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Effect of CeO_2 on heat transfer and crystallization behavior of rare earth alloy steel mold fluxes

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 565-572页

作者： Ze-yun Cai Bo Song long-fei li Zhen liu Xiao-kang Cui School of Metallurgical and Ecological Engineering University of Science and Technology Beijing

To improve the heat transfer capability and the crystallization property of the traditional mold flux, CaF_2 was replaced with B_2O_3. Then, the influences of CeO_2 on the heat transfer and the crystallization of the CaF_2-bearing mold flux and the new mold flux with 10 wt% B_2O_3 were studied using a slag film heat flux simulator and X-ray diffraction(XRD). The results revealed that the addition of CeO2 reduced the heat transfer by increasing the solid slag thickness and the crystallization of two mold fluxes. However, CeO_2 had less effect on the B_2O_3-containing mold flux compared with the CaF_2-bearing mold flux. According to the analyses, the CeO_2 contents in the CaF_2-bearing mold flux and the B_2O_3-containing mold flux should not exceed 8 wt% and 12 wt%, respectively. Therefore, these experimental results are beneficial to improve and develop the mold flux for casting rare earth alloy steels.

关键词： cerium oxide boron trioxide mold fluxes heat transfer crystallization rare earth alloy steels

Accelerating water dissociation at carbon supported nanoscale Ni/NiO heterojunction electrocatalysts for high-efficiency alkaline hydrogen evolution

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Nano Research 2023年第4期16卷 4742-4750页

作者： Cong li Jiang-Yan Xue Wei Zhang fei-long li Hongwei Gu Pierre Braunstein Jian-Ping Lang College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Chemistry and Materials Engineering Changshu Institute of TechnologyChangshu 215500China Universitéde Strasbourg-CNRS Institut de Chimie(UMR 7177 CNRS)4 rue Blaise Pascal-CS 90032Strasbourg 67081France

The synergistic catalysis of heterojunction electrocatalysts for the multi-step process in hydrogen evolution reaction(HER)is a promising approach to enhance the kinetics of alkaline ***,we proposed a strategy to form nanoscale Ni/NiO heterojunction porous graphitic carbon composites(Ni/NiO-PGC)by reduction-pyrolysis of the preformed Ni-metal-organic framework(MOF)under H2/N2 *** from low electron transfer resistance,increased number of active sites,and unique hierarchical micro-mesoporous structure,the optimized Ni/NiO-PGC_(10-1-400)exhibited excellent electrocatalytic performance and robust stability for alkaline HER(η10=30 mV,65 h).Density functional theory(DFT)studies revealed that the redistribution of electrons at the Ni/NiO interface enables the NiO phase to easily initiate the dissociation of alkaline H_(2)O,and shifts down the d-band center of Ni and optimizes the H*adsorption-desorption process of Ni,thereby leading to extremely high HER *** work contributes to a further understanding of the synergistic promotion of the multi-step HER processes by heterojunction electrocatalysts.

关键词： water dissociation Ni/NiO heterojunction metal-organic frameworks(MOFs)derivatives hydrogen evolution reaction reduction pyrolysis

NUMERICAL SIMULATION OF IRREGULAR WAVE-SIMULATING IRREGULAR WAVE TRAIN

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Journal of Hydrodynamics 2010年第4期22卷 537-545页

作者： liANG Xiu-feng YANG Jian-min li Jun XIAO long-fei li Xin State Key Laboratory of Ocean Engineering Shanghai Jiao Tong University Shanghai 200030 China

In real sea states,damage incidents on offshore floating structures are not due to the whole time series of wave elevation characterized as statistical one but due to few extreme waves or wave groups in irregular wave ***,using CFD tools to precisely simulate predetermined irregular wave train will lay sound basis for understanding the local characteristic of the flow field and impact loads on offshore floating structures when damage incidents *** this article,the generation of single extreme wave is investigated in a numerical wave ***,experimental irregular wave train is decomposed into certain number of small-amplitude *** Fourier series expansion is performed to determine the amplitude and initial phase angle of each wave component.A hydrodynamic transfer function is used to calculate the amplitude of wave-maker motion associated with each wave *** superposition is carried out on all of the wave-maker motion components to get the final wave-maker *** the wave-maker motion as input,simulation of the single extreme irregular wave train is modeled *** the method is applied to simulating a much more complicated irregular wave *** again main features of the complicated irregular wave train are reproduced compared with experiment carried out in the new deepwater experimental basin at Shanghai Jiao Tong *** the simulation,dynamic mesh method is enabled to model the piston-type wave-maker,the Volume Of Fluid（VOF） method is employed to capture the free surface and a dissipation zone is introduced to deal with wave reflection.

