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Enhanced baseline determination for formation flying LEOs by relative corrections of phase center and code residual variations

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Chinese Journal of Aeronautics 2022年第2期35卷 185-194页

作者： Bin YI Defeng GU Bing JU kai shao Houzhe ZHANG College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China TianQin Research Center for Gravitational Physics and School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China National Key Laboratory of Science and Technology on Aerospace Flight Dynamics Beijing Aerospace Control CenterBeijing 100094China

Formation flying Low Earth Orbiters(LEOs)are important for implementing new and advanced concepts in Earth observation missions.Precise Baseline Determination(PBD)is a prerequisite for LEOs to complete specified mission targets.PBD is usually performed based on space-borne GNSS data,the relative corrections of phase center and code residual variations play crucial roles in achieving the best relative orbit accuracy.Herein,the influences of antenna Relative Phase Centre Variations(RPCVs)and Single-Difference(SD)Melbourne-Wu¨bbena(MW)Combination Residuals Variations(SD MWVs)on PBD are studied.The methods were tested using flight data from Gravity Recovery And Climate Experiment(GRACE)and GRACE Follow-On(GRACE-FO).Results showed that the maximum values for RPCVs and SD MWVs were 14 mm and 0.32 cycles,respectively.Then,the RPCVs correction significantly enhanced the baseline accuracy;the K-Band Ranging(KBR)measurement consistency improved by 30.1%and 37.5%for GRACE and GRACE-FO,respectively.The application of SD MWVs further improved the accuracy and reliability of PBD results.For GRACE,the ambiguities fixing success rate increased from 85.1%to 97.9%and a baseline consistency of 0.57 mm was achieved for the KBR measurements.It was found that the correction of both RPCVs and SD MWVs reduced the carrier phase observation minus computation residuals from double-difference ionosphere-free combination.In addition,in-flight data processing demonstrated that RPCVs and SD MWVs estimations for the current period could be used for the previous and subsequent periods.

关键词： Ambiguity resolution Formation flying Precise baseline determination(PBD) Relative phase centre variations(RPCVs)estimation SD MW combination residuals variations(SD MWVs)estimation

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Progress in blood biomarkers of subjective cognitive decline in preclinical Alzheimer’s disease

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Chinese Medical Journal 2023年第5期136卷 505-521页

作者： Xianfeng Yu kai shao Ke Wan Taoran Li Yuxia Li Xiaoqun Zhu Ying Han Department of Neurology Xuanwu Hospital of Capital Medical UniversityBeijing 100053China Department of Neurology The First Affiliated Hospital of Anhui Medical UniversityHefeiAnhui 230022China Department of Neurology Tangshan Central HospitalTangshanHebei 063000China School of Biomedical Engineering Hainan UniversityHaikouHainan 570228China Center of Alzheimer’s Disease Beijing Institute for Brain DisordersBeijing 100053China National Clinical Research Center for Geriatric Diseases Beijing 100053China.

Alzheimer's disease(AD)is a neurodegenerative disease that gradually impairs cognitive functions.Recently,there has been a conceptual shift toward AD to view the disease as a continuum.Since AD is currently incurable,effective intervention to delay or prevent pathological cognitive decline may best target the early stages of symptomatic disease,such as subjective cognitive decline(SCD),in which cognitive function remains relatively intact.Diagnostic methods for identifying AD,such as cerebrospinal fluid biomarkers and positron emission tomography,are invasive and expensive.Therefore,it is imperative to develop blood biomarkers that are sensitive,less invasive,easier to access,and more cost effective for AD diagnosis.This review aimed to summarize the current data on whether individuals with SCD differ reliably and effectively in subjective and objective performances compared to cognitively normal elderly individuals,and to find one or more convenient and accessible blood biomarkers so that researchers can identify SCD patients with preclinical AD in the population as soon as possible.Owing to the heterogeneity and complicated pathogenesis of AD,it is difficult to make reliable diagnoses using only a single blood marker.This review provides an overview of the progress achieved to date with the use of SCD blood biomarkers in patients with preclinical AD,highlighting the key areas of application and current challenges.

