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The inhomogeneous incompressible Hall-MHD system with only bounded density

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Science China Mathematics 2024年

作者： Jin Tan Lan zhang Laboratoire de Math′ematiques AGM UMR CNRS 8088 Cergy Paris Universit′e Center for Mathematical Sciences and Department of Mathematics Wuhan University of Technology

This paper is dedicated to the global-in-time existence and uniqueness issues of solutions for the inhomogeneous incompressible Hall-magnetohydrodynamics(MHD) system with merely bounded density. In a three-dimensional case, assuming that the initial density is a small perturbation of a positive constant in the L∞norm, we prove global well-posedness for small initial velocity and magnetic fields in critical Besov spaces. Next, we consider the so-called 21/2D flows for the inhomogeneous Hall-MHD system(that is 3D flows independent of the vertical variable) and establish the global existence of strong solutions by only assuming that the initial magnetic field is small in critical spaces and the initial density is bounded and bounded away from zero. In particular, those solutions allow piecewise constant density with jumps so that a mixture of fluids can be considered. Compared with inhomogeneous incompressible Navier-Stokes equations, the new difficulties of proving these results come from the additional so-called Hall term, which endows the magnetic equation with a quasi-linear character. In order to overcome them, we reformulate the system by taking advantage of the curl form of the magnetic equation and develop some new maximal regularity estimates for the Stokes system with just bounded coefficients.

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Synthesis of highly stable Ni nanoparticles via electrostatic self-assembly for enhanced hydrogen storage of MgH_(2)

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Rare Metals 2024年第9期43卷 4356-4366页

作者： Qin-Ke Tang Jiang-Chuan Liu Rui Shi Yun-Feng Zhu Ji-Guang zhang Ya-Na Liu Jun Wang Yao zhang Xiao-Hui Hu Zhi-Bin Liu Li-Quan Li College of Materials Science and Engineering Jiangsu Collaborative Innovation Centre for Advanced Inorganic Function CompositesNanjing Tech UniversityNanjing 211816China School of Materials Science and Engineering Southeast UniversityNanjing 211189China

Magnesium-based hydrides have been widely recognized as an appropriate choice for solid-state hydrogen ***,its undesirable thermodynamics and sluggish hydrogenation/dehydrogenation kinetics are major bottlenecks for its ***,a highly stable and highly dispersed Ni-based catalyst(Ni/Al_(2)O_(3)/GN)was fabricated to promote the hydrogen storage performance of MgH_(2)via the electrostatic effect of NiAl-LDH/GN precursor with a co-calcination reduction ***_(2)-5wt%Ni/Al_(2)O_(3)/GN exhibits excellent hydrogen storage performance,releasing about 5.7 wt%hydrogen in 3500 s at 250℃,and can reach a saturation hydrogen absorption of about 6.15 wt%in 3000 s at 100℃.Furthermore,it also shows low dehydrogenation apparent activation energy of 89.1 and 118.2 kJ·mol^(-1).Impressively,the catalyst ensures the stability of both the physical phase and structure during ball milling and cycling *** role of each phase in Ni/Al_(2)O_(3)/GN on the hydrogen storage performance of MgH_(2)was also discussed through experiments and theoretical calculation,and the synergistic catalytic mechanism of Ni/Al_(2)O_(3)/GN was clearly *** work provides a unique perspective for the preparation of highly stable and highly dispersible catalysts.

关键词： Magnesium hydride Ni/Al_(2)O_(3)/GN Hydrogen storage performance Catalytic mechanism

Dirac-geodesics with curvature term

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Science China Mathematics 2024年

作者： Qun Chen Mingwei zhang School of Mathematics and Statistics Wuhan University

Dirac-geodesics with curvature term are Dirac-harmonic maps with curvature term from onedimensional domains. In this paper, we first describe the structure of Dirac-geodesics with curvature term in surfaces and give solutions on the unit 2-sphere and the hyperbolic plane, and then we give the structure of solutions in warped product spaces. Finally, we define the heat flow of Dirac-geodesics with curvature term and prove the global existence and sub-convergence of the heat flow into any closed surfaces and space forms. Our results provide the first examples and general existence theorems of Dirac-geodesics with curvature term.

