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Some Dichotomy Results for the Quenching Problem

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Acta Mathematica Sinica,English Series 2012年第7期28卷 1491-1506页

作者： Gao feng zheng Department of Mathematics Central China Normal University

It is shown that any solution to the semilinear problem{u（x,0=）u0（x）〈1,x∈[-1,1] u（±1,t）=0,t∈（0,T）, ut=uxx＋δ（1-u）^-p（x,t）∈（-1,1） ×（0,T）either touches 1 in finite time or converges smoothly to a ... 详细信息

关键词： Semilinear heat equation quenching in finite time finite energy steady state dichotomyproperty

The quasi-triangular structures over Hom-ω-smash coproduct Hopf algebras

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Applied Mathematics(A Journal of Chinese Universities) 2016年第2期31卷 219-236页

作者： zheng Nai-feng Department of Mathematics Ningbo University

Let （C,α） and （H, β） be Hom-bialgebras and ω ： C × H → H × C a linear map. We introduce a Horn-ω-smash coproduct （Cω H, γ） and give necessary and sufficient conditions for （Cω H, γ） to be a Hom-bialgebra. We study the quasi-triangular structures over （Cω H, γ） and show the necessary and sufficient conditions for （Cω H, γ R） to be a quasi-triangular Hom-Hopf algebra. As applications of our results, we introduce the concept of D（H）＊ and construct quasi-triangular structures over D（H）＊.

关键词： Hom-Hopf algebra Quasi-triangular Hom-Hopf algebra Hom-ω-smash coproduct.

Characterization of Zm26Sub5 and Its Potential Roles in Regulating Pollen Fertility of S-CMS in Maize

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Agricultural Sciences in China 2011年第4期10卷 481-489页

作者： ZHANG zheng-feng zheng Yong-lian College of Life Science Huazhong Normal University Wuhan 430079 P.R.China National Key Laboratory of Crop Genetic improvement Huazhong Agricultural University Wuhan 430070 PR. China

Mitochondrial orf355-orf77 and the nuclear fertility restorer locus Rf3/rf3 mutually control the fertility of male gametes in CMS-S in maize （Zea mays L.）. A fragment of gene Zm26Sub5 was identified through cDNA-AFLP from a set of Rf3/rf3 near-isogenic lines in a previous study. In the present study, real-time PCR analysis revealed that Zm26Sub5 expression levels were much higher in pollen of S-Mo17Rf3Rf3 than in pollen of S-Mo17rf3rf3, and also higher than in fresh leaves, mature leaves, and roots of both S-Mo17Rf3Rf3 and S-Mo17rf3rf3. In silico cloning of full-length cDNA was successfully implemented. Gene Zm26Sub5 was 1 451 bp in size, of which 1 329 bp encoded a protein with 443 amino acids. The structure of this gene was analyzed by comparing its full length cDNA to homologous genomic DNA sequence （GenBank accession： Ac209463.3）. Subsequent sequence analysis led to sub cellular localization of protein ZM26SUB5, and construction of a phylogenetic tree. In silico mapping indicated that Zm26Sub5 was located on chromosome 5 and closed to a reported starch-filled pollen ratio QTL. ZM26SUB5, therefore might have potential roles in repressing mitochondrial PCD which is associated with sterile activity in pollen in S-type cytoplasm.

关键词： maize (Zea mays L.) cytoplasmic male sterility Zm26Sub5 restorer of fertility PCD repression

Dimension by Dimension Finite Volume HWENO Method for Hyperbolic Conservation Laws

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Communications on Applied Mathematics and Computation 2024年第1期6卷 605-624页

作者： feng zheng Jianxian Qiu College of Mathematics and Statistics Fujian Normal UniversityFuzhou350117FujianChina School of Mathematical Sciences and Fujian Provincial Key Laboratory of Mathematical Modeling&High-Performance Scientific Computing Xiamen UniversityXiamen361005FujianChina

In this paper,we propose a finite volume Hermite weighted essentially non-oscillatory(HWENO)method based on the dimension by dimension framework to solve hyperbolic conservation *** can maintain the high accuracy in the smooth region and obtain the high resolution solution when the discontinuity appears,and it is compact which will be good for giving the numerical boundary ***,it avoids complicated least square procedure when we implement the genuine two dimensional(2D)finite volume HWENO reconstruction,and it can be regarded as a generalization of the one dimensional(1D)HWENO *** numerical tests are performed to verify the high resolution and high accuracy of the scheme.

关键词： Finite volume Dimension by dimension HWENO Hyperbolic conservation laws

Symbolic transfer entropy-based premature signal analysis

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Chinese Physics B 2012年第1期21卷 535-538页

作者： Wang Jun Yu zheng-feng Image Processing and Image Communications Key Laboratory School of Geography and Biological InformationNanjing University of Posts&TelecommunicationsNanjing 210003China

In this paper, we use symbolic transfer entropy to study the coupling strength between premature signals. Numerical experiments show that three types of signal couplings are in the same direction. Among them, normal signal coupling is the strongest, followed by that of premature ventricular contractions, and that of atrial premature beats is the weakest. The T test shows that the entropies of the three signals are distinct. Symbolic transfer entropy requires less data, can distinguish the three types of signals and has very good computational efficiency.

