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Deformations at Earth’s dayside magnetopause during quasi-radial IMF conditions:Global kinetic simulations and Soft X-ray Imaging

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Earth and Planetary Physics 2024年第1期8卷 59-69页

作者： ZhongWei Yang Riku Jarvinen XiaoCheng Guo TianRan Sun Dimitra koutroumpa George k.Parks Can Huang BinBin tang QuanMing Lu Chi Wang State key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Finnish Meteorological Institute FI-00101 HelsinkiFinland LATMOS/IPSL CNRSUVSQ UniversitéParis-SaclaySorbonne UniversitéGuyancourt78280France Space Sciences Laboratory University of CaliforniaBerkeleyCalifornia 94720USA CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029 China Deep Space Exploration Laboratory/School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China

The Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)is a joint mission of the European Space Agency(ESA)and the Chinese Academy of Sciences(CAS).Primary goals are investigating the dynamic response of the Earth's magnetosphere to the solar wind(SW)impact via simultaneous in situ magnetosheath plasma and magnetic field measurements,X-Ray images of the magnetosheath and magnetic cusps,and UV images of global auroral *** deformations associated with magnetosheath high speed jets(HSJs)under a quasi-parallel interplanetary magnetic field condition are studied using a threedimensional(3-D)global hybrid *** X-ray intensity calculated based on both physical quantities of solar wind proton and oxygen ions is *** obtain key findings concerning deformations at the magnetopause:(1)Magnetopause deformations are highly coherent with the magnetosheath HSJs generated at the quasi-parallel region of the bow shock,(2)X-ray intensities estimated using solar wind h+and self-consistentO7+ions are consistent with each other,(3)Visual spacecraft are employed to check the discrimination ability for capturing magnetopause deformations on Lunar and polar orbits,*** SMILE spacecraft on the polar orbit could be expected to provide opportunities for capturing the global geometry of the magnetopause in the equatorial plane.A striking point is that SMILE has the potential to capture small-scale magnetopause deformations and magnetosheath transients,such as HSJs,at medium altitudes on its *** results also demonstrate that a lunar based imager(e.g.,Lunar Environment heliospheric X-ray Imager,LEXI)is expected to observe a localized brightening of the magnetosheath during HSJ events in the meridian *** preliminary results might contribute to the pre-studies for the SMILE and LEXI missions by providing qualitative and quantitative soft X-ray estimates of dayside kinetic processes.

关键词： collisionless shock SMILE mission foreshock

An economic way to achieve all-weather CO2 reduction

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National Science Review 2024年第3期11卷 46-47页

作者： Junwang tang Department of Chemical Engineering University College London

Utilising solar power to convert carbon dioxide（CO2） into hydrocarbon fuels presents an eco-friendly method to address dependence on fossil fuels and contribute to a net-zero CO2emission goal[1,2].

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Highly effective design of high GFA alloys with different metalbased and various components by machine learning

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Science China(Technological Sciences) 2024年第5期67卷 1431-1442页

作者： tang YiChuan HE YiFan FAN ZhuoQun WANG ZhongQi tang ChengYing Guangxi key Laboratory for Informational Materials School of Materials Science and EngineeringGuilin University of Electronic TechnologyGuilin541004China

The glass-forming ability(GFA)is of great significance for the development of novel functional metal-based metallic *** this study,seven popular machine learning(ML)algorithms were employed to design novel M-based(M=Fe,Co,Ni,Ti,Zr,and rare earth metal(RE))and X-component(X=2,3,4,5,6,and>6)alloys with excellent GFA.A GFA containing 6957 data points with structural analysis was *** engineering was used to analyze the importance and correlation of *** algorithms were utilized for GFA prediction,revealing that Xtreme Gradient Boosting Trees exhibited the strongest predictive capability,achieving a high accuracy of 94.0%,a true positive rate of 97.6%,and a root mean squared error of 0.3705 across the entire ***,the GFA of ternary to hexahydroxy alloys based on Fe,Co,Ni,Zr,Ti,and Y was predicted using all possible compositions generated through ***,a series of alloys with good GFA was successfully designed and *** present work suggests that the proposed ML method can be utilized to design novel multiple-M-based amorphous alloys with high GFA.

