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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

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

Strength and ductility optimization of HPDC AlSi8MgCuZn2 alloys by modifying pre-aging treatment

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China Foundry 2024年第4期21卷 343-351页

作者： yuan-hang Jiang Hui-ting Zheng fei Liu Hai-dong Zhao National Engineering Research Center of Near-net Shape Forming for Metallic Materials South China University of TechnologyGuangzhou 510641China

Considering the components produced by high pressure die casting(HPDC)process usually with ultra-large sizes and complex morphologies,high temperature solid solution treatment is not a suitable method to further improve their mechanical *** this study,two-stage aging treatment with different pre-aging times was designed and employed to further improve the mechanical properties of HPDC Al8SiMgCuZn *** characteristics of precipitates were evaluated by a transmission electron microscope(TEM),and the precipitation strengthening mechanism was *** results reveal that the strengthening is mainly contributed by the precipitation ofβ″phase after two-stage aging,and the number density and size of the precipitates are significantly depended on the pre-aging *** number density of precipitates is increased with the pre-aging time prolonged from 0 h to 4 h,and then decreases with the further increase of pre-aging time from 4 h to 6 *** precipitates with the highest density and smallest size are observed after pre-aging for 4 *** pre-aged at 100℃for 4 h and then artificial aged at 200℃for 30 min,the yield strength of 207 MPa,ultimate tensile strength of 325 MPa and elongation of 7.6%are achieved.

关键词： high pressure die cast aluminum alloy microstructural heterogeneity mechanical properties precipitation strengthening two-stage aging

Progress of semitransparent emerging photovoltaics for building integrated applications

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Green Energy & Environment 2024年第6期9卷 992-1015页

作者： Zhisheng Zhou Zhangyu yuan Zhipeng Yin Qifan Xue Ning Li fei Huang State Key Laboratory of Luminescent Materials and Devices School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou510640China Pazhou Lab Guangzhou510320China

With the rapid development of emerging photovoltaics technology in recent years,the application of building-integrated photovoltaics(BIPVs)has attracted the research interest of photovoltaic *** meet the practical application requirements of BIPVs,in addition to the evaluation indicator of power conversion efficiency(PCE),other key performance indicators such as heat-insulating ability,average visible light transmittance(AVT),color properties,and integrability are equally *** traditional Si-based photovoltaic technology is typically limited by its opaque properties for application scenarios where transparency is *** emerging PV technologies,such as organic and perovskite photovoltaics are promising candidates for BIPV applications,owing to their advantages such as high PCE,high AVT,and tunable *** present,the PCE of semitransparent perovskite solar cells(ST-PSCs)has attained 14%with AVT of 22–25%;for semitransparent organic solar cells(ST-OSCs),the PCE reached 13%with AVT of almost 40%.In this review article,we summarize recent advances in material selection,optical engineering,and device architecture design for high-performance semitransparent emerging PV devices,and discuss the application of optical modeling,as well as the challenges of commercializing these semitransparent solar cells for building-integrated applications.

关键词： Building integrated photovoltaics Emerging photovoltaics Semitransparent solar cells Perovskite solar cells Organic solar cells

Impairment of Autophagic Flux After Hypobaric Hypoxia Potentiates Oxidative Stress and Cognitive Function Disturbances in Mice

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Neuroscience Bulletin 2024年第1期40卷 35-49页

作者： Shuhui Dai yuan Feng Chuanhao Lu Hongchen Zhang Wenke Ma Wenyu Xie Xiuquan Wu Peng Luo Lei Zhang fei fei Zhou fei Xia Li Department of Neurosurgery Xijing HospitalFourth Military Medical UniversityXi'an 710000China National Translational Science Center for Molecular Medicine and Department of Cell Biology Fourth Military Medical UniversityXi'an 710000China Department of Neurosurgery The Central Hospital of BaojiBaoji 721000China Department of Ophthalmology Xijing HospitalFourth Military Medical UniversityXi'an 710000China

Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude *** plays a critical role in ischemic brain injury,but its role in hypo-baric hypoxia(HH)remains *** we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain,and is partially responsible for HH-induced oxidative stress,neuronal loss,and brain *** autophagic agonist rapamycin only promotes the initiation of *** proteome analysis,a screen showed that protein dynamin2(DNM2)potentially regulates autophagic *** of DNM2 significantly increased the formation of autolysosomes,thus maintaining autophagic flux in combination with ***,the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH *** results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.

