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Tectonic Evolution of the Wanan Basin,Southwestern South China Sea

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Acta Geologica Sinica(English Edition) 2014年第4期88卷 1120-1130页

作者： lü Caili ZHANG Gongcheng YAO Yongjian wu Shiguo CNOOC Research Institute Postdoctoral research Center China University of Petroleum (Beijing) Guangzhou Marine Geological Survey Key laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of Sciences

Quantitative studies on the extension and subsidence of the Wanan Basin were carried out based on available seismic and borehole data together with regional geological data. Using balanced cross-section and backstripping techniques, we reconstructed the stratigraphic deposition and tectonic evolution histories of the basin. The basin formed from the Eocene and was generally in an extensional/transtensional state except for the late Miocene local compressoin. The major basin extension ocurred in the Oligocene and Early Miocene （before -16.3 Ma） and thereafter uniform stretch in a smaller rate. The northern and middle basin extended intensely earlier during 38.6-23.3 Ma, while the southern basin was mainly stretched during 23.3-16.3 Ma. The basin formation and development are related to alternating sinistral to dextral strike-slip motions along the Wanan Fault Zone. The dominant dynamics may be caused by the seafloor spreading of the South China Sea and the its peripheral plate interaction. The basin tectonic evolution is divided into five phases： initial rifting, main rifting, rift-drift transition, structural inversion, and thermal subsidence.

关键词： tectonic evolution stretch factor Wanan Basin South China Sea

Effect of tidal stress on fault nucleation and failure of the 2007 Ms6.4 Ning＇er earthquake

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Science China Earth Sciences 2016年第9期59卷 397-407页

作者： xIE ChaoDi lEI xinglin wu xiaoPing FU Hong xIONG ZiYao HU xionglin lI Sha Geophysics Department School of Resources & Earth Science Yunnan University Kunming 650091 China Geological Survey of Japan AIST Tsukuba 305-8567 Japan Earthquake Administration of Yunnan Province Kunming 650224 China

Based on calculations of the tidal Coulomb failure stress and investigations of the correlation between the Earth tide and the Ning＇er earthquake sequence, the processes of fault nucleation and failure were simulated. In these simulations we consider the influence of tidal stresses using the rate- and state-dependent friction laws. Furthermore, the effects on tidal trig- gering due to the stress amplitude and periodic oscillation properties were investigated, and the triggering effects between the tidal normal and tidal shear stresses were compared. The results showed that the Ning＇er earthquake sequence was a physical consequence of tidal effects. A transition period To exists between the nucleation and failure processes of a seismic fault. When the period T of stress is equal to or becomes larger than To, the fault response becomes dependent on the periodic features of the loading stress; however, for T 〈 To, the response of the fault is nearly independent of the period. Both the tidal normal and tidal shear stresses have similar effect in the nucleation and failure processes; the clock changes generally increase with the maximum amplitudes of the tidal stresses. Tidal normal and tidal shear stresses with positive amplitudes mainly induce earth- quake triggering; however, the triggering effects induced by negative tidal stresses are smaller and faults are not sensitive to negative tidal stresses. Our results primarily reveal the physical mechanisms of tidal stress triggering.

关键词： Tidal Coulomb failure stress Ning'er earthquake Rate- and state-dependent friction law Tidal period

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Microstructure and Mechanical Properties of Galvanized Steel/AA6061 Joints by laser Fusion Brazing Welding

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Acta Metallurgica Sinica(English letters) 2014年第4期27卷 670-676页

作者： Junxia l wuxiong Yang Shikai wu xudong Zhao Rongshi xiao Institute of laser Engineering Beijing University of Technology

laser fusion brazing welding was *** steel/AA6061 lapped joint was obtained by laser fusion brazing welding technique using the laser-induced aluminium molten pool spreading and wetting the solid steel *** joint interface was formed using the rectangular laser beam coupled with the synchronous powder *** result showed that the tiny structure with the composition of a-Al and Al–Si eutectic was formed in the weld close to the Al *** close to the steel side,a layer of compact Fe–Al–Si intermetallics,including the Al-rich FeAl3,Fe2Al5 phases and Al–Fe–Si s1 phase,was generated with the thickness of about 10–20 *** tensile shows the brittlefractured characteristic along to the seam/steel interface with the maximum yield strength of 152.5 MPa due to the existence of hardening phases s1 and Al–Fe intermetallics.

