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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1438-1452页

作者： Shasha Qu Yingju Li Bingyu Lu Cuiping Wang Yuansheng Yang institute of Metal research Chinese Academy of SciencesShenyang 110016China guangdong institute of special equipment inspection and research Foshan 528251China College of Materials and Fujian Provincial Key Laboratory of Materials Genome Xiamen UniversityXiamen 361005China

The effects of B addition on microstructure and mechanical properties of aγ′-strengthened CoNi-base superalloy are *** addition of B leads to a substantial increase in the volume fraction of both the eutectic structure and *** CoNi-base alloy shows a high solubility limit for the element *** become noticeable in the area surrounding the eutectic structure after the B level exceeds 0.46 at.%.It is found that the compression property and stress rupture life of the 4W2Ta alloys exhibit an initial rise followed by a subsequent drop as the B content gradually increases from 0.08 to 0.78 at.%.The 4W2Ta0.46B alloy demonstrates the most excellent high-temperature strength and stress rupture life,revealing that a moderate amount of B in the alloy noticeably enhances its mechanical properties by enhancing the grain boundary cohesion.

关键词： CoNi-base superalloy Borides Grain boundary Microstructure Mechanical properties

Hydrodynamics and OCM reaction performance in a bubbling fluidized bed reactor and a riser reactor

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Particuology 2024年第3期86卷 188-204页

作者： Min Cai Shuangzhu Kong Sheng Chen Mengxi Liu Chunxi Lu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China China special equipment inspection and research institute Beijing102249China

The reasonable reactor design is of great importance for increasing the C_(2) yield(C2H4 and C2H6)of the oxidative coupling of methane(OCM),and the OCM reactor should remove the heat released in reactions quickly and efficiently and minimize the consecutive reaction of ethylene to carbon *** fluidized bed reactor is characterized by excellent heat transfer,superior mass transport,and large handling capacity,while fewer studies focused on large-scale fluidized bed reactors for the OCM ***,large cold-model experiments and computational fluid dynamics simulations were conducted to investigate hydrodynamics and the OCM reaction performance in a large-scale bubbling fluidized bed(BFB)and a large-scale *** the BFB reactor,consecutive reactions of ethylene are acute because of the strong gas back-mixing,high solids holdup,and non-uniform solids *** the consecutive reactions of ethylene are negligible due to the plug flow structure and low solids holdup in the riser ***,both reactors can achieve isothermal operation for the OCM *** C_(2) selectivity of 45.4% and C_(2) yield of 21.1% are obtained in the riser reactor,increasing by 20.3% and 5.8% individually than that in the BFB *** study provides useful information and reference to the OCM reactor designandcommercialization.

关键词： Oxidative coupling of methane Bubbling fluidized bed reactor Riser reactor Hydrodynamics Isothermal operation

Simulation of gas-solid flow characteristics of the circulating fluidized bed boiler under pure-oxygen combustion conditions

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Chinese Journal of Chemical Engineering 2024年第6期70卷 9-19页

作者： Kaixuan Gao Xiwei Ke Bingjun Du Zhenchuan Wang Yan Jin Zhong Huang Yanhong Li Xuemin Liu Key Laboratory of special equipment Safety and Energy-Saving for State Market Regulation China Special Equipment Inspection&Research InstituteBeijing 100029China Department of Energy and Power Engineering Tsinghua UniversityBeijing 100084China School of Electrical and Power Engineering Taiyuan University of TechnologyTaiyuan 030024China

Under the pressure of carbon neutrality,many carbon capture,utilization and storage technologies have witnessed rapid development in the recent years,including oxy-fuel combustion(OFC)***,the conventional OFC technology usually depends on the flue gas recirculation system,which faces significant investment,high energy consumption,and potential low-temperature corrosion *** these deficiencies,the direct utilization of pure oxygen to achieve particle fluidization and fuel combustion may reduce the overall energy consumption and CO_(2)-capture *** this paper,the fundamental structure of a self-designed 130 t·h^(-1) pure-oxygen combustion circulating fluidized bed(CFB)boiler was provided,and the computational particle fluid dynamics method was used to analyze the gas-solid flow characteristics of this new-concept boiler under different working *** results indicate that through the careful selection of design or operational parameters,such as average bed-material size and fluidization velocity,the pure-oxygen combustion CFB system can maintain the ideal fluidization state,namely significant internal and external particle ***,the contraction section of the boiler leads to the particle backflow in the lower furnace,resulting in the particle suspension concentration near the wall region being higher than that in the center ***,the upper furnace still retains the classic core-annulus flow *** addition to increasing solid circulation rate by reducing the average bed-material size,altering primary gas ratio and bed inventory can also exert varying degrees of influence on the gas-solid flow characteristics of the pure-oxygen combustion CFB boiler.

