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Energy Scattering of a Generalized Davey–Stewartson System in Three Dimension

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Acta Mathematica Sinica,English Series 2017年第9期33卷 1206-1224页

作者： Jing LU xing dong TANG School of Mathematical Sciences Beijing Normal UniversityBeijing 100875P.R.China Institute of Applied Physics and Computational Mathematics Beijing 100088P.R.China

In this paper, we study the global scattering result of the solution for the generalized Davey-Stewartson system The main difficulties are the failure of the interaction Morawetz estimate and the asymmetrical structure of nonlinearity （in particular, the nonlinearity is non-local）. To compensate, we utilize the strategy derived from concentration-compactness idea, which was first introduced by Kenig and Merle .

关键词： Davey-Stewartson system scatter global well-posedness

Degradation kinetics and products of triazophos in intertidal sediment

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Journal of Environmental Sciences 2005年第6期17卷 933-936页

作者： LIN Kun-de YUAN dong-xing Institute of Environmental Science Zhejiang University Hangzhou 310029 China State Key Laboratory of Marine Environmental Science Environmental Science Research Center Xiamen University Xiamen 361005 China

This work presents taboratory studies on the degradation of triazophos in intertidat sediment. The overall degradations were found to follow the first-order decay model. After being incubated for 6 d, the percentage of degradations of triazophos in unsterilized and sterilized sediments were 94.5% and 20.5%, respectively. Between the temperatures of 15℃ and 35℃, the observed degradation rate constant（kob,d） enhanced as the incubation temperature increased. Triazophos in sediment degraded faster under aerobic condition than under anaerobic one. The water content of sediment had little influence on the degradation when it was in the range of 50%-100%. The values of kobsd decreased with increasing initial concentration of triazophos in sediment, which could result from the microorganism inhibition by triazophos. Four major degradation products, o, o-diethyl phosphorothioic acid, monoethyl phosphorothioic acid, phosphorothioic acid, and 1-phenyl-3-hydroxy-1, 2,4-triazole, were tentatively identified as their corresponding trimethylsilyl derivatives with a gas chromatography-mass spectrometer. The possible degradation pathway of triazophos in intertidal sediment was proposed. The results revealed that triazophos in intertidal sediment was relatively unstable and coutd be easily degraded.

关键词： triazophos degradation intertidal sediment

In situ FT-IR investigation on the reaction mechanism of visible light photocatalytic NO oxidation with defective g-C_3N_4

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Science Bulletin 2018年第2期63卷 117-125页

作者： Hong Wang Wenjie He xing’an dong Haiqiang Wang Fan dong Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and Resources Chongqing Technology and Business University Department of Environmental Engineering Key Laboratory of Polluted Environment Remediation and Ecological Health of Ministry of Education Zhejiang University

The g-C_3N_4 with different structures was prepared by heat treatment using urea(CN-U) and thiourea(CN-T) as precursors under the same conditions. The microstructure and optical properties of the photocatalyst were analyzed with advanced tools. The results showed that the CN-U has a porous structure, a high specific surface area and a wide band gap in comparison with CN-T. The in situ FT-IR technique was used to monitor the adsorption and reaction process of visible photocatalytic NO oxidation on g-C_3N_4. The corresponding reaction mechanism was proposed based on the results of reaction intermediate observation and electron paramagnetic resonance(EPR) radical scavenging. It was revealed that(1) the presence of defective sites favored the adsorption of gas molecules and electronically compensated it leading to promoted formation of the final products;(2) the high separation efficiency of photogenerated electron-hole pairs enhanced the production of radicals during the photocatalytic reaction;(3) the hydroxyl radicals(-OH) are not selective for the decomposition of pollutants, which are favorable to the complete oxidation of the reaction intermediates. The above three aspects are the main reasons for the CN-U possessing the efficient visible light photocatalytic activity. The present work could provide new insights and methods for understanding the mechanism of photocatalysis.

