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HIGH-TEMPERATURE TENSILE FRACTURE BEHAVIOR OF DIRECTIONALLY SOLIDIFIED Ni,Cr,Al-TaC EUTECTIC SUPERALLOY

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Acta Metallurgica Sinica(English Letters) 2004年第4期17卷 455-459页

作者： j.zhang j.j.Yu H.z.fu State Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072ChinaInstitute of Metal Research Chinese Academy of Sciences Shenyang 110016 ChinaState Key Laboratory of Solidification Processing Northwestern Polytechnical University Xi'an 710072China

The high-temperature tensile fracture behavior of the Ni, Cr, Al-TaC eutectic superal-loy directionally solidified under high temperature gradient is investigated. The high-temperature tensile fracture of this in situ composite has ductile character with lots of ductile nests whose diameters decrease with the increasing solidification rates. The maximum σb and δ are respectively 668.5MPa and 19.6%. There is α TaC whisker in the center of each nest, and the deformation of γ' and TaC is uneven. The high-temperature tensile behavior cannot be explained by the rule of mixtures but is decided by the formation of the plastic deformation band. The crack extension model is given.

关键词： Ni Cr Al-TaC eutectic superalloy directional solidification,in situ composite high-temperature tenslie fracture

Interfacial bonding mechanism in Al/coated steel dissimilar refill friction stir spot welds

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journal of Materials Science & Technology 2019年第6期35卷 1027-1038页

作者： z. Shen Y. Ding j. Chen B. Shalch Amirkhiz j.z. Wen L. fu A.P. Gerlich School of Materials Science and Engineering Northwestern Poly technical University Xi'an 710072 China Shanxi Key Laboratory of Friction Welding Technologies Northwestern Polytechnical University Xi'an 710072 China State Key Laboratory of Solidification Processing Northwestern Poly technical University Xi'an 710072 China Centre of Advance Materials joining Department of Mechanical and Mechatronics Engineering University of Waterloo 200 University Ave. Waterloo N2L3G1 Ontario Canada CanmetMATERIALS Natural Resources Canada Hamilton L8P 0A5 Canada

Defect-free dissimilar Al/zinc coated steel and Al/AlSi coated steel welds were successfully fabricated by refill friction stir spot welding. However, Al alloy and uncoated steel could not be welded under the same welding condition. Al-zn eutectic layer formed at the Al/zinc coated steel interface showed nonuniformity in thickness and nanoscale intermetallic(IMC) produced was discontinuous. The bonding formation between the Al-zn layer and the surrounding materials was attributed to a liquid/solid reaction mechanism. Bonding formation at Al alloy and AlSi coated steel interface was attributed to a solid/solid reaction mechanism, as the joining process did not involve with melting of base metals or AlSi coating materials. Kissing bond formed at the weld boundary acted as a crack initiation and propagation site,and the present study showed that weld strength of Al 5754/AlSi coated steel was greatly influenced by properties of original IMC layer.

关键词： Refill friction stir spot welding Al alloy Steel Coated materials joining mechanism

A Model of Tangential Contact Damping Considering Asperity Interaction and Lateral Contact

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Acta Mechanica Solida Sinica 2018年第6期31卷 758-774页

作者： W.P.fu z.Q.Gao W.Wang j.B.Wu School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048 China

A precise tangential contact damping model is proposed,which includes the lateral contact of the upper-lower asperities and the interaction of adjacent *** effects of the normal static preload,frequency,and amplitude of tangential displacement on the tangential contact damping were analyzed by simulation,***,the results of simulation are verified by *** tangential contact damping of considering the interaction and lateral contact of asperity is very close to the experimental results.

