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Fracture Mechanism of the Formation with a Natural Flaw Under a Single-Tooth Cutting

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Acta Mechanica Solida Sinica 2020年第5期33卷 719-730页

作者： Siqi li Wei li Tie Yan Fuqing Bi Huan Zhao Xin ling Institute of Petroleum Engineering Northeast Petroleum UniversityDaqing163318HeilongjiangChina The Fifth Oil Production Plant of Daqing Oilfield Daqing163513HeilongjiangChina

The process of a single-tooth cutting formation is taken as the representative to analyze the fracture mechanism of the formation with natural flaws under the PDC drill *** modeling of the stress field distribution of the formation under a single tooth is proposed ***,the modeling of the stress intensity factor K,T-stress and the initiation angleθof the flaw under two far-field compressive loads in two cases are presented based on the mode-II ***,the results of theoretical calculations and simulations are given and *** on the analysis undertaken,it can be concluded that the confinement ratioλapplying on the flaw changes nonlinearly with the variation inα+φ.The relationship between the dimensionless ratioβx/βy of T-stress and the rotational polar angleφis a parabola with an upward *** the direction of the cutting force is consistent with the flaw,the stress intensity factor K and the initiation angleθat the tip of the flaw reach the *** addition,the angle between the cutting force and the flaw weakens the T-stress and inhibits the crack initiation and propagation of the *** results of numerical simulations show good agreement with theoretical calculations.

关键词： Single-tooth cutting Stress field Stress intensity factor Initiation angle Extended finite element

Effects of process parameters on the growth behavior and granule size distribution of iron ore mixtures in a novel high-shear granulator

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International Journal of Minerals,Metallurgy and Materials 2022年第12期29卷 2152-2161页

作者： Yang You Jiabao Guo Gang li Zhuang Zheng Yong li Xuewei Lü College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium–Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

This work proposes a novel horizontal high-shear granulator for iron ore granulation before sintering *** granulation behavior such as growth process and structure of granules were firstly analyzed,followed by the effects of operation conditions such as water content,initial particle size distribution,and the concentrate *** results show that the granule size increased significantly with increasing the granulation time,and the structure of granule can be divided into three types:non-nuclei,single-nuclei,and *** promotes the coalescence and growth of particles,and a better granulation performance was obtained at the water content of 8.8wt%under the current raw material *** the nuclei particle ratio led to an increase in average size of granules and permeability of the granules bed,but a decrease in growth ***,with increasing of concentrate ratio,granulation performance such as granule size,bed permeability,and uniformity became worse.

关键词： horizontal high-shear granulation iron ore granule structure granulation performance size distribution

Bacteriophages in water pollution control:Advantages and limitations

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Frontiers of Environmental Science & Engineering 2021年第5期15卷 29-43页

作者： Mengzhi Ji Zichen liu Kaili Sun Zhongfang li Xiangyu Fan Qiang li School of Biological Science and Technology University of JinanJinan250022China College of Food and Bioengineering Hezhou UniversityHezhou542899China

Wastewater is a breeding ground for many pathogens,which may pose a threat to human health through various water transmission ***,a simple and effective method is urgently required to monitor and treat *** bacterial viruses,bacteriophages(phages)are the most widely distributed and abundant organisms in the *** to their capacity to specifically infect bacterial hosts,they have recently been used as novel tools in water pollution *** purpose of this review is to summarize and evaluate the roles of phages in monitoring pathogens,tracking pollution sources,treating pathogenic bacteria,infecting bloom-forming cyanobacteria,and controlling bulking sludge and biofilm pollution in wastewater treatment *** also discuss the limitations of phage usage in water pollution control,including phage-mediated horizontal gene transfer,the evolution of bacterial resistance,and phage concentration *** review provides an integrated outlook on the use of phages in water pollution control.

关键词： Phage Water pollution monitoring Harmful bacteria biocontrol Horizontal gene transfer Bacterial resistance

Enhancing the long-term Na-storage cyclability of conversion-type iron selenide composite by construction of 3D inherited hyperbranched polymer buffering matrix

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Nano Research 2021年第11期14卷 3952-3960页

作者： Hao li Changchun Hu Yaping Xia Ting li Daohong Zhang Fei Xu Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&Hubei Key Laboratory of Catalysis and Materials Science Hubei R&D Center of Hyperbranched Polymers Synthesis and ApplicationsSchool of Chemistry and Materials ScienceSouth-Central University for NationalitiesWuhan430074China Key Laboratory of Hydraulic Machinery Transients Ministry of EducationSchool of Power and Mechanical EngineeringWuhan UniversityWuhan430072China