关键词： Galvanized steel Aluminium alloy laser welding Interface Microstructural characterization Mechanical property

Direct joining of oxygen-free copper and carbon-fiber-reinforced plastic by friction lap joining

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Journal of Materials Science & Technology 2018年第1期34卷 192-197页

作者： l.H. wu K. Nagatsuka K. Nakata Joining and Welding Research Institute Osaka University 11-1 Mihogaoka Ibaraki Osaka 567-0047 Japan

Oxygen-flee copper （Cu） was successfully joined to carbon-fiber-reinforced thermoplastic （CFRTP, polyamide 6 with 20wt% carbon fiber addition） by friction lap joining （FlJ） at joining speeds of 200-1600 mm/min with a constant rotation rate of 1500 rpm and a nominal plunge depth of 0.9 ram. It is the first time to report the joining of CFRTP to Cu by FlJ. As the joining speed increased, the tensile shear force （TSF） of joints increased first, and decreased thereafter. The maximum TSF could reach 2.3 kN （ 15 mm in width）. Hydrogen bonding formed between the amide group of CFRTP and the thin Cu20 layer on the Cu surface, which mainly contributed to the joint bonding. The influence factors of the TSF of the joints at different joining speeds were discussed. The TSF was mainly affected by the joining area, the degradation of the plastic matrix and the number and the size of bubbles. As the joining speed increased, the influence factors varied as follows： the joining area increased first and then decreased; the degra- dation of the plastic matrix and the number and the size of bubbles decreased. The maximum TSF was the comprehensive result of the relatively large joining area, small degradation of the plastic matrix and small number and sizes of bubbles.

关键词： Friction lap joining Metal Plastic Carbon-fiber reinforced thermoplastic Dissimilar materials joining

Mathematical modelling of axonal microtubule bundles under dynamic torsion

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Applied Mathematics and Mechanics(English Edition) 2018年第6期39卷 829-844页

作者： J.Y.wu Hong YUAN l.Y.lI MOE Key laboratory of Disaster Forecast and Control in Engineering Institute of Applied MechanicsJinan University School of Engineering University of Plymouth

Owing to its viscoelastic nature, axon exhibits a stress rate-dependent me- chanical behavior. An extended tension-shear chain model with Kelvin-Voigt viscoelas- ticity is developed to illustrate the micromechanical behavior of the axon under dynamic torsional conditions. Theoretical closed-form expressions are derived to predict the de- formation, stress transfer, and failure mechanism between microtubule （MT） and tau protein while the axon is sheared dynamically. The results obtained from the present an- alytical solutions demonstrate how the MT-tau interface length, spacing between the tau proteins, and loading rate affect the mechanical properties of axon. Moreover, it is found that the MTs are more prone to rupture due to the contributions from the viscoelastic effects. Under the torsional force, the MTs are so long that the stress concentrates at the loaded end where axonal MTs will break. This MT-tau protein dynamics model can help to understand the underlying pathology and molecular mechanisms of axonal injury. Additionally, the emphasis of this paper is on the micromechanical behavior of axon, whereas this theoretical model can be equally applicable to other soft or hard tissues, owning the similar fibrous structure.

关键词： torsion biocomposite diffuse axonal injury (DAI) Kelvin-Voigt viscoelas-tic model dynamic response tension-shear chain model

De-emulsification of 2-ethyl-1-hexanol/water emulsion using oil-wet narrow channel combined with low-speed rotation

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Chinese Journal of Chemical Engineering 2018年第10期26卷 2048-2054页

作者： ling lü Kejing wu You Tang Siyang Tang Bin liang Multi-phases Mass Transfer and Reaction Engineering laboratory College of Chemical Engineering Sichuan University College of Chemical Engineering and Chemistry Technology Southwest Petroleum University

low-speed rotation of disc in an internal circulation of a novel de-emulsification with rotation-dise horizental contactor(RHC-D) realized de-emulsification for O/W emulsions due to repeated coalescence in oil-wet narrow channels at a low rotation speed. For three emulsions included ethanol/water/2-ethyl-1-hexanol, ethanol/water/2-ethyl-1-hexanol/SDS(Sodium Dodecyl Sulfonate) and 2-ethyl-1-hexanol/water/SDS emulsion, deemulsification ratios of oil phase could reach 1, 1 and 0.67 respectively at 170 r·min-1, and de-emulsification ratios increased obviously after agitating 10 min. De-emulsification experiment in the seam indicated that oil droplet sizes in O/W emulsion became larger after de-emulsification. The main de-emulsification mechanism in RHCD was the coalescence of oil droplets in oil-wet narrow channels. With increase of the rotation speed, oil droplets dispersed better in the aqueous phase. However, de-emulsification effect enhanced due to the increase of the coalescence rate at a bit higher rotation speed. In addition, internal circulation made those O/W emulsions to be broken repeatedly, consequently de-emulsification ratio increased. Repeated de-emulsification through internal circulation might make continuous extraction of ethanol come true at a low rotation speed.

