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China Foundry 2024年第5期21卷 577-587页

作者： Wei-li Peng Jian-hua Zhao Cheng Gu ya-jun Wang College of Materials Science and Engineering Chongqing UniversityChongqing 400045China National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China National Key Laboratory of Advanced Casting Technologies Chongqing UniversityChongqing 400044China

The properties of the magnetic mold in magnetic mold casting directly determine the quality of the final cast *** this study,the magnetic mold properties in magnetic mold casting,were studied utilizing a coupled electromagnetic-structural method through numerical *** study investigated key factors including equivalent stress,the distribution of tensile and compressive stresses,and the area ratio of tensile *** compared molds made entirely of magnetic materials with those made partially of magnetic *** results indicate that as current increases from 4 A to 8 A,both the initial magnetic mold and the material-replaced magnetic mold initially show an increasing trend in equivalent stress,tensile-compressive stress,and the area ratio of tensile stress,peaking at 6 A before *** material replacement,the area ratio of tensile stress at 6 A decreases to 19.84%,representing a reduction of 29.72%.Magnetic molds comprising a combination of magnetic and non-magnetic materials exhibit sufficient strength and a reduced area ratio of tensile stress compared to those made entirely from magnetic *** study provides valuable insights for optimizing magnetic mold casting processes and offers practical guidance for advancing the application of magnetic molds.

关键词： magnetic mold casting coupled electromagnetic-structural method numerical simulation stress analysis

Impact of Mo/Ni alloying on microstructural modulation and low-temperature toughness of high-strength low-alloy steel

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Journal of Iron and Steel Research International 2024年第7期31卷 1746-1762页

作者： Wei liu hong-li Zhao Bing-xing Wang Yong Tian State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina

The high-strength low-alloy steel plates with varying Ni/Mo contents were manufactured using the thermos-mechanical control *** investigation was conducted to explore the effect of Ni/Mo microalloying on microstructure evolution and mechanical properties of the *** results revealed that the increase in Ni content from 1 to 2 wt.%reduced the transition temperature of ferrite and the growth range of ferritic grain was narrowed,which promoted grain *** optimized combination of grain size,high-angle grain boundaries(HAGBs),and martensite-austenite(M-A)islands parameter contributed to the excellent impact toughness of S1 steel at-100℃(impact absorbed energy of 218.2 J at-100℃).As the Mo increases from 0 to 2 wt.%,the matrix structure changes from multiphase structure to granular bainite,which increases the average effective grain size to~4.62 pm and reduces HAGBs proportion to~36.22%.With these changes,the low-temperature impact toughness of S3 steel is *** addition,based on the analysis of the characteristics of crack propagation path,it was found that M-A islands with low content(~2.21%)and small size(~1.76 pm)significantly retarded crack propagation,and the fracture model of M-A islands with different morphologies was further ***,correlation between behaviour of delamination and toughness was further analysed by observing delamination size and impact energy parameters.

关键词： High-strength low-alloy steel Microstructural regulation Ni addition Mo addition Crack propagation Low-temperature toughness

Access to Axially Chiral Aryl Aldehydes via Carbene-Catalyzed Nitrile Formation and Desymmetrization Reaction

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Research 2024年第3期2024卷 715-721页

作者： Yuanlin Cai ya Lv liangzhen Shu Zhichao Jin Yonggui Robin Chi Tingting li National Key Laboratory of Green Pesticide Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationGuizhou UniversityGuiyang 550025China School of Chemistry Chemical Engineeringand BiotechnologyNanyang Technological UniversitySingapore 637371Singapore.

An approach utilizing N-heterocyclic carbene for nitrile formation and desymmetrization reaction is developed. The process involves kinetic resolution, with the axially chiral aryl monoaldehydes obtained in moderate yields with excellent optical purities. These axially chiral aryl monoaldehydes can be conveniently transformed into functionalized molecules, showing great potential as catalysts in organic chemistry.

