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Conjugate natural convection of non-Newtonian hybrid nanofluid in wavy-shaped enclosure

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Applied Mathematics and Mechanics(English Edition) 2022年第3期43卷 447-466页

作者： S.HUSSAIN T.TAYEBI T.ARMAGHANI A.M.RASHAD H.A.NABWEY Department of Mathematics Capital University of Science and TechnologyIslamabad 44000Pakistan lehrstuhl iii Department of MathematicsTechnical University of DortmundDortmund 44227Germany Faculty of Sciences and Technology University of Bordj Bou ArreridjEl-Anasser 34030Algeria Department of Engineering West Tehran BranchIslamic Azad UniversityTehran 11365Iran Department of Mathematics Aswan UniversityFaculty of ScienceAswan 81528Egypt Department of Mathematics College of Science and Humanities in Al-KharjPrince Sattam Bin Abdulaziz UniversityAl-Kharj 11942Saudi Arabia Department of Basic Engineering Science Faculty of EngineeringMenou¯a UniversityShebin El-Kom 32511Egypt

The present study concerns the modelization and numerical simulation for the heat and flow exchange characteristics in a novel configuration saturated with a nonNewtonian Ag-MgO hybrid nanofluid.The wavy shaped enclosure is equipped with onequarter of a conducting solid cylinder.The system of equations resulting from the mathematical modeling of the physical problem in its dimensionless form is discretized via the higher-order Galerkin-based finite element method(GFEM).The dependency of various factors and their interrelationships affecting the hydro-thermal behavior and heat exchange rate are delineated.The numerical experiments reveal that the best heat transfer rate is achieved for the pseudo-plastic hybrid nanoliquid with high Rayleigh number and thermal conductivity ratio and low Hartmann number.Besides,the power-law index has a major effect in deteriorating the heat convection at high Rayleigh number.

关键词： natural convection waved-shaped cavity magnetic field hybrid nanofluid higher order finite element method(FEM)

An inverted triplesalen ligand by a convergent synthesis and its influence on trinuclear Fe_3~Ⅲ complexes

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Science China Chemistry 2012年第6期55卷 951-966页

作者： FELDSCHER Bastian KRICKEMEYER Erich MOSELAGE Marc THEIL Hubert HOEKE Veronika KAISER Yvonne STAMMLER Anja BGGE Hartmut GLASER Thorsten lehrstuhl für Anorganische Chemie I Fakultt für Chemie Universitt Bielefeld Universittsstr. 25 D-33615 Bielefeld Germany

The inverted triplesalen ligand H 6 feld Me has been synthesized from 2,4,6-triformyl-phloroglucinol and a ketimine salen half-unit in a convergent synthesis. NMR, IR, and UV-vis spectroscopy reveal that this ligand is not in the O-protonated tautomer but in the N-protonated tautomer with substantial heteroradialene contribution. This ligand and the conventional triplesalen ligand H 6 talen t-Bu 2 have been used to synthesize the trinuclear Fe iii complexes [(feld Me )(FeCl) 3 ] and [(talen t-Bu 2 )(FeCl) 3 ], respectively. The molecular structures of these complexes were obtained by single-crystal X-ray diffraction. Two trinuclear Fe iii complexes of [(feld Me )(FeCl) 3 ] dimerize via two Fe-phenolate bonds, whereas due to steric hindrance no dimerization is observed for [(talen t-Bu 2 )(FeCl) 3 ]. The structural data also reveal some heteroradialene contribution in the trinuclear complexes. Whereas UV-vis and M bauer spectroscopy are not suitable to distinguish between the two complexes, FT-IR spectra show characteristic features due to the different substitution patterns of the conventional and the inverted triplesalen ligands. Another handle is provided by electrochemistry. Whereas both complexes exhibit an irreversible oxidation wave (0.94 V vs. Fc + /Fc for [(feld Me )(FeCl) 3 ] and 0.84 V vs. Fc + /Fc for [(talen t-Bu 2 )(FeCl) 3 ]), which is assigned to the oxidation of the central backbone, higher potential oxidations are reversible for [(talen t-Bu 2 )(FeCl) 3 ]) but irreversible for [(feld Me )(FeCl) 3 ]. This is attributed to the reversible oxidation of the terminal phenolates in the di-tert-butyl substituted [(talen t-Bu 2 )(FeCl) 3 ] in contrast to the mono-methyl-substituted phenolates in [(feld Me )(FeCl) 3 ]. The magnetic properties of [(talen t-Bu 2 )(FeCl) 3 ] reveal a very small ferromagnetic coupling with significant zero-field splitting of the FeⅢ S = 5/2 ions. In contrast, the dimerization of two trinuclear complexes in [(feld Me )(FeCl) 3 ] results in antiferromagnetic interactions between

关键词：三核配合物氯化铁复合物合成收敛反铁磁相互作用单晶X-射线衍射紫外可见光谱

Scalable Synthesis of Hierarchical Antimony/Carbon Micro-/Nanohybrid Lithium/Sodium-Ion Battery Anodes Based on Dimethacrylate Monomer

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Acta Metallurgica Sinica(English Letters) 2018年第9期31卷 910-922页