关键词： Autophagy-Proteomics Oxidative stress Hypobaric hypoxia-Brain injury

Passive imaging through dense scattering media

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Photonics Research 2024年第1期12卷 134-140页

作者： YAOMING BIAN fei WANG yuanZHE WANG ZHENFENG FU HAISHAN LIU HAIMING yuan GUOHAI SITU Shanghai Institute of Optics and Fine Mechanics Chinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Hangzhou Institute for Advanced Study University of Chinese Academy of SciencesHangzhou 310024China

Imaging through non-static and optically thick scattering media such as dense fog,heavy smoke,and turbid water is crucial in various ***,most existing methods rely on either active and coherent light illumination,or image priors,preventing their application in situations where only passive illumination is *** this study we present a universal passive method for imaging through dense scattering media that does not depend on any prior *** the selection of small-angle components out of the incoming information-carrying scattering light and image enhancement algorithm that incorporates timedomain minimum filtering and denoising,we show that the proposed method can dramatically improve the signal-to-interference ratio and contrast of the raw camera image in outfield experiments.

关键词： scattering media illumination

Responses of Nutrients to the Precipitation Variation and Land Use in Subtropical Monsoonal Small Mountainous Rivers:A Case Study of Baixi Watershed

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Journal of Ocean University of China 2024年第2期23卷 383-391页

作者： TIAN yuan GAO fei CAO Ke LV Shenghua DUAN Xiaoyong YIN Ping Qingdao Institute of Marine Geology China Geological SurveyMinistry of Natural ResourcesQingdao 266237China Laboratory for Marine Geology Laoshan LaboratoryQingdao 266237China

Small mountainous rivers are characterized by large instantaneous fluxes and susceptible to extreme weather events,which can rapidly transport materials into the sea and have a significant impact on the ecological environment of estuaries and *** order to investigate the seasonal characteristics of nutrients in small mountainous rivers in the subtropical monsoon region and the output pattern to the sea during heavy precipitation,surveys on the mountainous rivers were carried out in Baixi watershed in August 2020(wet season),March 2021(dry season)and June 2021(Meiyu period).The results showed that the dissolved inorganic nitrogen(DIN)of the rivers has an average concentration of 752μg L^(−1)in the wet season and 1472μg L^(−1)in the dry *** concentrations of dissolved inorganic phosphorus(DIP)in wet season and dry season were 63μg L^(−1)and 51μg L^(−1),*** by the changes of land use in sub-watersheds,DIN concentrations in the mainstream increased from 701μg L^(−1)in the upper reaches to 1284μg L^(−1)in the middle *** rainstorms during the Meiyu period in the watershed caused the pulse runoff in the *** maximum daily runoff reached 70 times that before *** maximum daily fluxes of DIN and DIP were 109 and 247 times that before rains,*** view that the watershed experienced several rainstorms in the wet season,the river,with pulse runoff,carries a large amount of nutrients into the sea in a short time,which will have a significant impact on the environment of Sanmen bay and its adjacent sea.

关键词： small mountainous river uneven precipitation rainstorm pulse runoff nitrogen and phosphorus

Hole-Transporting Materials with Rational Combination of Pyridine and Dibenzo[a,c]phenazine as Electron Acceptor for Dopant-Free Perovskite Solar Cells

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Chinese Journal of Chemistry 2024年第10期42卷 1100-1106页

作者： Weidong Ling fei Wu Wentao yuan Linna Zhu Qianqian Li Zhen Li Hubei Key Lab on Organic and Polymeric Opto-Electronic Materials Department of ChemistryWuhan UniversityWuhanHubei 430072China Chongqing Key Laboratory for Advanced Materials and Technologies of Clean Energy Faculty of Materials&EnergySouthwest UniversityChongqing400715China TaiKang Center for Life and Medical Sciences Wuhan UniversityWuhanHubei 430072China

Perovskite solar cells(PSCs)have been proven to be a promising option for photovoltaic *** the aim to achieve efficient and stable PSCs,it is essential to explore dopant-free hole-transporting materials(HTMs)with high hole ***,HTMs bearing electron donor(D)-electron acceptor(A)-electron donor(D)structures have been constructed with strong intramolecular charge transfer(ICT)effect,based on rational combination of dibenzo[a,c]phenazine and pyridine as electronic acceptors and anchoring groups to perovskite ***,high hole mobility(7.31×10^(-5) cm^(2)·V^(-1)·s^(-1))and photoelectric conversion efficiency(20.45%)have been achieved by dopant-free DPyP-based *** afforded an efficient way to design HTMs with high hole mobility by adjustment of molecular configurations and electronic property of conjugated systems.

关键词： Perovskite solar cell Charge transfer Donor-acceptor systems Energy conversion Hole mobility