关键词： machine learning amorphous alloy feature engineering materials design glass forming ability

Nuclear charge radius predictions by kernel ridge regression with odd-even effects

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Nuclear Science and Techniques 2024年第2期35卷 94-102页

作者： Lu tang Zhen-Hua Zhang Mathematics and Physics Department North China Electric Power UniversityBeijing 102206China Hebei key Laboratory of Physics and Energy Technology North China Electric Power UniversityBaoding 071000China

The extended kernel ridge regression(EkRR)method with odd-even effects was adopted to improve the description of the nuclear charge radius using five commonly used nuclear *** are:(i)the isospin-dependent A^(1∕3) formula,(ii)relativistic continuum Hartree-Bogoliubov(RCHB)theory,(iii)Hartree-Fock-Bogoliubov(HFB)model HFB25,(iv)the Weizsacker-Skyrme(WS)model WS*,and(v)HFB25**** the last two models,the charge radii were calculated using a five-parameter formula with the nuclear shell corrections and deformations obtained from the WS and HFB25 models,*** each model,the resultant root-mean-square deviation for the 1014 nuclei with proton number Z≥8 can be significantly reduced to 0.009-0.013 fm after considering the modification with the EkRR *** best among them was the RCHB model,with a root-mean-square deviation of 0.0092 *** extrapolation abilities of the kRR and EkRR methods for the neutron-rich region were examined,and it was found that after considering the odd-even effects,the extrapolation power was improved compared with that of the original kRR *** strong odd-even staggering of nuclear charge radii of Ca and Cu isotopes and the abrupt kinks across the neutron N=126 and 82 shell closures were also calculated and could be reproduced quite well by calculations using the EkRR method.

关键词： Nuclear charge radius Machine learning kernel ridge regression method

UAV-assisted data collection for wireless sensor networks with dynamic working modes

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Digital Communications and Networks 2024年第3期10卷 805-812页

作者： Jie Chen Jianhua tang Shien-Ming Wu School of Intelligent Engineering South China University of TechnologyGuangzhou511442China

Wireless Sensor Network(WSN)is a cornerstone of Internet of Things(IoT)and has rich application *** this work,we consider a heterogeneous WSN whose sensor nodes have a diversity in their Residual Energy(RE).In this work,to protect the sensor nodes with low RE,we investigate dynamic working modes for sensor nodes which are determined by their RE and an introduced energy ***,we employ an Unmanned Aerial Vehicle(UAV)to collect the stored data from the heterogeneous *** aim to jointly optimize the cluster head selection,energy threshold and sensor nodes’working mode to minimize the weighted sum of energy con-sumption from the WSN and UAV,subject to the data collection rate *** this end,we propose an efficient search method to search for an optimal energy threshold,and develop a penalty-based successive convex approximation algorithm to select the cluster *** we present a low-complexity iterative approach to solve the joint optimization problem and discuss the implementation *** results justify that our proposed approach is able to reduce the energy consumption of the sensor nodes with low RE significantly and also saves energy for the whole WSN.

关键词： Unmanned aerial vehicle Wireless sensor networks Cluster heads Dynamic working modes

Controlled synthesis of one-dimensional segmented heteronanostructures

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Science China Materials 2024年第8期67卷 2715-2716页

作者： Zhiyong tang CAS key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China

Telluride materials possess distinctive advantages,including the high theoretical volume capacity and electrical conductivity,rendering them promising candidates for a range of energy storage and optoelectronic applications[1].Heterogeneous compositions and interfaces in heteronanostructures have significant implications on the electron transport,magnetic coupling,and phonon scattering,thereby promoting the performances in photocatalysis,and thermoelectrics[2].

