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Inter-correlation between Sunspot Oscillations and Their Internal Structures

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Research in Astronomy and Astrophysics 2022年第11期22卷 97-106页

作者： Libo fu Zizhan Zhu ding Yuan Jiaoyang Wang Song Feng Sergey Anfinogentov Institute of Space Science and Applied Technology Harbin Institute of TechnologyShenzhen 518055China faculty of Information Engineering and Automation Kunming University of Science and TechnologyKunming 650500China Institute of Solar-Terrestrial Physics SB RAS Lermontov st.126a664033IrkutskRussia

Three-and five-minute oscillations are commonly observed in any *** they are modulated by the internal thermal and magnetic structures of a sunspot,they could be used as an effective tool for researching sunspot *** this paper,we investigate the properties of oscillations in sunspot groups with varying sizes and magnetic fields,and aim to establish the relationships between sunspot oscillations and its internal structure *** selected three groups of the unipolar sunspot with approximately axial-symmetric magnetic field and calculated their Fourier spectra based on the ultraviolet/extreme ultraviolet emission intensity variations recorded by the Solar Dynamics Observatory/Atmospheric Imaging *** found that the distribution of three-minute oscillation is defined by the joint effect of diverging magnetic field and the stratification of the sunspot *** distribution could be modified by any invading magnetic structures in the *** contrast,the five-minute oscillations are more prominent in small spots,implying that five-minute oscillation is very closely connected with umbral dynamics.

关键词： (Sun:)sunspots Sun:oscillations methods:data analysis

Grain erosion wear properties and grinding performance of porous aggregated cubic boron nitride abrasive wheels

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Chinese Journal of Aeronautics 2023年第6期36卷 446-459页

作者： Biao ZHAO Xin WANG Wenfeng ding Yang WANG Yucan fu Yanjun ZHAO Jianhui ZHU National Key Laboratory of Science and Technology on Helicopter Transmission Nanjing University of Aeronautics and AstronauticsNanjing 210016China State Key Laboratory of Superabrasives Zhengzhou Research Institute for Abrasive&GrindingZhengzhou 450001China

Cubic boron nitride(cBN)superabrasive grinding wheels exhibit unique advantages in the grinding of difficult-to-cut materials with high strength and toughness,such as titanium alloys and ***,grinding with multilayered metallic cBN superabrasive wheels faces problems in terms of grain wear resistance,the chip storage capability of the working layers and the stability and controllability of the dressing ***,in this work,novel metallic cBN superabrasive wheels with aggregated cBN(AcBN)grains and open pore structures were fabricated to improve machining efficiency and surface *** to the grinding trials,the airborne abrasive blasting process was conducted and the abrasive blasting parameters were optimized in view of wear properties of cBN grains and metallic matrix ***,the comparative experiments were performed and then the variations in grinding force and force ratio,grinding temperature,tool wear morphology and ground surface quality of the multilayered AcBN grinding wheels were investigated during machining Ti-6Al-4V *** consideration of the variations of grain erosion wear volume and material removal rate per unit of pure metallic matrix materials as the abrasive blasting parameters changes,the optimal abrasive blasting parameters were identified as the SiC abrasive mesh size of 60#and the abrasive blasting distance and time of 60 mm and 15 s,*** as-developed AcBN grains exhibited better fracture toughness and impact resistance than monocrystalline cBN(McBN)grains because of the existence of metal-bonded materials amongst multiple cBN particles that decreased crack propagation inside whole *** metallic porous AcBN wheels had lower grinding forces and temperature and better ground surface quality than vitrified McBN wheels due to the constant layer-by-layer exposure of cBN particles in the working layer of AcBN wheels.

