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Flower-like NiCo_(2)S_(4)/NiFeP/NF composite material as an effective electrocatalyst with high overall water splitting performance

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Chinese Chemical Letters 2022年第9期33卷 4367-4374页

作者： Jing Jiang fengyan li Hui Su Yangqin Gao Ning li Lei Ge State Key Laboratory of Heavy Oil Processing College of New Energy and MaterialsChina University of Petroleum BeijingBeijing 102249China Department of Materials Science and Engineering College of New Energy and MaterialsChina University of Petroleum BeijingBeijing 102249China

Rational design and building of high efficiency,secure and inexpensive electrocatalyst is a pressing demand and performance to promote sustainable improvement of hydrogen *** bifunctional electrocatalysts for oxygen evolution reaction(OER)and hydrogen evolution response(HER)with high catalytic performance and steadiness in the equal electrolyte are extra treasured and ***,a unique three-dimensional(3D)structure electrocatalyst for NiCo_(2)S_(4)growing on the flower-like NiFeP was designed and synthesized in this *** results show that the flower-like NiCo_(2)S_(4)/NiFeP/NF composite electrocatalyst has large specific surface area,appropriate electrical conductivity,and greater lively websites uncovered in the three-dimensional structure,and affords extraordinary electrocatalytic overall performance for the ordinary water *** alkaline solution,the OER and HER overpotentials of NiCo_(2)S_(4)/NiFeP/NF only need 293 mV and 205 mV overpotential to provide the current densities of 100 mA/cm^(2)and 50 mA/cm^(2),*** high electrocatalytic activity exceeds the catalytic activity of most nickel-iron based electrocatalysts for OER and HER ***,the optimized NiCo_(2)S_(4)/NiFeP/NF sample has higher stability(24 h)at 1.560 and 10 mA/cm^(2),which extensively speeds up the overall water splitting *** view of the above performance,this work offers a fine approach for the further improvement of low fee and excessive effectivity electrocatalyst.

关键词： NiCo_(2)S_(4) Electrocatalyst NiFeP Hydrogen evolution reaction Water splitting

Study on Synthesis and Catalytic Performance of Hierarchical Zeolite

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China Petroleum Processing & Petrochemical Technology 2007年第3期9卷 57-60页

作者： Zhang lingling li fengyan ZhaoTianbo Sun Guida Department of Chemical Engineering Beijing Institute of Petrochemical Technology Beijing 102617 School of Science Beijing Institute of Technology

A kind of hierarchical zeolite catalyst was synthesized by hydrothermal method. X-ray diffraction （XRD） and nitrogen adsorption-desorption method were used to study the phase and aperture structure o（ the prepared catalyst. Infrared （IR） spectra of pyridine adsorbed on the sample showed that the hierarchical zeolite really had much more Bronsted and Lewis acidic sites than the HZSM-5 zeolite. The catalytic cracking of large hydrocarbon molecules showed that the hierarchical zeolite had a higher catalytic activity than the HZSM-5 zeolite.

关键词： hierarchical zeolite catalytic cracking of large hydrocarbon molecules selectivity HZSM-5zeolite

High activity in catalytic cracking of large molecules over micro-mesoporous silicoaluminophosphate with controlled morphology

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Science China Chemistry 2010年第11期53卷 2279-2284页

作者： QI Jian ZHAO TianBo XU Xin li fengyan SUN GuiDa Institute for Chemical Physics Beijing Institute of TechnologyBeijing 100081China Department of Applied Chemistry Beijing Institute of Petrochemical TechnologyBeijing 102617China

A novel micro-mesoporous silicoaluminophosphate(MUS-5) with controlled morphology has been first synthesized in a two-step *** physical properties of the silicoaluminophosphate were characterized using XRD,SEM,TEM,nitrogen adsorption-desorption and NH3-TPD *** the pH value of the solution system was varied in the range from 2.0 to 5.0,three different morphologies of silicoaluminophosphate including chain-like,flower-like and barrel-like morphology were *** tests showed that the silicoaluminophosphate exhibited higher catalytic activity compared with the conventional microporous SAPO-5 under the same conditions for catalytic cracking of 1,3,5-triisopropylbenzene heavy *** remarkable catalytic reactivity was mainly attributed to the presence of the hierarchical porosity in the silicoaluminophosphate catalyst.