关键词： Alzheimer’s disease Biomarker Blood Evolving technologies Subjective cognitive decline

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Precise orbit determination for TH02-02 satellites based on BDS3 and GPS observations

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Chinese Journal of Aeronautics 2023年第5期36卷 475-485页

作者： Houzhe ZHANG Bing JU Defeng GU Ying LIU kai shao Xiaojun DUAN Zhiyong HUANG College of Science National University of Defense TechnologyChangsha 410073China National Key Laboratory of Science and Technology on Aerospace Flight Dynamics Beijing Aerospace Control CenterBeijing 100094China MOE Key Laboratory of TianQin Mission TianQin Research Center for Gravitational PhysicsFrontiers Science Center for TianQinCNSA Research Center for Gravitational WavesSun Yat-sen University(Zhuhai Campus)Zhuhai 519082China School of Artificial Intelligence Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China Information Engineering University Zhengzhou 450001China

The Tianhui-202(TH02-02)satellite formation,as a supplement to the microwave mapping satellite system Tianhui-201(TH02-01),is the first Interferometric Synthetic Aperture Radar(InSAR)satellite formation-flying system that supports the tracking of BeiDou global navigation Satellite system(BDS3)new B1C and B2a signals.Meanwhile,the twin TH02-02 satellites also support the tracking of Global Positioning System(GPS)L1&L2 and BDS B1I&B3I signals.As the spaceborne receiver employs two independent boards to track the Global Navigation Satellite System(GNSS)satellites,we design an orbit determination strategy by estimating independent receiver clock offsets epoch by epoch for each GNSS to realize the multi-GNSS data fusion from different boards.The performance of the spaceborne receiver is evaluated and the contribution of BDS3 to the kinematic and reduced-dynamic Precise Orbit Determination(POD)of TH02-02 satellites is investigated.The tracking data onboard shows that the average number of available BDS3 and GPS satellites are 8.7 and 9.1,respectively.The carrier-to-noise ratio and carrier phase noise of BDS3 B1C and B2a signals are comparable to those of GPS.However,strong azimuth-related systematic biases are recognized in the pseudorange multipath errors of B1C and B3I.The pseudorange noise of BDS3 signals is better than that of GPS after eliminating the multipath errors from specific signals.Taking the GPS-based reduced-dynamic orbit with single-receiver ambiguity fixing technique as a reference,the results of BDS3-only and BDS3+GPS combined POD are assessed.The Root Mean Square(RMS)of orbit comparison of BDS3-based kinematic and reduced-dynamic POD with reference orbit are better than 7 cm and 3 cm in three-Dimensional direction(3D).The POD performance based on B1C&B2a data is comparable to that based on B1I&B3I.The precision of BDS3+GPS combined kinematic orbit can reach up to 3 cm(3D RMS),which has a more than 25%improvement relative to the GPS-only solution.In addition,the consistency between the BDS3+GPS combin

关键词： BDS3 Multi-GNSS Precise orbit determination Spaceborne GNSS receiver TH02-02

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资源保存理论视域下我国职业足球发展的理性审视

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沈阳体育学院学报 2024年第3期43卷 92-98页

作者：邵凯沈阳体育学院管理与新闻传播学院辽宁沈阳110102

中国职业足球发展30年,出现了诸多社会性问题,给中国体育和中国足球带来破坏性影响。为积极探索新发展阶段我国职业足球面临的新问题与新挑战,运用文献研究、逻辑分析、案例研究等方法对我国职业足球发展问题进行分析。研究发现:现阶段... 详细信息

中国职业足球发展30年,出现了诸多社会性问题,给中国体育和中国足球带来破坏性影响。为积极探索新发展阶段我国职业足球面临的新问题与新挑战,运用文献研究、逻辑分析、案例研究等方法对我国职业足球发展问题进行分析。研究发现:现阶段,我国职业足球发展存在职业足球管理主体权限不清、责任不明,职业足球发展监管缺位,职业足球从业者道德迷失,职业俱乐部价值目标迷离等失范问题。在资源保存理论视域下审视这些问题,结合加快建设体育强国的背景,提出全面振兴策略:厘清我国职业足球现有资源存量,推动不同资源间的交互作用;结合我国职业足球资源动态过程,形成资源波动上的螺旋机制;合理促进职业足球资源人际流动,实现振兴发展上的群体效能。

