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Chinese Journal of chemical Engineering 2024年第5期69卷 1-12页

作者： Zhekun Chen Weitong Pan Longfei Tang Xueli Chen Fuchen Wang Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

Ensuring the consistency of electrode structure in proton-exchange-membrane fuel cells is highly desired yet challenging because of wide-existing and unguided cracks in the microporous layer(MPL). The first thing is to evaluate the homogeneity of MPL with cracks quantitatively. This paper proposes the homogeneity index of a full-scale MPL with an area of 50 cm~2, which is yet to be reported in the literature to our knowledge. Besides, the effects of the carbon material and surfactant on the ink and resulting MPL structure have been studied. The ink with a high network development degree produces an MPL with low crack density, but the ink with high PDI produces an MPL with low crack homogeneity. The polarity of the surfactant and the non-polarity of polytetrafluoroethylene(PTFE) are not mutually soluble,resulting in the heterogeneous PTFE distribution. The findings of this study provide guidelines for MPL fabrication.

关键词： Proton-exchange-membrane fuel cell Microporous layer Crack density Crack homogeneity Polytetrafluoroethylene distribution Surfactant

Casson hybrid nanofluid flow over a Riga plate for drug deliveryapplications with double diffusion

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Chinese Physics B 2024年第10期33卷 311-320页

作者： Abeer S.Alnahdi Taza Gul Department of Mathematics and Statistics Faculty of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)RiyadhSaudi Arabia Department of Mathematics City University of Science and Information Technology25000PeshawarPakistan DGoST-Directorate General of Science&technology Khyber PakhtunkhwaPeshawarPakistan

Casson fluid-mediated hybrid nanofluids are more effective at transferring heat than traditional heat transfer fluids in terms of thermal *** exchangers,cooling systems and other thermal management systems are ideal for use with Casson *** control of the flow and release of medication is necessary when using Casson fluids in drug delivery systems because of their unique rheological *** involves the creation of nanoparticles that are loaded with drugs and distributed in Casson fluid-based carriers for targeted *** this study,to create a hybrid nanofluid,both single-walled carbon nanotubes(SWCNTs)and multi-walled carbon nanotubes(MWCNTs)are dispersed in a Casson fluid with Fourier’s and Fick’s laws *** Casson fluid is suitable for various engineering and medical applications due to the enhancement of heat transfer and thermal conductivity by the carbon *** objective is to understand how SWCNTs and MWCNTs impact the flow field by studying the flow behavior of the Casson hybrid nanofluid when it is stretched against a Riga *** Darcy-Forchheimer model is also used to account for the impact of the porous medium near the stretching *** linear and quadratic drag terms are taken into account in this model to accurately predict the flow behavior of the *** addition,the homotopy analysis method is utilized to address the model *** outcomes are discussed and deliberated based on drug delivery *** findings shed valuable light on the flow characteristics of a Casson hybrid nanofluid comprising SWCNTs and *** is observed that the incorporation of carbon nanotubes makes the nanofluid a promising candidate for medical applications due to its improved heat transfer properties.

关键词： carbon nanotubes(CNTs) Riga plate Casson fluid with Fourier’s and Fick’s laws analytical solutions

Recent progress in carbene-catalyzed fluoroalkylation

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Science China Chemistry 2024年第8期67卷 2448-2460页

作者： Bei Zhang Xuan Zhang Jian Wang Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control Collaborative Innovation Center of Atmospheric Environment and Equipment TechnologySchool of Environmental Science and EngineeringNanjing University of Information Science and TechnologyNanjing 210044China School of Pharmaceutical Sciences Tsinghua UniversityBeijing 100084China

The fluoroalkyl fragment plays a vital role in various fields such as pharmaceuticals and materials science, and has a significant impact on human life not only on the present but also in the future. The insertion of fluoroalkyl groups into the chemical skeletons can cause considerable alternations in the chemical, physical and biological properties of molecules, which has attracted numerous scientists from different fields. This review focuses on N-heterocyclic carbene(NHC)-catalyzed fluoroalkylation reactions, providing a detailed analysis and summary of the achievements in the past two decades. Many successful examples clearly indicate that NHCs can catalyze the tranformation of fluoroalkylation reagents with various electronic characteristics, whether electrophilic, nucleophilic, or radical precursors. Herein, the fluoroalkylation reactions are classified based on different catalytic modes of NHCs: Lewis base catalysis, Umploung catalysis, radical catalysis and others. Meanwhile, by refining and systematically studying the contribution of NHC catalysis in fluoroalkylation reactions, this review is expected to provide valuable insights and enlightenment for related fields.