作者： Su-Zhe Liang Xiao-Yan Wang Yong-Gao Xia Sen-Lin Xia Ezzeldin Metwalli Bao Qiu Qing Ji Shan-Shan Yin Shuang Xie Kai Fang Lu-Yao Zheng Mei-Mei Wang Xiu-Xia Zuo Ru-Jiang Li Zhao-Ping Liu Jin Zhu Peter Müller-Buschbaum Ya-Jun Cheng North University of China Taiyuan 030051China Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo 315201China University of Chinese Academy of Sciences Beijing 100049China Physik-Department Lehrstuhl fur Funktionelle MaterialienTechnische Universitat MunchenJames-Franck-Str.185748 GarchingGermany The University of Nottingham Ningbo China Ningbo 315100China Nano Science and Technology Institute University ofScience and Technology of ChinaSuzhou 215123China Department of Materials University of OxfordParks RdOxford OX1 3PHUK

A facile scalable synthesis of hierarchical Sb/C micro-/nanohybrid has been addressed in this work, which possesses the advantages of both micrometer and nanometer scale structures as lithium-ion battery anode. Difunctional methacrylate monomers are used as solvent and carbon source as well. Liquid precursor of antimony（iii） n-butoxide is dissolved in the resin monomer solution, and further incorporated into the cross-linking polymer network via photo polymerization. Through calcination in argon/hydrogen atmosphere, antimony nanoparticles are in situ formed by carbothermal reduction, and homogeneously embedded in the in situ formed micrometer sized carbon matrix. The morphology, structure, crys- tallinity, spatial dispersion, composition, and electrochemical performance of the Sb/C micro-/nanohybrid are systemati- cally investigated. The cyclic and rate performance of the Sb/C micro-/nanohybrid anode have been effectively improved compared to the pure carbon anode. A reversible capacity of 362 mAh g-1 is achieved with a reasonable mass loading density after 300 cycles at 66 mA g-1, corresponding to capacity retention of 79%. With reducing mass loading density, the reversible capacity reaches 793 mAh g-1 after 100 cycles. Moreover, the electrochemical performance of Sb/C micro-/nanohybrid as sodium-ion battery anode is also investigated in this study.

关键词： Antimony/carbon micro-/nanohybrid Lithium-ion battery Sodium-ion battery. Anode Methacrylate Photo polymerization Thermosetting resin

植物种内变异对草地表层有机质碳同位素组成预测C_(3)/C_(4)植被比的影响

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Journal of Plant Ecology 2021年第4期14卷 628-637页

作者： Wentao Luo Xiaoguang Wang Karl Auerswald Zhengwen Wang Michael I.Bird Christopher J.Still Xiao-Tao Lv Xingguo Han Erguna Forest-Steppe Ecotone Research Station Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China College of Environment and Resources Dalian Minzu UniversityDalian 116600China Technische Universität München Lehrstuhl für GrünlandlehreAlte Akademie 1285350 Freising-WeihenstephanGermany College of Science and Engineering and ARC Centre of Excellence for Australian Biodiversity and Heritage James Cook UniversityCairnsQueensland 4870Australia Department of Forest Ecosystems and Society Oregon State UniversityCorvallisORUSA State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China University of Chinese Academy of Sciences Beijing 100049China

植物群落中C_(3)和C_(4)植物的比例和组成对诸多生态系统过程具有重要影响。解析C_(3)和C_(4)植物碳同位素的环境驱动过程与调控因子,对于从土壤碳同位素的角度来预测C_(3)/C_(4)植被比和组成具有重要意义。本研究旨在评估草原植物碳同... 详细信息

植物群落中C_(3)和C_(4)植物的比例和组成对诸多生态系统过程具有重要影响。解析C_(3)和C_(4)植物碳同位素的环境驱动过程与调控因子,对于从土壤碳同位素的角度来预测C_(3)/C_(4)植被比和组成具有重要意义。本研究旨在评估草原植物碳同位素特征的种内变异将如何影响C_(3)和C_(4)植物的碳同位素组成以及C_(3)/C_(4)植被比的预测。沿中国北方草原的自然干旱梯度选择26个植物群落,通过分析植物和土壤的碳同位素组成,采用混合模型来预测C_(4)植物对土壤有机碳的相对贡献。本研究对比分析了如下3种情境:(1)考虑C_(3)和C_(4)植物碳同位素的种内和种间效应;(2)仅考虑碳同位素的种间变异;(3)忽略碳同位素的种内和种间变异。研究结果表明,植物碳同位素组成沿中国北方草原自然干旱梯度的变化具有物种特异性。C_(3)和C_(4)植物的碳同位素组成与干旱指数之间呈显著负相关关系,但C_(3)植物比C_(4)植物对环境的干旱变化更为敏感。植物碳同位素特征的种内变异在驱动C_(3)植物功能群碳同位素沿干旱梯度的分布格局中发挥着重要作用。如果忽略植物碳同位素特征的种内变异将会显著高估C_(4)植物的相对贡献。本研究结果表明,草原植物碳同位素特征的种内变异对于准确预测C_(3)/C_(4)植被组成具有重要意义。

关键词：干旱和半干旱草原种间变异种内变异土壤有机质混合模型植被组成