关键词： numerical wave tank irregular wave train Volume of Fluid (VOF) dynamic mesh

A hybrid catalyst for efficient electrochemical N_(2)fixation formed by decorating amorphous MoS_(3)nanosheets with MIL-101(Fe)nanodots

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Science China Chemistry 2022年第5期65卷 885-891页

作者： Wan-Ying Xu Cong li fei-long li Jiang-Yan Xue Wei Zhang Hongwei Gu Brendan F.Abrahams Jian-Ping Lang College of Chemistry Chemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China State Key Laboratory of Organometallic Chemistry Shanghai Institute of Organic ChemistryChinese Academy of SciencesShanghai 200032China School of Materials Engineering Changshu Institute of TechnologyChangshu 215500China School of Chemistry University of MelbourneVictoria 3010Australia

Metal-organic frameworks possessing relatively large pores,high surface areas,and unsaturated metal sites are attractive materials for use as electrocatalysts in the reduction of N_(2)to NH_(3).In this work,a MIL-101(Fe)/MoS_(3)hybrid catalyst,prepared by using a precursor-transformation strategy,is shown to be an effective electrocatalyst for the N_(2)reduction reaction(NRR).Under solvothermal conditions,micro-sized octahedral MIL-101(Fe)precursors are converted into ultra-small nanodots,while amorphous MoS_(3)derived from(NH_(4))_(2)MoS_(4)provides a surface suitable for anchoring the MIL-101(Fe)*** asprepared composite exhibits excellent electrocatalytic activity and durability for the NRR with a Faraday efficiency of 36.71%and an NH_(3)yield of 25.7μg h^(-1)mg_(cat)^(-1)at-0.1 V *** in 0.1 M *** results show that the dispersion and adherence of MIL-101(Fe)nanodots on amorphous MoS_(3)improves the exposure of active centers and aids mass transfer,resulting in greatly enhanced catalytic activity and stability.

关键词： nitrogen reduction reaction MIL-101(Fe)nanodots amorphous MoS_(3) precursor-transformation hybrid electrocatalysts

MAIN TOPICS, ABSTRACTS ＆ KEY WORDS

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焊接技术 2014年第2期43卷 I0001-I0002页

作者： ZHENG long-fei FU li ZHA0 Peng-kang State Key Laboratory of Solidification Processing School of Material Science and Engineering Northwestern Poly- technical University Xi'an 710072 Shaanxi pro. China

Vanadium-based metal-organic frameworks and their derivatives for electrochemical energy conversion and storage

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SmartMat 2022年第3期3卷 384-416页

作者： Jing Zhu Xiaoyu Chen Ai Qin Thang fei‐long li Dong Chen Hongbo Geng Xianhong Rui Qingyu Yan Department of Applied Chemistry State Key Laboratory of Tea Plant Biology and UtilizationAnhui Agricultural UniversityAnhuiChina School of Materials Science and Engineering Nanyang Technological UniversitySingaporeSingapore School of Materials Engineering Changshu Institute of TechnologyChangshuJiangsuChina School of Materials and Energy Guangdong University of TechnologyGuangzhouChina

With the excessive consumption of nonrenewable resources,the exploration of effective and durable materials is highly sought after in the field of sustainable energy conversion and storage *** this aspect,metalorganic frameworks(MOFs)are a new class of crystalline porous organicinorganic hybrid *** have recently been gaining traction in energy-related *** to the coordination flexibility and multiple accessible oxidation states of vanadium ions or clusters,vanadium-MOFs(V-MOFs)possess unique structural characteristics and satisfactory electrochemical ***,V-MOFs-derived materials also exhibit superior electrical conductivity and stability when used as electrocatalysts and electrode *** review summarizes the research progress of V-MOFs(inclusive of pristine V-MOFs,V/M-MOFs,and POVbased MOFs)and their derivatives(vanadium oxides,carbon-coated vanadium oxide,vanadium phosphate,vanadate,and other vanadium doped nanomaterials)in electrochemical energy conversion(water splitting,oxygen reduction reaction)and energy storage(supercapacitor,rechargeable battery).Future possibilities and challenges for V-MOFs and their derivatives in terms of design and synthesis are ***,their applications in energy-related fields are also highlighted.

