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Acta Mechanica Sinica 2024年第7期40卷 19-28页

作者： Xuewei zhou Tianlong Zhang li Cheng Xusheng Yang Jiaming Zhu School of Civil Engineering Shandong UniversityJinan 250061China Department of Mechanical Engineering Hong Kong University of Science and TechnologyHong KongChina State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHong KongChina Shenzhen research institute of Shandong university Shenzhen 518057China institute of Materials Intelligent Technology Shenyang 110004China

The morphology of Ni_(4)Ti_(3) precipitates is important in tuning the martensitic transformation(MT)behavior and mechanical properties of *** ageing is effective in engineering the morphology of Ni_(4)Ti_(3) precipitates due to the variant selection effect of external load which is still *** this work,maps of variant selection effect of external load applied along all crystallographic directions are obtained by using a combination of theoretical analyses and phase field *** is found that maps produced by uniaxial tension and uniaxial compression are quite *** number and types of Ni_(4)Ti_(3) variants preferred by external load vary as the loading direction ***,factors influencing the strength of variant selection effect are *** work provides insights on understanding the Ni_(4)Ti_(3) precipitation process and sheds light on the engineering of morphology of Ni_(4)Ti_(3) precipitates for desired mechanical and functional properties.

关键词： Ni_(4)Ti_(3) Variant selection NiTi alloy phase field model precipitation morphology

A Comparison Study between Suspension Casting process and Low Superheat Casting process

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International Journal of Minerals,Metallurgy and Materials 1999年第1期13卷 31-34页

作者： Yan Yu Qijie Thai libo Zhang Hanqi Hu (Materials science and Engineering School, university of science and Technology Beliing, Beding 100083, china)(shenyang research institute of Foundry, shenyang 110021, china) Materials science and Engineering School University of Science and Technology Beijing Beijing 100083 China shenyang research institute of Foundry Shenyang 110021 China

Taking GCr15 bearing steel as experiment material, the effects of suspension casting process and low superheat casting process on the solidification of ingot were studied comparehvely. The results show that both suspension casting process and low superheat casting process can improve the censeal segregation and crystal structure of ingot. As the acting mechanism is different between the two kinds of processes, it is found that suspension casting process is more effective than low superheat casting process in improving the quality of ingot.

关键词： suspension casting process low superheat casting process solidification

Corrosion Behavior and protection Efficiency of 2024Al and SiC_p/2024Al Metal Matrix Composite

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Journal of Materials science & Technology 2002年第4期18卷 351-353页

作者： Chunlin HE, Changsheng liU, Fengqin li and Qingkui CAISchool of Materials and Metallurgy, northeastern university, shenyang 110004, chinaZhiming SHI, liqing CHEN and Jing BIinstitute of Metal research, Chinese Academy of sciences, shenyang 110016, china Sch. of Mat. and Metall. Northeastern Univ. Shenyang 110004 China Inst. of Metal res. Chinese Acad. of Sci. Shenyang 110016 China

The corrosion resistance of 2024 Al and SiC particle reinforced 2024 Al metal matrix composite (SiCp?024AI MMC) in 3.5% NaCl solution was investigated with electrochemical method and immersion test, and the corrosion protection of sulfuric acid anodized coatings on both materials was evaluated by electrochemical impedance spectroscopy. The results showed that the SiCp?024AI MMC is more susceptible to corrosion than its matrix alloy in 3.5% NaCI. For 2024AI, the anodized coating provides excellent corrosion resistance to 3.5% NaCI. The anodized coating on the SiCp?024AI provides satisfactory corrosion protection, but it is not as effective as that for 2024AI because the structure of the anodized layer is affected by the SiC particulates.

