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science china(Technological sciences) 2010年第6期53卷 1520-1525页

作者： LAI JianZhong1 & SUN Wei2 1 Department of materials science and engineering,nanjing university of science and Technology,nanjing 210094,china 2 college of materials science and engineering,southeast university,nanjing 211189,china Department of materials science and engineering Nanjing University of Science and Technology Nanjing China college of materials science and engineering Southeast University Nanjing China

Ultra-high performance cementitious composites (UHPCC) were prepared by replacing 60% of cement with ultra-fine industrial waste *** dynamic damage and compressive stress-strain relations of UHPCC were studied using split Hopkinson pressure bar (SHPB).The damage of UHPCC subjected to repeated impact was measured by the ultrasonic pulse velocity *** show that the dynamic damage of UHPCC increases linearly with impact times and the abilities of repeated impact resistance of UHPCC are improved with increasing fiber volume *** stress waves on impact were recorded and the average stress,strain and strain rate of UHPCC were calculated based on the wave propagation *** effects of strain rate,fibers volume fraction and impact times on the stress-strain relations of UHPCC were *** show that the peak stress and elastic modulus decrease while the strain rate and peak strain increase gradually with increasing impact times.

关键词： ultra-high performance cementitious composites (UHPCC) split Hopkinson pressure bar (SHPB) repeated impact damage stress-strain

Internal relative humidity and creep of concrete with modified admixtures

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Progress in Natural science:materials International 2011年第5期21卷 426-432页

作者： Zhi-hai HE~(1,2),Chun-xiang QIAN~(1,2) 1.college of materials science and engineering,southeast university,nanjing 211189,china 2.Jiangsu Key Lab of Construction materials,nanjing 211189,china college of materials science and engineering Southeast University Nanjing 211189 China Jiangsu Key Lab of Construction materials Nanjing 211189 China

The creep characteristics and internal relative humidity(IRH) of concrete with shrinkage reducing admixtures(SRA),poly vinyl alcohol fiber(PVAF) and a mixture of fly ash and slag(MFS) were investigated by the self-made loading *** pore structure was tested,and the relationship of creep and IRH of concrete was *** results indicate that MFS and SRA reduce the total creep and delay the change of ***,the effect of PVAF is contrary,relative to MFS and *** total creep depends largely on drying *** basic creep of concrete is similar,which is significantly influenced by volume fraction of pores whose diameter is between 3.5 nm and 50 nm to the total pore(VP),and IRH of concrete is connected with *** is easy to obtain a good linear relationship predicting the creep of concrete according to the change of IRH.

关键词： modified admixture internal relative humidity total creep drying creep basic creep porosity

Dynamic Mechanical Behaviour of Ultra-high Performance Fiber Reinforced Concretes

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Journal of Wuhan university of Technology(materials science) 2008年第6期23卷 938-945页

作者：赖建中 Department of materials science & engineering Nanjing University of Science & Technology

Ultra-high performance fiber reinforced concretes （UHPFRC） were prepared by replacing 60% of cement with ultra-fine industrial waste powder. The dynamic mechanical behaviour of UHPFRC with different fiber volume fraction was researched on repeated compressive impact in four kinds of impact modes through split Hopkinson pressure bar （SHPB）. The experimental results show that the peak stress and elastic modulus decrease and the strain rate and peak strain increase gradually with the increasing of impact times. The initial material damage increases and the peak stress of the specimen decreases from the second impact with the increasing of the initial incident wave. Standard strength on repeated impact is defined to compare the ability of resistance against repeated impact among different materials. The rate of reduction of standard strength is decreased by fiber reinforcement under repeated impact. The material damage is reduced and the ability of repeated impact resistance of UHPFRC is improved with the increasing of fiber volume fraction.

