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Photocatalytic Degradation of Rhodamine B Dye with MWCNT/TiO_2.C_(60) Composites by a Hydrothermal Method

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Journal of wuhan university of {2.(Materials Science) 2011年第1期26卷 65-69页

作者：史晓亮 School of Mechanical and Electronic engineering Wuhan University of Technology State Key Laboratory of Advanced technology for Materials Synthesis & Processing Wuhan University of Technology

Multi-walled carbon nanotube （MWCNT）/TiO2.C60 composite catalysts were prepared by hydrothermal method. TiO2.was deposited on the MWCNT surface. Their photocatalytic activities for degradation of Rhodamine B dye were studied. X-ray diffraction, field emission transmission electron microscopy, ultraviolet-visible light absorption spectrum and photoluminescence spectrum were carried out to characterize the composite catalysts. The results indicated that MWCNTs and C60 could greatly enhance the photocatalytic activity of TiO2.

关键词： semiconductors chemical synthesis optical properties surface properties

Magnesia Modification of Alkali-Activated Slag Fly Ash Cement

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Journal of wuhan university of {2.(Materials Science) 2011年第1期26卷 121-125页

作者：沈卫国 Key Laboratory of Silicate Materials Science and engineering of Ministry of Education Wuhan University of Technology School of Materials Science and engineering Wuhan University of Technology

A new type of magnesia modification alkali-activated cement was prepared, the strength, setting time, shrinkage ratio and cracking behavior, as well as the composition and structure of the hydration product were investigated. The results indicate that the setting time of this cement is similar to that of the ordinary commercial cements; its strength reaches the standard of 42.5 degree cement, its cracking resistance has been remarkably improved because of the micro-aggregate effect of fly ash and shrinkage compensating of magnesia.

关键词： alkali-activated cement crack magnesia volume stability hydration

Study on the isothermal oxidation behavior in air of Ti_(3)AlC_(2. sintered by hot pressing

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Science china(Technological Sciences) 2006年第5期49卷 513-520页

作者： XU Xuewen1, 2. LI Yangxian1, MEI Bingchu2. ZHU Jiaoqun2. LIU Heyan1 & QU Jingping1 1. School of Material Science and engineering, Hebei university of {2., Tianjin 300130, china 2. State Key Laboratory of Advanced {2. for Materials Synthesis and Processing, wuhan Univer- sity of {2., wuhan 430070, china 1. School of Material Science and engineering Hebei University of Technology Tianjin 300130 China 2. State Key Laboratory of Advanced technology for Materials Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

The isothermal oxidation behavior at 900–1300°C for 2. h in air of bulk Ti3AlC2.with 2.8 wt% TiC sintered by means of hot pressing was investigated in the work. The isothermal oxidation behavior generally followed a parabolic rate law. The parabolic rate constants increased from 1.39×10[10] kg[2.·m[4]·s[1] at 900°C to 5.56×10[9] kg[2.·m[4]·s[1] at 1300°C. The calculated activation energy was 136.45 kJ/mol. It was demonstrated that Ti3AlC2.had excellent oxidation resistance due to the continuous, dense; adhesive protect scales consisted of a mass of α-Al2.3; a little of TiO2./or Al2.iO5. In principle, the oxide scale was grown by the inward diffusion of O[2.; the outward diffusion of Ti[4+]; Al[3+]. The rapid outward diffusion of cations usually resulted in the formation of cracks, gaps,; holes.

关键词： Ti3AlC2. oxidation behavior, kinetics.

INFLUENCE OF SURFACE HARDENING ON CONTACT FATIGUE LIFE OF NODULAR CAST IRON

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Acta Metallurgica Sinica(English Letters) 1990年第3期3卷 188-193页

作者： TAO Zengyi LUO Jiaming huazhong university of Science and {2.,wuhan,china TAO Zengyi,Faculty of Metallic Materials,Dept.of Mechanical engineering No.2.huazhong university of Science and {2.,wuhan 43.074,china

The influence of laser surface melting and induction hardening on the surface structure,con- tact fatigue life and failure behaviour of the nodular cast iron has been *** con- tact fatigue life can be improved by both laser treatment and induction hardening,but the fail- ure process and type are different from each *** former is due to lumpy and deep spal- ling caused by crack propagation between the quenching zone and the substrate,and the latter is due to nubby and surface flaking caused by the oil wedged action into surface cracks.

关键词： surface hardening contact fatigue life laser melting induction hardening

Early Age Properties of Cementitious Materials by Electrical Resistivity Measurement

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Journal of wuhan university of {2.(Materials Science) 2010年第4期25卷 641-644页

作者：魏小胜 School of Civil engineering and Mechanics Huazhong University of Science and Technology

Three cement pastes were prepared with the fixed water-binder ratio and different fly ash contents. The compression test and electrical resistivity measurement of the paste mixes were conducted during 48 h. The changes of the CH content and the non-evaporable water content in the cement-fly ash hydration systems with time were obtained by the thermal gravimetric analysis. The experimental results show that dilution effect of fly ash as micro-filler is dominant mechanism before 48 h, which appears to decrease in the CH content and the non-evaporable water content, also in compressive strength and electrical resistivity, with the increase of fly ash replacement. The relationships between CH content, non-evaporable water content and electrical resistivity show that electrical resistivity can be the indicators of hydration products CH and non-evaporable water. The correlation of the compressive strength fc and the electrical resistivity ρcan be obtained as fc=8.342.ρ=6.7088 for the period of 48 h. The early age compressive strength can then be predicted by electrical resistivity measurement.