关键词： micro-mesoporous silicoaluminophosphate controlled morphology catalytic cracking large molecule

Synthesis, characterization and hydrotreating performance of supported tungsten phosphide catalysts

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Frontiers of Chemical Science and Engineering 2008年第2期2卷 155-164页

作者： Guida SUN Cuiqing li Zhijun ZHOU fengyan li Green Chemistry and New Catalytic Material Laboratory Beijing Institute of Petrochemical TechnologyBeijing 102617China

Supported tungsten phosphide catalysts were prepared by temperature-programmed reduction of their precursors(supported phospho-tungstate catalysts)in H2 and characterized by X-ray diffraction(XRD),BET,temperature-programmed desorption of ammonia(NH3-TPD)and X-ray photoelectron spectroscopy(XPS).The reduction-phosphiding processes of the precursors were investigated by thermogravimetry and differential thermal analysis(TG-DTA)and the suitable phosphiding temperatures were *** hydrodesulfurization(HDS)and hydrodenitrogenation(HDN)activities of the catalysts were tested by using thiophene,pyridine,dibenzothiophene,carbazole and diesel oil as the *** TiO2,c-Al_(2)O_(3) supports and the Ni,Co promoters could remarkably increase and stabilize active W species on the catalyst surface.A suitable amount of Ni(3%–5%),Co(5%–7%)and V(1%–3%)could increase dispersivity of the W species and the BET surface area of the WP/c-Al_(2)O_(3) *** WP/c-Al_(2)O_(3) catalyst possesses much higher thiophene HDS and carbazole HDN activities and the WP/TiO2 catalyst has much higher dibenzothiophene(DBT)HDS and pyridine HDN *** Ni,Co and V can obviously promote the HDS activity and inhibit the HDN activity of the WP/c-Al_(2)O_(3) *** G-Ni5 catalyst possesses a much higher diesel oil HDS activity than the sulphided industrial NiW/c-Al_(2)O_(3) *** general,a support or promoter in the WP/c-Al_(2)O_(3) catalyst which can increase the amount and dispersivity of the active W species can promote its HDS and HDN activities.

关键词： supported tungsten phosphide catalyst hydrodesulfurization(HDS) hydrodenitrogenation(HDN) dibenzothiophene carbazole

Synthesis of Waterborne Polyurethane Modified by Nano-SiO_2 Silicone and Properties of the WPU Coated RDX

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China Petroleum Processing & Petrochemical Technology 2015年第2期17卷 39-45页

作者： li Yang Zhao Tianbo Qu Xiaoling Ding Hongjing li fengyan School of Chemistry Beijing Institute of Technology Department of Applied Chemistry Beijing Institute of Petrochemical Technology

A series of nano silica/silicone modified waterborne polyurethane(WPU) have been synthesized from polytetramethylene glycol and isophorone diisocyanate, dihydroxymethyl propionic acid and triethylamine, ethylenediamine, trimethylolpropane, nano-SiO2 and the silane coupling agent KH550. The effect of the dosage of nano-SiO2 on the WPU-Si membrane and the coated RDX(cyclotrimethylenetrinitramine) particles have been studied in terms of their surface properties, mechanical properties, and thermal stability. The results showed that with the increase of Si content, the stability of the emulsion reduced gradually. The material with more Si content displayed an increased thermodynamic stability, an increased high temperature resistance, an increased tensile strength and a decreased elongation at break. With the increase of Si content, the surface tension of the material decreased, the bibulous rate reduced, and the contact angle increased gradually, so that the surface tension of the polyurethane and RDX are close to each other which could improve the performance of coating.

关键词： nano-SiO2 organic silicon waterborne polyurethane coating of RDX

Preparation of ZSM-5 Coated on Monolithic Interconnected Macroporous Al2O3 Using Cheap n-Butylamine as Template

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Chinese Journal of Chemistry 2015年第9期33卷 1057-1063页

作者： Mingliang Sun Tianbo Zhao Jia Wang Zhaofei Ma fengyan li Institute for Chemical Physics Beijing Institute of Technology Beijing 100081 China Department of Applied Chemistry Beijing Institute of Petrochemical Technology Beijing 102617 China

Using cheap n-butylamine as template, ZSM-5 zeolites have been successfully synthesized and coated on mon- olithic interconnected macroporous Al2O3 by the secondary growth method. The use of cheap n-butylamine could significantly reduce the synthesis cost. Hierarchical monolithic ZSM-5 zeolites were prepared from synthetic mix- tures with different H2O/Na2O or SiO2/Al2O3 ratio. The synthesized samples were characterized by scanning elec- tron microscopy （SEM）, X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FT-IR） and N2 ad- sorption-desorption. The results show that the hierarchical monolithic zeolites were obtained with cheap n-butylamine template as template. During the hydrothermal reaction process, the morphology of the microme- ter-sized support was well maintained. The irregular crystals were formed in a wide range of the H2O/Na2O or SiO2/Al2O3 ratio of synthetic mixtures and coated on monolithic Al2O3. The relative crystallinity of the zeolites was highest at H2O/Na2O=250 or SiO2/Al2O3= 160. This type of composites exhibited hierarchical porous structures and relatively high specific surface areas.