关键词：职业足球资源保存理性审视全面振兴体育强国

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Green Hydrothermal Synthesis and Applications of Sorbus pohuashanensis/Aronia melanocarpa Extracts Functionalized-Au/Ag/AuAg Nanoparticles

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Journal of Renewable Materials 2023年第4期11卷 1807-1821页

作者： Jin Huang Jixiang Sun kai shao Yamei Lin Zhiguo Liu Yujie Fu Liqiang Mu College of Chemistry Chemical Engineering and Resource UtilizationKey Laboratory of Forest Plant Ecology Ministry of EducationNortheast Forestry UniversityHarbin150040China School of Forestry Northeast Forestry UniversityHarbin150040China Heilongjiang Provincial Key Laboratory of Ecological Utilization of Forestry-Based Active Substances Harbin150040China National Engineering Laboratory of Bio-Resource Eco-Utilization Harbin150040China

Nanoparticles(NPs)have already been widely used in catalysis,antibacterial and coating fields.Compared with the traditional toxic and harmful reducing reagents,green synthesis of NPs by using plant extracts is not only environmental-friendly and cost-effective but also conducive to the multi-level and efficient utilization of wild plant resources.In this study,the aqueous extracts from Sorbus pohuashanensis(SP)and Aronia melanocarpa(AM)fruits were used as the reducing and protective reagents for synthesizing Au/AgNPs,with the characteristics of originality operation and high repeatability.The SP/AM fruit extracts functionalized Au/AgNPs were characterized by UV-vis spectroscopy(UV-vis),transmission electron microscopy(TEM),energy dispersive spectroscopy(EDS),scanning electron microscope(SEM),X-ray diffraction(XRD)and Fourier transform infrared spectroscopy(FTIR).UV-vis spectrums showed the NPs peaks verified by the presence between 400–550 nm;TEM and SEM demonstrated NPs displayed approximately spherical structures;EDS confirmed the existence of Au/Ag elements;XRD measurements confirmed that the obtained NPs showed highly crystalline structures;FTIR demonstrated the fruits extracts were adsorbed on the surface of NPs.Primary experiments indicated that SP/AM fruit extracts functionalized-NPs could be used as the reagents for removing the organic dyes efficiently;Zone of inhibition tests(ZOI)explained that NPs have slow-release antibacterial activity.

关键词： Green synthesis nanoparticles Sorbus pohuashanensis Aronia melanocarpa plant extracts dye removal

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“Block and attack”strategy for tumor therapy through ZnO_(2)/siRNA/NIR-mediating Zn^(2+)-overload and amplified oxidative stress

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聚集体(英文) 2023年第4期4卷 152-165页

作者： Yuping Jiang kai shao Fenglan Zhang Tianyi Wang Lei Han Xiaoying Kong Jinsheng Shi College of Chemistry and Pharmaceutical Sciences Qingdao Agricultural UniversityQingdaoChina School of Medicine and Pharmacy Ocean University of ChinaQingdaoChina Department of Central Laboratory Qilu Hospital(Qingdao)Cheeloo College of MedicineShandong UniversityQingdaoChina Department of Public Course Teaching University of Health and Rehabilitation SciencesQingdaoChina

Intracellular zinc ion(Zn^(2+))accumulation disrupts the Zn^(2+)homeostasis,providing an ion-overloading anticancer strategy with great potential.The self-adaptation of tumor cells to ion concentration,however,puts forward higher requirements for the design of ion-overloading strategy.Herein,“block and attack”antitumor strategy was applied through a composite nanomaterials(UHSsPZH NPs).The strategy demonstrated powerful ion interference ability through both“blocking”the efflux of excess Zn^(2+)via gene silencing and“attacking”tumor cells via target delivery of ZnO_(2).After cellular internalization,ZnO_(2) was degraded to Zn^(2+)and hydrogen peroxide(H_(2)O_(2)),and the gene expression of zinc transporter 1(ZnT1)was silenced by targeting of released siRNA,which together caused intracellular Zn2+-overload.Disorder of Zn^(2+)further interfered with intracellular Ca^(2+)homeostasis,inhibited the electron transport chain and promoted the production of endogenous reactive oxygen species(ROS),which assisted the“attack”to tumor cells together with the exogenous ROS generated by UHSsPZH NPs under 980 nm laser irradiation.In summary,this work supplies a“block and attack”strategy for the application of ion homeostasis interference in tumor therapy.

