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Tensile ductility and deformation mechanisms of a nanotwinned 316L austenitic stainless steel

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Journal of Materials Science & Technology 2020年第1期36卷 65-69页

作者： y.Z.Zhang J.J.Wang n.R.tao Sheny.n. national Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China University of Chinese Academy of Sciences Beijing 100049China

A nanotwinned 316 L austenitic stainless steel was prepared by means of surface mechanical grinding *** recovery annealing,the density of dislocations decreases obviously while the average twin/matrix lamella thickness still keeps in the nanometer *** annealed nanotwinned sample exhibits a high tensile yield strength of 771 MPa and a considerate uniform elongation of 8%.TEM observations showed that accommodating more dislocations and secondary twinning inside the nanotwins contribute to the enhanced ductility and work hardening rate of the annealed nanotwinned sample.

关键词： nanotwinned Stainless steel Ductility Deformation mechanism

STRUCTURAL DETERMInATIOn OF TITAnIUM-OXIDE nAnOPARTICLES By X-RAy ABSORPTIOn SPECTROSCOPy

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Acta Metallurgica Sinica(English Letters) 2002年第1期15卷 53-57页

作者： Z.y. Wu J. Zhang K. Ibrahim M.I. Abbas G. Li y. tao T.D. Hu F.Q. Liu H.J. Qian y.n. Xie Q.H. Zhang L. Gao Z.Z. Chen Beijing Synchrotron Radiat. Facility Inst. of High Energy Phys. Chinese Acad. of Sci. Beijing 100039 China

As a potential application of titanium-oxide nanoparticles, it is extremely important to investigate a detailed picture of the surface and interior structural properties of nanocrystalline materials, such as rutile and anatase with diameters 7.0 and 4.5nm, respectively. X-ray absorption spectroscopy has been used to identify the local Ti environment and related electronic structure. We combine the experimental results at the Ti edge in both bulk and nano-crystals to determine the lattice distortion in terms of differently characteristic preedge features and the variation in the multiple-scattering region of X-ray absorption near-edge structure (XAnES) spectra. The relationship between the transition peaks and the surface-to volume ratio is also discussed.

关键词： X-ray absorption near edge structure nano particle transition metal oxide

Mechanical properties of SWnT X-Junctions through molecular dynamics simulation

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International Journal of Smart and nano Materials 2012年第1期3卷 33-46页

作者： B.A.Stormer n.M.Piper X.M.y.n. J.tao y.Fu M.Kirca A.C.To Department of Mechanical Engineering and Materials Science&Department of Civil and Environmental Engineering University of PittsburghPittsburghPAUSA Department of Power Engineering North China Electric Power UniversityBaoding 071003China

The mechanical behavior of seven different carbon nanotube(CnT)X-junctions with a vary.n. number of bonds was investigated through molecular dynamics *** X-junctions are composed of two(6,0)single-walled carbon nanotubes(SWnTs)created via vibration-assisted heat *** junctions,containing anywhere between one and seven bonds,are subject to uniaxial tensile,shear and torsional strain,and then the stiffness values are determined for each *** subjected to tensile and shear strain,both the arrangement and orientation of bonds are found to affect the stiffness of junctions more substantially than the number of bonds,bond length or bond ***,anisotropic shear behavior is observed in the X-junctions,which can be attributed to the junction’s bond ***,the stiffness of X-junctions tested under an applied torque(torsion)differs from the stiffness under tensile and shear strain,however,in that it is more substantially affected by the number of bonds present in the junction than by any other property.

关键词： carbon nanotube molecular dynamics X-junction stiffness

HIGHLy DISPERSED MULTI-WALLED CARBOn nAnOTUBES In WATER/ETHAnOL AnD ITS APPLICATIOn FOR PVA COMPOSITE

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维普期刊数据库

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 389-396页

作者： X.y.tao J.M.Xu F.Liu G.L.Xu InstituteofMaterialsPhysicsandMicrostructures DepartmentofMaterialsScienceandEngmeeringZhejiangUniversityHangzhou310027China CollegeofElectronicInformation HangzhouDianziUniversityHangzhou310018China

Two carboxylation processes were carried out to modify multi-walled carbon nanot ube bundles (m-MWnTs). The results showed that both of the m-MWnTs could be high ly dispersed in water with the concentration up to 25 and 15mg/mL in ethanol wit hout obvious deposition or conglomeration over 6 months. FTIR, Raman, TGA and TE M characterizations of the m- MWnTs showed that hydroxyl and carboxyl groups hav e been attached with MWnTs, and that the nanotube structure was only damaged a l ittle after modification treatments in mixed acids over 24h. Above prepared nano tube suspensions in water were successfully used as a filler of thermoplastic PV A composite to enhance its electrical conductivity. The results showed that the addition of m-MWnTs greatly improved the conductivity and the threshold of mass fraction was about 5wt%. The results also proved that purification process was n ot needed because of high purity of the raw MWnTs prepared in our group.

