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Strong Convergence Theorems of Common Elements for Equilibrium Problems and Fixed Point Problems in Banach Spaces

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Acta Mathematicae Applicatae Sinica 2012年第2期28卷 337-350页

作者： Xing-hui gao hai-yun ZHOU College of Mathematics and Computer Science Yanan UniversityYanan 716000China Department of Mathematics Shijiazhuang Mechanical Engineering UniversityShijiazhuang 050003China

In this paper, we consider hybrid algorithms for finding common elements of the set of common fixed points of two families quasi-C-non-expansive mappings and the set of solutions of an equilibrium problem. We establish strong convergence theorems of common elements in uniformly smooth and strictly convex Banach spaces with the property （K）.

关键词： strong convergence projection quasi-Ф-nonexpansive mapping common elements theproperty (K)

Constructing ultrafine monodispersed Co_(2)P/(0.59-Cu_(3)P)on Cu doped CoZn-ZIF derived porous N-doped carbon for highly efficient dehydrogenation of ammonia borane

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Nano Research 2023年第5期16卷 6687-6700页

作者： Yinze Yang Liqing zhao Xiangyang gao Yafei zhao School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China State Key Laboratory of Electroanalytical Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Environmental Engineering and Chemistry Luoyang Institute of Science and TechnologyLuoyang 471023China Key Laboratory of Artificial Micro Nano-structures of Ministry of EducationSchool of Physics and TechnologyWuhan UniversityWuhan 430072China

Rational construction of highly dispersed,small size,low cost catalysts for release of hydrogen from ammonia borane(AB)is regarded as a prospective approach for promoting the development of upcoming hydrogen ***,the high price and scarcity of precious metal catalysts impose restrictions on their large-scale *** this end,with the aid of a Cu doped CoZn-zeolitic imidazolate frameworks(ZIFs)template strategy,we successfully construct ultrafine monodispersed Co_(2)P/(0.59-Cu_(3)P)on CoZn-ZIF derived porous N-doped carbon(Co_(2)P/(0.59-Cu_(3)P)-NC)as an efficient non-noble-metal ***,Co and Cu atoms can be geometrically separated to high degree due to the presence of Zn in the CuCoZn-ZIF precursor,evaporation of Zn during pyrolysis can generate porous structure with the framework well *** results show that porous Co_(2)P/(0.59-Cu_(3)P)-NC bimetallic phosphide exhibits large specific surface area,hierarchical pore structure,well-exposed active *** on the kinetics analyses and ion effects,the catalyst has achieved an unprecedentedly high total turnover frequency(TOF)of 798 mol·molcat^(−1)·min^(−1)in 0.4 M NaOH solution at 298 K,which surpasses all the ever-reported transition-metal phosphides catalysts for hydrogen generation from *** and theoretical studies confirm that the highly porous structure of the support,the ultrafine and high dispersion of nanoparticles,the N/P doping and their synergistic effects(e.g.,M-P,M-N,N-C,M-M',M-support)jointly induce strong electron transfer,which can reduce the reaction energy barrier and enhance their interaction with AB,thus correspondingly obtaining excellent catalytic *** mechanism and strategy presented in this work pave an avenue for the design of non-noble metal catalyst for hydrogen energy system.

关键词： non-noble metal transition-metal phosphides porous N-doped carbon hydrogen evolution ammonia borane catalytic hydrolysis

Use of Helical Strakes for FIV Suppression of Two Inclined Flexible Cylinders in A Side-by-Side Arrangement

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China Ocean Engineering 2018年第3期32卷 331-340页

作者： XU Wan-hai ZHANG Shu-hai ZHOU Li-dan gao Xi-feng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Collaborative Innovation Centre for Advanced Ship and Deep-Sea Exploration Shanghai 200240China