关键词： g-C3N4 Visible light photocatalysis Defects In situ FT-IR Reaction mechanism

Dynamic Active Sites in Bi_(5)O_(7)I Promoted by Surface Tensile Strain Enable Selective Visible Light CO_(2)Photoreduction

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Research 2023年第1期2022卷 301-311页

作者： Xian Shi xing'an dong Yanjuan Sun Shihan Zhang Fan dong Research Center for Environmental and Energy Catalysis Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province College of EnvironmentZhejiang University of TechnologyHangzhou 310014China

Surface defects with abundant localized electrons on bismuth oxyhalide catalysts are proved to have the capability to capture and activate CO_(2).However,bismuth oxyhalide materials are susceptible to photocorrosion,making the surface defects easily deactivated and therefore losing their function as active *** of deactivation-resistant surface defects on catalyst is essential for stable CO_(2)photoreduction,but is a universal *** this work,the Bi_(5)O_(7)I nanotubes with surface tensile strain are synthesized,which are favorable for the visible light-induced dynamic I defects *** CO_(2)molecules absorbed on I defects are constantly reduced by the incoming photogenerated electrons from I-deficient Bi_(5)O_(7)I nanotubes and the successive protonation of CO_(2)molecules is thus highly promoted,realizing the selective CO_(2)conversion process via the route of CO_(2)-COOH^(-)-*** efficient and stable photoreduction of CO_(2)into CO with 100%selectivity can be achieved even under visible light(>420 nm)irradiation benefited from the dynamic I defects as active *** results presented herein demonstrate the unique action mechanism of light-induced dynamic defects during CO_(2)photoreduction process and provide a new strategy into rational design of deactivation-resistant catalysts for selective CO_(2)photoreduction.

关键词： visible bismuth rational

Determination of neomycin in water samples by high performance anion chromatography with pulsed amperometric detection

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Chinese Chemical Letters 2007年第2期18卷 201-204页

作者： Bin Guan dong xing Yuan Environmental Science Research Center Xiamen University Xiamen 361005 China

A simple, fast and reliable method, using high performance anion chromatography with pulsed amperometric detection, had been developed for the analysis of neomycin in water samples. The elution and separation were carried out with an isocratic mobile phase, containing 10 mmol/L NaOH. The influence of the concentration and pH of the mobile phase on the separation and detection was investigated. A quadruple-potential waveform used for the detection was optimized. The detection limit of neomycin was down to 0.027 μg/mL. The linearity of neomycin calibration curve ranged from 0.050 to 0.505 μg/mL with correlation coefficient of 0.9997. R.S.D. (n = 11) was 4.0%.

关键词： Neomycin High performance anion chromatography Pulsed amperometric detection

On the Blowup Phenomenon for N-coupled Focusing Schrdinger System in R^d(d≥3)

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Acta Mathematica Sinica,English Series 2014年第7期30卷 1161-1179页

作者： xing dong TANG Ji Hui ZHANG Institute of Mathematics School of Mathematical SciencesNanjing Normal University

We study blow-up, global existence and ground state solutions for the N-coupled focusing nonlinear SchrSdinger equations. Firstly, using the Nehari manifold approach and some variational techniques, the existence of ground state solutions to the equations （CNLS） is established. Secondly, under certain conditions, finite time blow-up phenomena of the solutions is derived. Finally, by introducing a refined version of compactness lemma, the L2 concentration for the blow-up solutions is obtained.

