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Lagrangian simulation of multi-step and rate-limited chemical reactions in multi-dimensional porous media

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Water Science and Engineering 2018年第2期11卷 101-113页

作者： Bing-qing Lu Yong Zhang Hong-guang Sun Chun-miao Zheng Department of Geological Sciences University of Alabama College of Mechanics and Materials Hohai University School of Environmental Science and Engineering Southern University of Science and Technology

Management of groundwater resources and remediation of groundwater pollution require reliable quantification of contaminant dynamics in natural aquifers, which can involve complex chemical dynamics and challenge traditional modeling approaches. The kinetics of chemical reactions in groundwater are well known to be controlled by medium heterogeneity and reactant mixing, motivating the development of particle-based Lagrangian approaches. Previous Lagrangian solvers have been limited to fundamental bimolecular reactions in typically one-dimensional porous media. In contrast to other existing studies, this study developed a fully Lagrangian framework, which was used to simulate diffusion-controlled, multi-step reactions in one-, two-, and three-dimensional porous media. The interaction radius of a reactant molecule, which controls the probability of reaction, was derived by the agent-based approach for both irreversible and reversible reactions. A flexible particle tracking scheme was then developed to build trajectories for particles undergoing mixing-limited, multi-step reactions. The simulated particle dynamics were checked against the kinetics for diffusion-controlled reactions and thermodynamic wellmixed reactions in one-and two-dimensional domains. Applicability of the novel simulator was further tested by(1) simulating precipitation of calcium carbonate minerals in a two-dimensional medium, and(2) quantifying multi-step chemical reactions observed in the laboratory. The flexibility of the Lagrangian simulator allows further refinement to capture complex transport affecting chemical mixing and hence reactions.

关键词： Lagrangian framework Chemical reaction Diffusion-limited process Multi-step reactions Interaction radius

Cubic Auto-Catalysis reactions in Three-Dimensional Nanofluid Flow Considering Viscous and Joule Dissipations Under Thermal Jump

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Communications in Theoretical Physics 2019年第7期71卷 779-792页

作者： Rakesh Kumar Ravinder Kumar Reena Koundal Sabir Ali Shehzad Mohsen Sheikholeslami Department of Mathematics Central University of Himachal PradeshDharamshalaIndia Department of Mathematics COMSATS University IslamabadSahiwal 57000Pakistan Department of Mechanical Engineering Babol Noshirvani University of TechnologyBabolIran

In this problem,simultaneous effects of Joule and viscous dissipation in three-dimensional flow of nanoliquid have been addressed in slip flow regime under time dependent rotational oscillations.Silver nanoparticles are submerged in the base fluid(water)due to their chemical and biological features.To increment the novelty,effects of cubic autocatalysis chemical reactions and radiative heat transfer have been incorporated in the related boundary layer equations.Dimensionless partial differential system is solved by employing the proposed implicit finite difference approach.Convergence conditions and stability criteria are obtained to ensure the convergence and accuracy of solutions.A comparative analysis is proposed for no-slip nanofluid flow(NSNF)and slip nanofluid flow(SNF).Variations in skin-friction coefficients,Sherwood and Nusselt numbers against physical parameters are tabulated.It is investigated that velocity slip and temperature jump significantly control drag forces and rate of heat transfer.

关键词： cubic autocatalysis reactions viscous dissipation Joule heating rotating-fluctuating environment slip flow regime

SOLVABILITY OF A NONLINEAR PROBLEM ARISING IN reactions OVER INHOMOGENEOUS SURFACES

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Acta Mathematica Scientia 2019年第5期39卷 1380-1396页

作者： Vladas SKAKAUSKAS Faculty of Mathematics and Informatics Vilnius University

The existence and uniqueness theorem of classical solutions of a coupled system of nonlinear parabolic PDEs arising in modelling of chemical reactions between two polymeric reactants over inhomogeneous surfaces with n... 详细信息

关键词： coupled parabolic systems positive solutions of differential equations surface reactions spillover

Zinc-mediated reactions on salicylaldehyde for Botrytis cinerea control

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Chinese Chemical Letters 2020年第3期31卷 706-710页

作者： Antoine Franche Claire Imbs Antoine Fayeulle Franck Merlier Muriel Billamboz Estelle Léonard Sorbonne University Universitéde technologie de CompiègneESCOMEA TIMR 4297Centre de recherche de RoyallieuCS 6031960203 Compiègne cedexFrance ESCOM UTCEA TIMR 42971 allée du Réseau Jean-Marie Buckmaster60200 CompiègneFrance Sorbonne Universités Universitéde Technologie de CompiègneGénie Enzymatique et Cellulaire(GEC)UMR-CNRS 7025CS 6031960203 Compiègne CedexFrance Laboratoire de chimie durable et santé Yncrea Hauts-de-FranceHEI13 rue de Toul59046 Lille CedexFrance

Botrytis cinerea is a necrotrophic fungusth at a ffects various plant species.Chemical control is an ecessity and as much as possible,eco-friendly conditions and bioresources to obtain these chemicals should be used.In this context,a series of products w as obtained from salicylaldehyde using zinc as a powerful reagent and tested for antifungal activity against Botrytis cinerea.

关键词： Salicylaldehyde Zinc-mediated reactions Green solvents Alkoxymethylphenol PEG-cresol Botrytis cinerea control

Base initiated halogen-exchange reactions between perhaloalkanes

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Science China Chemistry 1997年第5期40卷 475-484页

作者：傅伟敏李兴亚蒋锡夔 Shanghai Institute of Organic Chemistry Chinese Academy of SciencesShanghai 200032China

Halophilic attacks on C-X bonds (X=Br,Cl) by a base can easily initiate mtermolecular bromme-chlonne exchange reactions either among bromine-or chlorine-containing perhaloalkane molecules of different compounds of among molecules of the same compound It provides a new and convenient method to synthesize perhaloal-kanes Apparently,it pertains to an amomc mechanism,i e.the reaction is initiated by halophilic attack on C-X bonds by the base,and an intermediate carbanion is formed.Distributions of the products depend on the equilibria involving all carbanion intermediates and perhaloalkane product molecules.