The experimental studies on flow-induced vibrations(FIV) reduction of two side-by-side flexible cylinders inclined at 45° by using the helical strakes were carried out in a towing tank. The main aim of the experiment is to check whether the helical strakes with a pitch of 17.5 D and a height of 0.25 D, which is considered as the most effective vibration suppression device for the isolated cylinder undergoing vortex-shedding, still perform very well to reduce FIV of two inclined flexible cylinders in a side-by-side arrangement. The vibration of two identical inclined cylinders with a mass ratio of 1.90 and an aspect ratio of 350 was tested in the experiment. The center-to-center distance between the two cylinders was 3.0 D. The uniform flow was simulated by towing the cylinder models along the *** towing velocity varied from 0.05 to 1.0 m/s with an interval of 0.05 m/s. The maximum Reynolds number can be up to 1.6×104. Three cases were experimentally studied in this paper, including two side-by-side inclined smooth cylinders, only one smooth cylinder fitted with helical strakes in the two side-by-side inclined cylinders system and both two cylinders attached with helical strakes. The variations of displacement amplitude, dominant frequency, FIV suppression efficiency and dominant mode for the two side-by-side inclined cylinders with reduced velocity were shown and discussed.

关键词： helical strakes FIV suppression inclined cylinder side-by-side towing tank experiment

Visible-light-driven photocatalysis degradation of antibiotic pollutants by La-doped CeO_(2) nanorods:synergy of La doping and oxygen vacancy

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Rare Metals 2024年第7期43卷 3134-3145页

作者： Shi-hai Cao Jing-Ru Qu Yu-Qi zhao Yun-Tong Sun Wen-Tong gao Bing Han Yao Lu College of Environmental Engineering Nanjing Institute of TechnologyNanjing 211167China School of Materials Science and Engineering Nanjing Institute of TechnologyNanjing 211167China School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological UniversitySingapore 637459Singapore Institute of Environmental Health and Ecological Security School of Environment and Safety EngineeringJiangsu UniversityZhenjiang 212013China Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment Suzhou University of Science and TechnologySuzhou215009China

Elemental doping is an effective strategy to enhance photocatalytic activity and extend the light absorption range of single-component *** this work,a series of La-doped CeO_(2) nanorods(La-CeO_(2)-x) with La content of 1 wt%-15 wt% are synthesized by a simple hydrothermal method and further used as photocatalyst for sulfamerazine(SMR) *** prepared La-CeO_(2)-x nanorods exhibit a great improvement in electron-hole pair migration and visible-light response due to the synergistic effect of abundant oxygen vacancies and heterogeneous elements(La).Consequently,La-CeO_(2)-x exhibited excellent visible-light photocatalytic performances and chemical stability for SMR degradation,the La-CeO_(2)-5 sample achieved the highest SMR degradation rate of 81%,which was 3.4 times higher than that of the original CeO_(2).Furthermore,three possible degradation pathways of SMR in La-CeO_(2) photocatalytic reactions were proposed by liquid chromatography-mass spectrometry ***,density functional theory calculations were carried out to provide an in-depth understanding of the structure-performance *** its excellent properties and better photocatalytic performance,this study demonstrates that La doping in CeO_(2) is an effective way to increase oxygen vacancy and improve the photochemical properties of photocatalysts.

关键词： CeO_(2)nanorod La-doped Photocatalysis Oxygen vacancy Sulfamerazine

The prediction on in-line vortex-induced vibration of slender marine structures

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Acta Mechanica Sinica 2012年第5期28卷 1303-1308页

作者： Wan-hai Xu Xi-Feng gao Jie Du State Key Laboratory of Hydraulic Engineering Simulation and Safety School of Civil EngineeringTianjin University

The in-line （IL） vortex-induced vibration （VIV） that occurs frequently in ocean engineering may cause severe fatigue damage in slender marine structures. To the best knowledge of the authors, in existing literatures, there is no efficient analytical model for predicting pure IL VIV. In this paper, a wake oscillator model capable of analyzing the IL VIV of slender marine structures has been developed. Two different kinds of van der Pol equations are used to describe the near wake dynamics related to the fluctuating nature of symmetric vortex shedding in the first excitation region and alternate vortex shedding in the second one. Some comparisons are carried out between the present model results and experimental data. It is found that many phenomena observed in experiments could be reproduced by the present wake oscillator model.

关键词： Vortex-induced vibration Wake oscillatormodel In-line Slender marine structures

Element nodal computation-based radial integration BEM for non-homogeneous problems

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Acta Mechanica Sinica 2013年第3期29卷 429-436页

作者： hai-Feng Peng Kai Yang Xiao-Wei gao State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology

This paper presents a new strategy of using the radial integration boundary element method （RIBEM） to solve non-homogeneous heat conduction and thermoelasticity problems. In the method, the evaluation of the radial in-tegral which is used to transform domain integrals to equivalent boundary integrals is carried out on the basis of elemental nodes. As a result, the computational time spent in evaluating domain integrals can be saved considerably in comparison with the conventional RIBEM. Three numerical examples are given to demonstrate the correctness and computational efficiency of the proposed approach.