关键词： 2024 Al Metal matrix composite Anodizing Electrochemical impedance spcctroscopy potentiodynamic polarization Corrosion resistance

Numerical Simulation and Experimental Investigation of Springback in U-Channel Forming of Tailor rolled Blank

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Journal of Iron and Steel research International 2012年第9期19卷 8-12页

作者： ZHANG Hua-wei 1 , liU li-zhong 1 , HU ping 1 , liU Xiang-hua 2 ( 1.Faculty of Vehicle Engineering and Mechanics , State Key Laboratory of Structural Analysis for Industrial Equipment , Dalian university of Technology , Dalian 116024 , liaoning , china 2.research institute of science and Technology , northeastern university , shenyang 110819 , liaoning , china ) [a] Faculty of Vehicle Engineering and Mechanics State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 Liaoning China [b] research institute of science and Technology Northeastern University Shenyang 110819 Liaoning China

In order to grasp the springback rule of TrB ( tailor rolled blank ) parts after forming , the springback behavior of TrB was investigated by integrating such three means as theoretical research , numerical simulation and stamping *** theories of springback were *** stamping and springback processes of annealed 1.2 / 2.0mm TrB , 1.2mm and 2.0mm plates for U-channel were simulated , and the simulation results were compared with the *** results indicate that the springback of TrB falls in between those of the 1.2mm and 2.0mm *** is desirable for the TrB U-channel to have die clearance of 1.1times maximum blank thickness and friction coefficient of about 0.12 , and longer thickness transition zone is *** simulation data demonstrate reasonably good agreement with the experiments.

关键词： tailor rolled blank U-channel springback annealing

Insight into the role of ethylene glycol on thermodynamics and nucleation kinetics of dimethyl terephthalate in mixed solvent system

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particuology 2024年第2期85卷 1-12页

作者： Yujin Zhang Chunyan Shi Jing Tang li liu Dongxia Yan Qing zhou Xingmei Lu Songyan Jia College of Chemical Engineering Shenyang University of Chemical TechnologyShenyang110142China Bejing Key Laboratoryoflonic liquids Clean process CAS Key LaboratoryofGreen Process and EngineeringState Key Laboratoryof Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing100190China School of Chemistry and Chemical Engineering Qingdao UniversityQingdao266071China Henan institute of Advanced Technology Zhengzhou UniversityZhengzhou450001China School of Chemical Engineering University of Chinese Academy of SciencesBeijing100049China

Dissolution and nucleation are two essential processes for industrial *** paper in-vestigates the effect of ethylene glycol addition on the crystallization behavior of dimethyl terephthalate(DMT)in *** DMT solubility in mixed solvent system(methanol-ethylene glycol)was deter-mined by isothermal satiation approach,and the solubility was associated using seven *** model fitting results were consistent with the experimental *** on the results,the metastable zone width(MSZW)of DMT was detected by the polythermal approach;the modified Sangwal's theory was used to investigate the nucleation behavior,which can provide a new way of thought for better analysis of the crystallization *** results demonstrated that MSZW was associated with various elements,such as cooling rate,saturation temperature and mass fraction of ethylene *** addition of ethylene glycol slowed down the nucleation rate as shown by the broadening of *** derive the solid-liquid interface energy,the nucleation driving force,the critical nucleation size and the critical Gibbs free energy according to the classical nucleation *** is demonstrated that the nucleation driving force and the solid-liquid interface energy are dependent and jointly influence the MSZW.

关键词： Dissolution Nucleation Solubility Apparent thermodynamic parameters Metastable zone width Solid-liquid interface energy

properties of Hot-pressed Al_2O_3-Fe Composites

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Journal of Materials science & Technology 2001年第5期17卷 538-542页

作者： M.M.El-Sayed Seleman, Xudong SUN and liang ZUO Department of Materials science and Engineering, northeastern university, shenyang 110006, china K.A.Khalil powder Metallurgy institute, Central South university, Changsha 410083, china northeastern Univ Dept Mat Sci & Engn Shenyang 110006 Peoples R China Cent S Univ Powder Met Inst Changsha 410083 Peoples R China