关键词： Asperity Lateral contact Interaction Tangential contact damping

Ultrasonic-based surface patterning and interfacial reaction of zrO_(2)ceramics

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journal of Materials Science & Technology 2023年第24期155卷 202-210页

作者： H.j. Dong z.L. Li X.G.Song j.C. Feng S.j. Wei j.H. fu Y. Shi State Key Laboratory of Advanced Welding and joining Harbin Institute of Technology Harbin 150001 China Shandong Provincial Key Lab of Special Welding Technology Harbin Institute of Technology at Weihai Weihai 264209 China

We demonstrate a process to achieve selective surface metallization of zrO_(2)ceramics using ultrasound technology in atmospheric environments at 350℃,which bestows good weldability of zrO_(2)to achieve rapid and reliable connections with other metals as well as ceramic *** challenge is that brazing or diffusion welding processes to accomplish metallurgical connections for zrO_(2) typically require holding at elevated temperatures for minutes to hours,while the selective ultrasonic metallization process requires only a few seconds of processing without the application of covering films or solder *** this study,the selected Sn-2Ti alloy could effectively wet and spread on zrO_(2)substrate under ultrasonication,and continuous interphase layers were rapidly formed in situ between zrO_(2)and *** bonding strength for the zrO_(2)/Sn-2Ti interface was well established with the highest shear strength of 37.1 MPa,and the fracture location occurred at the filler *** interfacial reaction layer thickened remarkably with the prolongation of sonication,accompanied by the partial crystallization of amorphous TiO and the formation of irregularly striped Ti_(11.31)Sn_(3)O_(10)nanocrystals.

关键词： Selective ultrasonic metallization zirconia surface patterning Low temperature connection Sono-oxidation Interfacial reaction

NEAR RAPID DIRECTIONAL SOLIDIFICATION AND ITS SUPERFINE MICROSTRUCTURE

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Acta Metallurgica Sinica(English Letters) 1996年第6期9卷 497-502页

作者： H.z. fu X.G. Gen j.G. Li and j.zhang(State Key Lab.of Solidification Processing, Northwestern Polytechnical University,Xi’an 710072,China ) Northwestern Polytechnical Univ Xi'an China

This paper briefly reviews the recent research on the near rapid directional solidification and microstructure superfining. The morphology transitions and the corresponding mechanical properties are presented. The critical velocities relevant to the morphology transitions are comprehensively given. Meanwhile the solidification characteristics near absolute stability limit are *** can be clearly seen that the superfine microstructures possess extremely better properties compared with the conventional microstructures.

关键词： near rapid directional solidification,superfine microstructure,morphology transition mechanical property

Effects of halobenzoquinone and haloacetic acid water disinfection byproducts on human neural stem cells

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journal of Environmental Sciences 2017年第8期29卷 239-249页

作者： Katherine z.fu jinhua Li Sai Vemula Birget Moe Xing-Fang Li Division of Analytical&Environmental Toxicology Department of Laboratory Medicine&PathologyFaculty of Medicine&DentistryUniversity of Alberta Alberta Centre for Toxicology Department of Physiology&PharmacologyFaculty of MedicineUniversity of Calgary

Human neural stem cells（h NSCs） are a useful tool to assess the developmental effects of various environmental contaminants; however, the application of h NSCs to evaluate water disinfection byproducts（DBPs） is scarce. Comprehensive toxicological results are essential to the prioritization of DBPs for further testing and regulation. Therefore, this study examines the effects of DBPs on the proliferation and differentiation of h NSCs. Prior to DBP treatment, characteristic protein markers of h NSCs from passages 3 to 6 were carefully examined and it was determined that h NSCs passaged 3 or 4 times maintained stem cell characteristics and can be used for DBP analysis. Two regulated DBPs, monobromoacetic acid（BAA） and monochloroacetic acid（CAA）, and two emerging DBPs, 2,6-dibromo-1,4-benzoquinone（2,6-DBBQ） and 2,6-dichloro-1,4-benzoquinone（2,6-DCBQ）, were chosen for h NSC treatment. Both 2,6-DBBQ and 2,6-DCBQ induced cell cycle arrest at S-phase at concentrations up to 1 μmol/L. Comparatively, BAA and CAA at 0.5 μmol/L affected neural differentiation. These results suggest DBP-dependent effects on h NSC proliferation and differentiation. The DBP-induced cell cycle arrest and inhibition of normal h NSC differentiation demonstrate the need to assess the developmental neurotoxicity of DBPs.

