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Liquid-phase epoxidation of propylene with molecular oxygen by chloride manganese meso-tetraphenylporphyrins

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Chinese Journal of Chemical Engineering 2022年第8期35卷 61-65页

作者： Xian-Tai Zhou ling-ling wang Yang Li Hong-Bing Ji Fine Chemical Industry Research Institute School of Chemical Engineering and TechnologySun Yat-sen UniversityZhuhai 519082China Fine Chemical Industry Research Institute School of ChemistrySun Yat-sen UniversityGuangzhou 510275China School of Chemical Engineering Guangdong University of Petrochemical TechnologyMaoming 525000China

Propylene molecule owns two active sites,the direct epoxidation of propylene by dioxygen is still a challenge due to the limitation of *** this work,the direct liquid-phase propylene aerobic epoxidation protocol by chloride manganese meso-tetraphenylporphyrin(MnTPPCl)was *** conversion of propylene was 12.7%,and the selectivity towards PO(propylene oxide)reached up to 80.5%.The formation of PO was attributed to the mechanism via high-valent Mn species,which was confirmed by means of in situ UV–vis spectrum.

关键词： Propylene Epoxidation Dioxygen Manganese porphyrins Liquid phase

Numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder

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Journal of Hydrodynamics 2023年第6期35卷 1101-1118页

作者： Cheng Zeng Yu-die Hu Yu-ran Yin Jie Zhou ling-ling wang College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing210098China China Water Resources Bei Fang Investigation Design and Research Co.LtdTianjin300222China College of Mechanics and Materials Hohai UniversityNanjing211100China

This paper presents a 2-D numerical investigation on interaction between regular waves and a fully submerged horizontal cylinder.A mathematical model of numerical wave tank with two-way fluid-solid interactions were developed and *** wave-induced vibrations of a single-degree-of-freedom cylinder were simulated at eleven gap ratios(d/a=8,10,12,14,16,18,20,22,24,28 and 32).Numerical results indicate that significant nonlinear characteristics are introduced into the originally linear waves with the presence of *** on the variation characteristics of cylinder vibration amplitude,the gap ratios can be divided into three ranges,i.e.,the uncertain range(8≤d/a≤14),quasi-linear range(14≤d/a≤20)and linear range(20≤d/a≤32).Under the same wave condition,the gap ratio does not affect the frequencies of vortex shedding and cylinder *** presence of the cylinder complicates the flow field and suppress the vortex shedding around the cylinder.

关键词： Numerical simulation linear wave wave-induced vibration gap ratio flow pattern

Facile Fabrication of Platinum Nanoparticles Supported on Nitrogen-doped Carbon Nanotubes and Their Catalytic Activity

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Chinese Journal of Chemical Physics 2014年第3期27卷 327-331页

作者： ling-ling wang Long Shen Hai-ying Jin Lu-ping Zhu Li-jun wang School of Urban Development and Environment Engineering Shanghai Second Polytechnic University Shanghai 201209 China Shanghai Shanshan Technology Co. Ltd. Shanghai 201209 China

A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes （CNx）. CNx do not need any pre-surface modification due to the inherent chemical activity. The structure and nature of Pt/CNx were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy spectrum. All the experimental results revealed that the large amount of doped nitrogen atoms in CNx was virtually effective for capturing the Pt（IV） ions. The improved surface nitrogen functionalities and hydrophilicity contributed to the good dispersion and immobi- lization of Pt nanoparticles on the CNx surface. The Pt/CNx served as active and reusable catalysts in the hydrogenation of allyl alcohol. This could be attributed to high dispersion of Pt nanoparticles and stronger interaction between Pt and the supports, which prevented the Pt nanoparticles from aggregating into less active Pt black and from leaching as well.