关键词： synthesis rendering thereby

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Flexible and Robust Functionalized Boron Nitride/Poly(p‑Phenylene Benzobisoxazole)Nanocomposite Paper with High Thermal Conductivity and Outstanding Electrical Insulation

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Nano-Micro Letters 2024年第2期16卷 423-437页

作者： Lin tang kunpeng Ruan Xi Liu Yusheng tang Yali Zhang Junwei Gu Chongqing key Laboratory of Green Synthesis and Applications College of ChemistryChongqing Normal UniversityChongqing 401331People’s Republic of China Shaanxi key Laboratory of Macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China

With the rapid development of 5G information technology,thermal conductivity/dissipation problems of highly integrated electronic devices and electrical equipment are becoming *** this work,“high-temperature solid-phase&diazonium salt decomposition”method is carried out to prepare benzidine-functionalized boron nitride(m-BN).Subsequently,m-BN/poly(pphenylene benzobisoxazole)nanofiber(PNF)nanocomposite paper with nacremimetic layered structures is prepared via sol–gel film transformation *** obtained m-BN/PNF nanocomposite paper with 50 wt%m-BN presents excellent thermal conductivity,incredible electrical insulation,outstanding mechanical properties and thermal stability,due to the construction of extensive hydrogen bonds andπ–πinteractions between m-BN and PNF,and stable nacre-mimetic layered ***λ∥andλ_(⊥)are 9.68 and 0.84 W m^(-1)k^(-1),and the volume resistivity and breakdown strength are as high as 2.3×10^(15)Ωcm and 324.2 kV mm^(-1),***,it also presents extremely high tensile strength of 193.6 MPa and thermal decomposition temperature of 640°C,showing a broad application prospect in high-end thermal management fields such as electronic devices and electrical equipment.

关键词： Poly(p-phenylene-2,6-benzobisoxazole)nanofiber Boron nitride Thermal conductivity Electrical insulation

Markovian Quadratic BSDEs with an Unbounded Sub-quadratic Growth

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Chinese Annals of Mathematics,Series B 2024年第3期45卷 441-462页

作者： Jingnan JU Shanjian tang Shanghai Center for Mathematical Sciences Fudan UniversityShanghai 200433China Department of Finance and Control Sciences School of Mathematical SciencesFudan UniversityShanghai 200433China

This paper is devoted to the solvability of Markovian quadratic backward stochastic differential equations(BSDEs for short)with bounded terminal *** generator is allowed to have an unbounded sub-quadratic growth in the second unknown variable *** existence and uniqueness results are given to these *** an application,an existence result is given to a system of coupled forward-backward stochastic differential equations with measurable coefficients.

关键词： Markovian BSDE Quadratic growth Unbounded sub-quadratic term coeficients Coupled FBSDE

A novel cascaded H-bridge photovoltaic inverter with flexible arc suppression function

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Global Energy Interconnection 2024年第4期7卷 513-527页

作者： Junyi tang Wei Gao College of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350108P.R.China

This paper presents a novel approach that simultaneously enables photovoltaic(PV)inversion and flexible arc suppression during single-phase grounding *** compensate for ground currents through an arc-elimination function,while outputting a PV direct current(DC)power *** method effectively reduces the residual grounding *** reduce the dependence of the arc-suppression performance on accurate compensation current-injection models,an adaptive fuzzy neural network imitating a sliding mode controller was *** online adaptive adjustment law for network parameters was developed,based on the Lyapunov stability theorem,to improve the robustness of the inverter to fault and connection ***,a new arc-suppression control exit strategy is proposed to allow a zerosequence voltage amplitude to quickly and smoothly track a target value by controlling the nonlinear decrease in current and reducing the regulation *** results showed that the proposed method can effectively achieve fast arc suppression and reduce the fault impact current in single-phase grounding *** to other methods,the proposed method can generate a lower residual grounding current and maintain good arc-suppression performance under different transition resistances and fault locations.

关键词： Photovoltaic inverter Flexible arc suppression Adaptive control Fuzzy neural network Sliding mode control Exit strategy