关键词： Disinfection byproducts Human neural stem cells Differentiation Halobenzoquinones Haloacetic acids Cell cycle arrest

NUMERICAL SIMULATION OF COLUMNAR TO EQUIAXED TRANSITION FOR DIRECTIONALLY SOLIDIFIED Ti-44Al ALLOY

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Acta Metallurgica Sinica(English Letters) 2008年第2期21卷 146-156页

作者： K.F. Wang j.j. Guo G.F. Mi C. Y. Li H.z. fu School of IVlaterials Science and Engineering Henan Polytechnic University Jiaozuo 454100 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

Solute diffusion controlled solidification model was applied to simulate the columnar to equiaxed transition （CET） during directional solidification of Ti-44Al alloy. The simulation results show that the solutal interactions from growing equiaxed grains play an important role on CET. The effects of the applied thermal gradient and pulling velocity, the equiaxed seed spacing and nucleation undercooling on the CET are investigated in the present simulation. The simulated results indicated that the columnar branch spacing depends not only on the thermal gradient and the pulling velocity, but also on number of the seeds. A spacing adjustment can occur through initiation of seeds that develop into new columnar grains. The dependence of the CET on the thermal gradient and pulling velocity, qualitatively agrees with the analytical CET model of Hunt,

关键词： Ti-44Al alloy Directional solidification columnar to equiaxedtransition (CET) Numerical simulation

Cyanobacterial bloom dynamics in Lake Taihu

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journal of Environmental Sciences 2015年第6期27卷 249-251页

作者： Katherine z. fu Birget Moe Xing-Fang Li X. Chris Le Division of Analytical and Environmental Toxicology Department of Laboratory Medicine and Pathology University of Alberta

Lake Taihu is the third largest freshwater lake in China and serves as an important drinking water source for the local populace;however,decades of excessive nutrient loading fueled by anthropogenic activities have resulted in hypertrophic conditions,promoting the annual formation of nuisance phytoplankton blooms（Chen et al.,2003;Duan et al.,2009）

关键词： Cyanobacteria Blue-green algae Microcystin Natural toxins Water quality Nutrients Nitrogen and phosphorus Carbon dioxide

湿式氧化用于染料废水脱色:过去20年回顾（英文）

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催化学报 2014年第1期35卷 1-7页

作者： jie fu George z.Kyzas Environmental Engineering Program Department of Civil Engineering Auburn University Department of Petroleum and Natural Gas Technology Technological Educational Institute of Kavala Division of Chemical Technology Department of Chemistry Aristotle University of Thessaloniki

Wet air oxidation(WAO), a liquid phase reaction between organic materials in water and oxygen, is one of the most economical and technologically viable advanced oxidation processes for wastewater treatment, particularly toxic and high organic content wastewater. WAO is the liquid phase oxidation of organics or oxidizable inorganic components at elevated temperatures(125–320 °C) and pressures(0.5–20 MPa) using gaseous oxygen(or air) as oxidant. In the past two decades, the WAO process was widely studied and applied in the treatment of dye wastewater. Compared to conventional WAO, catalytic WAO processes have higher efficiency and use moderate reaction conditions. The catalysts included homogenous and heterogeneous types. The key points that need to be solved are recycling of homogenous catalysts and better stability of heterogeneous catalysts. In the present review, the technological processes are first introduced, then some research history and hotspots of WAO research are presented, and finally, its application in the treatment of dye wastewater in the past two decades is summarized to reveal the impressive changes in modes, trends, and conditions used. The application includes model pollutant studies and wastewater tests.

关键词：染料废水处理湿式空气氧化非均相催化剂有机物含量脱色湿式氧化工艺液相反应催化剂包