关键词： chemistry. aldehydes chiral

Evolution hydrothermal aging resistance mechanism study of zirconium and manganese doped CeO_(2)catalysts in soot catalytic combustion based on low Miller indices crystal surface effect

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Journal of Rare Earths 2024年第7期42卷 1272-1281,I0003页

作者： Zonglin li Pan Wang hong Ni Chengcheng Ao lidong Zhang Hefeng Zhang Kai li School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang212013China State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental ScienceBeijing100012China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei230026China

The thermogravimetric analysis(TGA)experiments were carried out to reveal the mechanism of Zr and Mn doping on catalytic activity of CeO_(2)catalyst both fresh and after hydrothermal aging,and the lattice morphology and valence changes were characterized by means of Brunauer-Emmett-Teller(BET)method,X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),and H_(2)-temperature programmed reduction(H_(2)-TPR).Density functional theory(DFT)and molecular thermodynamics calculations were applied to investigate the change in catalytic activity,crystal surface energy and crystal morphology caused by hydrothermal *** maximum reaction rate temperature of fresh Mn/CeO_(2)(389℃)is similar to that of CeO_(2)(371℃)and lower than that of Zr/CeO_(2)(447℃),but the catalytic performance of CeO_(2)decreases more severely after hydrothermal *** catalyst crystals show different degrees of crystal surface migration after hydrothermal aging,which leads to the reduction of Ce^(3+)/Ce^(4+) ratio and the active sites *** calculations indicate that the doping of Zr and Mn reduces the surface energy of the low Miller indices surface and increases the oxygen vacancy formation energy,leading to better thermal stability and lower catalytic *** Zr and Mn doping also changes the adsorption energy and Gibbs free energy of H_(2)O,which dominates the migration of(111)to(110)and(100)in the vapor *** crystal surface migration mechanism of CeO_(2)catalysts doped with Zr and Mn induced by H_(2)O molecules at high temperature obtained in this study can provide a valuable addition to the regeneration of CeO_(2)catalysts in the after-treatment systems of diesel engines.

关键词： Soot CeO_(2)-based catalyst CDPF Rare earth metal oxides DFT calculations

Novel self-assembled porous yolk-shell NiO nanospheres with excellent electrochromic performance for smart windows

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Particuology 2024年第1期84卷 72-80页

作者： Baoshun Wang ya Huang Siming Zhao Run li Di Gao Hairong Jiang Rufan Zhang Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical EngineeringTsinghua UniversityBeijing100084China

With the rapid development of optoelectronics,electrochromic(EC)materials(ECMs)with the advan-tages of low power consumption,easy viewing,high contrast ratio,etc have attached more and more attention from the fields of smart windows,electronic billboards,emerging wearable and portable electronics,and other next-generation *** oxide(NiO)is a promising candidate for high-performance ECMs because of its neutral-colored states and low ***,NiO-based ECMs still face the problem of slow switching speed due to their low electrical conductivity and small lattice ***-organic frameworks(MOFs)are promising candidates to fabricate hollow and porous transition metal oxides(TMOs)with high ion transport efficiency,excellent specific capacitance,and electrochemical *** this work,porous yolk-shell NiO nanospheres(PYS-NiO NSs)were syn-thesized via a solvothermal and subsequent calcination process of Ni-MOF,which exhibited outstanding EC *** the large specific surface areas and hollow porous nanostructures were conducive to ionic transport,PYS-NiO NSs exhibited a fast coloring/bleaching speed(3.6/3.9 s per one coloring/bleaching cycle)and excellent cycling stability(82%of capacity retention after 3000 cycles).These superior EC properties indicated that the PYS-NiO NSs was a promising candidate for high-performance EC *** work provides a new and feasible strategy for the efficient preparation of TMOs ECMs with good EC performance,especially fast switching speed.

关键词： Electrochromic Nickel oxide Metal-organic frameworks Hollow structure Smart windows

Assessment of hydraulic performance changes of Dongting Lake after the Three Gorges Reservoir impoundment by a novel semi-empirical approach

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Journal of Geographical Sciences 2024年第8期34卷 1537-1557页

作者： SUN Zhaohua li Zhiqing CHEN li FAN Jiewei liU ya State Key Laboratory of Water Resources Engineering and Management Wuhan UniversityWuhan 430072China Yellow River Water&Hydropower Development Group Co. Ltd.Jiyuan 459017HenanChina Changjiang River Scientific Research Institute Wuhan 430010China

