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Phase diagram and transport properties of Sb-doped Ca0.88La0.12Fe2As2 single crystals

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Frontiers of physics 2017年第4期12卷 167-172页

作者： Xiang-Zhuo Xing Wei Zhou Chun-Qiang Xu Nan Zhou fei-fei yuan Yu-Feng Zhang Xiao-Feng Xu Zhi-Xiang Shi Department of Physics and Key Laboratory of MEMS of the Ministry of Education Southeast University Nanjing 211189 China Department of Physics and Hangzhou Key Laboratory of Quantum Matters Hangzhou Normal University Hangzhou 310036 China

The effects of isovalent Sb substitution on the superconducting properties of the Ca0.88La0.12Fe2（As1-ySby）2 system have been studied through electrical resistivity measure- ments. It is seen that the antiferromagnetic or structural transition is suppressed with Sb content, and a high-To superconducting phase, accompanied by a low-Tc phase, emerges at 0.02 ≤y ≤ 0.06. In this intermediate-doping regime, normal-state transport shows non-Fermi-liquid-like behaviors with nearly T-linear resistivity above the high-Tc phase. With further Sb doping, this high-Tc phase abruptly vanishes for y 〉 0.06 and the conventional Fermi liquid is restored, while the low-T,, phase remains robust against Sb inlpurities. The coincidence of the high-Tc phase and non-Fermi liquid transport behaviors in the intermediate Sb-doping regime suggests that AFM fluctuations play an important role in the observed non-Fermi liquid behaviors, which may be intimately related to the unusual nonbulk high-Tc phase in this system.

关键词： Sb doped Ca0.88La0.12Fe2As2 superconductors electrical resistivity measurement phase diagram

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中国股票市场的汇率风险研究

技术经济与管理研究 2016年第9期 83-87页

作者：吴菲菲李媛中央财经大学金融学院北京100081 中央财经大学中国金融发展研究院北京100081

2005年7月21日,我国对人民币汇率形成机制进行改革,实行以市场供求为基础、参考一篮子货币进行调节、有管理的浮动汇率制度。文章在汇率制度改革的背景下,对中国股票市场股票收益率的汇率风险问题进行研究。运用2000年1月至2015年4月A... 详细信息

2005年7月21日,我国对人民币汇率形成机制进行改革,实行以市场供求为基础、参考一篮子货币进行调节、有管理的浮动汇率制度。文章在汇率制度改革的背景下,对中国股票市场股票收益率的汇率风险问题进行研究。运用2000年1月至2015年4月A股股票市场的月度数据,在理论研究的基础上,文章对1125家A股上市公司股票收益率与汇率变动之间的关系进行研究,并对存有海外业务和不存在海外业务的上市公司加以比较分析。实证结果表明:第一,在1125家上市公司中,对汇率变动敏感的上市公司数量明显少于对汇率变动不敏感的上市公司。第二,汇率制度改革之后,对汇率变动敏感的上市公司数量增加。第三,在对汇率变动敏感的上市公司中,存在海外业务的上市公司数量多于不存在海外业务的上市公司。

关键词：汇率风险股票收益率汇率制度股票市场

Responses of Pinus tabulaeformis tree rings to climatic metrics in Hasi Mountain

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地球环境学报 2012年第6期3卷 1149-1155页

作者： LU Rui-jie JIA fei-fei SHANG yuan GAO Shang-yu Key Laboratory of Environmental Change and Natural Disaster Ministry of Education of the People's Republic of China Beijing Normal University Beijing 100875 China

A tree-ring width chronology developed from Pinus tabulaeformis tree-rings of Hasi Mountain was employed to analyze responses of tree-ring to different climatic *** analyses between tree-ring chronology and precipitation and temperature suggest that tree growth is both limited by precipitation and temperature,and moisture is the principal limiting factor of tree-ring *** find a suitable moisture index to be reconstructed,three moisture indices considering precipitation and evaporation even water balance are chosen to be *** results suggest that the PDSI is an appropriate index as predictor of tree-ring width and can be used to reconstruct in this area.

关键词： Pinus tabulaeformis tree-ring responses moisture indices

High-dose dexamethasone regulates microglial polarization via the GR/JAK1/STAT3 signaling pathway after traumatic brain injury

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Neural Regeneration Research 2025年第9期20卷 2611-2623页

作者： Mengshi Yang Miao Bai yuan Zhuang Shenghua Lu Qianqian Ge Hao Li Yu Deng Hongbin Wu Xiaojian Xu fei Niu Xinlong Dong Bin Zhang Baiyun Liu Beijing Tiantan Hospital Capital Medical UniversityBeijingChina Department of Neurology The First Hospital of Tsinghua UniversityBeijingChina Department of Neurotrauma and Beijing Key Laboratory of Central Nervous System Injury Beijing Neurosurgical InstituteCapital Medical UniversityBeijingChina Department of Critical Care Medicine Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Center for Nerve Injury and Repair Beijing Institute of Brain DisordersChina National Clinical Research Center for Neurological DiseasesBeijingChina

