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EXPLICIT CONSTRUCTION FOR LOCAL ISOMETRIC IMMERSIONS OF SPACE FORMS

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Chinese Annals of Mathematics,Series B 2003年第1期24卷 97-110页

作者： he qun SheN YIBING Department of Applied Mathematics Tongji University Shanghai 200092 China.Department of Mathematics West Brook Zhejiang University Hangzhou 310028 China.

By using Darboux transformations, the authors give the explicit construction for local iso-metric immersions of space forms Mn(c) into space forms M2n-1(c + ε2) via purely algebraicalgorithm.

关键词： Space form Isometric immersion Darboux transformation

The first eigenfunctions and eigenvalue of the p-Laplacian on Finsler manifolds

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Science China Mathematics 2016年第9期59卷 1769-1794页

作者： YIN SongTing he qun Department of Mathematics and Computer Science Tongling University School of Mathematical Sciences Tongji University

This paper proves that the first eigenfunctions of the Finsler p-Lapalcian are C^(1,α). Using a gradient comparison theorem and one-dimensional model, we obtain the sharp lower bound of the first Neumann and closed eigenvalue of the p-Laplacian on a compact Finsler manifold with nonnegative weighted Ricci curvature,on which a lower bound of the first Dirichlet eigenvalue of the p-Laplacian is also obtained.

关键词： the first eigenvalue p-Laplacian Ricci curvature S curvature

Soluble ST2:A Novel Biomarker for Diagnosis and Prognosis of Cardiovascular Disease

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Current Medical Science 2024年第4期44卷 669-679页

作者： Yin FENG Li-qun he Department of Cardiology Traditional Chinese and Western Medicine Hospital of WuhanTongji Medical CollegeHuazhong University of Science and TechnologyWuhan430030China

The increasing incidence of cardiovascular disease(CVD)is a significant global health concern,affecting millions of individuals each *** diagnosis of acute CVD poses a formidable challenge,as misdiagnosis can significantly decrease patient survival *** biomarkers have played a vital role in the diagnosis and prognosis of CVDs,but they can be influenced by various factors,such as age,sex,and renal *** ST2(sST2)is a novel biomarker that is closely associated with different *** low reference change value makes it suitable for continuous measurement,unaffected by age,kidney function,and other confounding factors,facilitating risk stratification of ***,the combination of sST2 with other biomarkers can enhance diagnostic accuracy and prognostic *** review aims to provide a comprehensive overview of sST2,focusing on its diagnostic and prognostic value as a myocardial marker for different types of CVDs and discussing the current limitations of sST2.

关键词： soluble ST2 cardiovascular disease combined biomarker diagnosis and prognosis limitations

Isoparametric hypersurfaces in Funk spaces

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Science China Mathematics 2017年第12期60卷 2447-2464页

作者： he qun YIN SongTing SheN YiBing School of Mathematical Sciences Tongji University Department of Mathematics and Computer Science Tongling University Department of Mathematics Zhejiang University

Funk metrics are a kind of important Finsler metrics with constant negative flag curvature. In this paper, it is proved that any isoparametric hypersurface in Funk spaces has at most two distinct principal curvatures.... 详细信息

关键词： Finsler-Laplacian isoparametric hypersurfaces Funk metric principal curvature

The mean curvature flow in Minkowski spaces

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Science China Mathematics 2018年第10期61卷 1833-1850页

作者： Fanqi Zeng qun he Bin Chen School of Mathematical Sciences Tongji University

Studying the geometric flow plays a powerful role in mathematics and physics. In this paper, we introduce the mean curvature flow on Finsler manifolds and give a number of examples of the mean curvature flow. For Minkowski spaces, a special case of Finsler manifolds, we prove the short time existence and uniqueness for solutions of the mean curvature flow and prove that the flow preserves the convexity and mean *** also derive some comparison principles for the mean curvature flow.