关键词： Schrodinger equations blow-up ground state mass concentration

The application of C–H bond functionalization in the total syntheses of indole natural products

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Organic Chemistry Frontiers 2022年第4期9卷 1195-1210页

作者： dong-xing Tan Fu-She Han CAS Key Lab of High-Performance Synthetic Rubber and its Composite Materials Changchun Institute of Applied ChemistryChinese Academy of Sciences5625 Renmin StreetChangchunJilin 130022China

The direct functionalization of unactivated C–H bonds has been a rapidly growing field in organic chem-istry in recent years because of its indisputable advantages in bond forming reactions in terms of step and atom-... 详细信息

关键词： functionalization bonds bond

N_(2)photofixation promoted by in situ photoinduced dynamic iodine vacancies at step edge in Bi_(5)O_(7)I nanotubes

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Nano Research 2023年第5期16卷 6679-6686页

作者： xing’an dong Kaiwen Wang Zhihao Cui Xian Shi Zhiming Wang Fan dong Research Center for Carbon-Neutral Environmental&Energy Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China Beijing Key Lab of Microstructure and Properties of Advanced Materials Beijing University of TechnologyBeijing 100124China Department of Chemistry and Biochemistry The Ohio State UniversityColumbusOhio 43210USA

Heterogeneous photosynthesis is a promising route for sustainable ammonia production,which can utilize renewable energy and water as the hydrogen source under ambient *** this study,a series of Bi_(5)O_(7)I(BOI)nanosheets and nanotubes are synthesized,the surface tensile strain is formed by curling the nanosheets into nanotubes to tune the concentration and location of dynamic *** transmission electron microscopy(STEM)with spherical aberration correction confirms the presence of intrinsic areal defects on the surface of the BOI nanotube resulted from surface tensile *** presence of areal defects lowers the formation energy of I vacancies(IV)at step edge site,thus the IV with higher concentration would be favorably generated under visible *** scan in situ Fourier transform infrared(FT-IR)analysis in the aqueous media reveals that the IV promotes photocatalytic N_(2) activation and reduction,proceeds through an associative alternating ***,after turning off the light,the surface vacancy sites can be reoccupied by I−ions,which enables the protection and regeneration of photocatalyst surface in an aerobic and dark *** work provides an innovative strategy to tune concentration and location of dynamic surface vacancies on photocatalysts by building surface tensile strain for advancing sustainable ammonia production.

关键词： nitrogen fixation halogen vacancy photoreduction surface tensile strain rapid scan in situ Fourier transform infrared(FTIR)

Tensile stress enhanced dynamic oxygen vacancies on interlayer stretched Bi_(2)O_(2)CO_(3) as pivotal knobs to promote sustainable selective CO_(2) photoreduction

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Journal of Energy Chemistry 2023年第8期83卷 173-179,I0006页

作者： Xian Shi Weidong Dai xing'an dong Qin Ren Ping Yan Fan dong School of Chemistry and Environmental Engineering Sichuan University of Science&EngineeringZigong 643000SichuanChina Research Center for Carbon-Neutral Environmental&Energy Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731SichuanChina State Centre for International Cooperation on Designer Low-Carbon and Environmental Materials(CDLCEM) School of Materials Science and EngineeringZhengzhou UniversityZhengzhou450001HenanChina College of Architecture and Environment Sichuan UniversityChengdu 610065SichuanChina

Surface oxygen vacancies(OVs) with abundant localized electrons on bismuth-oxygen based photocatalysts are proved to have the ability to capture and activate CO_(2).However,the surface OVs are easily filled with oxygen-containing species and destroyed,losing their effects as active sites and hindering the subsequent CO_(2)*** realistic and sustainable CO_(2)photoreduction,constructing sustainable and stable surface OVs as active sites on photocatalysts is *** work shows the synthesis of interlayer stretched Bi_(2)O_(2)CO_(3) ultrathin nanosheets with tensile stress,which are beneficial to continuously generating light-induced dynamic *** sufficient active sites,excellent,stable,and selective photoreduction of CO_(2)to CO under simulated solar light is *** light-induced OVs can reduce the energy barrier of rate-determining step,resulting in the 100% product *** results presented herein demonstrate the effect of dynamic OVs induced by interlayer tensile strain on catalysts for the enhanced selective CO_(2)photoreduction process.

关键词： Ultrathin Bi_(2)O_(2)CO_(3) Dynamic oxygen vacancies Product selectivity Charge transfer CO_(2) phororeduction