关键词： carbon nanotube polyvinylalcohol composite conductivity

Development of an in-situ H_(2)reduction and moderate oxidation method for 3,5-dimethylpyridine hydrogenation in trickle bed reactor

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Frontiers of Chemical Science and Engineering 2022年第12期16卷 1807-1817页

作者： tao Lin Xiaoxun Ma School of Chemical Engineering Northwest UniversityXi’an 710069China Kaili Catalyst&new Materials Co. Ltd.Xi’an 710201China Shaanxi Key Laboratory of Catalytic Materials and Technology Xi’an 710201China Chemical Engineering Research Center of the Ministry of Education(MOE)for Advanced Use Technology of Shanbei Energy Xi’an 710069China Shaanxi Research Center of Engineering Technology for Clean Coal Conversion Xi’an 710069China Collaborative Innovation Center for Development of Energy and Chemical Industry in northern Shaanxi Xi’an 710069China International Scientific and Technological Cooperation Base of the Ministry of Science and Technology(MOST)for Clean Utilization of Hydrocarbon Resources Xi’an 710069China

The Ru/C catalyst prepared by impregnation method was used for hydrogenation of 3,5-dimethylpyridine in a trickle bed *** the same reduction conditions(300°C in H_(2)),the catalytic activity of the non-in-situ reduced Ru/C-n catalyst was higher than that of the in-situ reduced Ru/C-y ***,an in-situ H_(2)reduction and moderate oxidation method was developed to increase the catalyst ***,the influence of oxidation temperature on the developed method was *** catalysts were characterized by Brunauer–Emmett–Teller method,hydrogen temperature programmed reduction H_(2)-TPR,hydrogen temperature-programmed dispersion(H_(2)-TPD),X-ray diffraction,energy dispersive spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,O2 chemisorption and oxygen temperature-programmed dispersion(O2-TPD)*** results showed that there existed an optimal Ru/RuO_(x)ratio for the catalyst,and the highest 3,5-dimethylpyridine conversion was obtained for the Ru/C-i1 catalyst prepared by in-situ H_(2)reduction and moderate oxidation(oxidized at 100°C).Excessive oxidation(200°C)resulted in a significant decrease in the Ru/RuO_(x)ratio of the in-situ H_(2)reduction and moderate oxidized Ru/C-i2 catalyst,the interaction between RuO_(x)species and the support changed,and the hard-to-reduce RuO_(x)species was formed,leading to a significant decrease in catalyst *** developed in-situ H_(2)reduction and moderate oxidation method eliminated the step of the non-in-situ reduction of catalyst outside the trickle bed reactor.

关键词： Ru C catalyst in-situ H_(2)reduction and moderate oxidation in-situ reduction non-in-situ reduction hydrogenation of 3,5-dimethylpyridine

Composition dependence of phase structure and electrical properties of(1-y)Bi_(1-x)nd_xFeO_(3-y)BiScO_3 ceramics

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Science China(Technological Sciences) 2016年第7期59卷 1029-1035页

作者： tao Hong WU JiaGang Department of Materials Science Sichuan University

In this work, we have studied a new lead-free ceramic of（1-y）Bi1-xndxFeO3-yBiScO3（0.05≤x≤0.15 and 0.05≤y≤0.15） prepared by a conventional solid-state method, and the influences of nd and Sc content on their phase structure and electrical properties were investigated in detail. The ceramics with 0.05≤x≤0.10 and 0.05≤y≤0.15 belong to an R3 c phase, and the rhombohedral-like and orthorhombic multiphase coexistence is established in the composition range of 0.125≤x≤0.15 and y=0. The electrical properties of the ceramics can be enhanced by modify.n. x and y values. The highest piezoelectric coefficient（d33～51 p C/n） is obtained in the ceramics with x=0.075 and y=0.125, which is superior to that of a pure BiFeO3 ceramic. In addition, a lowest dielectric loss（tan δ～0.095%, f=100 k Hz） is shown in the ceramics with x=0.15 and y=0 due to the involvement of low defect concentrations, and the improved thermal stability of piezoelectricity at 20–600℃ is possessed in the ceramics. We believe that the ceramics can play a meaningful role in the high-temperature lead-free piezoelectric applications.