关键词： Circulating fluidized bed Pure-oxygen combustion Gas-solid flow characteristics Simulation CO_(2)capture

Defect detection and repair algorithm for structures generated by topology optimization based on 3D hierarchical fully convolutional network

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Biomimetic Intelligence & Robotics 2024年第2期4卷 24-31页

作者： Zhiyu Wan Hai Lan Sichao Lin Houde Dai School of Advanced Manufacturing Fuzhou UniversityJinjiang 362251China Quanzhou institute of equipment Manufacturing Haixi InstitutesChinese Academy of SciencesJinjiang 362216China Fujian Key Laboratory of special Intelligent equipment Safety Measurement and Control Fujian Special Equipment Inspection and Research InstituteFuzhou 350008China

Customized 3D-printed structural parts are widely used in surgical *** satisfy the mechanical properties and kinematic functions of these structural parts,a topology optimization technique is adopted to obtain the optimal structural layout while meeting the constraints and ***,topology optimization currently faces some practical challenges that must be addressed,such as ensuring that structures do not have significant defects when converted to additive manufacturing *** address this problem,we designed a 3D hierarchical fully convolutional network(FCN)to predict the precise position of the defective *** on the prediction results,an effective repair strategy is adopted to repair the defective structure.A series of experiments is conducted to demonstrate the effectiveness of our *** to the 2D fully convolutional network and the rule-based detection method,our approach can accurately capture most defect structures and achieve 89.88%precision and 95.59%***,we investigate the impact of different ways to increase the receptive field of our model,as well as the trade-off between different defect-repairing *** results of the experiment demonstrate that the hierarchical structure,which increases the receptive field,can substantially improve the defect detection *** the best of our knowledge,this paper is the first to investigate 3D defect prediction and repair for topology optimization in conjunction with deep learning algorithms,providing practical tools and new perspectives for the subsequent development of topology optimization techniques.

关键词： Topology optimization Additive manufacturing Deep learning 3D semantic segmentation Defect detection

Molecular Dynamics-Based Simulation of Polyethylene Pipe Degradation in High Temperature and High Pressure Conditions

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Fluid Dynamics & Materials Processing 2024年第9期20卷 2139-2161页

作者： Guowei Feng Qing Li Yang Wang Nan Lin Sixi Zha Hang Dong Ping Chen Minjun Zheng School of Mechanical Engineering Xinjiang UniversityUrumqi830046China Xinjiang Yian special inspection Engineering Company Limited Urumqi830063China Xinjiang Uygur Autonomous Region inspection institute of special equipment Urumqi830000China Pressure Pipe Department China Special Equipment Inspection and Research InstituteBeijing100013China Tarim Oilfield Branch Company Korla841000China Yimai Cai Oil and Gas Management Area Tarim Oilfield Branch OfficeKorla841000China

High-density polyethylene(HDPE)pipes have gradually become the first choice for gas networks because of their excellent *** the use of pipes increases,there will unavoidably be a significant amount of waste generated when the pipes cease their operation life,which,if improperly handled,might result in major environmental contamination *** this study,the thermal degradation of polyethylene materials is simulated for different pressures(10,50,100,and 150 MPa)and temperatures(2300,2500,2700,and 2900 K)in the framework of Reactive Force Field(ReaxFF)molecular dynamics *** main gas products,density,energy,and the mean square displacement with temperature and pressure are also *** findings indicate that raising the temperature leads to an increase in the production of gas products,while changing the pressure has an impact on the direction in which the products are generated;the faster the temperature drops,the less dense the air;both temperature and pressure increase impact the system’s energy conversion or distribution mechanism,changing the system’s potential energy as well as its total energy;the rate at which molecules diffuse increases with temperature,and decreases with *** results of this investigation provide a theoretical basis for the development of the pyrolytic treatment of polyethylene waste materials.

关键词： ReaxFF MD high-density polyethylene degradation temperature pressure

Corrosion behavior of Gd_(2)Zr_(2)O_(7)thermal barrier coatings under Fe-containing environmental sediment attack

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Journal of Advanced Ceramics 2024年第4期13卷 447-462页

作者： Lei Guo Yanyan Li Kai Yan School of Materials Science and Engineering Tianjin UniversityTianjin 300072China Tianjin Key Laboratory of Advanced Joining Technology Key Lab of Advanced Ceramics and Machining Technology of Ministry of EducationTianjin 300072China Key Laboratory of special equipment Safety and Energy-saving for State Market Regulation China Special Equipment Inspection&Research InstituteBeijing 100029China