Electrochemical conversion reactions provide more selections for Na-storage materials, but the reaction suffers from low reversibility and poor cyclability. Introducing an electrochemically inactive component is a common strategy, but the effect is quite limited since it could not stabilize the structure during long-term cycling. In this study, a new approach is developed using an amino group-functioned hyperbranched polymer (AHP) as a template and electrode additive for the design of high-performance FeSe2-AHP composite with chemical interaction. The assembled FeSe2-AHP composite nanoneedles were prepared by the selenylation of FeS-AHP composite microflowers and entirely inherit the polymer network from the precursor. The amino groups of AHP in composite coordinate with iron cations to achieve uniform polymer dispersion in the composite, and maintain the molecular level mixed state during the long-term cycling. Moreover, the in-situ constructed uniform 3D elastic polymer network effectively accommodates volume expansion and alleviates nanoparticle aggregation during sodiation/de-sodiation. FeSe2-AHP composite provides a superior rate capability (584.8 mAh·g−1 at 20 A·g−1) and a remarkable cyclability with a capacity retention rate of 93.3% after 2,000 cycles. FeSe2-AHP composite shows a high pseudocapacitive behavior for the abundant nanometer interface established by AHP, enhancing the solid-state Na+ diffusion. The FeSe2-AHP anode is also compatible with Na3V2(PO4)3/C cathode in a full Na-ion battery, which provides a high-power performance (powering 51 LEDs). The work herein highlights an innovative and efficient strategy for conversion-type material design and demonstrates the function of chemical interaction of polymer additive in the enhancement of long-term cyclability for conversion electrode.

关键词： Na-ion batteries conversion materials hyperbranched polymer iron selenide chemical interaction

Mobile Robot Combination Autonomous Behavior Strategy to Inspect Hazardous Gases in Relatively Narrow Man–Machine Environment

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 110-122页

作者： Xueshan Gao Qingfang Zhang Mingkang li Bingqing Lan Xiaolong Fu Jingye li School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China School of Mechanical and Automotive Engineering Guangxi University of Science and TechnologyLiuzhou 545006China Xi’an Modern Chemistry Research Institute Xi’an 710065China.

Selecting the optimal speed for dynamic obstacle avoidance in complex man–machine environments is a challenging problem for mobile robots inspecting hazardous *** of personal space is important,especially in a relatively narrow man–machine dynamic environments such as warehouses and *** this study,human and robot behaviors in man–machine environments are analyzed,and a man–machine social force model is established to study the robot obstacle avoidance *** typical man–machine behavior patterns are investigated to design the robot behavior *** on the social force model and man–machine behavior patterns,the fuzzy-PID trajectory tracking control method and the autonomous obstacle avoidance behavior strategy of the mobile robot in inspecting hazardous gases in a relatively narrow man–machine dynamic environment are proposed to determine the optimal robot speed for obstacle *** simulation analysis results show that compared with the traditional PID control method,the proposed controller has a position error of less than 0.098 m,an angle error of less than 0.088 rad,a smaller steady-state error,and a shorter convergence *** crossing and encountering pattern experiment results show that the proposed behavior strategy ensures that the robot maintains a safe distance from humans while performing trajectory *** research proposes a combination autonomous behavior strategy for mobile robots inspecting hazardous gases,ensuring that the robot maintains the optimal speed to achieve dynamic obstacle avoidance,reducing human anxiety and increasing comfort in a relatively narrow man–machine environment.

关键词： Social force model Man–machine behavior pattern Dynamic obstacle avoidance

The Cell Modules of the Green Algebra of Drinfel'd Quantum Double D(H_(4))

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Acta Mathematica Sinica,English Series 2022年第6期38卷 1116-1132页

作者： liu Feng CAO Hui Xiang CHEN li Bin li School of Mathematical Science Yangzhou UniversityYangzhou 225002P.R.China

This paper is devoted to studying the structures of the cell modules of the complexified Green algebra R(D(H_(4))),where D(H_(4))is the Drinfel'd quantum double of Sweedler's 4-dimensional Hopf algebra H_(4).We show that R(D(H_(4)))has one infinite dimensional cell module,one 4-dimensional cell module generated by all finite dimensional indecomposable projective modules of D(H_(4))and infinitely many 2-dimensional cell *** precisely,we obtain the decompositions of all finite dimensional cell modules into the direct sum of indecomposable submodules,and show that the infinite dimensional cell module can be written as the direct sum of two infinite dimensional indecomposable submodules.

关键词： Green algebra positively based algebra Drinfel'd quantum double cell module

Enhancement effect of Mn doping on Co_(3)O_(4)derived from Co-MOF for toluene catalytic oxidation

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Chinese Journal of Chemical Engineering 2022年第12期52卷 1-9页

作者： Juan Lei Peng Wang Shuang Wang Jinping li Yongping Xu Shuying li Department of Environmental and Safety Engineering Taiyuan Institute of TechnologyTaiyuan 030018China College of Environmental Science and Engineering Taiyuan University of TechnologyJinzhong 030600China Dalian Syme Bioengineering Technology limited Company Dalian 045099China Shanxi Key Laboratory of Gas Energy Efficient and Clean Utilization Taiyuan University of TechnologyTaiyuan 030024China

The design of Co-Mn composite oxides catalysts derived from MOF is significant for catalytic combustion of ***,a series of M-CoaMnfbOx,with enhanced catalytic properties compared with that of MCo_(3)O_(4),were successfully prepared through pyrolysis of Mn-doped *** as-synthesized MCo1Mn1Ox(Co:Mn=1:1)exhibits an optimal catalytic activity with 90%toluene conversion reached at227℃,which benefits from the increase of Co^(3+),Oadsand the synergistic effect between Mn and *** to the analysis of the in situ diffuse reflectance infrared Fourier transform spectroscopy,toluene could be degraded easier on M-Co1Mn1Oxwith lower activation energy than M-Co_(3)O_(4).The main intermediate products are benzaldehyde,benzoic acid,anhydride,and maleate *** findings reveal the value of Mn doping for improved activity of toluene oxidation on MOF derived Co_(3)O_(4),which provide a feasible method for the construction of toluene-oxidation catalysts.

