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CONVERGENCE ANALYSIS FOR A NONCONFORMING MEMBRANE ELEMENT ON ANISOTROPIC MESHES

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Journal of Computational Mathematics 2005年第4期23卷 373-382页

作者： Dong-yang Shi shao-chun chen Ichiro Hagiwara Department of Mathematics Zhengzhou University Zhengzhou 450052 China Tokyo Institute of Technology 2-12-1 Ohokayama Megro Tokyo 152-8552 Japan

Regular assumption of finite element meshes is a basic condition of most analysis of finite element approximations both for conventional conforming elements and nonconforming elements. The aim of this paper is to present a novel approach of dealing with the approximation of a four-degree nonconforming finite element for the second order elliptic problems on the anisotropic meshes. The optimal error estimates of energy norm and L^2-norm without the regular assumption or quasi-uniform assumption are obtained based on some new special features of this element discovered herein. Numerical results are given to demonstrate validity of our theoretical analysis.

关键词： Anisotropic mesh Nonconforming finite element Optimal estimate

Effect of rare earth and alloying elements on the thermal conductivity of austenitic medium manganese steel

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International Journal of Minerals,Metallurgy and Materials 2017年第6期24卷 670-674页

作者： shao-chun chen Hong-xiang Ye Xin-qiang Lin School of Mechanical Engineering and Automation Fuzhou University Fuzhou 350116 China

The influence of different contents of Cr, Mo, and rare earth element(RE) additives on the thermal conductivity of austenitic medium manganese steel was studied and discussed. The results show that the addition of Cr in medium manganese steel can improved the ordering of C–Mn atomic clusters, so as to improve the steel's thermal conductivity. However, Cr will lead to precipitation of a great deal of carbides in medium manganese steel when its content is greater than 4wt%. These carbides would aggregate around the grain boundary, and as a result, the thermal conductivity is decreased. By the addition of Mo whose content is about 2wt%, spherical carbides will be formed, thus improving the thermal conductivity of the medium manganese steel. The interaction between rare earth elements and alloying elements will raise both the thermal conductivity and the wear-resisting property of medium manganese steel.

关键词： medium manganese steel alloying elements rare earth thermal conductivity

Some Numerical Quadrature Schemes of a Non-conforming Quadrilateral Finite Element

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 117-126页

作者： Xiao-fei GUAN Ming-xia LI shao-chun chen Department of Mathematics Tongji UniversityShanghai 200092China School of Information Engineering China University of Ceosciences(Beijing)Beijing 100083China Department of Mathematics Zhengzhou UniversityZhengzhou 450052China

Numerical quadrature schemes of a non-conforming finite element method for general second order elliptic problems in two dimensional （2-D） and three dimensional （3-D） space are discussed in this paper. We present and analyze some optimal numerical quadrature schemes. One of the schemes contains only three sampling points, which greatly improves the efficiency of numerical computations. The optimal error estimates are derived by using some traditional approaches and techniques. Lastly, some numerical results are provided to verify our theoretical analysis.

关键词： numerical integration non-conforming quadrilateral finite element optimal error estimate

Three-phase Fluid Numerical Simulation and Water Modeling Experiment of Supersonic Oxygen Jet Impingement on Molten Bath in EAF

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Journal of Iron and Steel Research International 2014年第6期21卷 589-595页

作者： shao-chun chen Rong ZHU Jing-she LI chun-lai HE Ming Lü School of Mechanical Engineering and Automation Fuzhou University School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

By means of the computational fluid dynamics software Fluent 6.3, a mathematical model of three-dimensional three-phase fluid flow field in the molten bath of electric arc furnace （EAF） with side accessorial oxygen lances was developed to study the transient phenomena of oxygen jet impingement on the molten steel and the molten slag. The water modeling experiment was carried out to verify the simulation results. The impingement of the supersonic oxygen jet caused impact dent on the molten steel surface accordingly. The area of impact dent changed almost in linear relationship to flow rate of oxygen jet, which can be expressed by a deduced mathematical equation. And the relationship between the impact force of oxygen iet and the correspondingly formed apparent static pressure on molten bath was obtained, which was in linear relationship and a direct proportion, and can also be expressed by a deduced mathematical equation.

关键词： electric arc furnace oxygen jet three-phase fluid numerical simulation water modeling experiment

Modulation Instability and Non-Degenerate Akhmediev Breathers of Manakov Equations

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Chinese Physics Letters 2022年第9期39卷 28-32页

作者： Chong Liu shao-chun chen Xiankun Yao Nail Akhmediev School of Physics Northwest UniversityXi’an 710127China Optical Sciences Group Department of Fundamental and Theoretical PhysicsResearch School of PhysicsThe Australian National UniversityCanberra ACT 2600Australia Shaanxi Key Laboratory for Theoretical Physics Frontiers Xi’an 710127China NSFC-SPTP Peng Huanwu Center for Fundamental Theory Xi’an 710127China

We reveal a special subset of non-degenerate Akhmediev breather(AB)solutions of Manakov equations that only exist in the focusing *** on exact solutions,we present the existence diagram of such excitations on the frequency-wavenumber *** single-frequency modulation instability leads to simultaneous excitation of three ABs with two of them being non-degenerate.