关键词： Radial integral Boundary element method Non-homogeneous problem Heat conduction Thermoe-lasticity

CROSSLINKED ORGANOSILOXANE HYBRID MATERIALS PREPARED BY CONDENSATION OF SILANOL AND MODIFIED SILICA: SYNTHESIS AND CHARACTERIZATION

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Chinese Journal of Polymer Science 2013年第7期31卷 974-983页

作者： Da-hai gao 贾梦秋 Ying Luo College of Materials Science and Engineering Beijing University of Chemical Technology Nuclear Power Institute of China

Hybrid materials based on polymethylphenylsiloxane （PMPS） and organic functionalized silica were synthesized via condensation reaction between silanol and alkoxysilyl groups in the presence of quaternary ammonium hydroxide. The structure of prepared materials was investigated by FTIR and NMR, which indicate that the products have incorporated modified silica into the polymer matrix. The prepared hybrid materials show a satisfactory thermal resistance because the initial decomposition of typical product occurred at nearly 100 K higher than that of the pure polymer according to the thermogravimetric analysis （TGA） results. Differential thermogravimetric analysis （DTGA） data confirm that the thermal degradation of prepared hybrid materials comprises of two steps, of which the first one could be controlled by adjusting the content of silica particles and the ratio of surface groups on the particles. The coating films obtained from hybrid products exhibit good thermal mechanical properties. Therefore, the materials are hoped to be used for the application in thermal resistant coating.

关键词： Hybrid material Crosslinked polysiloxane Condensation polymerization Thermal stability.

FeP nanoparticles derived from metal-organic frameworks/GO as high-performance anode material for lithium ion batteries

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Science China Chemistry 2018年第9期61卷 1151-1158页

作者： Man gao Xiaowu Liu hai Yang Yan Yu Key Laboratory of Materials for Energy Conversion Chinese Academy of Sciences(CAS) Department of Materials Science and EngineeringUniversity of Science and Technology of China

Double carbon coated Fe P composite(Fe P@NC@r GO)was in situ fabricated via the phosphorization process of the as-prepared Prussian blue@graphene oxide(PB@GO)*** Fe P nanocrystals were successfully embedded in the nitrogen-doped porous carbon *** used as the anode for lithium ion batteries(LIBs),the Fe P@NC@r GO anode shows superior lithium storage properties,delivering a high specific capacity of 830 m A h g^(-1)after 100 cycles at 100 m A g^(-1)and excellent rate capability of 359 m A h g^(-1)at 5 A g^(-1).The outstanding performance mainly ascribes to the synergistic effect of the double carbon coating and porous structure *** introduction of porous carbon and graphene coating on Fe P nanoparticles greatly enhance the electronic conductivity of the active material and well accommodates the large volume variation of Fe P during the cycling process.

关键词： FeP Prussian blue reduced graphene oxide anode lithium ion battery

Influence of laser scanning speed on Cu-Zr-Al composite coatings on Mg alloys

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International Journal of Minerals,Metallurgy and Materials 2013年第6期20卷 568-573页

作者： Ya-li gao Meng Jie hai-bo Zhang School of Mechanical Engineering Northeast Dianli University School of Mechanical and Electrical Engineering Jilin Institute of Chemical Technology

To improve the surface properties of magnesium alloys, a study was conducted on Cu-Zr-A1 composite coatings on AZ91HP magnesium alloy by laser cladding. The influence of laser scanning speed on the microstructures and properties of the coatings was discussed. The coatings consist of amorphous phase, CusZr3, and Cul0ZrT. With the increase of laser scanning speed, the amorphous phase content of the coatings increases and reaches 60.56wt% with the laser scanning speed of 2.0 m/min. Because of the influence of laser scanning speed on the amorphous and crystal phases, the coatings show the maximum elastic modulus, hardness, and wear resistance at the laser scanning speed of 1.0 m/min. At the laser scanning speed of 2.0 m/min, the coatings have the best corrosion resistance.

关键词： magnesium alloys composite coatings amorphous laser cladding speed