关键词： derivatives electrocatalysis rechargeable battery supercapacitor V-based metal-organic frameworks

Prediction of mushy zone permeability of Al-4.5wt%Cu alloy during solidification by phase field model and CFD simulation

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China Foundry 2019年第5期16卷 313-318页

作者： long-fei li Rui-jie Zhang Shi-jie Hu Dan Zhang Shi-di Yang Chang-sheng Wang Hai-tao Jiang University of Science and Technology Beijing Beijing 100083 China Sanying Precision Instruments Company limited Tianjin 300399 China University of Shanghai for Science and Technology Shanghai 200093 China

liquid permeability of the mushy zone is important for porosity formation during the solidification process. In order to investigate the permeability of the mushy zone, an integrated model was developed by combining the phase field model and computational fluid dynamics (CFD) model. The three-dimensional multigrain dendrite morphology was obtained by using the phase field model. Subsequently, the computer-aided design (CAD) geometry and mesh were generated based on calculated dendrite morphologies. Finally, the permeability of the dendritic mushy zone was obtained by solving the Navier-Stokes and continuity equations in ANSYS Fluent software. As an example, the dendritic mushy zone permeability of Al-4.5wt%Cu alloy and its relationship with the solid fractions were studied in detail. The predicted permeability data can be input to the solidification model on a greater length scale for macro segregation and porosity simulations.

关键词： phase field model mushy zone computational fluid dynamics permeability solidification

Phase-change composite filled natural nanotubes in hydrogel promote wound healing under photothermally triggered drug release

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Bioactive Materials 2023年第3期21卷 284-298页

作者： Jing-Jing Ye long-fei li Rui-Nan Hao Min Gong Tong Wang Jian Song Qing-Han Meng Na-Na Zhao Fu-Jian Xu Yuri Lvov li-Qun Zhang Jia-Jia Xue Beijing Laboratory of Biomedical Materials State Key Laboratory of Organic-Inorganic CompositesBeijing University of Chemical TechnologyBeijing100029PR China College of Materials Science and Engineering Beijing University of Chemical TechnologyBeijing100029PR China Beijing Laboratory of Biomedical Materials Beijing University of Chemical TechnologyBeijing100029PR China Institute for Micromanufacturing and Biomedical Engineering Program Louisiana Tech UniversityRustonLA71272USA

It is of great importance to treat a bacterial-infected wound by a smart dressing capable of delivering antibiotics in a smart manner without causing drug *** construction of smart release nanocontainers responsive to near-infrared(NIR)laser irradiation in an on-demand and stepwise way is a promising strategy for avoiding the emergence of multidrug-resistant ***,we develop a hydrogel composite made of alginate and nanotubes with an efficient NIR-triggered release of rifampicin and outstanding antibacterial *** composite hydrogel is prepared through co-encapsulating antibacterial drug(rifampicin),NIR-absorbing dye(indocyanine green),and phase-change materials(a eutectic mixture of fatty acids)into halloysite nanotubes,followed by incorporation into alginate hydrogels,allowing the in-situ gelation at room temperature and maintaining the integrity of drug-loaded *** them,the eutectic mixture with a melting point of 39℃ serves as the biocompatible phase-change material to facilitate the NIR-triggered drug *** resultant phase-change material gated-nanotubes exhibit a prominent photothermal efficiency with multistep drug release under laser *** an in vitro assay,composite hydrogel provides good antibacterial potency against Staphylococcus aureus,one of the most prevalent microorganisms of dangerous gas gangrene.A bacterial-infected rat full-thickness wound model demonstrates that the NIR-responsive composite hydrogel inhibits the bacteria colonization and suppresses the inflammatory response caused by bacteria,promoting angiogenesis and collagen deposition to accelerate wound *** NIR-responsive composite hydrogel has a great po-tential as an antibacterial wound dressing functionalized with controlled multistep treatment of the infected sites.

关键词： Anti-bacteria Clay nanotubes Alginate hydrogel Phase-change material NIR-Triggered drug release Infected wound healing

ANALYZING AND TUNING longITUDINAL-WAVE BANDS IN PERIODIC PIEZOELECTRIC RODS

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ANALYZING AND TUNING LONGITUDINAL-WAVE BANDS IN PERIODIC PIE...