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Synthesis and Characterization of a New Organic Up-conversion Laser Dye HMASPS

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Chinese Chemical Letters 2000年第5期11卷 395-398页

作者： Ren, y Fang, q yan, yX Wang, XM liu, Z Zhou, Gy Wang, C Zhao, X Jiang, MH Shandong Univ State Key Lab Crystal Mat Jinan 250100 Peoples R China

A new organic dye, trans-4-[4'-(N-hydroxyethyl-N-methylamino)styryl]-N-methylpyridinium p-toluene sulfonate (HMASPS) has been synthesized and its structure has been determined. Pumped with a 1064 nm, 50 ps laser pulses, 0.05 mol/L HMASPS/DMF solution showed the two-photon pumped (TPP) output/input efficiency of 8.4% which is higher than that of trans-4-[p-(N-hydroxyethyl-N-methylamino) styryl]-N-methylpyridinium iodide (ASPI)(1) at the same pump level.

关键词： C24H28N2O4S.H2O TPP up-conversion laser dye

Study on the fatigue and wear characteristics of four wheel materials

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Journal of Modern Transportation 2013年第3期21卷 182-193页

作者： G.y.Zhou J.H.liu W.J.Wang G.Wen q.y.liu State Key Laboratory of Traction Power Tribology Research Institute Southwest Jiaotong University

The fatigue and wear characteristics of four different steel wheel materials are investigated in detail by using rolling contact fatigue and wear bench tests on a JD-1 apparatus, analyzing chemical composition and hardness, and performing profile analysis and micro-morphology analysis. The wear and fatigue behavior of one of the materials under different operation speeds is also investigated. The results show that the wear resistance of the materials has a positive correlation with their carbon content, while fatigue resistance has a negative correlation. Based on hardness analysis as a function of depth into the specimen, the thickness of layers with a steep hardness gradient has a negative correlation with the initial surface hardness in the tests using different materials. The hardness increments, however, have a positive correlation with initial surface hardness. The rolling tests on one material using different rotation speeds show that the hardness increments and the thickness of layers with a steep hardness gradient increase with the rotation speed. The analyses and experimental results demonstrate that two of the four materials exhibit good wear resistance and rolling contact fatigue resistance, making them suitable for either highspeed or heavy axle railroad operations.

关键词： Wheel material . Fatigue . Wear . Hardness

Influencing mechanism of pre-existing nanoscale Al5Fe2 phase on Mg-Fe interface in friction stir spot welded Al-free ZK60-q235 joint

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Journal of Materials Science & Technology 2020年第7期42卷 220-228页

作者： R.Z.Xu q.yang D.R.Ni B.L.Xiao C.Z.liu Z.y.Ma Institute of Metal Research Chinese Academy of SciencesShenyang110016China College of Material Science and Engineering Shenyang Aerospace UniversityShenyang110136China Department of Materials Science and Engineering University of Illinois at Urbana-Champaign1304 W Green StUrbanaIL61801United States Fredrick Seitz Materials Research Laboratory University of Illinois at Urbana-Champaign104 S Goodwin AveUrbanaIL61801United States

Al-free ZK60 magnesium (Mg) alloy sheet was selected as substrate material of Mg-steel pinless friction stir spot welding (FSSW), avoiding the effect of the Al element in the substrate on the alloying reaction of Mg-iron (Fe) interface. The sound FSSW joint of ZK60 Mg alloy and q235 steel with a hot-dipped aluminum (Al)-containing zinc (Zn) coating was successfully realized. The detailed microstructural examinations proved that Al5Fe2 phase at the Mg-Fe interface came from the pre-existing Al5Fe2 phase in the coating and acted as the transition layer for promoting the metallurgical bonding of Mg and Fe. The interfaces with well-matched lattice sites among Fe, Al5Fe2 and Mg were formed during FSSW. A low energy interface with good match of lattice sites ((002)Al5Fe2//(110)Fe, [110]Al5Fe2//[113]Fe) between Al5Fe2 and Fe was identified. For the interface between Al5Fe2 and Mg, an orientation relationship of (622)Al5Fe2//(3112)Mgand[158]Al5Fe2//[2423]Mg was observed. The tensile-shear load of the ZK60-steel joint could reach 4.6 kN. Moreover, the joint fracture occurred at the interface between the Al5Fe2 layer and the Mg alloy substrate, suggesting the brittle fracture characteristic.