关键词： photodynamic therapy siRNA tumor therapy Zn^(2+)-overload ZnO_(2)

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可重构智能表面辅助通信系统时变级联信道估计

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通信学报 2024年第1期45卷 119-128页

作者：邵凯鲁奔王光宇重庆邮电大学通信与信息工程学院重庆400065 移动通信技术重庆市重点实验室重庆400065 移动通信教育部工程研究中心重庆400065

针对可重构智能表面(RIS)辅助通信系统时变级联信道的估计中需解决的级联信道稀疏表示、时变信道参数跟踪和信号重构等关键问题,提出了一种结合Khatri-Rao积的分层贝叶斯卡尔曼滤波(KR-HBKF)算法。该算法首先利用信道的稀疏特性,通过Kha... 详细信息

针对可重构智能表面(RIS)辅助通信系统时变级联信道的估计中需解决的级联信道稀疏表示、时变信道参数跟踪和信号重构等关键问题,提出了一种结合Khatri-Rao积的分层贝叶斯卡尔曼滤波(KR-HBKF)算法。该算法首先利用信道的稀疏特性,通过Khatri-Rao积和克罗内克积变换得到RIS级联信道的稀疏表示,将RIS级联信道估计问题转化为低维度的稀疏信号恢复问题。然后,根据RIS级联信道的状态演化模型,在HBKF算法的预测模型中引入了时间相关性参数,应用改进的HBKF解决时变信道参数跟踪和信号重构问题,完成时变级联信道的估计。KR-HBKF算法综合利用了信道的稀疏性和时间相关性,能以较小的导频开销获得更好的估计精度。仿真结果表明,与传统压缩感知算法相比,所提算法具有约5 dB的估计性能提升,且在不同的时变信道条件下具有更好的鲁棒性。

关键词：可重构智能表面信道估计贝叶斯压缩感知卡尔曼滤波

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Multi-task regression learning for survival analysis via prior information guided transductive matrix completion

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Frontiers of Computer Science 2020年第5期14卷 99-112页

作者： Lei Chen kai shao Xianzhong Long Lingsheng Wang Jiangsu Key Laboratory of Big Data Security and Intelligent Processing Nanjing University of Posts and TelecommunicationsNanjing210023China MIIT Key Laboratory of Pattern Analysis and Machine Intelligence Nanjing University of Aeronautics and AstronauticsNanjing211106China

Survival analysis aims to predict the occurrence time of a particular event of interest,which is crucial for the prognosis analysis of diseases.Currently,due to the limited study period and potential losing tracks,the observed data inevitably involve some censored instances,and thus brings a unique challenge that distinguishes from the general regression problems.In addition,survival analysis also suffers from other inherent challenges such as the high-dimension and small-sample-size problems.To address these challenges,we propose a novel multi-task regression learning model,i.e.,prior information guided transductive matrix completion(PigTMC)model,to predict the survival status of the new instances.Specifically,we use the multi-label transductive matrix completion framework to leverage the censored instances together with the uncensored instances as the training samples,and simultaneously employ the multi-task transductive feature selection scheme to alleviate the overfitting issue caused by high-dimension and small-sample-size data.In addition,we employ the prior temporal stability of the survival statuses at adjacent time intervals to guide survival analysis.Furthermore,we design an optimization algorithm with guaranteed convergence to solve the proposed PigTMC model.Finally,the extensive experiments performed on the real microarray gene expression datasets demonstrate that our proposed model outperforms the previously widely used competing methods.