关键词： hierarchical monolithic zeolites template synthesis secondary growth

Study on Preparation of Waterproofing Agent for Mineral Wool Board from Modified C_9 Petroleum Resin

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China Petroleum Processing & Petrochemical Technology 2013年第4期15卷 92-96页

作者： li fengyan Yang Yajun Dai Danghui Yuan Yadong Department of Chemical Engineering Beijing Institute of Petrochemical Technology

The modified petroleum resin emulsion prepared from the C9petroleum resin was modified with maleic *** effects of maleic rosin and maleic anhydride addition level,the modification time and the alkali liquor on the properties of the emulsion were *** results showed that the optimum process conditions covered:a maleic anhydride mass fraction of 1.5%,a maleic rosin mass fraction of 10%,a KOH mass fraction of 1%,a petroleum resin modification temperature of 200℃,a petroleum resin modification duration of 3 h,and a modified petroleum resin emulsion/wax emulsion mixing ratio of 1:*** particle size of modified petroleum resin emulsion prepared under these conditions was equal to 104.166μm.

关键词： C9 petroleum resin modifier waterproofing agent maleic rosin maleic anhydride

Energy Stable Nodal DG Methods for Maxwell’s Equations of Mixed-Order Form in Nonlinear Optical Media

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Communications on Applied Mathematics and Computation 2024年第1期6卷 30-63页

作者： Maohui Lyu Vrushali A.Bokil Yingda Cheng fengyan li State Key Laboratory of Scientific and Engineering Computing(LSEC) Academy of Mathematics and System SciencesChinese Academy of SciencesBeijing100190China Department of Mathematics College of ScienceOregon State UniversityCorvallisOR97331USA Department of Mathematics Michigan State UniversityEast LansingMI48824USA Department of Computational Mathematics Science and EngineeringMichigan State UniversityEast LansingMI48824USA Department of Mathematical Sciences Rensselaer Polytechnic InstituteTroyNY12180USA

In this work,we develop energy stable numerical methods to simulate electromagnetic waves propagating in optical media where the media responses include the linear Lorentz dispersion,the instantaneous nonlinear cubic Kerr response,and the nonlinear delayed Raman molecular vibrational *** the first-order PDE-ODE governing equations considered previously in Bokil et al.(J Comput Phys 350:420–452,2017)and Lyu et al.(J Sci Comput 89:1–42,2021),a model of mixed-order form is adopted here that consists of the first-order PDE part for Maxwell’s equations coupled with the second-order ODE part(i.e.,the auxiliary differential equations)modeling the linear and nonlinear dispersion in the *** main contribution is a new numerical strategy to treat the Kerr and Raman nonlinearities to achieve provable energy stability property within a second-order temporal discretization.A nodal discontinuous Galerkin(DG)method is further applied in space for efficiently handling nonlinear terms at the algebraic level,while preserving the energy stability and achieving high-order *** with d_(E)as the number of the components of the electric field,only a d_(E)×d_(E)nonlinear algebraic system needs to be solved at each interpolation node,and more importantly,all these small nonlinear systems are completely decoupled over one time step,rendering very high parallel *** evaluate the proposed schemes by comparing them with the methods in Bokil et al.(2017)and Lyu et al.(2021)(implemented in nodal form)regarding the accuracy,computational efficiency,and energy stability,by a parallel scalability study,and also through the simulations of the soliton-like wave propagation in one dimension,as well as the spatial-soliton propagation and two-beam interactions modeled by the two-dimensional transverse electric(TE)mode of the equations.

关键词： Maxwell’s equations Kerr and Raman Discontinuous Galerkin method Energy stability

24 h continuous observation of sodium layer over Wuhan by lidar

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Science China(Physics,Mechanics & Astronomy) 2007年第3期50卷 287-293页

作者： CHENG XueWu GONG ShunSheng li FaQuan DAI Yang SONG Juan WANG JiaMin li fengyan State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China

Based on the dual-wavelength lidar we have developed, the 24 h continuous ob- servation has been realized in its sodium channel by using Faraday atomic filter technology and other relevant technologies. This will facilitate the continuous ob- servation of the sodium layer and the relevant upper atmosphere over Wuhan. A result of about 50 h observation indicates that the daytime column density of so- dium layer over Wuhan is slightly increased compared to that during the nighttime, and the characteristics of the sporadic sodium layer occurring during the daytime are compared with that during the nighttime.

关键词： lidar 24 h continuous observation sodium layer Faraday atomic filter