关键词： De-emulsification Oil-wet channel low rotation speed O/W emulsion Internal circulation

Continuous selections for pseudo-lower semicontinuous set-valued mappings on convex structure spaces and hyperspace contractibility

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Chinese Science Bulletin 1997年第14期42卷 1230-1231页

作者： li, l wu, Cx Department of Mathematics Harbin Institute of Technology Harbin China

SINCE 1956, Michael’s continuous selection theory has been applied to functional analysis,topology, approximation theory and other mathematical fields. In this letter, the concept ofthe pseudo-lower semicontinuity is introduced, and a convex structure of metric space is de-fined. A continuous selection theorem for pseudo-lower semicontinuity is given. This

关键词： Continuous selections for pseudo-lower semicontinuous set-valued mappings on convex structure spaces and hyperspace contractibility

Preparation of Al matrix nanocomposites by diluting the composite granules containing nano-SiCp under ultrasonic vibaration

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Journal of Materials Science & Technology 2018年第9期34卷 1609-1617页

作者： Shulin lü Pan xiao Du Yuan Kun Hu Shusen wu State Key laboratory of Materials Processing and Die & Mould Technology Huazhong University of Science and Technology

In this work, an efficient process by diluting the nano-SiCp/Al composite granules in the molten matrix under ultrasonic vibration（UV） was developed to prepare metal matrix nano-composites（MMNCs）.Millimeter-sized composite granules with high content of SiC particle（8 wt%） were specially fabricated by dry high-energy ball milling（HBM） without process control agent, and then remelted and diluted in molten Al alloy under UV. The MMNCs melt was finally squeeze cast under a squeeze pressure of 200 MPa, Microstructure of the composite granules during dry HBM was investigated, and the effect of UV on microstructure and mechanical properties of the MMNCs was discussed. The results indicate that nano-SiC particles are uniformly distributed in the nano-SiCp/Al composite granules, which are covered by vestures of pure Al. During diluting, nano-SiC particles released from the composite granules are quickly dispersed in the molten matrix by UV within 4 min. Microstructure of MMNCs is significantly refined under UV and squeeze casting, eutectic Si phase modified to fine islands with an average length of 1.4 μm. Tensile strength of the squeeze cast MMNCs with 1 wt% of nano-SiC particles is 269 MPa, which is improved by 25% compared with the A356 alloy matrix.

关键词： Al matrix nano-composites Dry high-energy ball milling Ultrasonic vibration Composite granules Microstructure

Achieving superior mechanical properties in friction lap joints of copper to carbon-fiber-reinforced plastic by tool offsetting

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Journal of Materials Science & Technology 2018年第9期34卷 1628-1637页

作者： l.H.wu K.Nagatsuka K.Nakata Joining and Welding Research Institute Osaka University

It is a challenge to achieve a sound welded metal/carbon-fiber-reinforced thermoplastic（CFRTP） joint with high strength and few bubbles. In this study, sound lap joints of Cu and CFRTP were obtained by friction lap joining（FlJ） directly at rotation rates of 600-2000 rpm, with the welding tool at the joint center and offsetting the tool 7 mm away from the center toward the retreating side, respectively. Tool offsetting reduced the non-uniform temperature distribution in the lap joints resulting from the high conductivity of Cu, which not only enhanced the tensile shear force from 0.89-2.25 kN to 1.71-3.54 kN,with the maximum increasing rate of 135%, but also reduced the bubble area to only 19% of the original level of 2000 rpm. It is the first time to report a high-quality Cu/CFRTP joint with a high strength and few bubbles. The large increase of the strength after tool offsetting was attributed to the increase of the joining area, the decrease of bubbles and the decrease of the CFRTP degradation. The details on the generation,quantitative distribution and expulsion of the bubbles in the FlJ joints were discussed.

关键词： Hybrid joining Plastic Metal Carbon-fiber-reinforced plastic Properties