Although microglial polarization and neuroinflammation are crucial cellular responses after traumatic brain injury,the fundamental regulatory and functional mechanisms remain insufficiently *** potent anti-inflammato ry agents,the use of glucoco rticoids in traumatic brain injury is still controversial,and their regulatory effects on microglial polarization are not yet *** the present study,we sought to determine whether exacerbation of traumatic brain injury caused by high-dose dexamethasone is related to its regulatory effects on microglial polarization and its mechanisms of *** vitro cultured BV2 cells and primary microglia and a controlled cortical impact mouse model were used to investigate the effects of dexamethasone on microglial ***,dexamethasone,RU486(a glucocorticoid receptor antagonist),and ruxolitinib(a Janus kinase 1 antagonist)were ***-sequencing data obtained from a C57BL/6 mouse model of traumatic brain injury were used to identify potential targets of *** Morris water maze,quantitative reverse transcription-polymerase chain reaction,western blotting,immunofluorescence and confocal microscopy analysis,and TUNEL,Nissl,and Golgi staining were performed to investigate our ***-throughput sequencing results showed that arginase 1,a marker of M2 microglia,was significantly downregulated in the dexamethasone group compared with the traumatic brain injury group at3 days post-traumatic brain *** dexamethasone inhibited M1 and M2 microglia,with a more pronounced inhibitory effect on M2microglia in vitro and in *** receptor plays an indispensable role in microglial polarization after dexamethasone treatment following traumatic brain ***,glucocorticoid receptor activation increased the number of apoptotic cells and neuronal death,and also decreased the density of dendritic spines.A possible downstream receptor signaling mechanism is th

关键词： apoptosis BV2 microglia dexamethasone glucocorticoid receptor glucocorticoids innate immune system microglial polarization neuroinflammation primary microglia traumatic brain injury

A modified stochastic model for LS+AR hybrid method and its application in polar motion short-term prediction

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Geodesy and Geodynamics 2024年第1期15卷 100-105页

作者： fei Ye Yunbin yuan State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China BeiDou High-precision Satellite Navigation and Location Service Hunan Engineering Research Center Hunan Institute of Geomatics Sciences and TechnologyChangsha 410007China Hunan Continuously Operating Reference Stations(HNCORS)Data Center Hunan Institute of Geomatics Sciences and TechnologyChangsha 410007China

Short-term(up to 30 days)predictions of Earth Rotation Parameters(ERPs)such as Polar Motion(PM:PMX and PMY)play an essential role in real-time applications related to high-precision reference frame ***,least squares(LS)+auto-regressive(AR)hybrid method is one of the main techniques of PM ***,the weighted LS+AR hybrid method performs well for PM short-term ***,the corresponding covariance information of LS fitting residuals deserves further exploration in the AR *** this study,we have derived a modified stochastic model for the LS+AR hybrid method,namely the weighted LS+weighted AR hybrid *** using the PM data products of IERS EOP 14 C04,the numerical results indicate that for PM short-term forecasting,the proposed weighted LS+weighted AR hybrid method shows an advantage over both the LS+AR hybrid method and the weighted LS+AR hybrid *** to the mean absolute errors(MAEs)of PMX/PMY sho rt-term prediction of the LS+AR hybrid method and the weighted LS+AR hybrid method,the weighted LS+weighted AR hybrid method shows average improvements of 6.61%/12.08%and 0.24%/11.65%,***,for the slopes of the linear regression lines fitted to the errors of each method,the growth of the prediction error of the proposed method is slower than that of the other two methods.

关键词： Stochastic model LS+AR Short-term prediction The earth rotation parameter(ERP) Observation model

Improved LS+MAR hybrid method to UT1-UTC ultra-short-term prediction by using first-order-difference UT1-UTC

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Geodesy and Geodynamics 2024年第4期15卷 379-385页

作者： fei Ye Yunbin yuan BeiDou High-precision Satellite Navigation and Location Service Hunan Engineering Research Center Hunan Institute of Geomatics Sciences and TechnologyChangsha410007China State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan430077China HNCORS Data Center Hunan Institute of Geomatics Sciences and TechnologyChangsha 410007China

