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Suzuki Reaction of Aryl Bromides Using a Phosphine-Free Magnetic Nanoparticle-Supported Palladium Catalyst

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催化学报 2011年第11期32卷 1667-1676页

作者： Nghia t. BUI trung B. DANG Ha V. LE Nam t. S. PHAN Department of Chemical Engineering HCMC University of Technology VNU-HCM 268 Ly Thuong Kiet Distriet 10 Ho Chi Minh City Viet Nam

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. the catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. the immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the Suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. the recovery of catalyst was simply by magnetic decantation in the presence of a magnet. the immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.

关键词： superparamagnetic nanoparticle Suzuki reaction palladium aryl bromide

Existence and Nonexistence of Nontrivial Weak Solution for a Class of General Capillarity Systems

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Acta Mathematicae Applicatae Sinica 2014年第4期30卷 1121-1130页

作者： G.A.AFROUZI N.t.CHUNG Z.NAGHIZADEH Department of Mathematics Faculty of Mathematical SciencesUniversity of Mazandaran Department of Mathematics Quang Binh University312 Ly Thuong Kiet

the aim of this paper is to study the nonexistence and existence of nonnegative, nontrivial weak solution for a class of general capillarity systems. the proofs rely essentially on the minimum principle combined with ... 详细信息

关键词： weak solutions nonexistence multiplicity capillarity systems variational methods

沸石咪唑酯骨架结构材料ZIF-8催化Friedel-Crafts酰基化反应(英文)

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催化学报 2012年第4期33卷 688-696页

作者： Lien t. L. NGUYEN Ky K. A. LE Nam t. S. PHAN Department of Chemical Engineering Hochiminh City University of Technology VNU-HCM 268 Ly Thuong Kiet District 10 Ho Chi Minh Citv 740128. Met Nam

A zeolite imidazolate framework,ZIF-8,was synthesized and characterized by dynamic laser light scattering,X-ray powder diffraction,scanning electron microscopy,transmission electron microscopy,thermogravimetric analysis,Fourier transform infrared,atomic absorption spectrophotometry,and nitrogen adsorption *** ZIF-8 was highly crystalline and porous with a surface area of over 1600 m2 /***-Crafts acylation of anisole and benzoyl chloride proceeded well in the presence of ZIF-8(2-6 mol%) without the need for an inert *** reaction afforded a selectivity of 93%-95% to the *** solid catalyst can be separated from the reaction mixture by simple centrifugation and reused without significant degradation in catalytic *** was no leaching of active acid species into the reaction solution.

关键词：化学催化高压高温

Interplay of S and As in Mekong Delta sediments during redox oscillations

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Geoscience Frontiers 2019年第5期10卷 1715-1729页

作者： Van t.H. Phan Fabrizio Bardelli Pierre Le Pape Raoul-Marie Couture Alejandro Fernandez-Martinez Delphine tisserand Rizlan Bernier-Latmani Laurent Charlet University Grenoble Alpes CNRSIRDIFSTTARISTerre38000GrenobleFrance Ho Chi Minh City University of technology (HCMUt) Vietnam National UniversityHo Chi Minh City (VNU-HCM)268 Ly Thuong KietDistrict 10Ho Chi Minh CityViet Nam Institute of Nanotechnology (CNR-Nanotec) 00186RomeItaly Institut de Mineralogie de Physique des Materiaux et de Cosmochimie (IMPMC)UMR 7590 CNRS-UPMC-IRD-MNHN4 Place Jussieu75252Paris cedex 05France Département de chimie Université Laval1045 Avenue de la MédecineQuébecQCG1V 0A6Canada Ecole Polytechnique Fédérale de Lausanne (EPFL) e Environmental Microbiology Laboratory (EML) EPFL-ENAC-IIE-EMLStation 6CH-1015LausanneSwitzerland

the cumulative effects of periodic redox cycling on the mobility of As,Fe,and S from alluvial sediment to groundwater were investigated in bioreactor *** particular sediments from the alluvial floodplain of the Mekong Delta River were investigated: Matrix A (14 m deep) had a higher pyrite concentration than matrix B (7 m deep) *** present in matrix B but absent in matrix *** the reactors,the sediment suspensions were supplemented with As(III) and SO4^2-,and were subjected to three full-redox cycles entailing phases of nitrogen/CO2,compressed air sparging,and cellobiose *** differences in As concentration and speciation were observed upon redox *** support the fact that initial sediment composition is the main factor controlling arsenic release and its speciation during the redox ***,a high pyrite content associated with a low SO4^2- content resulted in an increase in dissolved As concentrations,mainly in the form of As(III),after anoxic half-cycles;whereas a decrease in As concentrations mainly in the form of As(V),was instead observed after oxic *** addition,oxic conditions were found to be responsible for pyrite and arsenian pyrite oxidation,increasing the As pool available for *** same processes seem to occur in sediment with the presence of gypsum,but,in this case,dissolved As were sequestered by biotic or abiotic redox reactions occurring in the FeeS system,and by specific physico-chemical condition (***).the contrasting results obtained for two sediments sampled from the same core show that many complexes and entangled factors are at work,and further refinement is needed to explain the spatial and temporal variability of As release to groundwater of the Mekong River Delta (Vietnam).

关键词： Redox oscillation Pyrite oxidation Gypsum dissolution Isotope sulfur Isotope oxygen

High-performance carbon fiber/gold/copper composite wires for lightweight electrical cables

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Journal of Materials Science & technology 2020年第7期42卷 46-53页

作者： thang Q.tran Jeremy Kong Yoong Lee Amutha Chinnappan Nguyen Huu Loc Long t.tran Dongxiao Ji W.A.D.M.Jayathilaka Vishnu Vijay Kumar Seeram Ramakrishna Department of Mechanical Engineering National University of Singapore9 Engineering Drive 1EA-07-05Singapore 117575Singapore Faculty of Mechanical Engineering Ho Chi Minh City University of TechnologyVNUHCM268 Ly Thuong KietDistrict 10Ho Chi Minh City 740400Viet Nam

In this study,we synthesized high-performance Carbon Fiber/Gold/Copper(CF/Au/Cu)composite wires by using a 2-step deposition method via sputtering and *** Au was sputtered on PANbased CFs as a pre-treatment,the wettability and surface reactivity of the CFs were improved,resulting in a homogeneous deposition of Cu on their *** different Cu electrodeposition time,the resulting CF/Au/Cu composite wires could possess a high strength of up to 3.27 GPa(~10 times stronger than copper wires)while their electrical conductivity could be as high as 4.4×10^5 S/cm(~75%of that for copper).More importantly,since the composite wires were lightweight(up to 70%lower than Cu mass density),they are a promising candidate to substitute conventional heavy metal wires in the future electrical applications.

关键词： Carbon fiber Copper composite wires Strength Electrical properties