Floodplain lakes are important water storage areas in lowland regions that often undergo geomorphologic evolution,and timely topographic data are generally *** this study,to assess the impacts of lakebed deformation on hydraulic performance in Dongting Lake,a set of semi-empirical methods was proposed to establish performance graphs(PGs)using only hydrological *** methods were used to evaluate the changes in water level,storage capacity,and flood detention ability in Dongting Lake caused by topographic adjustment after the Three Gorges Reservoir *** methods showed that PGs can effectively simulate the water level and outflow processes of Dongting Lake with Nash-Sutcliffe efficiency coefficients(NSEs)above 0.9.A comparison of the estimated water level and discharge using PGs from different periods suggested that bed erosion in Dongting Lake caused water level decreases of 0.18 m and 0.32 m during the flood and dry seasons,*** the magnitude of erosion at high elevations in the lake is small,the impacts of bed adjustment on the storage capacity and flood detention ability are not currently *** study showed that the hydraulic performance of a floodplain lake can be evaluated independently of topographic data under the condition of no reverse flows or negative watersurface slopes.

关键词： Dongting Lake hydraulic performance graph bed adjustment semi-empirical approach backwater effect

In-situ SEM characterization of fracture mechanism of TiB/Ti-2Al-6Sn titanium matrix composites after electroshocking treatment

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Rare Metals 2024年第6期43卷 2805-2818页

作者： ya-ya Wu Jian Zhou Guo-Lei Han yan Wen Zhou Wang li-Qiang Wang Wei-Jie Lv Le-Chun Xie lin Hua Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

In this article,in-situ scanning electron microscope characterization of the tensile properties of TiB/Ti-2Al-6Sn titanium matrix composite(TMC)was conducted before and after electroshocking treatment(EST).After EST,the tensile strength increased by 113.2 *** effect of EST on the tensile strength and fracture behavior of TiB was investigated using in-situ characterization of the fracture morphology and crack propagation path of the matrix and *** EST,TiB fracture introduced cracks that extended into the matrix,resulting in material *** EST,the refined TiB improved the bearing capacity of the matrix,thereby improving TMC ***,after EST,the cracks were introduced into the matrix,and resulting the fracture of matrix *** an increase in the external load,cracks in the matrix were observed to propagate to TiB,and the refined TiB was fractured,detached,and pulled out,resulting in the formation of *** the propagation path of the main crack after EST showed that the deflection angle of the main crack *** micro structure of the fracture surface indicated that the fracture of the matrix was plastic,whereas that of TiB was *** EST,the size and area of the dimples increased,confirming the increase in *** results revealed that the comprehensive mechanical properties of TiB/Ti-2Al-6Sn improved after ***,EST is an efficient method for tailoring the micro structures and mechanical properties of TMCs.

关键词： TiB/Ti-2Al-6Sn In-situ microstructure characterization Tensile properties Reinforcement Electroshocking treatment(EST)

Purification performance on molten steel of novel Al_(2)O_(3)-based ceramic filter prepared from microporous powder and nano-Al_(2)O_(3) powder

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Journal of Iron and Steel Research International 2024年第6期31卷 1535-1546页

作者： Zhe Chen Wen yan Ying liu Guang-qiang li Shao-song hong Nan li The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Jiangsu Shengnai New Materials Co. Ltd.Taizhou 225534JiangsuChina

Reticulated ceramic foam filters provide an effective way to purify molten steel by removing non-metallic *** proposed a novel strategy to improve the purification performance of Al_(2)O_(3)-based ceramic filters by using microporous corundum-spinel raw materials to replace dense raw *** kinds of Al_(2)O_(3)-based ceramic filters fabricated from dense α-Al_(2)O_(3) micro-powder or microporous corundum-spinel powder were selected to carry out the immersion tests with molten *** the one hand,the higher surface roughness of the filter skeleton prepared from microporous raw materials increased the adsorption capacity of skeleton surface on inclusions in molten *** the other hand,the higher apparent porosity and larger pore size of the filter skeleton were more beneficial to the penetration of molten steel in the micropores of *** reaction process at the solid-liquid interface also improved the wettability of the interface between skeleton and molten steel,resulting in a larger penetration depth and a better adsorption effect on the *** summary,the novel Al_(2)O_(3)-based ceramic filter prepared with microporous corundum-spinel powder and addition of 5 wt.% nano-Al_(2)O_(3) powder reduced the total oxygen content of the steel from 40.2×10^(-4) to 12.7×10^(-4) wt.% by 68.4% and the Al content from 0.46 to 0.18 wt.% by 60.9% after immersion test,presenting the most excellent purification performance on molten steel.

