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

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

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An efficient parallel algorithm of variational nodal method for heterogeneous neutron transport problems

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Nuclear Science and Techniques 2024年第4期35卷 29-45页

作者： han Yin Xiao-Jing Liu Teng-fei Zhang School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 2002040China

The heterogeneous variational nodal method(HVNM)has emerged as a potential approach for solving high-fidelity neutron transport ***,achieving accurate results with HVNM in large-scale problems using high-fidelity models has been challenging due to the prohibitive computational *** paper presents an efficient parallel algorithm tailored for HVNM based on the Message Passing Interface *** algorithm evenly distributes the response matrix sets among processors during the matrix formation process,thus enabling independent construction without *** the formation tasks are completed,a collective operation merges and shares the matrix sets among the *** the solution process,the problem domain is decomposed into subdomains assigned to specific processors,and the red-black Gauss-Seidel iteration is employed within each subdomain to solve the response matrix ***-to-point communication is conducted between adjacent subdomains to exchange data along the *** accuracy and efficiency of the parallel algorithm are verified using the KAIST and JRR-3 test *** results obtained with multiple processors agree well with those obtained from Monte Carlo *** parallelization of HVNM results in eigenvalue errors of 31 pcm/-90 pcm and fission rate RMS errors of 1.22%/0.66%,respectively,for the 3D KAIST problem and the 3D JRR-3 *** addition,the parallel algorithm significantly reduces computation time,with an efficiency of 68.51% using 36 processors in the KAIST problem and 77.14% using 144 processors in the JRR-3 problem.

关键词： Neutron transport Variational nodal method Parallelization KAIST JRR-3

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Development of a database system for operational use in the selection of titanium alloys

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International Journal of Minerals,Metallurgy and Materials 2011年第4期18卷 444-449页

作者： yuan-fei han Wei-dong Zeng Yu Sun Yong-qing Zhao State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi＇an 710072 China Northwest Institute for Nonferrous Metal Research Xi＇an 710016 China

The selection of titanium alloys has become a complex decision-making task due to the growing number of creation and utilization for titanium alloys,with each having its own characteristics,advantages,and *** choosing the most appropriate titanium alloys,it is very essential to offer a reasonable and intelligent service for technical *** possible solution of this problem is to develop a database system（DS） to help retrieve rational proposals from different databases and information sources and analyze them to provide useful and explicit *** this purpose,a design strategy of the fuzzy set theory is proposed,and a distributed database system is *** ranking of the candidate titanium alloys,the most suitable material is *** is found that the selection results are in good agreement with the practical situation.

关键词： titanium alloys database system fuzzy set theory evaluation

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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

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The medium-temperature dependence of jet transport coefficient in high-energy nucleus-nucleus collisions

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Nuclear Science and Techniques 2024年第7期35卷 173-191页

作者： Man Xie Qing-fei han En-Ke Wang Ben-Wei Zhang han-Zhong Zhang Key Laboratory of Atomic and Subatomic Structure and Quantum Control(MOE) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of MatterInstitute of Quantum Matter South China Normal UniversityGuangzhou510006China Guangdong-Hong Kong Joint Laboratory of Quantum Matter Guangdong Provincial Key Laboratory of Nuclear ScienceSouthern Nuclear Science Computing CenterSouth China Normal UniversityGuangzhou 510006China Key Laboratory of Quark and Lepton Physics(MOE)and Institute of Particle Physics Central China Normal UniversityWuhan430079China

The medium-temperature T dependence of the jet transport coefficient̂q was studied via the nuclear modification factor RAA(pT)and elliptical flow parameter v_(2)(pT)for large transverse momentum pT hadrons in high-energy nucleus-nucleus *** a next-to-leading-order perturbative QCD parton model for hard scatterings with modified fragmentation functions due to jet quenching controlled bŷq,we check the suppression and azimuthal anisotropy for large pT hadrons,and extract̂q by global fits to RAA(pT)and v_(2)(pT)data in A+A collisions at RHIC and LHC,*** numerical results from the best fits show that̂q∕T^(3) goes down with local medium-temperature T in the parton jet *** with the case of a constant̂q∕T^(3),the going-down T dependence of̂q∕T^(3) makes a hard parton jet to lose more energy near Tc and therefore strengthens the azimuthal anisotropy for large pT *** a result,v_(2)(pT)for large pT hadrons was enhanced by approximately 10%to better fit the data at RHIC/*** the first-order phase transition from QGP to the hadron phase and the additional energy loss in the hadron phase,v_(2)(pT)is again enhanced by 5-10%at RHIC/LHC.

