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Investigation of 'chazi'(damaged-enamels)on Chenghua doucai Porcelains

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science china(Technological sciences) 2009年第6期52卷 1722-1729页

作者： DU Feng1 & SU BaoRu2.1 Institute of Chemistry & Molecular engineering,Qingdao University of science & {2.,Qingdao,china 2.College of Information science & {2.,Qingdao University of science & {2.,Qingdao,china Institute of Chemistry & Molecular engineering Qingdao University of Science & Technology Qingdao China College of Information science & technology Qingdao University of Science & Technology Qingdao China

At the end of the 1950s,Sun Yingzhou considered that the 'chazi'(damaged colour)on Chenghua doucai imperial porcelain as a defect was originally produced in firing process during Chenghua period(1465―1487).Researchers in china have accepted his *** any fragment with the 'chazi' has never been found in several tons of Chenghua imperial sherds excavated from Ming imperial kiln site in *** china,few scholars have questioned the formation of 'chazi',and further investigated *** researchers at the Research Laboratory in the British Museum,employing unde-structive EDXRF,have analyzed the chemical composition of the 'chazi'(damaged colour)on a Chen-ghua doucai stem cup in the museum,and they have confirmed that the 'chazi'(damaged colour)was caused by the fire of the Jianfu palace in the Forbidden City in *** on their research,the authors studied the colour chemical principle of the 'chazi's' formation *** to the ceramic {2. principle,scientific reasoning for the 'chazi' was carried *** the help of the history of Qing court,the brainteaser of the 'chazi' was totally uncovered,the misunderstanding for the 'chazi' has also been *** research also suggests that employing modern science and {2. is a direction to study Chinese ancient ceramic further.

关键词： Chenghua doucai porcelains court eunuchs the set on fire at the Jianfu palace ’chazi’(damaged-enamels) the British Museum colour chemical principle archaeology using science and technology

Early Age Properties of Cementitious materials by Electrical Resistivity Measurement

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Journal of Wuhan University of technology(materials {2.) 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

Effects of Surface-Active Elements Sulfur on Flow Patterns of Welding Pool

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Journal of materials science & {2. 2005年第3期21卷 408-414页

作者： Yuzhen ZHAO, Yongping LEI and Yaowu SHI school of materials {2. and engineering, Beijing University of technology, Beijing 10002., china school of materials {2. and engineering Beijing University of Technology Beijing 100022 China

A 3D mathematical model is developed to calculate the temperature and velocity distributions in a moving gas tungsten arc (GTA) welding pool with different sulfur concentrations. It has been shown that, the weld penetration increases sharply with increasing sulfur content. When sulfur content increases beyond 80 × 10-6, the increase in sulfur content does not have an appreciable difference on the welding pool size and shape, and the depth/width remains constant. Sulfur changes the temperature dependence of surface tension coefficient from a negative value to a positive value and causes significant changes on flow patterns. The increase in soluble sulfur content and the decrease at free surface temperature can extend the region of positive surface tension coefficient. As sulfur content exceeds 12.×10-6, the sign of surface tension coefficient is positive. Depending upon the sulfur concentrations, three, one or two vortexes that have different positions, strength and directions may be found in the welding pool. The contrary vortexes can efficiently transfer the thermal energy from the arc, creating a deep welding pool. An optimum range of sulfur content is 2.-150×10-6.

关键词： Surface-active elements Sulfur Plow patterns Depth/width

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 Institute of {2. and technology, Yanjiao, Beijing 101601, china 2. Key Laboratory of Geophysics Exploration, china University of Petroleum, Beijing 100083, china Safety engineering College North China Institute of Science and Technology Yanjiao Beijing China Key Laboratory of Geophysics Exploration China University of Petroleum Beijing 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.

Removal of Volatile Organic Compounds by Adsorption and Photocatalytic Oxydation

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Journal of Wuhan University of technology(materials {2.) 2007年第3期22卷 450-452页

作者：许德平黄正宏 Lab of Advanced materials Department of Materials Science and EngineeringTsinghua University school of Chemical and Environmental engineering China University of Mining and Technology

Based on the study of equilibrium adsorption on viscose rayon-based activated carbon fiber （ACF） by gravimetric method, mounting of TiO2.on PAN-based activated carbon cloth （ACC） and their photocatalytic activity as well as adsorption performance for benzene were investigated. The crystallinity of TiO2.and pore structure were characterized by XRD and N2.adsorption. The results show that crystallinity of TiO2.and pore structure could be postulated by heat treatment condition. Both crystallinity of TiO2.and pore structure of hybrid have effects on photocatalytic performance of TiO2.mounted ACC. It would be more attractive and prospective for the combination of TiO2.photocatalytic activity and adsorption ability of porous materials.