关键词： excitation degenerate subset

Effects of elemental Sn on the properties and inclusions of the free-cutting steel

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International Journal of Minerals,Metallurgy and Materials 2015年第2期22卷 141-148页

作者： shao-chun chen Rong Zhu Li-qiu Xue Teng-chang Lin Jing-she Li Yang Lin School of Mechanical Engineering and Automation Fuzhou University School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

A new environment-friendly free-cutting steel alloyed with elemental Sn （Y20Sn） was developed to meet the requirements of machinability and mechanical properties according to GB/T8731--1988. The machinability of the steel is enhanced by the segregation of elemental Sn at grain boundaries. The effect of Sn segregation on intergranular brittle fracture at normal cutting temperature from 250℃ to 400℃ is confirmed. The formation mechanism of main inclusions MnS is influenced by the presence of Sn and the attachment of Sn around MnS itself as a surfactant, and this mechanism also explains the improvement in machinability and mechanical properties of the steel. In the steel, the relevant inclusions are mainly spherical or axiolitic, and are uniformly distributed in small volume. Such inclusions improve the machinability of the steel and do not impair the mechanical properties as well. Experimental results demonstrate that the appropriate content of Sn in the steel is 0.03wt% to 0.08wt%, and the remaining composition is close to that of standard Y20 steel.

关键词： flee-cutting steel machinability mechanical properties inclusions surfactant

ON THE ANISOTROPIC ACCURACY ANALYSIS OF ACMES NONCONFORMING FINITE ELEMENT

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Journal of Computational Mathematics 2005年第6期23卷 635-646页

作者： Dong-yang Shi Shi-peng Mao shao-chun chen Department of Mathematics Zhengzhou University Zhengzhou 450052 China

The main aim of this paper is to study the superconvergence accuracy analysis of the famous ACM＇s nonconforming finite element for biharmonic equation under anisotropic meshes. By using some novel approaches and techniques, the optimal anisotropic interpolation error and consistency error estimates are obtained. The global error is of order O（h^2）. Lastly, some numerical tests are presented to verify the theoretical analysis.

关键词： Superconvergence Nonconforming finite element Anisotroplc interpolation error Consistency error

Molecular Characteristics of Cephalosporin-Resistant Neisseria gonorrhoeae Strains in China:A Retrospective Study

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International Journal of Dermatology and Venereology 2024年第2期7卷 78-83页

作者： Jin Zhang Xiao-Yu Zhu Jing-Wei Liu Yue-Ping Yin shao-chun chen Reference Laboratory for STD Control Hospital for Skin Diseases(Institute of Dermatology)Chinese Academy of Medical Sciences&Peking Union Medical CollegeNanjingJiangsu 210042China National Center for STD Control Chinese Center for Disease Control and PreventionNanjingJiangsu 210042China

Objective:An increasing level of antimicrobial resistance to extended-spectrum cephalosporins has been reported,so we conducted this study to investigate the molecular characteristics of cephalosporin resistant Neisseria gonorrhoeae(NG)strains isolated from China Gonococcal Antimicrobial Resistance Surveillance Programme(China-GRSP).Methods:In total,2,038 NG isolates were collected from the China-GRSP between 2015 and *** multiantigen sequence typing(NG-MAST),multilocus sequence typing(MLST),and NG sequence typing for antimicrobial resistance(NG-STAR)were used to determine characteristics and resistant determinants of cephalosporin-resistant *** results are described as ***:Seventy-four(3.6%)cephalosporin-resistant isolates were ***_(ST7363)was the most prevalent MLST among cefixime-resistant(CFX-R)isolates,whereas MLST_(ST7365)(n=8)in was the most prevalent sequence type among ceftriaxone-resistant(CRO-R)***-R strains were mainly associated with penA-X(n=27,44.3%),penA-XIII(n=6,9.8%),penA-XVIII(n=5,8.2%),and CRO-R strains were mainly related to penA-XVIII(n=10,25.6%),penA-43(n=9,23.1%),penA-XIII(n=7,17.9%).Conclusion:The main conclusion of this study is that the predominant cephalosporin-resistant clones in China include locally emerged and imported *** CFX-R and CRO-R strains are primarily related to penA mutations,and their predominant genotypes are *** the increase in international travel,tracking high-risk-resistant clones and identifying outbreaks and their associations with epidemiological characteristics are critical to improve public health.

关键词： gonorrhea resistance cephalosporin cefixime ceftriaxone

Spread of Neisseria gonorrhoeae FC428 Subclone MLST ST13871

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Infectious Microbes & Diseases 2024年第4期6卷 203-205页

作者： Hao Li Bang-Yong Zhu Quan Gan Tam Thi Nguyen shao-chun chen Hospital for Skin Diseases Institute of DermatologyChinese Academy of Medical Sciences&PekingUnion Medical CollegeNanjingChina National Center for STD Control Chinese Center for Disease Control and PreventionNanjingChina Institute of Dermatology Guangxi Autonomous RegionNanningChina Oxford University Clinical Research Unit HanoiVietnam.

The main objective of this study was to investigate the relationship between a ceftriaxone-resistant Neisseria gonorrhoeae strain GX211022,isolated from China,and MLST ST13871 strains reported *** this study,we determined the susceptibility of the *** isolate to antibiotics using the agar dilution *** was performed through *** sequence typing for antimicrobial resistance(NG-STAR),*** multiantigen sequence typing(NG-MAST),and multilocus sequence typing(MLST).Additionally,phylogenetic analysis was conducted to explore the genetic relatedness to other MLST ST13871 *** GX211022 was identified to possess penA allele 60.001 with a ceftriaxone MIC=1 mg/L and was classified as MLST ST13871 and NG-STAR *** analysis indicated that GX211022 was clustered with isolates from Vietnam and confirmed that all MLST ST13871 strains are a subclone of the internationally disseminated high-level ceftriaxone-resistant FC428 *** findings highlight abundant regional spread of MLST ST13871 in Southeast Asia.

关键词： Neisseria gonorrhoeae gonorrhea FC428 subclone whole-genome sequencing Asia