关键词： anisotropic mean curvature mean curvature flow Finsler manifold Minkowski space convexity

Nonexistence of Majorana fermions in Kerr-Newman type spacetimes with nontrivial charge

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Chinese Physics C 2024年第11期48卷 156-161页

作者： he-qun Zhang Xiao Zhang Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China

We show that the Dirac equation is separated into four differential equations for time-periodic Majorana fermions in Kerr-Newman and Kerr-Newman-(A)dS *** they cannot be transformed into radial and angular equations,the four differential equations yield two algebraic *** the electric or magnetic charge is nonzero,they conclude that there is no differentiable time-periodic Majorana fermions outside the event horizon in Kerr-Newman and Kerr-Newman-AdS spacetimes,or between the event horizon and the cosmological horizon in Kerr-Newman-dS spacetime.

关键词： Dirac equation Majorana fermion Kerr-Newman-type spacetime

Classifications of Isoparametric Hypersurfaces in Randers Space Forms

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Acta Mathematica Sinica,English Series 2020年第9期36卷 1049-1060页

作者： qun he Pei Long DONG Song Ting YIN School of Mathematical Sciences Tongji UniversityShanghai 200092P.R.China Department of Mathematics and Computer Science Tongling UniversityTongling 244000P.R.China Key Laboratory of Applied Mathematics(Putian University) Fujian Province University

In this paper,we give the complete classifications of isoparametric hypersurfaces in Randers space *** studying the principal curvatures of anisotropic submanifolds in a Randers space(N,F)with the navigation data(h,W),we find that a Randers space form(N,F,dμBH)and the corresponding Riemannian space(N,h)have the same isoparametric hypersurfaces,but in general,their isoparametric functions are *** give a necessary and sufficient condition for an isoparametric function of(N,h)to be isoparametric on(N,F,dμBH),from which we get some examples of isoparametric functions.

关键词： Isoparametric hypersurface Randers space form principal curvature anisotropic sub-manifold

Undersea safety mining of the large gold deposit in Xinli District of Sanshandao Gold Mine

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International Journal of Minerals,Metallurgy and Materials 2012年第7期19卷 574-583页

作者： Zhi-xiang Liu Wen-gang Dang Xian-qun he School of Resources and Safety Engineering Central South University Changsha 410083 China

The exploration of undersea resources becomes popular as land resources decrease. Researches were conducted with emphasis on the safety and efficiency of undersea mining of the large gold deposit in Xinli District of Sanshandao Gold Mine. A series of tests for the physical and mechanical characteristics of rock mass were carried out, and the three-dimensional geo-stress distribution was tested in the mining area. Further, a similar experimental simulation platform, which revealed the mechanism of water inrush and ascertained the reason- able thickness of the safety isolate layer, was established for the undersea mining. Meanwhile, the feasibility of cancelling the ore pillars and the safety conditions was checked by numerical simulation. The simulation results show that it is safe to exploit the ore body below the -85 m level （presently, the exploitation level is below -160 m in Xinli District）, and the ore pillars can be cancelled below the -560 m level. Fur- thermore, a novel backfill method was designed to reduce the rock strata disturbance and settlement, and the settlement of roof strata was monitored during the mining process. Engineering practice shows that the settlement of roof strata was small and that no disaster happened. This indicates that the undersea safety mining technology of the large gold deposit is achieved in Xinli District.

关键词： undersea mining gold deposits rock mechanics mine roof control computer simulation

Isoparametric hypersurfaces in Finsler space forms

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Science China Mathematics 2021年第7期64卷 1463-1478页

作者： qun he Yali Chen Songting Yin Tingting Ren School of Mathematical Sciences Tongji UniversityShanghai 200092China Department of Mathematics and Computer Science Tongling UniversityTongling 244000China

In this paper, we study isoparametric hypersurfaces in Finsler space forms by investigating focal points, tubes and parallel hypersurfaces of submanifolds. We prove that the focal submanifolds of isoparametric hypersurfaces are anisotropic-minimal and obtain a general Cartan-type formula in a Finsler space form with vanishing reversible torsion, from which we give some classifications on the number of distinct principal curvatures or their multiplicities.

关键词： Finsler space form isoparametric hypersurface focal submanifold Randers space principal curvature anisotropic mean curvature