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The role of FMO3 in metabolic diseases

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Traditional Medicine Research 2024年第9期9卷 42-50页

作者： Hui-Wen Ren He-Yuan Lu Hai-Bo zhang Rui-Jing zhang Che Bian Advanced Institute for Medical Sciences Dalian Medical UniversityDalian 116044China College of Basic Medical Sciences Dalian Medical UniversityDalian 116044China Department of Nephrology Xijing HospitalThe Fourth Military Medical UniversityXi’an 710032China Department of Endocrinology and Metabolism The Fourth Affiliated Hospital of China Medical UniversityShenyang 110032China

Flavin containing monooxygenase 3(FMO3)is a member of the flavin monooxygenase family,which can oxidize the precursor Trimethylamine(TMA)provided from food to produce Trimethylamine N-oxide(TMAO).The autosomal recessive inherited disease caused by partial functional loss of Fmo3 gene,which leads to excessive excretion of TMA in body fluids and emits fishy odor,is called Fish Odor Syndrome or *** disease has been documented for 3,000 years ago and was first reported in the case report in ***3 mainly exists in the liver and can participate in the TMA-TMAO metabolic balance in intestinal microorganisms,liver,and kidneys,closely related to insulin resistance,diabetes,cholesterol metabolism,and cardiovascular *** to its wide range of catalytic substrates and low susceptibility to metabolite accumulation,its role in drug metabolism,new drug development,and discovery of new drug targets are increasingly *** review will summarize the research progress on the metabolic process and localization of FMO3,congenital genetic defects,metabolic diseases,and its related possible mechanisms.

关键词： metabolic diseases FMO3 TMA TMAO

The moment map for the variety of associative algebras

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Science China Mathematics 2024年

作者： Hui zhang Zaili Yan School of Mathematics Southeast University School of Mathematics and Statistics Ningbo University

We consider the moment map m:PV_n→iu（n） for the action of GL（n） on Vn=?2（C~n）*?C~n,and study the critical points of the functional ■:PVn→***,we prove that[μ]∈PV_n is a critical point if and only if Mμ=cμI+Dμfor some cμ∈R and Dμ∈Der（μ）,where ■.Then we show that any algebraμadmits a Nikolayevsky derivation?μwhich is unique up to automorphism,and if moreover,[μ]is a critical point of Fn,then■ .Secondly,we characterize the maxima and minimatof the functional F_n:A_n→R,where An denotes the projectivization of the algebraic varieties of all the n-dimensional associative ***,for an arbitrary critical point[μ]of F_n:A_n→R,we obtain a description of the algebraic structure ofμ.Finally,we classify the critical points of F_n:A_n→R for n=2and n=3,respectively.

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粳稻LSD基因家族的生物信息学分析

贵州农业科学 2024年第8期52卷 1-7页

作者：张佳玉张煜涛韩雪杨郝爱平牡丹江师范学院生命科学与技术学院黑龙江牡丹江157011

【目的】探明粳稻LSD基因家族的结构功能,为研究LSD基因家族在粳稻生长发育过程中的作用奠定理论基础。【方法】利用生物信息学方法,分析粳稻LSD基因家族成员、蛋白质的理化性质、染色体位置、系统进化关系、保守基序及结构域。【结果... 详细信息