关键词： Jet quenching Jet transport parameter Hadron suppression Elliptic flow coefficient Energy loss asymmetry

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Xiao Tan San Jie Fang Hampers the Growth of Colon Cancer Stem Cells through the Wnt/β-catenin Signaling Pathway

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World Journal of Traditional Chinese Medicine 2024年第2期10卷 171-179页

作者： Yu-Qi Zhou Jun-fei yuan Hong-Shi Shen Ya-Ping Wang han-fei Shi De-Jian Pan Min Ye Department of Hematology and Oncology The 904^(th) Hospital of PLA Joint Logistic Support ForceWuxiJiangsuChina Department of Clinical Laboratory The 904^(th)Hospital of PLA Joint Logistic Support ForceWuxiJiangsuChina Department of Traditional Chinese Medicine Second Affiliated Hospital of Naval Medical UniversityShanghaiChina

Objective: The purpose of this research was to examine the potential anticancer properties of Xiao Tan San Jie Fang(XTSJF) and its potential mechanism of action against colorectal cancer. Materials and Methods: HCT116 cells were induced into HCT116 spheres in DMEM/F12 medium by treatment with epidermal growth factor + fibroblast growth factor + leukemia inhibitory factor + B27. The proliferation ability and stemness of HCT116 spheres was examined. Various concentrations of XTSJF were used to treat HCT116 spheres to observe the impact on proliferation, apoptosis, and expression of stem cell markers. Next, Wnt/β-catenin pathway-related factor proteins were detected. Results: The findings revealed that XTSJF suppressed cell growth and induced cell death in HCT116 cells in a dosage-dependent manner. Similarly, XTSJF promotes apoptosis, inhibits cell proliferation, prolongs survival, and maintains the expression of stem cells through the Wnt/-catenin/TCF4 axis. XTSJF also inhibits AKT activity and subsequently activates glycogen synthesis kinase-3β expression, inhibiting Wnt/beta-catenin pathway activity and downstream target gene transcript expression. The Wnt/β-catenin signaling pathway is inhibited by the XTSJF, leading to the suppression of colon cancer stem cell proliferation. Conclusion: Xiaotan Sanjie Prescription inhibited colon cancer stem cell growth through Wnt/β-catenin signaling pathway.

关键词： Apoptosis colorectal cancer proliferation traditional Chinese medicine Wnt/β-catenin signaling

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Data-driven discovery of linear dynamical systems from noisy data

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Science China(Technological Sciences) 2024年第1期67卷 121-129页

作者： WANG YaSen yuan Ye FANG HuaZhen DING han School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China Department of Mechanical Engineering University of KansasLawrence 66045USA

In modern science and engineering disciplines,data-driven discovery methods play a fundamental role in system modeling,as data serve as the external representations of the intrinsic mechanisms within ***,empirical data contaminated by process and measurement noise remain a significant obstacle for this type of *** this study,we have developed a data-driven method capable of directly uncovering linear dynamical systems from noisy *** method combines the Kalman smoothing and sparse Bayesian learning to decouple process and measurement noise under the expectation-maximization framework,presenting an analytical method for alternate state estimation and system ***,the discovered model explicitly characterizes the probability distribution of process and measurement noise,as they are essential for filtering,smoothing,and stochastic *** have successfully applied the proposed algorithm to several simulation *** results demonstrate its potential to enable linear dynamical system discovery in practical applications where noise-free data are intractable to capture.

关键词： system identification sparse Bayesian learning Kalman smoothing process and measurement noise

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Two-Dimensional Materials for Highly Efficient and Stable Perovskite Solar Cells

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Nano-Micro Letters 2024年第10期16卷 176-212页

作者： Xiangqian Shen Xuesong Lin Yong Peng Yiqiang Zhang fei Long Qifeng han Yanbo Wang Liyuan han State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong UniversityShanghai 200240People's Republic of China Xinjiang Key Laboratory of Solid State Physics and Devices School of Physical Science and TechnologyXinjiang UniversityUrumqi 830046People's Republic of China Special Division of Environmental and Energy Science College of Arts and SciencesKomaba Organization for Educational ExcellenceUniversity of TokyoTokyo 153-8902Japan State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan 430070People's Republic of China College of Chemistry Henan Institute of Advanced TechnologyZhengzhou UniversityZhengzhou 450001People's Republic of China Guangxi Key Laboratory of Optical and Electronic Materials and Devices Collaborative Innovation Center for Exploration of Nonferrous Metal Deposits and Efficient Utilization of ResourcesSchool of Materials Science and EngineeringGuilin University of TechnologyGuilin 541004People's Republic of China