关键词： Dissimilar welding Friction stir spot welding Magnesium alloys Steels Zinc coating

Stress-rupture behavior of a Re-containing Ni-base single crystal superalloy at high temperatures

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Journal of Materials Science & Technology 2023年第32期163卷 237-244页

作者： G.L.Wang D.q.qi J.L.liu J.D.liu J.G.Li y.Z.Zhou X.F.Sun Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

A Re-containing Ni-base single crystal superalloy was used to investigate the elementary processes associated with stress-rupture behavior at different temperatures where theγʹrafting *** 900°C,the rupture behavior is mainly determined by the multiplication of dislocations within the wideningγchannels,which is closely linked with the propagation of microcracks along the inherentγ/γʹ*** rapid formation of lamellaγ/γʹraft structure,along with the developed-well interfacial dislocation networks,and its elastic instability are primarily responsible for the rupture behavior at 1100°*** is a clear curvature tendency in the Larson-Miller plot of stress-rupture lifetime in relation to stress at high *** indicates that the influence extent ofγʹrafting on stress-rupture behavior is sensitive to the acting conditions of temperature and stress.

关键词： Ni-based single crystal superalloy Re effect γʹrafting Stress-rupture behavior Elementary process Larson-Miller plot

MICROSTRUCTURE TRANSFORMATION IN THE WELDING HEAT AFFECTED ZONE OF 800MPa GRADE ULTRA FINE STRUCTURED STEEL

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Acta Metallurgica Sinica(English Letters) 2004年第3期17卷 238-246页

作者： J.B. liu L.J. Hu y.T.Wang Z. q. liu K. Miao Z.L. Tian Huazhong University of Science and Technology Wuhan 430074 China Technology Center of Wuhan Iron and Steel (Group) Corporation Wuhan 430080 China Central Iron and Steel Research Institute Beijing 100080 China

The transformation behavior and microstructure development in the heat affected zone(HAZ)of 800MPa grade ultra fine structured steel was *** was found that the HAZ has intermediate temperature transformation characteristics in a wide range of cooling rates,with the bainite sheaves consisting of bainite ferrite plates without carbide precipitation and retained austenite in the fast cooling *** relatively high cooling rates,which corresponded to low heat inputs,the hardness of the simulated HAZ was above that of the base *** the cooling rate was below 9C/s,the welding HAZ would have an obvious *** analysis of transformation rates in continuous cooling processes was completed by numerical differential *** result indicated that the microstructure transformation rate of the HAZ in 800MPa grade ultra fine structured steel changed sharply to slow speeds when the cooling time t8/5 is longer than 7s.

关键词： ultra fine structured steel weld heat affected zone transformation rate microstructure

Synthesis of New Squarains Used as Organic Electroluminescent Materials

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Chinese Chemical Letters 1997年第5期8卷 403-406页

作者： liu, N Lu, Zy Xie, MG Jiang, q SICHUAN UNIV DEPT CHEMCHENGDU 610064PEOPLES R CHINA

Two types of eight kinds of new squarains were designed and synthesized. Their structures were elucidated by IR,NMR,MS and elementary analysis. Their luminescent properties were determined,which indicated that they ca... 详细信息

关键词： OC Cl

Turbulence and mixing in a freshwater-influenced tidal bay: Observations and numerical modeling

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Science China Earth Sciences 2015年第7期58卷 2049-2058页

作者： LIAN qiang liu Zhiyu Department of Physical Oceanography College of Ocean & Earth Sciences Xiamen University State Key Laboratory of Marine Environmental Science Xiamen University

