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Scientific objectives and payload configuration of the Chang'E-7 mission

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National Science Review 2024年第2期11卷 285-300页

作者： Chi Wang Yingzhuo jia Changbin xue Yangting Lin jianzhong Liu Xiaohui Fu Lin xu Yun Huang Yufen Zhao Yigang xu Rui Gao Yong wei Yuhua Tang Dengyun Yu Yongliao Zou China Aerospace Science and Technology Corporation State Key Laboratory of Space Weather National Space Science Center Chinese Academy of Sciences National Space Science Center Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences Institute of Geochemistry Chinese Academy of Sciences Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and Physics Institute of Space SciencesShandong University Institute of Drug Discovery Technology Ningbo University State Key Laboratory of Isotope Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of Sciences School of Earth Science and Engineering Sun Yat-sen University Lunar Exploration and Space Engineering Center

As the cornerstone mission of the fourth phase of the Chinese Lunar Exploration Program, Chang'E-7(CE-7) was officially approved, and implementation started in 2022, including a main probe and a communication relay satellite. The main probe, consisting of an orbiter, a lander, a rover and a mini-flying probe, is scheduled to be launched in 2026. The lander will land on Shackleton crater's illuminated rim near the lunar south pole, along with the rover and mini-flying probe. The relay satellite(named Queqiao-2) will be launched in February 2024 as an independent mission to support relay communication during scientific exploration undertaken by Chang'E-4, the upcoming Chang'E-6 in 2024 and subsequent lunar missions.The CE-7 mission is mainly aimed at scientific and resource exploration of the lunar south pole. We present CE-7's scientific objectives, the scientific payloads configuration and the main functions for each scientific payload with its key technical specifications.

关键词： Chang’ E-7 scientific objectives scientific payloads

An Innovative Coupled Common-Node Discrete Element Method-Smoothed Particle Hydrodynamics Model Developed with LS-DYNA and Its Applications

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China Ocean Engineering 2024年第3期38卷 467-482页

作者： SHEN Zhong-xiang WANG Wen-qing xu Cheng-yue LUO jia-xin LIU Ren-wei School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China College of Harbor Coastal and Offshore EngineeringHohai UniversityNanjing 210098China

In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SPH)method is developed using LS-DYNA software.The DEM and SPH are established on the same node to create common-node DEM-SPH particles,allowing for fluid–structure interactions.Numerical simulations of various scenarios,including water entry of a rigid sphere,dam-break propagation over wet beds,impact on an ice plate floating on water and ice accumulation on offshore structures,are conducted.The interaction between DS particles and SPH fluid and the crack generation mechanism and expansion characteristics of the ice plate under the interaction of structure and fluid are also studied.The results are compared with available data to verify the proposed coupling method.Notably,the simulation results demonstrated that controlling the cutoff pressure of internal SPH particles could effectively control particle splashing during ice crushing failure.

关键词： common-node DEM-SPH fluid-structure interaction discrete element method smoothed particle hydrodynamics

Barrier Option Pricing in Regime Switching Models with Rebates

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 849-861页

作者： Yue-xu ZHAO jia-yong BAO School of Economics Hangzhou Dianzi UniversityHangzhou 310018China School of Sciences Hangzhou Dianzi UniversityHangzhou 310018China

This paper is concerned with the valuation of single and double barrier knock-out call options in a Markovian regime switching model with specific rebates.The integral formulas of the rebates are derived via matrix Wiener-Hopf factorizations and Fourier transform techniques,also,the integral representations of the option prices are constructed.Moreover,the first-passage time density functions in two-state regime model are derived.As applications,several numerical algorithms and numerical examples are presented.

