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CFD-DEM simulation of fluorination reaction in fluidized beds with local grid and time refinement method

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Particuology 2024年第1期84卷 145-157页

作者： Mofan Qiu Lin Jiang Rongzhen Liu Yaping Tang malin Liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing100084China

The gas-solid reaction process with wide particle size distribution is extensively used in the chemical engineering field,especially the particle reacts with the gas gradually,such as fluorination reactions in fluidized *** the computational fluid dynamics-discrete element method(CFD-DEM)is used for the coupling simulation of multiphase and polydisperse particle reaction system,the grid size directly affects the accuracy of flow field information and simulation of chemical ***,particle calculation time step will directly affect the efficiency of coupling *** this work,a local grid and time step refinement method is proposed to simulate multiphase and polydisperse particle fluid-ization reaction *** this method,the refined DEM grids are automatically generated in the computational domain around the fine particles,and the detailed fluid phase information is obtained with the interpolation *** the two-phase coupling process,particles are divided into different groups based on physical properties,each group has its own independent time *** multistage conical-cylindrical spouted bed is proposed for the fluorination reaction process;the operating gas ve-locity range of the polydisperse particle system is extended by the new design while the particle size distribution changes with the gas-solid reaction *** is demonstrated that the local grid and time step refinement method can improve the accuracy and efficiency of the traditional CFD-DEM method in the reaction process simulation,which describes a polydisperse particle system with wide particle size *** at improving the simulation accuracy and efficiency,this paper will be helpful for simulating the particle reaction process in the gas-solid fluidized bed and beneficial for the development of the CFD-DEM method.

关键词： CFD-DEM Polydisperse particle Two-phase flow Fluidized bed

CFD-DEM simulation of high density particles fluidization behaviors in 3D conical spouted beds

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Particuology 2024年第5期88卷 266-281页

作者： Lin Jiang Mofan Qiu Rongzheng Liu Bing Liu Youlin Shao malin Liu Institute of Nuclear and New Energy Technology Collaborative Innovation Center of Advanced Nuclear Energy TechnologyTsinghua UniversityBeijing 100084China

The spouted bed has been used in the coating process of high-density nuclear fuel *** particle fluidization behaviors in pseudo-2D and 3D spouted beds were simulated and *** effects of four independent variables(cone angle,particle density,inlet gas velocity,and particle loading)on particle fluidization behaviors in the 3D spouted bed were investigated *** cone angle effect on fluidization mechanism was studied quantitatively first time.A new fluidization quality index was proposed based on the particle entrainment principle,and an extreme value was obtained when the cone angle was 60°,considered to be the optimum value for the 3D conical spouted *** was indicated the gas–solid contact efficiency can be kept up if the gas velocity was proportional to ρ_(p)^(0.65) and N_(p)^(0.78) when the particle density or loading was *** results will be useful for geometry and operation parameters design of the 3D conical spouted bed and helpful for developing the fluidization mechanism of high-density particles.

关键词： Spouted bed High-density particle CFD-DEM Fluidization quality index Particle loading

我国学前教育可持续发展评价指标体系及其测算

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华南师范大学学报（社会科学版） 2024年第2期 32-48,205页

作者：蔡迎旗胡马琳华中师范大学教育学院武汉430079 湖北第二师范学院教育科学学院武汉430205

可持续发展是我国学前教育事业发展的战略目标和未来向往,也是学前教育事业健康稳定发展的必有表征、必需保障和必然路径。学前教育可持续发展亟需构建科学、完善的指标体系加以指引。基于可持续发展系统论,从高度与水平、空间结构、时... 详细信息

可持续发展是我国学前教育事业发展的战略目标和未来向往,也是学前教育事业健康稳定发展的必有表征、必需保障和必然路径。学前教育可持续发展亟需构建科学、完善的指标体系加以指引。基于可持续发展系统论,从高度与水平、空间结构、时间进程三个维度出发,构建了由发展度、协调度和永续度组成的学前教育可持续发展评价指标体系,并测算了当前我国学前教育可持续发展综合水平和“三度”水平,发现我国学前教育可持续发展整体处于中等水平,全国四大区域之间差异明显,发展度、协调度和永续度三者之间均衡性不足,“三度”内在构成要素之间也存在明显差异。我国学前教育可持续发展的实现,应以经费投入为重点,多措并举提高学前教育发展水平;以公平均衡为导向,推动城乡、园际学前教育协调发展;以内外合力为保障,驱动学前教育健康永续发展。