关键词： BiFeO_3 ceramics composition design phase structure piezoelectric properties

Confined Crystallization Behaviors of Cross-linked Comb-like Copolymers

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Chinese Journal of Polymer Science 2016年第8期34卷 1039-1046页

作者： Xian-jing Gong 施德安 y.n.-kui y.n. tao Jiang y.n.feng Meng Robert K.y.Li 蒋世春 School of Materials Science andEngineering Tianjin UniversityTianjin 300072China Ministry of Education Key Laboratory for the Green Preparation and Application of Functional Materials Hubei Collaborative Innovation Center for Advanced Origanic Chemical MaterialsFaculty of Materials Science and EngineeringHubei UniversityWuhan 430062China School of Chemistry and Materials Science Ludong UniversityYantai 264025China Department of Physics and Materials Science City University of Hong KongHong KongChina

Cross-linked PEG-based copolymers were obtained via synthesis of polyethylene glycol （PEG） and methoxy polyethylene glycol （MPEG） by the bridging and/or cross-linking agent of 2,4-tolylene diisocy.n.te （TDI） and/or hexamethylene-l,6-diisocy.n.te homopolymer （HDI trimer）. The effects on the crystallization behaviors of the samples could be found with the changes in molecular weight of MC-PEG and molecular weight of SC-PEG in certain cross-linked density. It is revealed that the samples appear not to crystallize when the molecular weight of MC-PEG and SC-PEG are 1000 g/mol or less than that. The samples begin to crystallize when the molecular weight of either MC-PEG or SC-PEG reaches 2000 g/mol. The crystallinity of crystallized MC-PEG decreases with the increasing molecular weight of uncrystallized SC-PEG and the crystallinity of crystallized SC-PEG declines with the rise of molecular weight of uncrystallizable MC-PEG. The chains of SC-PEG （M_n = 2000 g/mol） can fold and align easilier than those of MC-PEG （M_n = 2000 g/mol）, when the content of PEG is the same.

关键词： PEG-based copolymers Cross-linking Comb-like Confined crystallization behavior.

Exopolysaccharide produced by Vibrio neocaledonicus sp. as a green corrosion inhibitor:Production and structural characterization

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Journal of Materials Science & Technology 2018年第12期34卷 2447-2457页

作者： Masoumeh Moradi Zhenlun Song tao Xiao Key Laboratory of Marine Materials and Related Technologies Zhejiang Key Laboratory of Marine Materials and Protective TechnologiesNingbo Institute of Materials Technology and EngineeringChinese Academy of Sciences College of Materials Science and Engineering Taiyuan University of Technology

An exopolysaccharide substances produced by Vibrio neocaledonicus sp. was introduced as a novel green inhibitor against the corrosion of carbon steel in artificial seawater and acidic media. The produced extracellular polymeric substance（EPS） is heterogeneous with composition of polysaccharides, nucleic acids and protein and average molecular weight of 29,572 Da. Adsorption of EPS on the metal surfaces and formation of Fe-EPS complexes acted as a barrier to prevent the oxygen penetration and hindered anodic and cathodic reactions. The inhibitory effect increases with increasing EPS concentration and exposure time. The highest corrosion inhibitory effect（95.1%） was observed for 10 g/L of EPS after 5 days of exposure in seawater. This is the highest inhibitory effect ever been reported by EPSs. While, the optimum concentration of EPS with the highest inhibition efficiency in 1 n H;SO;was 1000 ppm. The influence of different parameters, such as initial pH, growth phase, various nitrogen and carbon sources on the production of EPS and its corrosion inhibitory effect were also investigated. According to results,the optimum culture medium for EPS production is contained artificial seawater including 5% mannitol as carbon source and 0.1%（nH;）;SO;as nitrogen source at pH = 8. This medium could produce 22.24 g/L EPS during 3 days’ incubation at 30 ℃. The corrosion inhibitory efficiency of obtained EPS was 95.97%.

关键词： Extracellular polymeric substances Vibrio neocaledonicus sp. Green corrosion inhibitor Chemical analysis

Fabrication and sustained release properties of porous hollow silica nanoparticles

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Science China Chemistry 2010年第3期53卷 555-560页

作者： Xu, Hong tao Wang, Xin Shou tao, Lei Ming Wu, Si Xin Key Laboratory for Special Functional Materials of Ministry of Education Henan University Kaifeng 475004 China

MCM-41-type mesoporous silica nanospheres(MSn) have been prepared using n-cetyltrimethylammonium bromide(CTAB) as a soft *** pseudo-moire' rotational pattern inside the MSn results in many interior *** mesoporous silica(HMS) spheres were synthesized by solvent extraction of the template from *** morphology and structure of MSn and HMS were studied by TEM,XRD and nitrogen sorption techniques.A model drug,bromocresol green dye,was packed inside different regions of HMS through impregnation at different pressures and temperatures,and the drug release performance of the resulting materials was *** results showed that vacuum evaporation of solvents may enhance the controlled release properties.

关键词： pseudo-moire’ rotational pattern hollow silica release