In situ observations and numerical simulations of turbulence are essential to understanding vertical mixing processes and their dynamical controls on both physical and biogeochemical processes in coastal embayments. Using in situ data collected by bottom-mounted acoustic Doppler current profilers(ADCPs) and a free-falling microstructure profiler, as well as numerical simulations with a second-moment turbulence closure model, we studied turbulence and mixing in the Xiamen Bay, a freshwater-influenced tidal bay located at the west coast of the Taiwan Strait. Dynamically, the bay is driven predominantly by the M2 tide, and it is under a significant influence of the freshwater discharged from the Jiulong River. It is found that turbulence quantities such as the production and dissipation rates of the turbulent kinetic energy(TKE) were all subject to significant tidal variations, with a pronounced ebb-flood asymmetry. Turbulence was stronger during flood than ebb. During the flooding period, the whole water column was nearly well mixed with the depth-averaged TKE production rate and vertical eddy viscosity being up to 5?10?6 W kg?1 and 2?10?2 m2 s?1, respectively. In contrast, during the ebb strong turbulence was confined only to a 5?8 m thick bottom boundary layer, where turbulence intensity generally decreases with distance from the seafloor. Diagnosis of the potential energy anomaly showed that the ebb-flood asymmetry in turbulent dissipation and mixing was due mainly to tidal straining process as a result of the interaction between vertically shared tidal currents and horizontal density gradients. The role of vertical mixing in generating the asymmetry was secondary. A direct comparison of the modeled and observed turbulence quantities confirmed the applicability of the second-moment turbulence closure scheme in modeling turbulent processes in this weakly stratified tidally energetic environment, but also pointed out the necessity of further refinements of the model.

关键词： tidal bay turbulent mixing second-moment turbulence closure model turbulent kinetic energy dissipation rate vertical eddy viscosity

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Synthesis and Properties of Layered Oxides LiCo_(1-x)Ni_xO_2

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Journal of Materials Science & Technology 1997年第5期13卷 405-408页

作者： Lin, q Chen, N ye, W liu, RM Luo, JS GEN RES INST NONFERROUS MET BEIJING 100088PEOPLES R CHINA

The mechanism of LiCo1－xNixO2(x=0, 0.5, 1) synthesis from carbonates or hydrates was studied by thermogravimetric analysis and X-ray diffraction to identify the medium and final products. The synthesis process from carbonates can be divided into two steps. Below 300℃cobalt carbonate and/or nickel carbonate decompose forming oxides. Over 300℃ Li2CO3 decomposes and reacts with Co and/or Ni oxides gradually, as a result Co++ and/or Ni++ areoxidized to Co+++ and/or Ni+++, finally LiCo1-xNixO2 forms. The proportion of cobalt tonickel in the starting mixture and atmosphere during synthesis affects the structure of ***1-xNixO2(x≤0.5) can be synthesized in air or oxygen and characterized by solid solutionof LiCoO2 and LiNiO2. LiNiO2 can be obtained only from hydrates and in oxygen *** and LiCo0.5Ni0.5O2 have higher first charge capacity than that of LiCoO2. Their discharge capacity reaches a level with that of LiCoO2 and has reasonable reversibility.

关键词： Lithium batteries

STUDy ON THE SHOCK WAVE CRySTALLIZATION OF AMORPHOUS ALLOyS By DSC

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Acta Metallurgica Sinica(English Letters) 2002年第5期15卷 431-438页

作者： H. y. Zhao, H. Wang, q.J. liu, J.D. Kan and Z.q. liuDepartment of Materials Science and Engineering, yunnan University, Kunming 650091, China Dept. of Mat. Sci. and Eng. Yunnan Univ. Kunming 650091 China

Shock wave and annealing crystallization of amorphous alloys FeSiB, FeMoSiB and FeCuNbSiB were studied by isothermal and non-isothermal DSC technique. It was found that the shock wave crystallization is very perfect, the fraction crystallized is very close to 100%, though the period of crystallization is very short, only about 10-4-10-6s. Their produced phases differ from the parent phase in structure and composition. The high velocity of the transformation is very difficult to explain by the diffusion theory of solid state phase transition.

关键词： amorphous alloy nano-crystallization shock wave crystalliza-tion