关键词： halophilic attack perhaloalkanes bromine-chlorine exchange reactions carbanion’s mechanism

STUDIES　ON　THE　SYNTHESIS　AND　reactions　OF　N－（1－OXO－4－CARBONYL－2，6，7－TRIOXA－1－PHOSPHABICYCLO　［2．2．2］　OCTANE）－N＇－ARYL　THIOUREAS

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Chinese Chemical Letters 1995年第1期6卷 19-22页

作者： Yu Gui LI Xue Feng ZHU Institute of Elemento-Organic Chemistry, Nanka i University,Tianjin, 300071 Nankai Univ Inst Elementoorgan Chem Tianjin 300071 Peoples R China

N- (1 -oxo-4-carbony 1-2. 6, 7- trioxa- 1 -phosphabicyclo[2. 2. 2] octane) - N- aryl thioureas (4)were syntbesized in this paper. (4) reacted,with AgNO3-H2O and chloroacetyl cblor ide to afford the corresponding urea herivatives (5) and cycli- zed produets (10), respectively, The mechanism of desulphurisation of (4) bas also been studied.

关键词： OXO CARBONYL OF reactions ARYL AND

Alkaline generation and reactions of CF3CHN2

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Science China Chemistry 2019年第8期62卷 923-924页

作者： Nicolai Rosenbaum Christoph Zippe Stefan Brase Institute of Organic Chemistry Karlsruhe Institute of TechnologyFritz-Haber- Weg 676131 KarlsruheGermany Institute of Toxicology and Genetics Karlsruhe Institute of TechnologyHermann-von-Helmholtz-Platz I 76344 Eggenstein-LeopoldshafenGermany

Fluorinated organic compounds display significant impact in the fields of agrochemicals, pharmaceuticals and materials science. However, very few fluorine-containing compounds are available from nature, and therefore studies of the distinct effect of fluorine substitution mainly depend on the ease of access to fluorinated scaffolds. Among fluorination strategies, the development and application of fluorinated diazo compounds has provided a convenient and effective method for the construction of various fluorinated structural moieties.

关键词： Alkaline generation reactions of CF3CHN2 fluorination strategies

Calibration of CR-39 solid-state track detectors for study of laser-driven nuclear reactions

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Nuclear Science and Techniques 2020年第4期31卷 118-122页

作者： Yang-Fan He Xiao-Feng Xi Shi-Lun Guo Bing Guo Chuang-Ye He Fu-Long Liu Di Wu Ji-Hong Wei Wan-Sha Yang Luo-Huan Wang Dong-Hai Zhang Meng-Lin Qiu Guang-Fu Wang Chao-Yang Li Xiao-Fei Lan School of Physics and Space Sciences China West Normal UniversityNanchong 637002China China Institute of Atomic Energy Beijing 102413China College of Nuclear Science and Technology Beijing Normal UniversityBeijing 100875China School of Physics and Information Engineering Shanxi Normal UniversityLinfen 041004China

It is of particular interest to investigate nuclear fusion reactions generated by high-intensity lasers in plasma environments that are similar to real astrophysical conditions.We have experimentally investigated2H(d,p)3H,one of the most crucial reactions in big bang nucleosynthesis models,at the Shenguang-Ⅱlaser facility.In this work,we present a new calibration of CR-39 solidstate track detectors,which are widely employed as the main diagnostics in this type of fusion reaction experiment.We measure the dependence of the track diameter on the proton energy.It is found that the track diameters of protons with different energies are likely to be identical.We propose that in this case,the energy of the reaction products can be obtained by considering both the diameters and gray levels of these tracks.The present results would be very helpful for analyzing the2 H(d,p)3H reaction products recorded with the same batch of CR-39 solid-state track detectors.

关键词： Big bang nucleosynthesis Laser-driven nuclear reactions CR-39 detectors Gray levels

A qualitative study on the adverse reactions of mass treatment for lymphatic filariasis in Orissa,India

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Asian Pacific Journal of Tropical Medicine 2010年第1期3卷 55-58页

作者： Babu BV Division of Epidemiology Regional Medical Research CentreIndian Council of Medical ResearchBhubaneswar-751 023India & Indian Council of Medical ResearchNew Delhi 110 029India

Objective:To describe the perceptions of community members and programme partners regarding severity,management and impact of adverse reactions on mass drug administration (MDA) compliance.Methods:Based on various qualitative data collected from five districts of Orissa,India,where MDA had been implemented during 2002 and 2004.The qualitative surveys included focus group discussions with community members and health workers,and semi-structured interviews with key informants in the community,medical officers at primary health centres,district level health officers and private practitioners.Results:It showed that many people suffered from adverse reactions,though the reactions were not serious.The paper reported different ways of management of adverse reactions at the community level.The impact of adverse reactions on MDA compliance was serious,as many people did not consume the drug due to fear of adverse reactions.The rumours of adverse reactions and news in media deterred people from consuming the tablets.Conclusion:All categories of respondents indicates the need of more information to address the problem of adverse reactions during MDA.The present paper warrants incorporating the messages on adverse reactions during health communication and social mobilization campaigns of MDA.

关键词： Lymphatic filariasis Mass drug administration Adverse reactions Qualitative study Orissa India