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Study for System of Nonlinear Differential Equations with Riemann-Liouville Fractional Derivative

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Applied Mathematics 2013年第7期4卷 5-8页

作者： yanping zheng Wenxia Wang Department of Mathrmatics Taiyuan Normal University Taiyuan China

In this work, we study existence theorem of the initial value problem for the system of fractional differential equations where Dα denotes standard Riemann-Liouville fractional derivative, 0 and A ?is a square matrix... 详细信息

关键词： Riemann-Liouville Fractional Derivative Weighted Cauchy-Type Problem Fractional Differential Equations

New steelmaking process based on clean deoxidation technology

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1249-1262页

作者： Zhongliang Wang yanping Bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

After the converter steelmaking process,a considerable number of ferroalloys are needed to remove dissolved oxygen from the molten steel,but it also forms a lot of oxide inclusions that cannot be completely *** the same time,it increases the carbon emis-sions in the steel production *** years of research,our team have developed a series of clean deoxidation technologies,includ-ing carbon deoxidation,hydrogen deoxidation,and waste plastic deoxidation of molten steel to address the aforementioned *** this study,thermodynamic calculations and laboratory experiments were employed to verify that carbon and hydrogen can reduce the total oxygen content in the molten steel melt to below 5×10^(-6) and 10×10^(-6),*** analysis of the deoxidation mechanisms and ef-fects of polyethylene and polypropylene was also *** addition,the applications of carbon deoxidation technology in different steels with the hot-state experiment and industrial production were discussed *** carbon deoxidation experimental results of different steels were as follows:(1)the oxygen content of bearing steel was effectively controlled at 6.3×10^(-6) and the inclusion number density was lowered by 74.73%compared to aluminum deoxidized bearing steel;(2)the oxygen content in gear steel was reduced to 7.7×10^(-6) and a 54.49%reduction of inclusion number density was achieved with almost no inclusions larger than 5μm from the average level of industry gear steels;(3)a total oxygen content of M2 high-speed steel was as low as 3.7×10^(-6).In industrial production practice,car-bon deoxidation technique was applied in the final deoxidation stage for non-aluminum deoxidized bearing steel,and it yielded excellent results that the oxygen content was reduced to below 8×10^(-6) and the oxide inclusions in the steel mainly consist of silicates,along with small amounts of spinel and calcium aluminate.

关键词： clean deoxidation carbon deoxidation hydrogen deoxidation waste plastics deoxidation

Development and prospects of molten steel deoxidation in steelmaking process

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International Journal of Minerals,Metallurgy and Materials 2024年第1期31卷 18-32页

作者： Zhongliang Wang yanping Bao State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

In the long traditional process of steelmaking,excess oxygen is blown into the converter,and alloying elements are used for *** inevitably results in excessive deoxidation of products remaining within the steel liquid,affecting the cleanliness of the *** the increasing requirements for steel performance,reducing the oxygen content in the steel liquid and ensuring its high cleanliness is *** more than a hundred years of development,the total oxygen content in steel has been reduced from approximately 100×10^(-6)to approximately 10×10^(-6),and it can be controlled below 5×10^(-6)in some steel grades.A relatively stable and mature deoxidation technology has been formed,but further reducing the oxygen content in steel is no longer significant for improving steel *** research team developed a deoxidation technology for bearing steel by optimizing the entire conventional *** technology combines silicon–manganese predeoxidation,ladle furnace diffusion deoxidation,and vacuum final *** successfully conducted industrial experiments and produced interstitial-free steel with natural decarbonization ***-aluminum deoxidation was found to control the oxygen content in bearing steel to between 4×10^(-6) and 8×10^(-6),altering the type of inclusions,eliminating large particle Ds-type inclusions,improving the flowability of the steel liquid,and deriving a higher fatigue *** natural decarbonization predeoxidation of interstitial-free steel reduced aluminum consumption and production costs and significantly improved the quality of cast billets.