关键词： Air-borne abrasive blasting Aggregated cBN abrasive grains Grinding performance Ground surface quality Self-sharpening ability

Unveiling the precipitation behavior and mechanical properties of Co-free Ni_(47-x)Fe_(30)Cr_(12)Mn_(8)Al_(x)Ti_(3) high-entropy alloys

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Journal of Materials Science & Technology 2022年第23期118卷 25-34页

作者： Jiantao fan Liming fu Yanle Sun Feng Xu Yi ding Mao Wen Aidang Shan School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai200240China Shanghai Key Laboratory of High Temperature Materials and Precision Forming Shanghai Jiao Tong UniversityShanghai200240China Baowu Special Metallurgy Co.Ltd Shanghai200940China

Precipitate hardening is considered as an effective method to strengthen High-and medium-entropy alloys(HEAs and MEAs),especially the recently developed Co-free HEAs/MEAs,In this work,a systematic study on precipitation and mechanical behaviors of a Co-free HEAs with dilute amount of Al addition,Ni_(47-x)Fe_(30 C)r_(12)Mn_(8) Al_(x)Ti_(3)(x=2 at.%,5 at.% and 7 at.%),is *** shown that the Ni_(45)Fe_(30)Cr_(12)Mn_(8) Al_(2) Ti_(3) has a face-centered cubic(FCC)+L1_(2)+η three-phased *** increasing Al content,the formation of η phase is inhibited,accompanying with an enhanced formation of B2 phase,and FCC+L1_(2)+B2 three-phased structure is thus observed in alloys with x=5 and *** constrained lattice mismatch between FCC matrix and L1_(2) precipitates is decreased with increasing Al content,leading to an enhanced precipitation behavior of L1_(2) *** a result of microstructural evolution,the mechanical properties of the aged HEAs changed:the Ni_(42)Fe_(30)Cr_(12)Mn_(8) Al_5 Ti_(3) alloy exhibits a better combination of a yield strength of 661 MPa and tensile ductility of 29.7% as compared to the 2 at.% Al alloyed HEA;and addition of Al beyond 5 at.% results in an increase of strength with a large expense of *** believe that the present work is helpful for developing high-performance Co-free HEAs/MEAs strengthened by nanoprecipitates via composition optimizing.

关键词： High-entropy alloys Microstructures Precipitation behavior Mechanical properties

Characterization and life prediction of single-pass honing tool for fuel injection nozzle

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Chinese Journal of Aeronautics 2021年第4期34卷 225-240页

作者： Changyong YANG Hao SU Shaowu GAO Qingfeng AI Yucan fu Wenfeng ding Jiuhua XU College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Kompetenzzentrum für Spanende Fertigung Furtwangen UniversityTuttlingen 78532Germany

Single-pass honing is an important machining method for finish machining of holes,which can meet the requirement for high efficiency and consistency of *** and life prediction of single-pass honing tool are necessary to improve the machining accuracy of holes honed,especially dimension ***-pass honing tool is a single layer abrasive tool with fixed dimension,which still remains problematic for characterization and life *** fuel injection nozzles with bore diameter under 1 mm,the stiffness of the single-pass honing tool is *** article presents a novel analytical model that predicts life of the tool with poor ***,according to the bore diameter and dimension tolerance,the single-pass honing tool is designed and *** on the prepared single-pass honing tool,the measurement and characterization methods are ***,the tool wear tests are carried out,and the tool contour evolution model is established to predict the tool life.

关键词： fuel injection nozzle Life prediction Single-pass honing tool Tool contour evolution Tool stiffness

Using multiple regression analysis to predict directionally solidified TiAl mechanical property

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Journal of Materials Science & Technology 2022年第9期104卷 285-291页

作者： Seungmi Kwak Jaehwang Kim Hongsheng ding Xuesong Xu Ruirun Chen Jingjie Guo Hengzhi fu National Key Laboratory for Precision Hot Processing of Metals School of Materials Science and EngineeringHarbin Institute of TechnologyHarbin 150001China Carbon Materials Application R&D Group Korea Institute of Industrial TechnologyJeonju 54853 Republic of Korea