关键词： option pricing Markovian regime switching Wiener-Hopf factorization Fourier transform

On-surface synthesis and characterization of polyynic carbon chains

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National Science Review 2024年第3期11卷 192-199页

作者： Wenze Gao wei Zheng Luye Sun Faming Kang Zheng Zhou wei xu Interdisciplinary Materials Research Center School of Materials Science and Engineering Tongji University

Carbyne, an elusive sp-hybridized linear carbon allotrope, has fascinated chemists and physicists for decades. Due to its high chemical reactivity and extreme instability, carbyne was much less explored in contrast to the sp2-hybridized carbon allotropes such as graphene. Herein, we report the on-surface synthesis of polyynic carbon chains by demetallization of organometallic polyynes on the Au（111） surface;the longest one observed consists of ～60 alkyne units（120 carbon atoms）. The polyynic structure of carbon chains with alternating triple and single bonds was unambiguously revealed by bond-resolved atomic force microscopy. Moreover, an atomically precise polyyne, C14, was successfully produced via tip-induced dehalogenation and ring-opening of the decachloroanthracene molecule(C14Cl10) on a bilayer NaCl/Au（111） surface at 4.7 K, and a band gap of 5.8 eV was measured by scanning tunnelling spectroscopy,in a good agreement with the theoretical HOMO–LUMO gap（5.48 eV）.

关键词： polyyne scanning probe microscopy carbon allotrope on-surface synthesis organometallic polyyne

Accurate Analysis of Multi-Mode Interferometric Optical Fiber Sensor

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Photonic Sensors 2024年第1期14卷 48-58页

作者： Lijun LI Congying jia Qian MA Tianzong xu College of Electronic and Information Engineering Shandong University of Science and TechnologyQingdao 266590.China State Key Laboratory of Mining Disaster Prevention and Control Co-Founded by Shandong Province and the Ministry of Science and Technology Qingdao 266590China

In view of the problem that the sensing characteristics of the multi-mode interferometric fiber sensors cannot be accurately analyzed,an analysis method based on the fast Fourier transform(FFT)and inverse fast Fourier transform(IFFT)is proposed and demonstrated theoretically and experimentally.The suitabilities of the rectangular window function with the narrow main lobe(high spectrum resolution)and low side lobe(high main mode energy leakage)and the Hanning window function with the wide main lobe(low spectrum resolution)and high side lobe(high energy concentration)in this kind of sensor analysis are discussed,respectively.This method can not only realize the sensing performance analysis of the various modes,but also overcome the inconsistency of the different interference wavelength(dip)sensing characteristics in the conventional analysis methods.At the same time,this method is also beneficial to solve the repetitive problem of such sensors.

关键词： Window function FFT optical fiber interferometric sensor analysis method

High-Order Decoupled and Bound Preserving Local Discontinuous Galerkin Methods for a Class of Chemotaxis Models

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Communications on Applied Mathematics and Computation 2024年第1期6卷 372-398页

作者： wei Zheng Yan xu School of Mathematical Sciences University of Science and Technology of ChinaHefei230026AnhuiChina

In this paper,we explore bound preserving and high-order accurate local discontinuous Galerkin(LDG)schemes to solve a class of chemotaxis models,including the classical Keller-Segel(KS)model and two other density-dependent problems.We use the convex splitting method,the variant energy quadratization method,and the scalar auxiliary variable method coupled with the LDG method to construct first-order temporal accurate schemes based on the gradient flow structure of the models.These semi-implicit schemes are decoupled,energy stable,and can be extended to high accuracy schemes using the semi-implicit spectral deferred correction method.Many bound preserving DG discretizations are only worked on explicit time integration methods and are difficult to get high-order accuracy.To overcome these difficulties,we use the Lagrange multipliers to enforce the implicit or semi-implicit LDG schemes to satisfy the bound constraints at each time step.This bound preserving limiter results in the Karush-Kuhn-Tucker condition,which can be solved by an efficient active set semi-smooth Newton method.Various numerical experiments illustrate the high-order accuracy and the effect of bound preserving.

关键词： Chemotaxis models Local discontinuous Galerkin(LDG)scheme Convex splitting method Variant energy quadratization method Scalar auxiliary variable method Spectral deferred correction method

Design of an automated robotic microinjection system for batch injection of zebrafish embryos and larvae

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Microsystems & Nanoengineering 2024年第1期10卷 89-103页

作者： Zhongyi Guo Nana Ai wei Ge Qingsong xu Department of Electromechanical Engineering Faculty of Science and TechnologyUniversity of MacaoMacaoChina Department of Biomedical Sciences and Centre of Reproduction Development and Aging(CRDA)Faculty of Health SciencesUniversity of MacaoMacaoChina