关键词：学前教育可持续发展发展度协调度永续度

新型城镇化促进水生态文明建设:影响机制及空间效应

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地理科学进展 2024年第1期43卷 1-16页

作者：张胜武韩日李小胜宋马林刘海猛安徽财经大学工商管理学院安徽蚌埠233030 安徽财经大学统计与应用数学学院安徽蚌埠233030 中国科学院地理科学与资源研究所北京100101

新型城镇化是生态文明建设的重要载体,如何通过新型城镇化来推动水生态文明建设,是淮河生态经济带打造人与自然和谐共生的现代化面临的重大现实问题。针对这一问题,论文在解析城镇化影响水生态文明建设理论机制的基础上,基于淮河生态经... 详细信息

新型城镇化是生态文明建设的重要载体,如何通过新型城镇化来推动水生态文明建设,是淮河生态经济带打造人与自然和谐共生的现代化面临的重大现实问题。针对这一问题,论文在解析城镇化影响水生态文明建设理论机制的基础上,基于淮河生态经济带2006—2020年的城市面板数据,运用空间计量模型实证检验了城镇化对水生态文明建设的影响机制及空间效应。研究结果表明:①淮河生态经济带综合城镇化、人口城镇化对水生态文明建设的影响均呈典型的环境库兹涅茨曲线,即城镇化先抑制、达到一定阈值后转为促进水生态文明建设;②淮河生态经济带各城市的人口城镇化在2014年皆达到拐点值,而综合城镇化水平尚未达到拐点值,需要加快促进农业转移人口市民化、切实推进以人为核心的新型城镇化;③淮河生态经济带城镇化对水生态文明建设具有显著的倒“U”型溢出效应,同时,在当前研究期内水生态文明建设具有负向外溢效应。论文为深入解析城镇化与水资源互动关系提供新的研究视角,也为深化新型城镇化提升水生态文明建设提供了理论借鉴和经验证据。

关键词：城镇化水生态文明 “U”型曲线空间杜宾模型淮河生态经济带

Children with Sickle Cell Disease in Northern Benin: Follow up of a Cohort at the Borgou/Alibori Branch of Integrated Medical Healthcare Center for Infants and Pregnant Women with Sickle Cell Disease from 2017 to 2022

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Open Journal of Pediatrics 2024年第3期14卷 445-458页

作者： Falilatou Agbeille Mohamed Alphonse Noudamadjo Médétinmè Gérard Kpanidja Yémalin Zinsou François Anikè Akinola Kpedio Clarisse Marie Chantal Bossa Julien Didier Adédémy Joseph Agossou Teaching and Research Unit Department of Mother and Child Faculty of Medicine University of Parakou Parakou Benin Integrated Healthcare Center for Infants and Pregnant Women with Sickle Cell Disease (CPMI-NFED) Branch of Borgou/Alibori Parakou Benin

Introduction: Sickle cell disease is a public health problem in sub-Saharan Africa. A national referral center for the management of infants and pregnant women with sickle cell disease (CPMI-NFED) was created three decades ago in Cotonou, in the south of Benin with two regional branches including that of Parakou in the North for better access of patients to specialized care. This work is a review of five years of activities in order to describe the epidemiological, clinical, hematological and evolutionary profiles of the children followed up in the said branch. Method: This was a descriptive and retrospective cross-sectional study on the medical records of children with sickle cell disease, followed up at the regional branch of CPMI-NFED in Borgou/Alibori from June 1, 2017 to May 31, 2022. The variables studied were epidemiological, clinical, biological and evolutionary. Results: A total of 101 children with sickle cell disease were included in the study, including 78 homozygous SS (77.2%) and 23 heterozygous SC (22.8%). Their mean age at inclusion was 51.2 ± 37.6 months [6 - 204]. The sex ratio was 1.4. Vaso-occlusive crises were the main diagnostic circumstances in 42.3% of homozygotes. More than half of the children (51.5%) had a regular follow-up. The average baseline level of hemoglobin (Hb) in homozygous children was 8.8 ± 1.4 g/dl [5.8 - 11.5];and the rate of Hb S varied between 61.9 and 94.7%. In heterozygous SC children, the mean baseline level of Hb was 10.7 ± 0.6 g/dl [9.7 - 11.5]. Acute complications observed during follow-up were dominated by pneumonia and vaso-occlusive crises in both phenotypes. The overall mortality was 3% and only affected homozygous patients. Conclusion: On average, three out of four children were homozygous in our cohort. The main acute complications were infectious and vaso-occlusive. The mortality only affected homozygous carriers. Specialized follow-up has contributed to improving the quality of life of children with sickle cel