The mechanical properties of TiAl alloy prepared by directional solidification were predicted through a machine learning algorithm *** composition,input power,and pulling speed were designated as input variables as representative factors influencing mechanical properties,and multiple linear regression analysis was conducted by collecting data obtained from the *** this study,the R^(2)value of the tensile strength prediction result was 0.7159,elongation was 0.8459,nanoindentation hardness was 0.7573,and interlamellar spacing was *** the R^(2)value of the elongation obtained through the analysis was higher than the R^(2)value of the tensile strength,it was confirmed that the elongation had a closer relationship with the input variables(composition,input power,pulling speed)than the tensile *** adding the elongation to the tensile strength as an input variable,it was observed that the R^(2)value was further *** tensile test prediction results were divided into four groups:The group with the lowest residual value(predicted value-actual value)was designated as group A,and the group with the largest residual value was designated as group *** comparing the values of group A and group D,more overpredictions occurred in group A,while more under predictions occurred in group *** the residuals and R^(2)values,the cause of the well-prediction was studied,and through this,the relationship between the mechanical properties and the microstructure was quantitatively investigated.

关键词： Directionally solidified TiAl alloy Microstructure control Tensile strength Interlamellar space Prediction Multiple linear regression

Recent advances and perspectives towards emission inventories of mobile sources:Compilation approaches,data acquisition methods,and case studies

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Journal of Environmental Sciences 2023年第1期123卷 460-475页

作者： Han Jiang Hefeng Zhang Mingliang fu Zhihui Huang Hong Ni Hang Yin Yan ding State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental SciencesBeijing 100012China Vehicle Emission Control Center of Ministry of Ecology and Environment Chinese Research Academy of Environmental SciencesBeijing 100012China

In recent years,great efforts have been devoted to reducing emissions from mobile sources with the dramatic growth of motor vehicle and nonroad mobile source *** of a mobile source emission inventory is conducive to the analysis of pollution emission characteristics and the formulation of emission reduction *** study summarizes the latest compilation approaches and data acquisition methods for mobile source emission *** motor vehicles,a high-resolution emission inventory can be developed based on a bottom-up approach with a refined traffic flow model and real-world speed-coupled emission *** top-down approach has advantages when dealing with macroscale vehicle emission estimation without substantial traffic flow *** nonroad mobile sources,nonroad machinery,inland river ships,locomotives,and civil aviation aircraft,a top-down approach based on fuel consumption or power is *** ocean-going ships,a bottom-up approach based on automatic identification system(AIS)data is *** typical cases are studied,including emission reduction potential,a cost-benefit model,and marine shipping emission *** and suggestions are given on future research directions for emission inventories for mobile sources:building localized emission models and factor databases,improving the dynamic updating capability of emission inventories,establishing a database of emission factors of unconventional pollutants and greenhouse gas from mobile sources,and establishing an urban high temporalspatial resolution volatile organic compound(VOC)evaporation emission inventory.

关键词： Emission inventory Mobile source Emission factor Emission control policy

High Fluorescence Porous Organic Cage for Sensing Divalent Palladium Ion and Encapsulating Fine Palladium Nanoparticles

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Chinese Journal of Chemistry 2022年第3期40卷 385-391页

作者： Huimin Ren Chao Liu Xu ding Xianzhang fu Hailong Wang Jianzhuang Jiang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline MaterialsDepartment of Chemistry and Chemical EngineeringSchool of Chemistry and Biological EngineeringUniversity of Science and Technology BeijingBeijing 100083China

Porous organic cages(POCs)as an innovative type of porous molecular materials enable multifunctional ***,a fluorescence POC(denoted as 1)has been constructed by means of 5/5'-((2/5-dimethoxy-l/4-phenylene)bis(ethyne-2/1-diyl))diiso-phthalaldehyde condensing with cyclohexanediamine enantiomer with the aid of trifluoroacetic acid.1 exhibits the permanent void and prominent fluorescence with relative quantum yield of 73%confirmed by gas sorption and emission experiments,***,this organic cage is capable of sensing diavalent Pd2+according to the fluorescence response to the addition of various metal *** dispersion of 1 in methanol containing palladium acetate was stirred at 25℃and then 80℃to reduce Pd2+ions into nanoparticles(NPs),leading to the composite(Pd@l)composed of fine Pd NPs with the size of co.1.8 *** catalytic nature of Pd@l over NaBH4 promoted the degeneration of nitrobenzene and congo *** work introduces one new case of POCs with versatile properties and functions,including ion fluorescence recognition,fine Pd NPs stabilizer,and gas adsorption,enriching the family of POC-based materials.