【目的】探明粳稻LSD基因家族的结构功能,为研究LSD基因家族在粳稻生长发育过程中的作用奠定理论基础。【方法】利用生物信息学方法,分析粳稻LSD基因家族成员、蛋白质的理化性质、染色体位置、系统进化关系、保守基序及结构域。【结果】从粳稻中共鉴定出6个LSD基因,并命名为OsLSD1~OsLSD6。OsLSD蛋白氨基酸数量为131~1 463个,分子量为13 723.41~151 718.18 Da,且大部分为碱性蛋白。6个基因家族成员分别分布在粳稻12条染色体的5条上,OsLSD1、 OsLSD2、 OsLSD3、 OsLSD4/OsLSD5和OsLSD6分别分布在chr1、chr3、chr7、chr8和chr12上。根据系统发育分析,粳稻LSD基因家族可分为3个亚族,其中,OsLSD2、OsLSD4和OsLSD6为同一亚族;OsLSD5为同一亚族中的同一分支;OsLSD1、OsLSD3为同一亚族并与AtLSD1、AtLSD2、AtLSD3和AtLSD12为同一亚族;同一亚族中的LSD基因结构及排列顺序具有相似性。Motif分析发现,粳稻的6个LSD基因包含10个保守基序,其中,Motif 1是这些基因共有的保守基序,推测其与保守结构域相关。该基因主要在粳稻的幼嫩叶片、幼嫩花序及种子中表达。【结论】推测LSD基因家族在粳稻生长发育过程中起重要调控作用。

关键词：粳稻 LSD 基因家族生物信息学分析染色体保守基序结构域

Event-triggered adaptive tracking control of a class of nonlinear systems with asymmetric time-varying output constraints

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Frontiers of Information Technology & Electronic Engineering 2024年第8期25卷 1134-1144页

作者： Yitao YANG Lidong zhang School of Science Tianjin University of TechnologyTianjin 300384China

This article investigates the event-triggered adaptive neural network(NN)tracking control problem with deferred asymmetric time-varying(DATV)output *** deal with the DATV output constraints,an asymmetric time-varying barrier Lyapunov function(ATBLF)is first built to make the stability analysis and the controller construction ***,an event-triggered adaptive NN tracking controller is constructed by incorporating an error-shifting function,which ensures that the tracking error converges to an arbitrarily small neighborhood of the origin within a predetermined settling time,consequently optimizing the utilization of network *** is theoretically proven that all signals in the closed-loop system are semi-globally uniformly ultimately bounded(SGUUB),while the initial value is outside the constraint ***,a single-link robotic arm(SLRA)application example is employed to verify the viability of the acquired control algorithm.

关键词： Adaptive control Deferred asymmetric time-varying output constraints Error-shifting function Event-triggered control

The positive energy theorem for weighted asymptotically anti-de Sitter spacetimes

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Science China Mathematics 2024年

作者： Yaohua Wang Xiao zhang School of Mathematics and Statistics Henan University Guangxi Center for Mathematical Research Guangxi University Academy of Mathematics and Systems Science Chinese Academy of Sciences School of Mathematical Sciences University of Chinese Academy of Sciences

The positive energy theorem for weighted asymptotically flat spin manifolds was proved by Baldauf and Ozuch(2022) and for the non-spin case by Chu and Zhu(2024). In this paper, we generalize the positive energy theorem for 3-dimensional asymptotically anti-de Sitter initial data sets to weighted asymptotically anti-de Sitter initial data sets assuming that the weighted dominant energy condition holds.

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Simulation and reconstruction of particle trajectories in the CEPC drift chamber

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Nuclear Science and Techniques 2024年第8期35卷 9-22页

作者： Meng‑Yao Liu Wei‑Dong Li Xing‑Tao Huang Yao zhang Tao Lin Ye Yuan Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China Institute of High Energy Physics Beijing 100049China University of Chinese Academy of Sciences Beijing 100049China

The circular electron-positron collider(CEPC)is designed to precisely measure the properties of the Higgs boson,study electroweak interactions at the Z-boson peak,and search for new physics beyond the Standard *** a component of the 4th conceptual CEPC detector,the drift chamber facilitates the measurement of charged *** study implemented a Geant4-based simulation and track reconstruction for the drift *** the simulation,detector construction and response were implemented and added to the CEPC simulation *** development of track reconstruction involves track finding using the combinatorial Kalman filter method and track fitting using the tool of *** the simulated data,the tracking performance was *** results showed that both the reconstruction resolution and tracking efficiency satisfied the requirements of the CEPC experiment.

关键词： CEPC Drift chamber Detector simulation Track reconstruction