关键词： volatile organic compounds activated carbon cloth TiO2

Bio-regeneration of p-complexation desulfurization adsorbents

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science china Chemistry 2005年第6期48卷 538-544页

作者： LI Wangliang1,2. XING Jianmin1, XIONG Xiaochao1,2. SHAN Guobin1,2.& LIU Huizhou1 1. Laboratory of Separation science and engineering, Institute of Process engineering, Chinese Academy of sciences, Beijing 100080, china 2. Graduate school of the Chinese Academy of sciences,Beijing 100039, china Laboratory of Separation science and engineering Institute of Process Engineering Chinese Academy of Sciences Beijing China Graduate school of the Chinese Academy of sciences Beijing China

The coupling of adsorption desulfurization and biodesulfurization is a new approach to produce clean fuels. Sulfur compounds are firstly adsorbed on adsorbents, and then the ad-sorbents are regenerated by microbial conversion. p-Complexation adsorbent, Cu(I)-Y, was ob-tained by ion exchanging Y-type zeolite with Cu2. and then by auto-reduction in helium at 450℃ for 3 h. Dibenzothiophene (DBT) was used as a model compound. The effects of cell concentra-tion, volume of oil phase, the ratio of aqueous phase to adsorbent on DBT desorption by a bac-terium were studied. The amounts of DBT desorbed and 2.HBP produced can be apparently increased with addition of n-octane. BDS activity can be improved by increasing cell concentra-tion and the ratio of water-to-adsorbent. 89% of DBT desorbed from the adsorbents can be converted to 2.HBP within 6 h and almost 100% within 2. h, when the volume ratio of oil-to-water was 1/5 mL/mL, the cell concentration was 60 g·L?1, and the ratio of adsorbent-to-oil was 0.03 g·mL?1. The amount of 2.HBP produced was strongly dependent on the volume ratio of oil-to- water, cell concentration and amount of adsorbent. Adsorption capacity of the regenerated ad-sorbent is 95% that of the fresh one after being desorbed with Pseudomonas delafieldii R-8, washed with n-octane, dried at 100℃ for 2. h and auto-reduced in He.

关键词： adsorption desulfurization p-complexation adsorbents bio-regeneration Pseudomonas delafieldii desorption.

Surface characteristics of rapidly solidified nickel-based superalloy pow-ders prepared by PREP

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Rare Metals 2003年第4期22卷 309-314页

作者： CHEN Huanming , HU Benfu , and LI Huiying1) school of materials {2. and engineering, University of {2. and technology Beijing, Beijing 100083, china2. school of Physics and Electrical Information engineering, Ningxia University, Yinchuan 75002., china school of materials {2. and engineering University of Science and Technology Beijing 北京 100083

The surface microstructure and the surface segregation of FGH 95 nickel-basedsuperalloy powders prepared through plasma rotating electrode processing (PREP) have beeninvestigated by using SEM and AES. The results indicate that the surface microstructure of powderschanges from dendrite into cellular stricture as the particle size of powders decrease, and thepredominant precipitates solidified on the particle surfaces were identified as MC' type carbidesenriched with Nb and Ti. It was also indicated that along with the depth of particle surfaces, thesegregation layer of S, C and O elements are thick, and that of Ti, Cr elements are thin for largesire powders while they are in reverse for median size particles.

关键词： FGH 95 nickel-based superalloy powders surface characteristics microstructure plasma rotating electrode processing

Reaction Products of MgO and Microsilica Cementitious materials at Different Temperatures

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Journal of Wuhan University of technology(materials {2.) 2011年第4期26卷 745-748页

作者：韦江雄 school of materials {2. and engineering South China University of Technology

The paste was prepared by mixing MgO, microsilica and H2. in the presence of water reducer at different reaction ratios and temperatures, and characterized by XRD, DTA, TGA, IR, and solid-state 2.Si NMR. The experimental results showed that, besides Mg（OH）2. magnesium silicate hydrate （M-S-H） was formed at a low temperature such as 2. and 50 ℃. At a high temperature of 100 ℃, Mg（OH）2.can be further transformed into M-S-H completely, for instance, within ca. 1 month in an excess of microsilica. The average composition and structure of M-S-H was mainly related to the reaction mixture and curing temperature and was discussed in detail.

关键词： MgO microsilica magnesium silicate hydrate (M-S-H)

Molecular Dynamics Simulation of Dealloyed Layer-induced Tensile Stress in Cu_3Au

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Journal of University of science and technology Beijing 2001年第4期8卷 295-298页

作者： Qikai L, Yue Zhang, Mark Hoffman, Wuyang Chu 1)materials science and {2. school. University of science and technology Beijing. Beijing 100083, china 2.school of materials science & {2., University of New South Wales, Sydney 2.52. Austral materials science and {2. school University of Science and Technology Beijing Beijing 100083 China school of materials {2. and engineering University of New South Wales Sydney NSW 2052 Australia

During stress corrosion cracking of Cu3Au alloy, there is a dealloyed layer on its surface because of preferential dissolution of Cu, and there is a linear distribution of Cu vacancy concentration in the dealloyed layer. Molecular dynamics simulation has been done on the three-dimensional crystal (about 148 000 atoms) by employing the embedded-atom method (EAM) potential. Simulation shows that Cu3Au crystal in which there is a dealloyed layer on one surface and one end is fixed will be deflected after relaxing for a long time because of a tensile stress generated at or near the dealloyed layer interface. The deflection and then the tensile stress increase with increasing the depth of dealloyed layer and the vacancy concentration in the dealloyed layer.

关键词： dealloyed layer-induced stress molecular dynamics simulation Cu3Au