment Location and Capacity Planning Method Considering Energy Internet Attribute from the Perspective of Life Cycle Cost

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Energy Engineering 2022年第3期119卷 1059-1074页

作者： Qiang Li Lei Xue xia lin State Grid Shanxi Electric Power Company Economic and Technical Research Institute TaiyuanChina State Grid Shanxi Electric Power Company TaiyuanChina

For facing the challenges brought by large-scale renewable energy having access to the system and considering the key technologies of energy Internet,it is very necessary to put forward the location method of distribution network equipment and capacity from the perspective of life cycle *** with the traditional energy network,the equipment capacity problem of energy interconnected distribution network which involves in electricity network,thermal energy network and natural gas network is comprehensively considered in this *** this basis,firstly,the operation architecture of energy interconnected distribution network is ***,taking the grid connection location and configuration capacity of key equipment in the system as the control variables and the operation cost of system comprehensive planning in the whole life cycle as the goal,the equipment location and capacity optimization model of energy interconnected distribution network is ***,an IEEE 33 bus energy mutual distribution grid system is taken for example analysis,and the improved chaotic particle swarmoptimization algorithm is used to solve *** simulation results show that the method proposed in this paper is suitable for the equipment location and capacity planning of energy interconnected distribution network,and it can effectively improve the social and economic benefits of system operation.

关键词： Locating and sizing method distribution energy internetwork whole life cycle cost distribution network planning

Ba（d）^o-Ba（d）^o Mixing and New Physics Effects in a Top Quark Two-Higgs Doublet Model

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Communications in Theoretical Physics 2007年第6期47卷 1099-1105页

作者： LU lin-xia xiaO Zhen-Jun Department of Physics and Institute of Theoretical Physics Nanjing Normal University Nanjing 210097 China Department of Physics Nanyang Teacher＇s College Nanyang 473061 China

We calculate the new physics contributions to the neutral Bd^o and Ba^o meson mass splitting △Md and △Ma induced by the box diagrams involving the charged-Higgs bosons in the top quark two-Higgs doublet model （T2HDM）. Using the precision data, we obtain the bounds on the parameter space of the T2HDM：（a） For fixed MH = 400 GeV and 5= [0°, 60°], the upper bound on tan β is tan β≤ 30 after the inclusion of major theoretical uncertainties; （b） For the case of tan β≤ 20, a light charged Higgs boson with a mass around 300 GeV is allowed; and （c） The bounds on tan β and MH are strongly correlated： a smaller （larger） tan β means a lighter （heavier） charged Higgs boson.

关键词： B meson mixing new physics effects two-Higgs-doublet model