关键词： N-heterocyclic carbene fluoroalkylation radical catalysis

A review of in-situ high-temperature characterizations for understanding the processes in metallurgical engineering

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International Journal of Minerals,Metallurgy and Materials 2024年第11期31卷 2327-2344页

作者： Yifan Zhao Zhiyuan Li Shijie Li Weili Song Shuqiang Jiao Institute of Advanced Structure technology Beijing Institute of TechnologyBeijing 100081China State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China

For the rational manipulation of the production quality of high-temperature metallurgical engineering,there are many challenges in understanding the processes involved because of the black box chemical/electrochemical *** overcome this issue,various in-situ characterization methods have been recently developed to analyze the interactions between the composition,microstructure,and solid-liquid interface of high-temperature electrochemical electrodes and molten *** this review,recent progress of in-situ hightemperature characterization techniques is discussed to summarize the advances in understanding the processes in metallurgical ***-situ high-temperature technologies and analytical methods mainly include synchrotron X-ray diffraction(s-XRD),laser scanning confocal microscopy,and X-ray computed microtomography(X-rayμ-CT),which are important platforms for analyzing the structure and morphology of the electrodes to reveal the complexity and variability of their *** addition,laser-induced breakdown spectroscopy,high-temperature Raman spectroscopy,and ultraviolet-visible absorption spectroscopy provide microscale characterizations of the composition and structure of molten *** importantly,the combination of X-rayμ-CT and s-XRD techniques enables the investigation of the chemical reaction mechanisms at the two-phase ***,these in-situ methods are essential for analyzing the chemical/electrochemical kinetics of high-temperature reaction processes and establishing the theoretical principles for the efficient and stable operation of chemical/electrochemical metallurgical processes.

关键词： in-situ characterization methods high-temperature electrochemistry electrodes molten salts interfacial reaction

Application of Isogeometric Analysis Method in Three-Dimensional Gear Contact Analysis

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 817-846页

作者： Long Chen Yan Yu Yanpeng Shang Zhonghou Wang Jing Zhang School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai200093China Zhejiang Fine-Motion Robot Joint technology Co. Ltd.Taizhou317600China

Gears are pivotal in mechanical drives,and gear contact analysis is a typically difficult problem to *** isogeometric analysis(IGA)methods have developed new ideas to solve this *** this paper,a threedimensional body parametric gear model of IGA is established,and a theoretical formula is derived to realize single-tooth contact *** were benchmarked against those obtained from commercial software utilizing the finite element analysis(FEA)method to validate the accuracy of our *** findings indicate that the IGA-based contact algorithmsuccessfullymet theHertz contact *** juxtaposed with the FEA approach,the IGAmethod demonstrated fewer node degrees of freedomand reduced computational units,all whilemaintaining comparable ***,the IGA method appeared to exhibit consistency in analysis accuracy irrespective of computational unit density,and also significantlymitigated non-physical oscillations in contact stress across the tooth *** underscores the prowess of IGA in contact *** conclusion,IGA emerges as a potent tool for addressing contact analysis challenges and holds significant promise for 3D gear modeling,simulation,and optimization of various mechanical components.

关键词： Contact analysis involute gear isogeometric analysis finite element analysis

Thermodynamics of charged black holes in Maxwell-dilaton-massive gravity

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Chinese Physics C 2024年第7期48卷 232-243页

作者：岳瑞宏钱凯强刘博邹德成 Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China School of Physics Northwest UniversityXi'an 710127China School of Physics and Information Science Shaanxi University of Science and TechnologyXi'an 710021China College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China

Considering the nonminimal coupling of the dilaton field to the massive graviton field in Maxwelldilaton-massive gravity,we obtain a class of analytical solutions of charged black holes,which are neither asymptotically flat nor(A)*** calculated thermodynamic quantities,such as mass,temperature,and entropy,verify the validity of the first law of black hole ***,we further investigate the critical behaviors of these black holes in the grand canonical and canonical ensembles and find a novel critical phenomenon never before observed,known as the"reverse"reentrant phase transition with a tricritical *** implies that the system undergoes a novel"SBH-LBH-SBH"phase transition process and is the reverse of the"LBH-SBH-LBH"process observed in reentrant phase transitions.

关键词： Maxwell-dilaton-massive gravity charged black hole reverse reentrant phase transition VdW-like phase transitions

Mapping the antiparallel aligned domain rotation by microwave excitation

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Chinese Physics B 2024年第9期33卷 599-605页

作者： Jing Zhang Yuanzhi Cui Xiaoyu Wang Chuang Wang Mengchen Liu Jie Xu Kai Li Yunhe Zhao Zhenyan Lu Lining Pan Chendong Jin Qingfang Liu Jianbo Wang Derang Cao College of Physics Qingdao UniversityQingdao 266071China National Demonstration Center for Experimental Applied Physics Education Qingdao UniversityQingdao 266071China SKLSM Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China College of Chemistry Chemical Engineering and Resource UtilizationNortheast Forestry UniversityHarbin 150040China Hunan Provincial Key Laboratory of Intelligent Sensors and Advanced Sensor Materials School of Physics and ElectronicsHunan University of Science and TechnologyXiangtan 411201China CAS Key Laboratory of Magnetic Materials and Devices Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Key Laboratory of Optic-Electronic Information and Materials of Hebei Province Research Center for Computational PhysicsCollege of Physics Science and TechnologyHebei UniversityBaoding 071002China Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education Lanzhou UniversityLanzhou 730000China Key Laboratory of Special Functional Materials and Structural Design Ministry of EducationLanzhou UniversityLanzhou 730000China

The evolution process of magnetic domains in response to external fields is crucial for the modern understanding and application of *** this study,we investigated the domain rotation in stripe domain films of varying thicknesses by examining their response to microwave excitation in four different *** resonance spectra indicate that the rotation field of stripe domain film under an applied magnetic field approaches the field where the resonance mode of sample *** saturation field of the stripe domain film corresponds to the field where the resonance mode disappears when measured in the stripe direction parallel to the microwave magnetic *** results are reproducible and consistent with micromagnetic simulations,providing additional approaches and techniques for comprehending the microscopic mechanisms of magnetic domains and characterizing their rotation.