关键词： premature signal symbolic transfer entropy signal coupling

Current-limiting Characteristics of a Modified Flux-coupling Type Superconducting Fault Current Limiter and Its Effects on the Transient Stability of a Multi-machine Power System

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Chinese Journal of Electrical Engineering 2021年第2期7卷 93-102页

作者： Yonghui He Langheng Cao feng zheng Department of Automation Engineering Fujian Polytechnic of Information TechnologyFuzhou 350003China China Energy Construction Group Guangdong Electric Power Design and Research Institute Co. Ltd.Guangzhou 510663China School of Electrical Engineering and Automation Fuzhou UniversityFuzhou 350116China

A modified flux-coupling type superconducting fault current limiter(SFCL)is proposed here for suppressing fault *** modified SFCL consists of a coupling transformer,an yttrium barium copper oxide(YBCO)pancake coil,and a controlled *** flexibly adjusting the controlled switch’s contact states based on the system operational conditions,the coupling transformer’s primary inductance as well as the YBCO coil’s normal-state resistance are incorporated into the main system for current *** the modified SFCL has the advantages of resistive and inductive SFCLs,it may improve the power system’s transient ***,the SFCL’s effect on the transient stability of a multi-machine power system was also theoretically ***,simulations were conducted for accessing the SFCL’s performance characteristics under different fault *** results show that using the proposed SFCL can effectively restrain the increased fault current and improve the bus voltage sag;meanwhile,the imitated multi-machine system’s power-angle oscillation can be obviously reduced.

关键词： Current-limiting characteristics flux-coupling type SFCL multi-machine power system transient stability

Effects of solution treatment on mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy

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Journal of Central South University 2013年第8期20卷 2083-2089页

作者： YU Cheng YIN Deng-feng zheng feng YU Xin-xiang School of Materials Science and Engineering Central South University Changsha 410083 China Key Laboratory of Nonferrous Materials of Ministry of Education (Central South University) Changsha 410083 China

Mechanical properties and microstructures of Al-Li-Cu-Mg-Ag alloy after solution treatments were investigated by means of optical microscopy （OM）, tensile test, hardness measurement and electrical conductivity test, differential scanning calorimetric （DSC）, energy dispersive X-ray （EDX）, scanning electron microscopy （SEM） and transition electron microscopy （TEM）, respectively The results show that both tensile strength and hardness increase first and then decrease with temperature at constant holding time of 30 min with maximum strength and hardness appearing at 520 ℃. Tensile strength, hardness and elongation of samples treated at 520 ℃ for 30 min are 566 MPa （σb）, 512 MPa （σ0.2）, HB 148 and 8.23% （δ）, respectively. There are certain amount of fine T1 （AI2CuLi） phase dispersing among AI substrates according to TEM images. This may result in mixed fracture morphology with trans-granular and inter-granular delamination cracks observed in SEM images.

关键词： Al-Li-Cu-Mg-Ag alloy solution treatment microstructure mechanical properties

Intestinal Microbiota and Kidney Diseases

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Chinese Journal of Integrative Medicine 2018年第6期24卷 406-408页

作者： XIE Ao SHENG Jie zheng feng Advanced Institute for Medical Science The Second HosptialDalian Medical University

Kidney diseases are common and the incidence rate is increasing. Gut microbiota is involved in metabolic and immune regulation of the host. Genetic, alimentary and environmental disease factors may change gut flora and increase opportunistic and pathogenic bacteria, contributing to immune or non-immune mediated kidney diseases including IgA nephropathy and diabetic nephropathy. Additionally, bacterial metabolites may be a source of uremic toxins. Thus, identification of diversity, composition, and metabolic and immunologic features of gut bacteria in chronic kidney diseases may help understand pathogenetic mechanism and develop therapy for diseases.

关键词： microbiota IgA nephropathy chronic kidney disease uremia

Martensitic transformation and magnetic properties of Ti-doped NiCoMnSn shape memory alloy

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Rare Metals 2014年第5期33卷 511-515页

作者： feng Chen Yun-Xiang Tong Bing Tian Li Li Yu-feng zheng Center for Biomedical Materials and Engineering Harbin Engineering University Department of Materials Science and Engineering College of Engineering Peking University

Martensitic transformation, microstructure, and magnetic properties of Ti-doped Ni43-xTixCo7Mn43Sn7（at%）（x = 0, 0.5, 1.0, 2.0, and 4.0） shape memory alloys were investigated. The results show that transformation temperatures of Ni43Co7Mn43Sn7 can be efficiently adjusted by the substitution of Ti for Ni. For example, the martensitic transformation starting temperature（Ms） is reduced by about 278 K with 4 at% addition of Ti. Room temperature microstructure evolves from single tetragonal martensite for the Ti-free alloy to dual phases（tetragonal martensite ＋ second phase） with 0.5 at%, 1.0 at%, and2.0 at% addition of Ti to dual phases（cubic austenite ＋ second phase） for 4.0 at% Ti-doped alloy. The mechanical properties can be obviously improved by adding an appropriate amount of Ti. A noteworthy point is that magnetic-field-induced reverse transformation is observed in Ni39Ti4Co7Mn43Sn7 alloy.

关键词： NiCoMnSn Shape memory alloy Martensitic transformation Magnetic property