关键词： steel deoxidation deoxidizer metallurgical equipment bearing steel IF steel

面向卓越工程师培养的智能车辆工程人才培养策略探讨

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时代汽车 2024年第17期 49-51页

作者：马会杰郑燕萍徐晓美吕立亚万茂松南京林业大学汽车与交通工程学院江苏南京210037

面对车辆电动化、智能化、网联化、共享化的新四化发展趋势,本校依托传统车辆工程专业特色优势,新增了智能车辆工程专业。智能车辆工程专业的设立不仅顺应了时代发展的需求,也为高校培养新一代卓越工程师提供了新的契机。本文在“卓越... 详细信息

面对车辆电动化、智能化、网联化、共享化的新四化发展趋势,本校依托传统车辆工程专业特色优势,新增了智能车辆工程专业。智能车辆工程专业的设立不仅顺应了时代发展的需求,也为高校培养新一代卓越工程师提供了新的契机。本文在“卓越计划”指导思想的基础上,提出了一系列教学改革措施,涵盖课程体系优化、实践教学创新、校企合作深化和实验室建设等方面。通过系统的改革措施,旨在提升本专业学生的专业素养、工程实践能力和创新思维,为智能车辆领域培养高素质的工程技术人才。

关键词：智能车辆工程卓越工程师本科专业建设教学改革

Unveiling strain-enhanced moiréexciton localization in twisted van der Waals homostructures

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Nano Research 2024年第4期17卷 3245-3252页

作者： Henry Rui He Haihong zheng Biao Wu Shaofei Li Junnan Ding Zongwen Liu Jian-Tao Wang Anlian Pan yanping Liu Institute of Quantum Physics School of PhysicsCentral South UniversityChangsha 410083China State Key Laboratory of Precision Manufacturing for Extreme Service Performance Central South UniversityChangsha 410083China School of Chemical and Biomolecular Engineering The University of SydneyNSW 2006Australia Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Materials Science and Engineering Hunan UniversityChangsha 410082China State Key Laboratory of High-Performance Complex Manufacturing Central South UniversityChangsha 410083China Shenzhen Research Institute of Central South University Shenzhen 51800China

Moirésuperlattices,arising from the controlled twisting of van der Waals homostructures at specific angles,have emerged as a promising platform for quantum emission ***,the manipulation of strain provides a versatile strategy to finely adjust electronic band structures,enhance exciton luminescence efficiency,and establish a robust foundation for two-dimensional quantum light ***,the intricate interplay between strain and moirépotential remains partially ***,we introduce a meticulously designed fusion of strain engineering and the twisted 2L-WSe_(2)/2L-WSe_(2) homobilayers,resulting in the precise localization of moiré*** low-temperature photoluminescence spectroscopy,we unveil the emergence of highly localized moiré-enhanced emission,characterized by the presence of multiple distinct emission ***,our investigation demonstrates the effective regulation of moirépotential depths through strain engineering,with the potential depths of strained and unstrained regions differing by 91%.By combining both experimental and theoretical approaches,our study elucidates the complex relationship between strain and moirépotential,thereby opening avenues for generating strain-induced moiréexciton single-photon sources.

关键词： moirésuperlattices strain engineering moiréexcitons moirépotential

Nitsche-XFEM for a time fractional diffusion interface problem

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Science China Mathematics 2024年第3期67卷 665-682页

作者： Tao Wang yanping Chen China Nuclear Power Technology Research Institute Co.Ltd. Shenzhen 518028China School of Mathematical Sciences South China Normal UniversityGuangzhou 510631China

In this paper, we propose a space-time finite element method for a time fractional diffusion interface problem. This method uses the low-order discontinuous Galerkin(DG) method and the Nitsche extended finite element method(Nitsche-XFEM) for temporal and spatial discretization, respectively. Sharp pointwise-in-time error estimates in graded temporal grids are derived, without any smoothness assumptions on the ***, three numerical examples are provided to verify the theoretical results.

关键词： fractional diffusion interface discontinuous Galerkin Nitsche-XFEM error estimates

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含不同矩形孔各向异性板孔边应力状态

同济大学学报（自然科学版） 2007年第12期35卷 1670-1673页

作者：李成郑艳萍郑州大学机械工程学院河南郑州450001

针对含矩形孔的复合材料板,根据非均质各向异性弹性理论,建立了基于准确的边界条件的边界积分方程,得到开口结构的应力分布,给出了含矩形孔复合材料板的精确解析解.按照所建立的数学模型对不同的矩形孔在偏轴荷载作用下对孔边应力集中... 详细信息

针对含矩形孔的复合材料板,根据非均质各向异性弹性理论,建立了基于准确的边界条件的边界积分方程,得到开口结构的应力分布,给出了含矩形孔复合材料板的精确解析解.按照所建立的数学模型对不同的矩形孔在偏轴荷载作用下对孔边应力集中系数的影响进行探讨.