关键词： Catalysis Fluorescence recognition Nanoparticles Cage compounds Palladium

Heterogeneous fiberous structured Mg-Zn-Zr alloy with superior strength-ductility synergy

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Journal of Materials Science & Technology 2023年第3期134卷 67-80页

作者： Wei fu Pengfei Dang Shengwu Guo Zijun Ren Daqing fang Xiangdong ding Jun Sun State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049China

Here we reported a heterogeneous fiberous structured Mg-5.6Zn-0.6Zr(wt%)alloy obtained by conventional extrusion method,which exhibited high yield strength of∼345 MPa,ultimate tensile strength of∼370 MPa,and high tensile strain of∼20.5%,superior to most of the Mg-Zn based alloys reported so *** extraordinarily high mechanical properties were mainly attributed to the heterogeneous fiberous structure consisting of alternating coarse-and fine-grain *** in the different layers grew into the neighboring layers,ensuring a good layer bonding.A high Schmid factor and geometric compatibility factor for pyramidal slip led to full slip transfer between the neighboring coarse grains and fine grains,which could help to release the stress concentration and avoid early *** profuse acti-vatedglide dislocations could render the unprecedented high tensile *** constraint by the hard fine-grain domains made the soft coarse-grain domains strong like the hard fine-grain domains,as well as the nanoscale precipitates pinning dislocations,contributed to the high *** hetero-geneous microstructure design was shown to have synergistic improvement in strength-ductility balance,which could be an inspiring strategy to improve mechanical properties of hexagonal close-packed(hcp)metals.

关键词： ZK60 Mg alloy Heterogeneous fiberous structure High strength-ductility synergy Pyramidal dislocations Bimodal grain sizes

Antibacterial Activity of Novel 18β-Glycyrrhetinic Hydrazide or Amide Derivatives

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Chemical Research in Chinese Universities 2021年第3期37卷 662-667页

作者： ZHANG Ling fu Yihong ding Yue MENG Jiao WANG Zhenchao WANG Peiyi State Key Laboratory Breeding Base of Green Pesticide and Agricultural Bioengineering Key Laboratory of Green Pesticide and Agricultural BioengineeringMinistry of EducationCenter for R&n of Fine ChemicalsGuizhou UniversityGuiyang550025P.R.China College of Pharmacy Drug Synthetic Engineering Laboratory of Guizhou ProvinceGuizhou UniversityGuiyang550025P.R.China

Through a facile structural modification on the natural bioactive ingredient 18β-glycyrrhetinic acid(GA),a series of novel GA hydrazide or amide derivatives was obtained,and their final molecular frameworks were characterized by NMR and HRMS *** bioassays revealed that some of the GA hydrazide or amide derivatives were able to suppress the growth of three tested plant ***,compound 3c exhibited excellent in vitro activity against Xanthomonas oryzae ***(Xoo),Pseudomonas syringae ***(Psa),and Xanthomonas axonopodis ***(Xac),providing the EC_(50) values of 5.89,16.1,and 3.64µg/mL,*** data were better than those of the positive controls thiodiazole copper(92.7,77.8,and 89.9µg/mL,respectively)and bismerthiazol(31.1,125.6,and 77.4µg/mL,respectively).In addition,in vivo experiments suggested that,compared with thiodiazole copper(41.93%and 39.73%,respectively),compound 3c exerted prominently curative and protective activities against rice bacterial leaf blight at 200µg/mL with the control effects of 52.36%and 51.40%,*** these obtained results,GA hydrazide or amide derivatives could serve as the feasible leads for exploring highly bioactive substrates.

关键词： 18β-Glycyrrhetinic Hydrazide or amide derivative Synthesis Antibacterial activity