关键词： electrical resistivity fly ash compressive strength hydration

Early Hydration of Composite Cement with Thermal Activated Coal Gangue

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Journal of wuhan university of {2.(Materials Science) 2010年第1期25卷 162-166页

作者：郭伟 Department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

Composite cement samples were prepared by mixing clinker, gypsum with burnt coal gangues which was calcined at various temperatures. The mechanical strength and Ca（OH）2.content in the cement paste were tested, and the paste composition and microstructure were analyzed by thermogravimetry-differential thermal analysis （TG-DSC）, X-ray diffraction（XRD）, scanning electronic microscopy （SEM） and pore structure analysis. Results demonstrate that the thermal activated coal gangue could accelerate the early hydration of cement clinker obviously, which promotes the gangue hydration itself. The early hydrated products of the cement are C-S-H gel, Ca（OH）2.and AFt. The cement with 30% （in mass） the gangue exhibits higher mechanical strength, and among all the cement samples the one with the gangue burnt at 700 ℃ displays the highest hydration rate, mechanical strength, the most gel pores and the lowest total porosity.

关键词： blended cement hydration microstructure hydration product

Structure and Pozzolanic Activity of Calcined Coal Gangue during the Process of Mechanical Activation

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Journal of wuhan university of {2.(Materials Science) 2009年第2期24卷 326-329页

作者：郭伟 Department of Material engineering Yancheng Institute of Technology institute of Material Science and engineering Nanjing University of Technology

On the basis of analyzing coal gangue＇s chemical and mineral compositions, the structure change of coal gangue during the mechanical activation was investigated by XRD, FTIR, NMR, and the mechanical strength of the cement doped coal gangue with various specific surface area was tested. The experimental results indicate that, the lattice structure of metakaolin in coal gangue samples calcined at 700 ℃ disorganizes gradually and becomes disordered, and the lattice structure of α-quartz is distorted slightly. The pozzolanic activity of the coal gangue increases obviously with its structural disorganization.

关键词： coal gangue mechanical activation structure NMR tetrahedron

Effect and mechanism of stresses on rock permeability at different scales

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Science china Earth Sciences 2006年第7期49卷 714-723页

作者： YIN Shangxian1 & WANG Shangxu2.1. Safety engineering College, North china {2. of Science and technology, Yanjiao, Beijing 101601, china 2. Key Laboratory of Geophysics Exploration, china university of Petroleum, Beijing 100083, china 1. Safety engineering College North China Institute of Science and Technology Yanjiao Beijing 101601 China 2. Key Laboratory of Geophysics Exploration China University of Petroleum Beijing 100083 China

The effect of geo-stress fields on macroscopic hydro-geological conditions or micro-cosmic permeability of water-bearing media should follow some laws or principles. Cases study and tests show that: (1) At macro-geologic large scale, deformed and crashed rocks which were induced by geo-stress fields changing provided space for groundwater storage and flow. Groundwater adjusts water-bearing space and dilatants fractures by flowing and press transferring. Coupling of liquid and solid can be implemented for rocks and groundwater. Although tectonic fields witness several times of change and build-up in geological time, stress fields forming regional tectonic framework are coherent with seepage fields, orientation of the maximum horizontal stress demonstrates main seepage direc-tions. (2. At macro-geologic middle scale, zones of stresses changing sharply, quite low stresses, stress or shear concentration can be used to show locations and types of main fractures, zones of geo-stresses changing equably can be acted as normal base media zones of tri-porosity media. (3) At micro-geologic small scale, tri-porosity media include fractured rocks, porous rocks and capillary rocks. Investigations indicate that porosity or permeability is functions of effective stresses, and po-rosity or permeability changing rules of porous rocks with variation of effective stresses can be de-scribed as the index model, the model of power exponent functions is suitable for those of fractured rocks, the model of the second power parabola for capillary rocks. The porosity and permeability loss in fractured rocks, which are greater than that in porous rocks, are shown by calculation of effective compressive coefficient and closing pressure in cracks. The calculations can also explain the mecha-nism why porosity changes are always larger than permeability changes. It is proved by the thick wall cylinder theory that the second power parabola relation between porosity or permeability loss and effective

关键词： geo-stress fields, seepage fields, tri-porosity media, effective stresses, permeability, porosity,scale.

MICROSTRUCTURE IN laser FUSED HIGH SPEED STEEL W6Mo5Cr4V2.M2.

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Acta Metallurgica Sinica(English Letters) 1993年第1期6卷 36-39页

作者： LIU Ning CUI Kun huazhong university of Science and {2.,wuhan.china DENG Zonggang Hefei university of {2.,Hefei,china CHENG Benpei KONG Jie institute of Solid State Physics,Academia Sinica,Hefei,china Doctorate student,Department of Mechanical engineering No.2.huazhong university of Science and {2.,wuhan 43.074,china huazhong Univ of Science and Technology Wuhan China

Microstructure of the deepest zone of high speed steel W6Mo5Cr4V2.M2.melt after laser fu-sion was found to be so fine as the ehill zone of a solidified *** narrower chill zoneformed,the long columnar dendrites grow into the melt and then the fine equiaxed cellularstructure appears in upper melt region nearly *** substructure of cellular grains anddendrites was observed to consist of martensite and retained austenile,while the carbides asM_6C_■ Cr_7C_3 and MC distributed at their *** is believed that the highermicrohardness up to HV_(0.1)=865-960 of the laser fused structure of the alloy is due to the oc-currence of martensite.

关键词： High speed steel W6Mo5Cr4V2.M2. laser fused treatment micrstructure