关键词：复合材料偏轴荷载正交各向异性具有不同顶点弧度的矩形应力集中系数边界积分方程

Traditional Chinese Medicine in the treatment of recurrent respiratory tract infections in children: an overview of systematic reviews and Meta-analyses

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Journal of Traditional Chinese Medicine 2024年第5期44卷 871-884页

作者： DENG Yasheng HAN Siyin XI Lanhua HUANG Hui LIANG Tianwei zheng Yiqing FAN yanping LIN Jiang School of Basic Medical Sciences Guangxi University of Chinese Medicine School of Basic Medical Sciences Guangxi University of Chinese MedicineGuangxi Key Laboratory of Marine Drugs Department of Pharmacy Hainan Traditional Chinese Medicine Hospital

OBJECTIVE: To evaluate and summarise the evidence from published Meta-analyses/systematic reviews(MAs/SRs) of Traditional Chinese Medicine(TCM) in the treatment of recurrent respiratory tract infections(RRTIs) and to provide a scientific basis for the clinical treatment of RRTIs with TCM. METHODS: Studies were retrieved from Chinese and English databases including the China National Knowledge Infrastructure, Wanfang database, China Science and Technology Journal Database, SinoM ed, PubM ed, Web of Science, the Cochrane Library and EMbase from their establishment date to March 2023. Involved studies were screened, extracted, and evaluated for quality by two researchers independently. The a measurement tool to assess systematic reviews(AMSTAR) 2 scale was used for methodological quality evaluation, as well as the preferred reporting items for systematic reviews and Meta-analyses(PRISMA) 2020 statement for report quality evaluation, the risk of bias in systematic reviews(ROBIS) tool for risk of bias, and the grading of recommendations, assessment, development and evaluation(GRADE) quality assessment tool for evidence quality. RESULTS: Twenty MAs/SRs studies were included, including analyses of 274 original studies involving 38 335 patients with RRTIs. The AMSTAR 2 scale evaluation results showed that 19 studies were of very low quality and one of moderate quality. The ROBIS evaluation results showed that 11 MAs/SRs were at high risk and nine at low risk of bias. The PRISMA 2020 report quality showed the included studies had scores between 23.5 and 35.5, among them one with high quality, 17 with moderate quality and two with low quality. The GRADE system results showed that among 126 outcome indicators, only 17 had moderate quality of evidence, 27 had low quality, 82 had very low quality, and none had high quality. CONCLUSIONS: The MAs/SRs methodological quality of using TCM for treatment RRTIs is generally poor, the quality of reports as well as of evidence is generall

关键词： Meta-analysis child medicine, Chinese traditional randomized controlled trial respiratory tract infections systematic review

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TWO-GRID FINITE ELEMENT METHOD FOR TIME-FRACTIONAL NONLINEAR SCHRODINGER EQUATION

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Journal of Computational Mathematics 2024年第4期42卷 1124-1144页

作者： Hanzhang Hu yanping Chen Jianwei Zhou School of Mathematics Jiaying UniversityMeizhou 514015China School of Mathematical Science South China Normal UniversityGuangzhou 510631China School of Mathematics and Statistics Linyi UniversityLinyi 276005China

A two-grid finite element method with L1 scheme is presented for solving two-dimen-sional time-fractional nonlinear Schrodinger *** finite element solution in the L-norm are proved bounded without any time-step size conditions(dependent on spatial-step size).The classical L1 scheme is considered in the time direction,and the two-grid finite element method is applied in spatial *** optimal order error estimations of the two-grid solution in the LP-norm is proved without any time-step size *** is shown,both theoretically and numerically,that the coarse space can be extremely coarse,with no loss in the order of accuracy.

关键词： Time-fractional nonlinear Schrodinger equation Two-grid finite element me-thod The L1 scheme