Alumina-(0 similar to 20 vol. pct) iron composites were fabricated by hot-pressing of well-mixed-alumina and iron powders at 1400 degreesC and 30 Mpa for 30 min. Hot-pressed bodies with nearly theoretical density were obtained for addition up to 10 vol. pct Fe, but relative density decreased gradually with further increase in Fe addition. The materials exhibit a homogeneous dispersion of Fe. Fracture strength of the composites exhibits a maximum value of 604 Mpa at 15 vol. pct Fe, which is 1.5 times that of alumina alone. Fracture toughness increases with the increase in Fe content, reaching 7.5 Mpa.m(1/2) at 20 vol. pct Fe. The theoretical values of fracture toughness was calculated and compared with the experimental one. Toughening mechanisms of the composites are also discussed.

关键词： Fe properties of Hot-pressed Al2O3-Fe Composites Al

Application of controlled-release urea increases maize N uptake,environmental benefits and economic returns via optimizing temporal and spatial distributions of soil mineral N

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pedosphere 2024年第1期34卷 222-235页

作者： Mingxue SUN juan li lili ZHANG Xiaomeng SU Ning liU Xiaori HAN Songjiang WU Zhentao SUN Xiangdong YANG institute of Agricultural resources and regional planning Chinese Academy of Agricultural Sciences/State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Key Laboratory of Plant Nutrition and FertilizerMinistry of Agriculture and Rural AffairsBeijing 100081China Agricultural Development Service Center of Zhuanghe Zhuanghe 116499China Agricultural Technology Extension Center Wafangdian 116300China College of Land and Environment Shenyang Agricultural UniversityShenyang 100866China

The creation of controlled-release urea (CrU) is a potent substitute for conventional fertilizers in order to preserve the availability of nitrogen (N) in soil,prevent environmental pollution,and move toward green *** main objectives of this study were to assess the impacts of CrU’s full application on maize production and to clarify the connection between the nutrient release pattern of CrU and maize nutrient *** order to learn more about the effects of CrU application on maize yields,N uptake,mineral N (N_(min)) dynamics,N balance in soil-crop systems,and economic returns,a series of field experiments were carried out in 2018–2020 in Dalian City,liaoning province,*** were 4 different treatments in the experiments:no N fertilizer input (control,CK);application of common urea at 210 kg ha^(-1)(U),the ideal fertilization management level for the study site;application of polyurethane-coated urea at the same N input rate as U (pCU);and application of pCU at a 20% reduction in N input rate (0.8pCU).Our findings showed that using CrU (i.e.,pCU and 0.8 pCU) may considerably increase maize N absorption,maintain maize yields,and increase N use efficiency (NUE) compared to *** grain yield showed considerable positive correlations with total N uptake in leaf in U and 0.8 pCU,but negative correlations with that in pCU,indicating that pCU caused excessive maize absorption while 0.8 pCU could achieve a better yield response to N ***,pCU was able to maintain N fertilizer in the soil profile 0–20 cm away from the fertilization point,and higher N_(min)content was observed in the 0–20 cm soil layer at various growth stages,particularly at the middle and late growing stages,optimizing the temporal and spatial distributions of N_(min).Additionally,compared to that in U,the apparent N loss rate in pCU was reduced by 36.2%,and applying CrU (pCU and 0.8 pCU) increased net profit by 8.5% to 15.2% with less labor and fertilization *** was co

关键词： apparent N loss fertilization management green agriculture maize yield N balance N use efficiency

properties of nonadiabatic quantum fluctuations of the strongly coupled electron-phonon systems

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science china(physics,Mechanics & Astronomy) 2008年第3期51卷 258-268页

作者： pANG XiaoFeng institute of life science and Technology,university of Electronic science and Technology of china,Chengdu 610054,china International Centre for Materials physics,Chinese Academy of sciences,shenyang 110015,china institute of life science Technology University of Electronic Science Technology of china Chengdu 610054 China International Centre for Materials physics Chinese Academy of Sciences Shenyang 110015 China