关键词： survival analysis matrix completion multi-task regression transductive learning multi-task feature selection

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Controllable broadband multicolour single-mode polarized laser in a dye-assembled homoepitaxial MOF microcrystal

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Light(Science & Applications) 2020年第1期9卷 686-695页

作者： Huajun He Yuanjing Cui Hongjun Li kai shao Banglin Chen Guodong Qian State Key Laboratory of Silicon Materials Cyrus Tang Center for Sensor Materials and ApplicationsSchool of Materials Science and EngineeringZhejiang University310027 HangzhouChina Department of Chemistry University of Texas at San AntonioSan AntonioTX 78249USA Present address:Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological University21 Nanyang LinkSingapore 637371Singapore

Multicolour single-mode polarized microlasers with visible to near-infrared output have very important applications in photonic integration and multimodal biochemical sensing/imaging but are very difficult to realize.Here,we demonstrate a single crystal with multiple segments based on the host-guest metal-organic framework ZJU-68 hierarchically hybridized with different dye molecules generating controllable single-mode green,red,and nearinfrared lasing,with the lasing mode mechanism revealed by computational simulation.The segmented and oriented assembly of different dye molecules within the ZJU-68 microcrystal causes it to act as a shortened resonator,enabling us to achieve dynamically controllable multicolour single-mode lasing with a low three-colour-lasing threshold of ~1.72 mJ/cm^(2)(approximately seven times lower than that of state-of-the-art designed heterostructure alloys,as reported by Fan F et al.(Nat.Nanotechnol.10:796-803,2015)considering the single pulse energy density)and degree of polarization>99.9%.Furthermore,the resulting three-colour single-mode lasing possesses the largest wavelength coverage of ~186 nm(ranging from ~534 to ~720 nm)ever reported.These findings may open a new route to the exploitation of multicolour single-mode micro/nanolasers constructed by MOF engineering for photonic and biochemical applications.

关键词： polarization resonator mode

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Integrating BDS and GPS for precise relative orbit determination of LEO formation flying

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Chinese Journal of Aeronautics 2018年第10期31卷 2013-2022页

作者： Bin YI Defeng GU Xiao CHANG kai shao College of Liberal Arts and Sciences National University of Defense Technology

Low-Earth-Orbit（LEO） formation-flying satellites have been widely applied in many kinds of space geodesy. Precise Relative Orbit Determination（PROD） is an essential prerequisite for the LEO formation-flying satellites to complete their mission in space. The contribution of the BeiDou Navigation Satellite System（BDS） to the accuracy and reliability of PROD of LEO formation-flying satellites based on a Global Positioning System（GPS） is studied using a simulation method. Firstly, when BDS is added to GPS, the mean number of visible satellites increases from9.71 to 21.58. Secondly, the results show that the 3-Dimensional（3 D） accuracy of PROD, based on BDS-only, GPS-only and BDS ＋ GPS, is 0.74 mm, 0.66 mm and 0.52 mm, respectively. When BDS co-works with GPS, the accuracy increases by 29.73%. Geostationary-Earth-Orbit（GEO） satellites and Inclined Geosynchronous-Orbit（IGSO） satellites are only distributed over the Asia-Pacific region; however, they could provide a global improvement to PROD. The difference in PROD results between the Asia-Pacific region and the non-Asia-Pacific region is not apparent. Furthermore, the value of the Ambiguity Dilution Of Precision（ADOP）, based on BDS ＋ GPS, decreases by 7.50% and 8.26%, respectively, compared with BDS-only and GPS-only. Finally, if the relative position between satellites is only a few kilometres, the effect of ephemeris errors on PROD could be ignored. However, for a several-hundred-kilometre separation of the LEO satellites, the SingleDifference（SD） ephemeris errors of GEO satellites would be on the order of centimetres. The experimental results show that when IGSO satellites and Medium-Earth-Orbit（MEO） satellites co-work with GEO satellites, the accuracy decreases by 17.02%.

关键词： Ambiguity Dilution Of Precision BeiDou Navigation Satellite System Geostationary-Earth-Orbit Global Positioning System LEO formation flying Precise Relative Orbit Determination

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