This paper presents the design of a vision-based automated robotic microinjection system for batch injection of both zebrafish embryos and larvae.A novel visual recognition algorithm based on an automatic threshold and excessive dilatation is introduced to accurately identify the center of zebrafish embryos and larval yolks.A corresponding software system is developed using the producer-consumer model as the framework structure,and a friendly user interface is designed to allow operators to choose from a range of desired functions according to their different needs.In addition,a novel microstructural agarose device is designed and fabricated to simultaneously immobilize mixed batches of embryos and larvae.Moreover,a prototype microinjection system is fabricated by integrating hardware devices with visual algorithms.An experimental study is conducted to verify the performance of the robotic microinjection system.The results show that the reported system can accurately identify zebrafish embryos and larvae and efficiently complete batch microinjection tasks of the mixtures with an injection success rate of 92.05%in 13.88 s per sample.Compared with manual and existing microinjection systems,the proposed system demonstrates the merits of versatility,excellent efficiency,high success rate,high survival rate,and sufficient stability.

关键词： zebra automated hardware

Association between the cumulative triglyceride-glucose index and the recurrence of atrial fibrillation after radiofrequency catheter ablation

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Journal of Geriatric Cardiology 2024年第2期21卷 200-210页

作者： Qing YAN jia-Qi LIANG Yi-De YUAN Yuan LI jia-Li FAN Wen-Huan WU Pan xu jia-Hong xuE Department of Cardiovascular Medicine the Second Affiliated Hospital of Xi’an Jiaotong UniversityShaanxiChina Department of Cardiovascular Medicine Zichang People’s HospitalShaanxiChina Department of Ultrasound Xijing HospitalAir Force Military Medical UniversityShaanxiChina

BACKGROUND Triglyceride-glucose(TyG)index values are a new surrogate marker for insulin resistance.This study aimed to explore the relationship between cumulative TyG index values and atrial fibrillation(AF)recurrence after radiofrequency catheter ablation(RFCA).METHODS A total of 576 patients with AF who underwent RFCA at the Second Affiliated Hospital of Xi'an jiaotong University were included in this study.The participants were grouped based on cumulative TyG index values tertiles within 3 months after ablation.Cox regression and restricted cubic spline analyses were used to determine the relationship between cumulative TyG index values and AF recurrence.The predictive value of all risk factors was assessed by receiver operating curve analysis.RESULTS There were 375 patients completed the study(age:63.23±10.73 years,64.27%male).The risk of AF recurrence increased with increasing cumulative TyG index values tertiles.After adjusting for potential confounders,patients in the medium cumulative TyG index group[hazard ratio(HR)=4.949,95%CI:1.778–13.778,P=0.002]and the high cumulative TyG index group(HR=8.716,95%CI:3.371–22.536,P<0.001)had a higher risk of AF recurrence than those in the low cumulative TyG index group.The restricted cubic spline regression model also showed an increased risk of AF recurrence with increasing cumulative TyG index values.When considering cumulative TyG index values,left atrial diameter,and lactate dehydrogenase levels as a comprehensive factor,the model could effectively predict AF recurrence after RFCA[area under the curve(AUC)=0.847,95%CI:0.797–0.897,P<0.001].CONCLUSIONS Cumulative TyG index values were a risk factor for AF recurrence after RFCA.Monitoring longitudinal TyG index values may assist with optimized for risk stratification and outcome prediction for AF recurrence.

关键词： atrial fibrillation index

Soft coarse-grained particle model for particle-fluid systems

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Particuology 2024年第1期84卷 178-193页

作者： Yanhao Ye Ji xu wei Ge State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China Innovation Academy for Green Manufacture Chinese Academy of SciencesBeijing100190China

By modeling a group of neighboring real particles as a single coarse-grained particle(CGP),discrete particle method(DPM)is now capable of simulating industrial-scale particle-fluid systems.However,a systematic approach to determine the CGP properties and develop their interaction models is still lacking,which casts uncertainty on the predictivity of the method.In this study,collisions between predefined particle groups are analyzed to construct kernel functions for modeling the CGPs and then the model parameters are determined by equating the statistical properties of the CGPs and the real particles in the physical process studied.This approach is implemented for homogeneous cooling of granular gas,then demonstrated effective in simulating experimental fluidized beds.

关键词： Coarse-grain(CG) Discrete particle method(DPM) Fluidized bed Multi-scale simulation