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Manifolds of positive Ricci curvature,quadratically asymptotically nonnegative curvature,and infinite Betti numbers

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Science China Mathematics 2022年第10期65卷 2183-2200页

作者： Huihong Jiang yihu yang Mathematics and Science College Shanghai Normal UniversityShanghai 200234China Department of Mathematics Shanghai Jiao Tong UniversityShanghai 200240China

In a previous paper(Jiang and yang(2021)),we constructed complete manifolds of positive Ricci curvature with quadratically asymptotically nonnegative curvature and infinite topological type but dimensions greater than or equal to *** purpose of the present paper is to use a different technique to exhibit a family of complete I-dimensional(I≥5)Riemannian manifolds of positive Ricci curvature,quadratically asymptotically nonnegative sectional curvature,and certain infinite Betti numbers bj(2≤j≤I-2).

关键词： Riemannian manifold positive Ricci curvature quadratically asymptotically nonnegative curvature

Gradient Estimates for a Nonlinear Diffusion Equation on Complete Manifolds

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Chinese Annals of Mathematics,Series B 2015年第6期36卷 1011-1018页

作者： Jiaxian WU Qihua RUAN yihu yang School of Mathematics and Statistics Nanjing University of Information Science & Technology Department of Mathematics Putian University Department of Mathematics Shanghai Jiao Tong University

This paper deals with the gradient estimates of the Hamilton type for the positive solutions to the following nonlinear diffusion equation：on a complete noncompact Riemannian manifold with a Bakry-Emery Ricci curvature bounded below by -K （K 〉 0）, where φ is a C2 function, a（x） and b（x） are C1 functions with certain conditions.

关键词： Gradient estimate Bakry-Emery Ricci curvature Nonlinear diffusion equation 58J35

Topics in Metric Riemannian Geometry

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Frontiers of Mathematics in China 2016年第5期11卷 1097-1098页

作者： Fuquan FANG Xiaochun RONG Wilderich TUSCHMANN yihu yang School of Mathematical Sciences Capital Normal University Beijing 100048 China Mathematics Department Rutgers University New Brunswick NJ 08903 USA Karlsruher Institut fur Technologie (KIT) Fakultat fur Mathematik Institut fur Algebra und Geometrie Arbeitsgruppe Differentialgeometrie Englerstraβe 2 D-76131 Karlsruhe Germany School of Mathematical Sciences Shanghai Jiao Tong University Shanghai 200240 China

It is our great pleasure to present the proceedings of the first Chinese-German Workshop on Metric Riemannian Geometry, which took place at Shanghai Jiao Tong University from October 12-16, 2015.

关键词： RIEMANNIAN metric GEOMETRY GENERALIZED spaces (Mathematics) MATHEMATICAL analysis CONGRESSES

FATOU　PROPERTY　ON　HARMONIC　MAPS　FROM　COMPLETE　MANIFOLDS　WITH　NONNEGATIVE　CURVATURE　AT　INFINITY　INTO　CONVEX　BALLS

维普期刊数据库评论

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维普期刊数据库

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Chinese Annals of Mathematics,Series B 1995年第3期16卷 341-350页

作者： yang yihu(Department of Mathematics,Fudan University,Shanghai 200433, China.) FUDAN UNIV DEPT MATHSHANGHAI 200433PEOPLES R CHINA

The author considers harmonic maps on complete noncompact manifolds, solves the Dirichlet problem in manifolds with nonnegative sectional curvature out of a compact set, and proves the Fatou theorem for harmonic maps ... 详细信息

关键词： Complete manifold Harmonic map Convex ball Fatou property.

The Application of Permanent Magnet Synchronous Motor with Small Electrical Time Constant in Fiber Positioner

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Research in Astronomy and Astrophysics 2024年第1期24卷 212-222页

作者： Shaoxiong Guo Yan yang Yanbin Yin yihu Tang yang Tian Chao Zhai Department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China School of Biomedical Engineering Division of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230026China Experiment Center of Engineering and Material Science University of Science and Technology of ChinaHefei 230026China

With the development of cutting-edge multi-object spectrographs,fiber positioners located in the focal plane are being scaled down in size,and miniature hollow-cup Permanent Magnet motors are now being considered as a suitable replacement for Faulhaber Precistep stepper ***,the small electrical time constant of such coreless motors poses a challenge,as the problem of severe commutation torque ripple in a fiber positioner running a position loop has been *** overcome this challenge,it is advised to increase the Pulse Width Modulation(PWM)frequency as much as possible to mitigate the effects of the current *** must be done while ensuring adequate resolution of the PWM *** employing a voltage open-loop field-oriented control based on a modulation frequency of 1 MHz,the drive current only costs 25 m A under a 3.3 V power *** sine degree of phase current is immaculate,and the repeat positioning accuracy can reach 2μ***,it is possible to further shrink the bill of devices and the layout area of the Printed Circuit Board,especially in sizesensitive *** device has been developed under the new generation of The Large Sky Area MultiObject Fiber Spectroscopic Telescope.