关键词： stripe domain magnetic film microwave excitation micromagnetic simulation

The extraction of effective components and an antioxidant activity study of Tulipa edulis

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Food Science and Human Wellness 2024年第1期13卷 276-286页

作者： Doudou Zhang Dong Xiao Tingting Yin Shuangzhi Zhao Olena Zhur Xun Xiao Hailun He Leilei Chen Beijing Advanced Innovation Center for Food Nutrition and Human Health Beijing Technology and Business UniversityBeijing 102488China School of Life Sciences Central South UniversityChangsha 410013China State Key Laboratory of Coal Resources and Safe Mining University of Mining and TechnologyXuzhou 221116China Institute of Agro-Food Science and technology Shandong Academy of Agricultural SciencesJinan 250100China

Plant extracts from natural sources are an excellent choice for food additives and natural *** this study,the active components of Tulipa edulis were extracted and analysed,and their antioxidant capacity was ***,the crude extract mixture was separated and purified using a Sephadex LH-20 gel,and the antioxidant activity of the purified products was *** umbilical vein endothelial human umbilical vein endothelial cells(HUVEC)cells were treated with 35 mmol/L glucose to construct a model of oxidative ***,the cells were treated with the active component to observe whether the products of *** could have a good protective effect on HUVEC cells induced by *** analysis was also performed on HUVEC cells after same treatment to explore the possible mechanism of the component F2 protecting HUVEC cells from oxidative stress induced by high *** results showed that component F2 obtained from *** has strong antioxidant ***,F2 can play a strong antioxidant protective role in HUVEC ***,the gene expression of heme oxygenase 1(HO-1),γ-glutamyl cysteine ligase catalytic subunit(GCLC)and NAD(P)H quinone oxidoreductase-1(NQO1)in HUVEC cells was up-regulated after treated with *** study provides reference value for the further development and application of *** and the d evelopment of functional food.

关键词： Tulipa edulis Oxidative stress Purification Antioxidant

Benzoyl cyanide, a general radical acylating reagent for photoredox-catalyzed benzylic site-selective acylation reactions

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Science China Chemistry 2024年第11期67卷 3833-3843页

作者： Zhaodong Zhu Jingjing Wu Frontiers Science Center for Transformative Molecules Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs School of Chemistry and Chemical Engineering Zhangjiang Institute for Advanced Study Shanghai Jiao Tong University

Based on rational design, benzoyl cyanide, a well-known ionic acylating reagent, has been developed as a general radical acylating reagent for benzylic site-selective acylation reactions for the first time. Using visible-light photoredox-catalyzed single electron transfer(SET) and hydrogen atom transfer(HAT) strategies, two different direct benzylic C–H acylation reactions with high atom economy have been developed. This newly developed radical acylating reagent could also be used to achieve three component acyltrifluoromethylation of styrenes, which is usually challenging to achieve by other means. All of these reactions proceed under mild nickel-free and NHC-free conditions with high functional group tolerance. In addition, based on our detailed mechanistic experiments, the process of radical-radical cross-coupling mechanism was suggested for these transformations.

关键词： photoredox catalysis benzylic C–H acylation radical acylating reagent HAT catalysis acyltrifluoromethylation

Theoretical Models on Interfacial Thermal Conductance of Nanoscale Solid Interfaces in Chips:A Mini Review

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Chinese Physics Letters 2024年第10期41卷 70-77页

作者： Zhicheng Zong Xiandong Chen Bin Yan Yelei Xie Jian Pang Guangyao Li Jiqiang Hu Zhipeng Wu Bo Li Haisheng Fang Nuo Yang School of Energy and Power Engineering Huazhong University of Science and TechnologyWuhan 430074China Department of Packaging and Testing Institution Sanechips Technology Co.Ltd.Shenzhen 518055China State Key Laboratory of Mobile Network and Mobile Multimedia technology ZTE CorporationShenzhen 518055China

With the rapid increase in power density of electronic devices,thermal management has become urgent for the electronics *** temperature in the back-end-of-line is crucial for maintaining the reliability of integrated circuits,where many atomic-scale interfaces *** theoretical models of interface thermal conductance not only accurately predict the values but also help to analyze the underlying *** review picks up and introduces some representative theoretical models considering interfacial roughness,elastic and inelastic processes,and electron–phonon couplings,***,the limitations and problems of these models are also discussed.

关键词： mechanism. roughness limitations