Accurate ultra-short-term prediction of the Earth rotation parameters(ERP)holds paramount impor-tance for real-time applications,particularly in reference frame *** them,diurnal rota-tion(UT1-UTC)which cannot be directly estimated through Global Navigation Satellite System(GNSS)techniques,significantly affects the rapid and ultra-rapid orbit determination of GNsS ***-ently,the traditional LS(least squares)+AR(autoregressive)and LS+MAR(multivariate autoregressive)hybrid methods stand as primary approaches for UT1-UTC ultra-short-term predictions(1-10 days).The LS+MAR hybrid method relies on the UT1-UTC and LOD(length of day)***,the correlation between LOD and first-order-difference UT1-UTC is stronger than that between LOD and *** light of this,and with the aid of the first-order-difference UT1-UTC,we propose an enhanced LS+MAR hybrid method to UT1-UTC ultra-short-term *** using the UT1-UTC and LOD data series of the IERS(International Earth Rotation and Reference Systems Service)EOP 14 C04 product,we conducted a thorough analysis and evaluation of the improved method's prediction performance compared to the traditional LS+AR and LS+MAR hybrid *** to the numerical results over more than 210 days,they demonstrate that,when considering the correlation information between the LoD and the first-order-difference UT1-UTC,the mean absolute errors(MAEs)of the improved LS+MAR hybrid method range from 21 to 934μs in 1-10 days *** comparison to the traditional LS+AR hybrid method,the MAEs show a reduction of 7-53μs in 1-10 days predictions,with corresponding improvement percentages ranging from 1 to 28%.Similarly,when compared to the traditional LS+MAR hybrid method,the MAEs have a reduction of 5-42μs in 1-10 days predictions,with corresponding improvement percentages ranging from 4-20%.Additionally,when aided by GNSS-derived LOD data series,the MAEs of improved LS+MAR hybrid method experience further

关键词： UT1-UTCultra-short-termprediction Rapidandultra-rapidproducts LS+AR and LS+MAR Correlation First-order-differenceUT1-UTC

Product Systems of C^(*)-correspondences and Baaj-Skandalis Duality

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Acta Mathematica Sinica,English Series 2023年第2期39卷 240-256页

作者： fei fei MIAO Li Guang WANG Wei yuan School of Mathematical Sciences Qufu Normal UniversityQufu273165China Institute of Mathematics Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing100049China

Let X={X_(p)}p∈Pbe a product system over a lattice ordered group(G,P)with coefficients in a C*-algebra *** this paper,we study the reduced crossed product of the gauge coactionδof G on the Cuntz-Pimsner algebra NO_(X)^(r).When X is a product system of Morita equivalence bimodules,we show that the reduced crossed product of the gauge coaction is Morita equivalent to the C*-algebra A.

关键词： Cuntz-Pimsner algebras product systems reduced crossed products Morita equivalence

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Bounded Evaluation:Querying Big Data with Bounded Resources

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International Journal of Automation and computing 2020年第4期17卷 502-526页

作者： Yang Cao Wen-fei Fan Teng-fei yuan University of Edinburgh Edinburg EH89ABUKUniversity of EdinburghEdinburg EH89ABUK Shenzhen Institute of Computing Sciences Shenzhen UniversityShenzhen 518060China Beijing Advanced Innovation Center for Big Data and Brain Computing Beihang UniversityBeijing 100191China

This work aims to reduce queries on big data to computations on small data,and hence make querying big data possible under bounded resources.A query Q is boundedly evaluable when posed on any big dataset D,there exists a fraction DQ of D such that Q(D)=Q(DQ),and the cost of identifying DQ is independent of the size of *** has been shown that with an auxiliary structure known as access schema,many queries in relational algebra(RA)are boundedly evaluable under the set semantics of *** paper extends the theory of bounded evaluation to RAaggr,i.e.,RA extended with aggregation,under the bag semantics.(1)We extend access schema to bag access schema,to help us identify DQ for RAaggr queries Q.(2)While it is undecidable to determine whether an RAaggr query is boundedly evaluable under a bag access schema,we identify special cases that are decidable and practical.(3)In addition,we develop an effective syntax for bounded RAaggr queries,i.e.,a core subclass of boundedly evaluable RAaggr queries without sacrificing their expressive power.(4)Based on the effective syntax,we provide efficient algorithms to check the bounded evaluability of RAaggr queries and to generate query plans for bounded RAaggr queries.(5)As proof of concept,we extend PostgreSQL to support bounded *** experimentally verify that the extended system improves performance by orders of magnitude.

关键词： Bounded evaluation resource-bounded query processing effective syntax access schema boundedness

Challenges of the Sensor Web for disaster management

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International Journal of Digital Earth 2010年第3期3卷 260-279页

作者： fei Wang Hongyong yuan Center for Public Safety Research Department of Engineering PhysicsTsinghua UniversityBeijing 100084P.R.China

Sensor Web has been widely promoted and its application has evolved from original military usages to current ubiquitous civil and commercial *** emergence has become a great strength to facilitate the Digital Earth *** many Sensor Web applications and methods have been proposed to assist disaster management,they are not well suited to the unique features and application requirements of disaster *** researches focus on how to use the Sensor Web to monitor a certain phenomenon before a disaster happens and to provide early ***,there is a lack of study on the negative effects that a disaster may bring to the Sensor *** example,severe weather conditions,damaged infrastructure,and spatial isolation may directly make the Sensor Web ***,disaster management is a complex subject and its domain knowledge needs to be *** this paper,the domain of the disaster management is explored and its unique features are *** the Sensor Web concept and its role in disaster management are ***,the challenges of the Sensor Web for disaster management and the possible solutions are *** on the above,we introduce a high-mobility emergency system to demonstrate a good solution of the Sensor Web for multipurpose disaster management.

关键词： Digital Earth disaster management Sensor Web GIS Internet of Things