关键词： instrumentation:adaptive optics instrumentation:spectrographs proper motions reference systems

A novel modular organization of the binding region of the serin-rich repeat adhesin SraP in Staphylococcus aureus

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A novel modular organization of the binding region of the se...

Metal–ligand interfaces for well-defined gold nanoclusters

生命的分子机器及其调控网络——2012年全国生物化学与分子生物学学术大会

作者： yihu yang Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences

SraP is a serin-rich repeat(SRR) adhesin of Staphylococcus aureus that mediates binding of this organism to human platelets via its interaction with unknown *** interaction appears to be a virulence determinant in endovascular *** recent attention,the structural details and precise adhesion mechanisms have yet to be *** ad-dress these questions,we report

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来源： cnki会议评论

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cnki会议

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Science China Chemistry 2024年第3期67卷 806-823页

作者： Dan yang Yating Wu Zhaotong Yuan Chunmei Zhou yihu Dai Xiaoyue Wan Yan Zhu Yanhui yang Institute of Advanced Synthesis School of Chemistry and Molecular EngineeringNanjing Tech UniversityNanjing 211816China School of Chemistry and Chemical Engineering Nanjing UniversityNanjing 210093China College of Material and Chemical Engineering Minjiang UniversityFuzhou 350108China

Ligand engineering for well-defined gold nanoclusters(Au NCs) is getting more extensive attention. Organizing the Au-ligand interfaces on gold NCs can achieve the structural and functional control. This review focuses on the Au-ligand interfaces including gold-phosphorus(Au-P), gold-sulfur(Au-S), gold-selenium(Au-Se), gold-carbon(Au-C), and gold-nitrogen(Au-N), derived from the bonding between Au atoms and the different ligands(e.g., organic phosphine, thiolate, selenolate, alkynyl,n-heterocyclic carbene and nitrogenous ligands). The formation mechanism of Au-ligand interfaces is well discussed. In addition, the effects of Au-ligand interfaces on the stability, optical property, and catalysis are also presented. We hope the advances in this research area can boost the development of Au NC sciences.

关键词： Au nanoclusters well-defined structures metal–ligand interfaces formation mechanism structure–property correlation

HARMONIC FUNCTIONS ON PRODUCT OF CERTAIN KAHLER MANIFOLDS WITH A POLE

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Chinese Annals of Mathematics,Series B 2001年第3期22卷 381-384页

作者： yang yihu Department of Mathematics, Tongji University, Shanghai 200092, China ICTP, P. O. Box 586, Trieste 34100, Italy. Department of Mathematics Tongji University Shanghai 200092 China ICTP P. O. Box 586 Trieste 34100 Italy

It is proved that there is no nonconstant harmonic function of finite energy on product of certain Kahlerian manifolds with a pole.

关键词： Harmonic functions Kahlerian manifolds with a pole Pluriharmonicity

Effects of plasma spraying process on microstructure and mechanical properties of Cr2AlC/410 composite coatings

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High-Speed Railway 2024年第2期2卷 110-115页

作者： yihu Ma Chaosheng Ma Guozheng Ma Wenbo Yu Center of Materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China

To investigate the influences of Cr2AlC mass fraction and supersonic plasma spraying process on the microstructure and mechanical properties of Cr2AlC reinforced 410 stainless steel composite coatings,the coatings containing different mass fractions of Cr2AlC were prepared and *** composite coating exhibited low porosity and high adhesion *** addition of Cr2AlC significantly enhanced the hardness of the composite coatings through particle ***,when the mass fraction of Cr2AlC was 20%,the aggregation of Cr2AlC resulted in a strong decrease in the coating preparation efficiency,as well as a decline in adhesion *** the supersonic plasma spraying process,the Ar flow rate mainly influenced the flight velocity of the particles,while the H2 flow rate and the current mainly affected the temperature of the plasma ***,all of them influenced the melting degree of particles and the quality of the *** lowest porosity and the highest hardness and adhesion strength could be obtained when the Ar flow rate is 125 L/min,the H2 flow rate is 25 L/min,and the current is 385 A.

关键词： MAX phase Plasma spray Parameter Coating