Environmental sediments mainly consisting of CaO–MgO–Al_(2)O_(3)–SiO_(2)(CMAS)corrosion are a serious threat to thermal barrier coatings(TBCs),in which Fe element is usually ***_(2)Zr_(2)O_(7)TBCs are famous for their excellent CMAS *** this study,the characteristics of Fe-containing environmental sediments(CMAS-Fe)and their corrosiveness to Gd_(2)Zr_(2)O_(7)coatings were *** types of CMAS-Fe glass with different Fe contents were *** melting points were measured to be 1322–1344℃,and the high-temperature viscosity showed a decreasing trend with increasing Fe *** corrosion behavior of four types of CMAS-Fe to Gd_(2)Zr_(2)O_(7)coatings at 1350℃was *** the initial corrosion stage(0.1 h),anorthite was precipitated in CMAS-Fe with a high Ca:Si ratio,while Fe-garnet was formed in the melt with the highest Fe *** the corrosion time resulted in the formation of a reaction layer,which exhibited an interpenetrating network composed of Gd-oxyapatite,ZrO_(2),and residual *** spinel was precipitated within the reaction *** 1 h or even longer time,the reaction layers tended to be stable and compact,which had comparable hardness and fracture toughness to those of Gd_(2)Zr_(2)O_(7)*** the cyclic CMAS-Fe attack,the residual CMAS-Fe in the interpenetrating network provided a pathway for the redeposited CMAS-Fe infiltration,resulting in the continuous growth of the reaction *** a result,the Gd_(2)Zr_(2)O_(7)coatings had a large consumption in the thickness,degrading the coating ***,the Gd_(2)Zr_(2)O_(7)coatings exhibit unsatisfactory corrosion resistance to CMAS-Fe attack.

关键词： thermal barrier coatings(TBCs) Gd_(2)Zr_(2)O_(7) Fe-containing CaO-MgO-Al2O3-SiO_(2)(CMAS) corrosion resistance reaction layer

A novel weld-pool-length monitoring method based on pixel analysis in plasma arc additive manufacturing

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Advances in Manufacturing 2024年第2期12卷 335-348页

作者： Bao-Ri Zhang Yong-Hua Shi Bionic Robot research Department Ji Hua LaboratoryFoshan528200GuangdongPeople’s Republic of China guangdong Provincial Engineering research Center for special Welding Technology and equipment School of Mechanical and Automotive EngineeringSouth China University of TechnologyGuangzhou510640People’s Republic of China

The real-time monitoring of the weld pool during deposition is important for automatic control in plasma arc additive *** obtain a high deposition accuracy,it is essential to maintain a stable weld pool *** this study,a novel passive visual method is proposed to measure the weld pool *** the proposed method,the image quality was improved by designing a special visual system that employed an endoscope and a *** also includes pixel brightness-based and gradient-based algorithms that can adaptively detect feature points at the boundary when the weld pool geometry *** algorithm can also be applied to materials with different solidification *** was performed to measure the real weld pool length in world coordinates,and outlier rejection was performed to increase the accuracy of the ***,tests were carried out on the intersection component,and the results showed that the proposed method performed well in tracking the changing weld pool length and was applicable to the real-time monitoring of different types of materials.

关键词： Plasma arc additive manufacturing(PAAM) Weld pool geometry Gradient analysis Real-time detection

Nonlinear Impact Damage Evolution of Charpy Type and Analysis of Its Key Influencing Factors

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 254-264页

作者： Jianfeng Mao Qian Xu Jiadong Yang Chi Cao Dasheng Wang Fengping Zhong Mingya Chen institute of Process equipment and Control Engineering Zhejiang University of TechnologyHangzhou 310032China Taizhou Key Laboratory of Advanced Manufacturing Technology Taizhou InstituteZhejiang University of TechnologyTaizhou 318014China State Key Laboratory of Nuclear Power Safety Monitoring Technology and equipment Shenzhen 518172China Zhejiang Academy of special equipment Science Hangzhou 310020China Suzhou Nuclear Power research institute Suzhou 215004China

The current research of Charpy impact mainly focuses on obtaining the ductile brittle transition temperature of materials by *** with experiments,numerical simulation can study many problems with harsh ***,there are still few studies on the influence of geometric factors such as side *** this paper,the geometry of standard Charpy impact test is *** with different widths and side grooves are *** finite element model of Charpy impact was established by ABAQUS *** test results and simulation results to verify each *** effects of sample width,side groove depth and side groove bottom fillet on the impact fracture resistance of the sample were *** results show that the specimen width is positively correlated with the impact toughness of the *** side groove greatly reduces the impact toughness of the material;the toughness of side groove decreases with the increase of depth;the fracture toughness of side groove decreases with the increase of fillet at the bottom of side *** proportion of toughness energy to impact energy of samples was *** results show that the toughness energy accounts for about 70%of the impact energy of the sample,which has little to do with the geometric characteristics of the *** study presents a reliable method for studying Charpy impact *** influence of geometric parameters is obtained,which provides a reference method for the study of impact toughness of high toughness materials.