Perovskite solar cells(PSCs)offer low costs and high power conversion ***,the lack of long-term stability,primarily stemming from the interfacial defects and the sus-ceptible metal electrodes,hinders their practical *** the past few years,two-dimensional(2D)materials(e.g.,graphene and its derivatives,transitional metal dichalcogenides,MXenes,and black phosphorus)have been identified as a promising solution to solving these problems because of their dangling bond-free surfaces,layer-dependent electronic band structures,tunable functional groups,and inherent ***,recent progress of 2D material toward efficient and stable PSCs is summarized,including its role as both interface materials and *** discuss their beneficial effects on perovskite growth,energy level alignment,defect passivation,as well as blocking external *** particular,the unique properties of 2D materials to form van der Waals heterojunction at the bottom interface are ***,perspectives on the further development of PSCs using 2D materials are provided,such as designing high-quality van der Waals heterojunction,enhancing the uniformity and coverage of 2D nanosheets,and developing new 2D materials-based electrodes.

关键词： Perovskite solar cells Two-dimensional materials Interface engineering Van der Waals heterojunction Electrodes

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Real-time pore structure evolution difference between deep and shallow coal during gas adsorption:A study based on synchrotron radiation small-angle X-ray scattering

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Particuology 2024年第4期87卷 114-123页

作者： Yingfeng Sun Shuaipeng Zhu fei Xie Chujian han Yixin Zhao Zetian Zhang Research Institute of Macro-Safety Science University of Science and Technology BeijingBeijing100083China Schoolof Civiland Resource Engineering University of Science and Technology BeijingBeijing100083China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230029China Beijing Key Laboratory for Precise Mining of Intergrown Energy and Resources China University of Mining and Technology(Beijing)Bejing10003 China School of Energy and Mining Engineering China University of Mining and Technology(Beijing)Beijing100083China Key Laboratory of Deep Earth Science and Engineering(Sichuan University) Ministry of EducationChengdu610065China

Coal seam CO_(2) sequestration is an important option to address global warming.A better knowledge on coal pore structure evolution during gas adsorption can provide guidance for coal seams CO_(2) ***,few investigations on the pore structure evolution differences between the deep and shallow coal were conducted during gas *** this study,based on the real-time synchrotron radiation small-angle X-ray scattering(SAXS)observation,the average pore diameter and pore surface fractal dimension evolution differences between deep and shallow coal were investigated from the as-pects of coal compositions and stress *** types of coal deformation(inner-swelling and outer-swelling)coexist during gas *** compositions have significant impact on the dominance of deformation *** dominance of inner-swelling in deep coal is induced by the higher ash contents,and there is the decrease of average pore diameter during gas *** impact of stress-history(burial depth)on adsorption-induced deformation is more prominent than that of gas adsorption *** deep coal,the surface fractal dimension evolution presents a negative correlation with the evolution of pore *** shallow coal,the surface fractal dimension evolution presents a Langmuir-type correlation with the adsorption time.

关键词： Coal Gas adsorption Synchrotron radiation small-angle X-ray scattering Pore diameter Surface fractal dimension

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Hydration lubrication modulated by water structure at TiO2–aqueous interfaces

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Friction 2024年第4期12卷 591-605页

作者： Pingsu MA yuan LIU Ke han Yu TIAN Liran MA State Key Laboratory of Tribology in Advanced Equipment Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China

The nature of solid-liquid interfaces is of great significance in *** advances have been made in lubrication based on hydration ***,a detailed molecular-level understanding is still ***,we investigated water molecule behaviors at the TiO2-aqueous interfaces by the sum-frequency generation vibrational spectroscopy(SFG-VS)and atomic force microscope(AFM)to elucidate the fundamental role of solid-liquid interfaces in *** contributions of water structures and hydration effects were revealed,where water structures played the dominant role in lubrication for TiO2 surfaces of varying hydrophilicity,while hydration effects dominated with the increasing of ion *** lubrication is observed on the initial TiO2 surfaces with strongly H-bonded water molecules compared to the hydrophilic TiO2 surfaces with more disordered *** stable ordered water arrangement with strong hydrogen bonds and the shear plane occurring between the ordered water layer and subsequent water layer may play a significant role in achieving lower *** adsorbed hydrated molecules with the increasing ionic concentration perturb ordered water but lead to the enhancement of hydration effects,which is the main reason for the improved lubrication for both *** work provides more insights into the detailed molecular-level understanding of the mechanism of hydration lubrication.

关键词： hydration lubrication interfacial water structures hydration effects titanium dioxide(TiO2)

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