关键词： Al_(2)O_(3)-based ceramic filter Microporous corundum-spinel powder Non-metallic inclusion-Microstructure Molten steel purification

Numerical and experimental study of the effects of wind turbine operation on sand-dust transport characteristics

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 97-113页

作者： Gaosheng Ma hong Han Ye li Deshun li yan Wang Ning Fu Quan Zheng Rennian li School of Energy and Power Engineering Lanzhou University of TechnologyLanzhou 730050China Gansu Provincial Technology Center for Wind Turbines Lanzhou 730050China Key Laboratory of Fluid Machinery and Systems Lanzhou 730050China Multiple Function Towing Tank Laboratory State Key Laboratory of Ocean EngineeringSchool of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Given factors such as reduced land availability for onshore wind farms,wind resource enrichment levels,and costs,there is a growing trend of establishing wind farms in deserts,the Gobi,and other arid ***,the relationship between sanddust weather environments and wind turbine operations has garnered significant *** investigate the impact of wind turbine wakes on sand-dust transportation,this study employs large eddy simulation to model flow fields,coupled with an actuator line model for simulating rotating blades and a multiphase particle in cell model for simulating sand *** research focuses on a horizontal axis wind turbine model and examines the motion and spatiotemporal distribution characteristics of four typical sizes of sand particles in the turbine *** findings reveal that sand particles of varying sizes exhibit a spiral settling pattern after traversing the rotating plane of wind turbine blades,influenced by blade shedding vortex and *** particles tend to cluster in the peripheries of the vortex cores of low vorticity in the wind turbine *** rotation of wind turbines generates a wake vortex structure that causes a significant clustering of sand particles at the tip *** the wake distance increases,the particles that cluster at the turbine's tip gradually spread outward to approximately twice the rotor diameter and then begin to mix with the incoming flow *** turbines have a noticeable impact on sand-dust transportation,hindering their movement to a significant *** average sand-blocking rate exhibits a trend of initially increasing and then decreasing as the wake distance *** its peak,the sand-blocking rate reaches an impressive 67.55%.The presence of wind turbines induces the advanced settling of sand particles,resulting in a“triangular”distribution of the deposition within the ground projection area of the wake.

关键词： wind turbine particle transportation actuator line model dry deposition particle clustering

Research on casing deformation prevention technology based on cementing slurry system optimization

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Petroleum Science 2024年第2期21卷 1231-1240页

作者： yan yan Meng Cai Wen-Hai Ma Xiao-Chuan Zhang li-hong Han Yong-hong liu State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials CNPC Tubular Goods Research InstituteXi©an710077ShaanxiChina College of Mechanical and Electrical Engineering China University of Petroleum(East China)Qingdao266580ShandongChina Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province Chengdu610095SichuanChina CNPC Daqing Oilfield Company Daqing163453HeilongjiangChina

The casing deformation prevention technology based on the optimization of cement slurry is proposed to reduce the casing deformation of shale oil and gas wells during hydraulic fracturing. In this paper, the fracture mechanism of hollow particles in cement sheath was firstly analyzed by discrete element method, and the effect of hollow particles in cement on casing deformation was investigated by laboratory experiment method. Finally, field test was carried out to verify the improvement effect of the casing deformation based on cement slurry modification. The results show that the formation displacement can be absorbed effectively by hollow particles inside the cement transferring the excessive deformation away from casing. The particles in the uncemented state provide deformation space during formation slipping. The casing with diameter of 139.7 mm could be passed through by bridge plug with the diameter of 99 mm when the mass ratio of particle/cement reaches 1:4. According to the field test feedback, the method based on optimization of cement slurry can effectively reduce the risk of casing deformation, and the recommended range of hollow microbeads content in the cement slurry is between 15% and 25%.

关键词： Cement slurry Hollow ceramsite Casing deformation Formation slip Field test