A new variational-ansatz of states of electrons and phonons was proposed on the basis of the Holstein model in strongly coupled electron-phonon systems for studying the influence of nonadiabatic phonon fluctuation,arising from the motion and density fluctuation of electrons,on the properties of ground state,uncertainty relation,stability of polarons,charge density wave (CDW) and phonon staggered ordering. The new ansatz represents the correlation among the displacement and squeezing states of phonons and polaron’s state of electrons as well as the squeezing-antisqueezing effect. The correlation and squeezing-antisqueezing ef-fect result in the decrease of ground state energy,enhancement of stability of the systems,increase of binding energy of the polarons,weakening of the growing speed of polaron narrowing of the electron band,increase of the charge density wave order and suppression of the increased tendency of anomalous quantum fluctuation of the phonons in such a case,when compared with the uncorrelated case in the systems. The results obtained show that the ground state determined by the new state ansatz is most stable,thus the new ansatz describing the properties of the coupled electron phonon systems is very relevant and available,especially in strongly coupled and largely squeezed cases.

关键词： squeezing-antisqueezing effect state-ansatz polaron coupled electron-phonon systems quantum fluctuation

Exponential networked synchronization of master-slave chaotic systems with timevarying communication topologies

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Chinese physics B 2012年第4期21卷 151-158页

作者：杨东升刘振伟赵琰刘兆冰 College of Information science and Engineering Northeastern UniversityShenyang 110004China Department of Automatic Control Engineering Shenyang Institute of EngineeringShenyang 110136China

The networked synchronization problem of a class of master-slave chaotic systems with time-varying communication topologies is investigated in this paper. Based on algebraic graph theory and matrix theory, a simple linear state feedback controller is designed to synchronize the master chaotic system and the slave chaotic systems with a time- varying communication topology connection. The exponential stability of the closed-loop networked synchronization error system is guaranteed by applying Lyapunov stability theory. The derived novel criteria are in the form of linear matrix inequalities （LMIs）, which are easy to examine and tremendously reduce the computation burden from the feedback matrices. This paper provides an alternative networked secure communication scheme which can be extended conveniently. An illustrative example is given to demonstrate the effectiveness of the proposed networked synchronization method.

关键词： exponential networked synchronization master-slave chaotic systems algebraic graph theory communication topology

Structure characterization of the oxide film on FGH96 superalloy powders with various oxidation degrees

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2037-2047页

作者： Yang liu Yufeng liu Sha Zhang lin Zhang peng Zhang Shaorong Zhang Na liu zhou li Xuanhui Qu Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China science and Technology on Advanced High Temperature Structural Materials Laboratory AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China

The structure of the oxide film on FGH96 alloy powders significantly influences the mechanical properties of *** this study,FGH96 alloy powders with various oxygen contents were investigated using high-resolution transmission electron microscopy and atomic probe technology to elucidate the structure evolution of the oxide *** dispersive spectrometer analysis revealed the presence of two distinct components in the oxide film of the alloy powders:amorphous oxide layer covering the γ matrix and amorphous oxide particles above the *** alloying elements within the oxide layer showed a laminated distribution,with Ni,Co,Cr,and Al/Ti,which was attributed to the decreasing oxygen equilibrium pressure as oxygen diffused from the surface into the γ *** the other hand,Ti enrichment was observed in the oxide particles caused by the oxidation and decomposition of the carbide *** analysis of the oxide film with oxygen contents of 140,280,and 340 ppm showed similar element distributions,while the thickness of the oxide film varies approximately at 9,14,and 30 nm,*** findings provide valuable insights into the structural analysis of the oxide film on FGH96 alloy powders.

关键词： Ni-based superalloys surface structure oxide layer thickness oxidation behavior element distribution