关键词： Sickle Cell Disease Children CPMI-NFED Parakou Benin

黄河流域新型城镇化与水生态环境耦合协调的时空格局及影响因素

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中国沙漠 2024年第3期44卷 172-181页

作者：张胜武葛宇梦李小胜宋马林安徽财经大学工商管理学院安徽蚌埠233030 安徽财经大学统计与应用数学学院安徽蚌埠233030

厘清城镇化与水生态环境之间的耦合关系及其影响因素,对促进黄河流域生态保护和高质量发展具有重要意义。在理论揭示新型城镇化与水生态环境耦合作用机理的基础上,利用耦合协调度及空间计量模型分析二者耦合协调的时空格局及其影响因素... 详细信息

厘清城镇化与水生态环境之间的耦合关系及其影响因素,对促进黄河流域生态保护和高质量发展具有重要意义。在理论揭示新型城镇化与水生态环境耦合作用机理的基础上,利用耦合协调度及空间计量模型分析二者耦合协调的时空格局及其影响因素。结果表明:(1)黄河流域新型城镇化和水生态环境耦合协调度趋好但总体水平低,总体由濒临失调逐步发展到初级协调,下游耦合协调发展水平高于中上游。(2)黄河流域新型城镇化和水生态环境耦合协调度具有显著的空间溢出效应,影响强度下游>中游>上游。(3)黄河流域新型城镇化和水生态环境耦合协调发展的影响因素方面,政府能力正向推动本地但对邻近地区产生负向溢出效应,环境规制、人口集聚抑制本地耦合协调发展,资本积累通过正向溢出效应对全流域产生正向影响但对下游产生负向影响,工业化通过负向溢出效应阻碍全流域耦合协调发展,开放型、创新型经济仅对中游产生正向带动和外溢效应。

关键词：新型城镇化水生态环境耦合协调空间杜宾模型黄河流域

Nonlinear Korn Inequalities on a Hypersurface

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Chinese Annals of Mathematics,Series B 2018年第3期39卷 513-534页

作者： Maria malin Cristinel MARDARE Department of Mathematics University of CraiovaCraiova200585Romania Sorbonne Universite CNRSLaboratoire Jacques-Louis LionsLHLLF-75005ParisFrance

The authors establish several estimates showing that the distance in W^(1,p),1 < p < ∞,between two immersions from a domain of R^n into R^(n+1) is bounded by the distance in L^p between two matrix fields defined in terms of the first two fundamental forms associated with each immersion. These estimates generalize previous estimates obtained by the authors and P. G. Ciarlet and weaken the assumptions on the fundamental forms at the expense of replacing them by two different matrix fields.

关键词： Differential geometry Hypersurface Nonlinear shell theory

Benefits of skin-to-skin contact during the neonatal period: Governed by epigenetic mechanisms?

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Genes & Diseases 2018年第1期5卷 24-26页

作者： malin Almgren Center of Molecular Medicine Department of Clinical NeuroscienceKarolinska InstitutetSweden

The perinatal period experiences are important for later life *** born babies have been shown to benefit from close contact with their mothers,and evidence suggests that epigenetic mechanisms are involved in these ear... 详细信息

关键词： Epigenetics Kangaroo mother care Neurodevelopment Premature Skin-to-skin contact

Degenerate Nonlinear Elliptic Equations Lacking in Compactness

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Chinese Annals of Mathematics,Series B 2016年第1期37卷 53-72页

作者： Maria malin Cristian UDREA Department of Mathematics University of Craiova

In this paper, the authors prove the existence of solutions for degenerate elliptic equations of the form-div(a(x)▽_p u(x)) = g(λ, x, |u|^(p-2)u) in R^N, where ▽_pu =|▽u|^(p-2)▽u and a(x) is a degenerate nonnegative weight. The authors also investigate a related nonlinear eigenvalue problem obtaining an existence result which contains information about the location and multiplicity of eigensolutions. The proofs of the main results are obtained by using the critical point theory in Sobolev weighted spaces combined with a Caffarelli-Kohn-Nirenberg-type inequality and by using a specific minimax method, but without making use of the Palais-Smale condition.

关键词： Degenerate equations p-Laplacian Sobolev weighted spaces Mountain-pass theorem