关键词： Carbon nanotube Nitrogen doping Allyl alcohol hydrogenation Pt nanoparticles Heterogeneous catalyst

Synthesis of Nitrogen Incorporated Carbon Nanotubes with Different Diameters by Catalytic Pyrolysis of Butylamine

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Chemical Research in Chinese Universities 2011年第6期27卷 903-905页

作者： JIN Hai-ying BING Nai-ci wang ling-ling wang Li-jun School of Urban Development and Environment Engineering Shanghai Second Polytechnic University Shanghai 201209 P. R. China

Bamboo-like nitrogen-doped carbon（CNx） nanotubes were synthesized by chemical vapor deposition （CVD） at a high reaction temperature of 600―900 °C. The butylamine and Fe/SBA-15 molecular sieve have been used as precursor and catalyst, respectively. Transmission electron microscopy（TEM） and high resolution transmission electron microscopy（HRTEM） observations show that the outer diameter and wall thickness as well as the inner diameter were increased with increasing reaction temperature in a temperature range of 600―800 °C. A synergism mechanism of the growth through bulk diffusion and the competitive growth through surface diffusion functions during the synthesis of CNx nanotubes was proposed.

关键词： Carbon nanotube Bamboo-like structure Nitrogen-doped carbon Multilayer structure

Impact of depth ratio on flow structure and turbulence characteristics of compound open channel flows

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Water Science and Engineering 2022年第3期15卷 265-272页

作者： Shao-wei Ding Cheng Zeng Jie Zhou ling-ling wang Chen Chen College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China College of Mechanics and Materials Hohai UniversityNanjing 211100China

Compound open channel flows appear in most natural rivers are of great importance in river management and flood *** this study,large eddy simulations were carried out to simulate the compound open channel flows with four different depth ratios(hr=0.10,0.25,0.50,and 0.75).The main flow velocity,secondary flow,Reynolds stress,and bed shear stress were obtained from numerical *** depth-averaged stream wise momentum equation was used to quantify the lateral momentum exchange between the main channel and *** instantaneous coherent structures were presented by the Q criterion *** impact of hr on flow structure and turbulence charac-teristics was *** results showed that with the increase of hr,the high velocity area in the main channel shifted to the floodplain,and the dip phenomenon became more obvious;the Reynolds stress largely contributed to the lateral momentum exchange within the flows near the side walls of floodplain;and the vortex structures were found to significantly increase in the floodplain region.

关键词： Large eddy simulation Compound open channel Depth ratio Flow structure Turbulence characteristics

Scalar transport by propagation of an internal solitary wave over a slope-shelf

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Journal of Hydrodynamics 2019年第2期31卷 317-325页

作者： Jin Xu ling-ling wang Hong-wu Tang Zhu Hai John James Reginald Williams State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hobai UniversityNanjing 210098China College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China School of Engineering and Materials Science Queen Mary University of LondonLondonUK

Internal solitary waves(ISWs)of depression are commonly found in the coastal environment and are believed to re-suspend sediments in coastal regions where the waves *** this research,the direct numerical simulation is used to study the scalar transport induced by the ISWs of depression propagating over a slope-shelf *** scalar in this paper is considered to represent the concentrations of very fine suspended solids or *** are observed from the numerical results at the bottom boundary layer on the slope during the ISW shoaling process,resulting in a scalar *** in cident ISWs of depression are observed to produce a waveform inversion on the *** scalar transport from a slope to a shelf is the consequence of the combined vortices at the bottom boundary layer and the overturning of the ISWs of depression,and the latter was commonly ignored in previous *** study shows that the ISW-induced scalar transport consists of the following four stages:the slip transport,the wash transport,the vortex transport,and the secondary transport.A dimensionless time scales of the four stages are calculated,and the beginning times of the wash transport and the secondary transport are found to be uncorrelated with the slope gradients,taking values of 1.26,4,respectively.