关键词： Toluene Catalytic oxidation Co-MOF Doping Co-Mn

Recent advances in synthesis strategies and solar-to-hydrogen evolution of 1T phase MS_(2)(M=W,Mo)co-catalysts

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Journal of Materials Science & Technology 2022年第6期101卷 242-263页

作者： Shuo li Jinyan Xiong Xueteng Zhu Weijie li Rong Chen Gang Cheng School of Chemistry and Environmental Engineering Wuhan Institute of TechnologyDonghu New&High Technology Development ZoneWuhan 430205China College of Chemistry and Chemical Engineering Hubei Key Laboratory of Biomass Fibers and Ecodyeing&FinishingWuhan Textile UniversityWuhan 430200China School of Materials Science and Hydrogen Energy Foshan UniversityFoshan 528000China Institute for Superconducting and Electronic Materials Innovation CampusSquires WayUniversity of WollongongNorth WollongongNSW 2500Australia Henan Institute of Advanced Technology Zhengzhou UniversityZhengzhou 450002China

Photocatalytic water splitting is a promising strategy to produce hydrogen as a sustainable and clean energy carrier,based on abundant solar energy and semiconductor photocatalysts,and it has received extensive research and discussion over the past several *** is challenging,however,to achieve an efficient solar-to-hydrogen evolution process with a single particulate photocatalyst due to the weak solar spectrum harvest and the rapid recombination of photogenerated electron-hole pairs during the photocatalysis *** semiconductors to create different co-catalysts presents a viable solution to the above ***,semiconductor photocatalysts modified by different transition metal sulfidebased co-catalysts with designed functions,especially in light absorption enhancement and chargecarrier-separation efficiency promotion,have attracted much *** continued breakthroughs have been made in the preparation,modification,and solar-to-hydrogen evolution application of the 1T phase MS_(2)(M=W,Mo)co-catalyst-based photocatalysis system in recent years,we believe that a comprehensive review of this kind of co-catalyst would further promote its research and development to address the energy and environmental challenges that we are currently ***,recent studies and progress are summarized on the fabrication of 1T phase MS_(2)(M=W,Mo)-based co-catalyst materials,as well as their roles and functional mechanisms for photocatalytic H;***,concluding perspectives on the opportunities in and challenges for the further exploration of the 1T-MS_(2)(M=W,Mo)-based solar-tohydrogen evolution system are presented.

关键词： Solar-to-hydrogen evolution Co-catalysts 1T-MS_(2)(M=W Mo) Water splitting Synthesis strategies Photocatalysis

Catalytic urea hydrolysis by composite metal oxide catalyst towards efficient urea-based SCR process:performance evaluation and mechanism investigation

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Frontiers of Environmental Science & Engineering 2023年第5期17卷 67-80页

作者： Yuchen li Zhen Chen Xiangyu Zhang Kun Yang lidong Wang Junhua li MOE Key Laboratory of Resources and Environmental Systems Optimization Department of Environmental Science and EngineeringNorth China Electric Power UniversityBeijing 102206China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Xi’an Thermal Power Research Institute Co. Xi’an 710032China

As a promising option to provide gaseous NH_(3) for SCR system,catalytic urea hydrolysis has aroused great attention,and improving surface area and activity of catalysis are the crucial issues to be solved for efficient urea ***,a composite metal oxide(TiO_(2)@Al_(2)O_(3))catalyst was prepared by a simple hydrothermal method,with mesoporous alumina(γ-Al_(2)O_(3))as *** results verify the mesoporous structure and submicron cluster of TiO_(2)@Al_(2)O_(3),with exposed crystal faces of(101)and(400)for TiO_(2)andγ-Al_(2)O_(3),*** electronegativity difference of Ti4+and Al3+changes the charge distribution scheme around the interface,which provides abundant acid/base sites to boost the urea ***,for an optimal proportioning with nano TiO_(2)content at 10 wt.%,the hydrolysis efficiency can reach up to 35.2%at 100℃ in 2 h,increasing by~7.1%than that of the blank experiment.^(13)C NMR spectrum measurements provide the impossible intermediate species during urea *** calculations are performed to clarify the efficient H_(2)O decomposition at the interface of TiO_(2)@Al_(2)O_(3).The result offers a favorable technology for energy-efficiency urea hydrolysis.

关键词： SCR Urea hydrolysis Catalytic Water dissociation Electronegativity