关键词： Johnson-Cook model Impact toughness Charpy impact

Atmospheric VOCs in an industrial coking facility and the surrounding area:Characteristics,spatial distribution and source apportionment

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Journal of Environmental Sciences 2024年第4期138卷 660-670页

作者： Meicheng Wen Weiqiang Deng Jin Huang Shu Zhang Qinhao Lin ChaoWang Shengtao Ma Wanjun Wang Xin Zhang Guiying Li Taicheng An guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and Health Guangdong Key Laboratory of Environmental Catalysis and Health Risk ControlInstitute of Environmental Health and Pollution controlGuangdong University of TechnologyGuangzhou 510006China guangdong Engineering Technology research Center for Photocatalytic Technology Integration and equipment Guangzhou Key Laboratory of Environmental Catalysis and Pollution ControlSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China institute of Environmental Science Shanxi UniversityTaiyuan 030006China

Industrial coking facilities are an important emission source for volatile organic compounds(VOCs).This study analyzed the atmospheric VOC characteristics within an industrial coking facility and its surrounding *** concentrations of total VOCs(TVOCs)in the surrounding residential activity areas(R1 and R2),the coking facility(CF)and the control area(CA)were determined to be 138.5,47.8,550.0,and 15.0μg/m^(3),*** cold drum process and coking and quenching areas within the coking facility were identified as the main polluting *** spatial variation in VOCs composition was analyzed,showing that VOCs in the coking facility and surrounding areas were mainly dominated by aromatic compounds such as BTX(benzene,toluene,and xylenes)and naphthalene,with concentrations being negatively correlated with the distance from the coking facility(p<0.01).The sources of VOCs in different functional areas across the monitoring area were analyzed,finding that coking emissions accounted for 73.5%,33.3% and 27.7% of TVOCs in CF,R1 and R2,*** results demonstrated that coking emissions had a significant impact on VOC concentrations in the areas surrounding coking *** study evaluates the spatial variation in exposure to VOCs,providing important information for the influence of VOCs concentration posed by coking facility to surrounding residents and the development of strategies for VOC abatement.

关键词： Coking facility Volatile organic compounds Emission inventory Spatial distribution Source apportionment

Photodegradation of xylene isomers:Kinetics,mechanism,secondary pollutant formation potential and health risk evaluation

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Journal of Environmental Sciences 2024年第2期136卷 658-669页

作者： Xiaoyan Chen Weikun Zhu Sufen Feng Jiangyao Chen guangdong Key Laboratory of Environmental Catalysis and Health Risk Control Guangdong Technology Research Center for Photocatalytic Technology Integration and Equipment EngineeringInstitute of Environmental Health and Pollution ControlGuangdong University of TechnologyGuangzhou 510006China Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control Guangdong-Hong Kong-Macao Joint Laboratory for Contaminants Exposure and HealthSchool of Environmental Science and EngineeringGuangdong University of TechnologyGuangzhou 510006China

Photodegradation technology has been widely applied in the purification of industrial aromatic ***,whether this technology efficiently removes the pollutants to prevent secondary pollution and health risk is still ***,the photodegradation processes of three xylenes were compared under designed reaction atmospheres and light *** lamp showed poor photodegradation ability toward xylenes,no matter in N_(2) or N_(2)+O_(2)system,while much higher photodegradation performance of xylenes were obtained under ultraviolet(UV)and vacuum ultraviolet(VUV)irradiation,especially in N_(2)+O_(2)+VUV system,where 97.9%of m-xylene,99.0%of o-xylene or 87.5%of p-xylene with the initial concentration of 860 mg/m^(3) was removed within 240 *** xylenes underwent three processes of photo-isomerization,photodecomposition and photo-oxidation to produce intermediates of aromatics,alkanes and *** them,the photo-isomerization products showed the highest concentration percentage(e.g.,≥50%in o-xylene system),confirming that photo-isomerization reaction was the dominated photodegradation process of ***,these isomerized products not only contributed about 97%and91%to the formation potential of O3(OFP)and secondary organic aerosols(SOAFP),but also displayed obvious non-carcinogenic risk,although one of photodecomposition product—benzene showed the highest occupational exposure ***,the secondary pollution and health risks of photodegradation products of xylenes were non-ignorable,although the OFP,SOAFP and health risks of the generated products reduced at least 4.5 times in comparison with that of the degraded *** findings are helpful for the appropriate application of this technology in the purification of industrial organic waste gas.

关键词： Isomer aromatics Photodegradation Ozone formation Secondary organic aerosols Health risk