关键词： Internal solitary waves slope-shelf scalar transport wave inversion dimensionless time scale

Image Restoration Using Hybrid Features Improvement on Morphological Component Analysis

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Journal of Electronic Science and Technology 2019年第4期17卷 371-381页

作者： Der-Chang Tseng Ru-Yin Wei Ching-Ta Lu ling-ling wang the Department of Electronic Engineering National Taipei University of TechnologyTaipei 10608 Quanta Computer Inc. Taipei 11167 the Department of Information Communication Asia UniversityTaichung 41354

Images are generally corrupted by impulse noise during acquisition and *** deteriorates the quality of *** remove corruption noise,we propose a hybrid approach to restoring a random noisecorrupted image,including a block matching 3D(BM3D)method,an adaptive non-local mean(ANLM)scheme,and the K-singular value decomposition(K-SVD)*** the proposed method,we employ the morphological component analysis(MCA)to decompose an image into the texture,structure,and edge ***,the BM3D method,ANLM scheme,and K-SVD algorithm are utilized to eliminate noise in the texture,structure,and edge parts of the image,*** results show that the proposed approach can effectively remove interference random noise in different parts;meanwhile,the deteriorated image is able to be reconstructed well.

关键词： Adaptive non-local mean(ANLM) block matching 3D(BM3D) image restoration morphological component analysis(MCA) singular value decomposition(SVD).

SYNTHESIS OF POLY(GLUTAMIC ACID-co-ASPARTIC ACID) VIA COMBINATION OF N-CARBOXYANHYDRIDE RING OPENING POLYMERIZATION WITH DEBENZYLATION

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Chinese Journal of Polymer Science 2013年第12期31卷 1706-1716页

作者： Wei-xi Yang ling-ling wang Han Zhu Ri-wei Xu 吴一弦 State Key Laboratory of Chemical Resource Key Laboratory of Carbon Fiber and Functional Polymers(Ministry of Education)Beijing University of Chemical Technology

The random copolymers of glutamic acid （LG） and aspartic acid （ASP）, poly（LG-co-ASP）, with designed compositions could be successfully synthesized via combination of N-carboxyanhydride ring opening copolymerization with debenzylation. Ring opening copolymerizations of y：benzyl-L-glutamate N-carboxyanhydride （BLG-NCA） and β-benzyl-Laspartate N-carboxyanhydride （BLA-NCA） were carried out by using different amines including triethylamine （TEA）, diethylamine, n-hexylamine （NHA）, triphenylamine, diphenylamine or aniline as initiators. All the 6 amines were highly efficient to get well-defined poly（BLG-co-BLA） copolymers with designed compositions although the polymerizations proceeded via different mechanisms （normal amine mechanism or/and activated monomer mechanism）, which are based on chemical structure of amines. The molecular weights of poly（BLG-co-BLA） copolymers could be mediated by both TEA concentration and polymerization time. Then, debenzylation ofpoly（BLG-co-BLA） copolymers was conducted to prepare the corresponding hydrophilic random eopolymers of poly（LG-co-ASP） with a-subunit structure in ASP structural units. The contents of LG structural units in poly（LG-co-ASP） copolymers matched with those of BLG-NCA in NCA-monomer feeds in ring opening copolymerizations initiated by NHA or TEA and were closed to the theoretical line. The diblock copolymer of poly（BLG-b-BLA） could also be synthesized via living NCA ring opening copolymerization by sequential addition of BLG- NCA and BLA-NCA.

关键词： Peptide Ring opening polymerization Copolymer Glutamic acid Aspartic acid.

Large eddy simulation of water flow over series of dunes

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Water Science and Engineering 2011年第4期4卷 421-430页

作者： Jun LU ling-ling wang Hai ZHU Hui-chao DAI College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 P. R. China Zhangjiagang Water Conservancy Bureau Zhangjiagang 215600 P. R. China

Large eddy simulation was used to investigate the spatial development of open channel flow over a series of dunes. The three-dimensional filtered Navier-Stokes （N-S） equations were numerically solved with the fractional-step method in sigma coordinates. The subgrid-scale turbulent stress was modeled with a dynamic coherent eddy viscosity model proposed by the authors The computed velocity profiles are in good agreement with the available experimental results. The mean velocity and the turbulent Reynolds stress affected by a series of dune-shaped structures were compared and analyzed. The variation of turbulence statistics along the flow direction affected by the wavy bottom roughness has been studied. The turbulent boundary layer in a complex geographic environment can be simulated well with the proposed large eddy simulation （LES） model.

关键词： large eddy simulation (LES) dunes turbulent boundary layer flow separation