关键词： ultra-high performance fiber reinforced concretes split Hopkinson pressurebar dynamic repeated impact

Two-and Three-Dimensional Chloride Ingress into Fly Ash Concrete

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Journal of Wuhan university of Technology(materials science) 2011年第5期26卷 978-982页

作者：张云升 Jiangsu Key Laboratory for Construction materials Southeast University college of materials science and engineering Southeast University

2D,3D chloride ion concentration at the edge and corner zones were systematically investigated for fly ash concretes made with different cement replacement percentage by fly ash （0%,10%,20%,40%,60%）,water to binder ratios （0.3,0.35,0.4）,and curing ages （28 d,90 d）.An interaction effect caused by 2D and 3D diffusion could obviously be observed through the comparison with 1D testing *** order to quantify the interaction effect,2D and 3D diffusion interaction coefficients was proposed in this ***,the changes of 2D and 3D interaction coefficients with the change in the free chloride ion concentration were *** above research provide an insight into chloride ion attack on the edge and corner reinforcing bars of concrete structures in the field of civil engineering.

关键词： fly ash concrete chlorides two and three dimension ingress

Comparison of the fracture process of the rubberized concrete and plain concrete under bending load

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science china(Technological sciences) 2010年第6期53卷 1526-1533页

作者： ZHANG YaMei1,WANG Chao2,LU Yi1 & MA AiBin2 1 Jiangsu Key Laboratory of Construction materials,southeast university,nanjing 211189,china 2 college of materials science and engineering,Hohai university,nanjing 210098,china Jiangsu Key Laboratory of Construction materials Southeast University Nanjing China college of materials science and engineering Hohai University Nanjing China

Acoustic emission (AE) technique is employed to investigate the damage process of the notched plain concrete and rubberized concrete specimens under 3-point bending *** signals in the fracture process of notched specimens are illustrated by analyzing the distribution of amplitude and hit rate of AE *** signals in the rubberized concrete have lower activity and amplitude than in the plain *** AE location analysis,it is found that the high energy events mainly are distributed near the notch *** to AE energy,the fracture process zone (FPZ) is *** comparing the FPZ of both concretes,it is found that the incorporation of rubber particles in concrete can greatly alleviate the damage process of concrete specimens and the damage zone in the rubberized concrete is much smaller than in the plain *** moment tensor is also used to analyze the type of cracks and it is found that tensile cracks dominate the early period of loading,while shear cracks become dominant with propagation of cracks in late load period.

关键词： concrete rubberized concrete acoustic emission damage moment tensor

Hydroisomerization of n-heptane over bimetal-bearing H_3PW_(12)O_(40) catalysts supported on dealuminated USY zeolite

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science china Chemistry 2008年第2期51卷 120-127页

作者： WEI RuiPing1,2, GU YanBo1 & WANG Jun1 1 State Key Laboratory of materials-Oriented Chemical engineering, college of Chemistry and Chemical engineering, nanjing Uni- versity of Technology, nanjing 210009, china 2 college of Chemistry and Chemical engineering, southeast university, nanjing 211189, china State Key Laboratory of materials-Oriented Chemical engineering College of Chemistry and Chemical Engineering Nanjing University of Technology Nanjing China college of Chemistry and Chemical engineering Southeast University Nanjing China

The bimetal-bearing (CePt or LaPt) 12-tungstophosphoric acid (H3PW12O40 (PW)) catalysts supported on dealuminated USY zeolite (DUSY) were prepared by impregnation and characterized by XRD, BET, IR, and H2-chemisorption. Their catalytic activities were tested in the hydroisomerization of n-heptane with a continuous atmospheric fixed-bed reactor. After the steam treatment combined with the acid leaching, as well as the supporting with PW and the bimetals, the DUSY support retains the Y zeolite porosity and the PW well keeps its Keggin structure in catalysts. The doping of Ce into the catalysts enhances the dispersion of Pt on the catalyst surface. The Pt-bearing PW catalysts doped with Ce or La, especially Ce, exhibit much higher catalytic activity and selectivity than the catalysts without dopants at lowered reaction temperatures. At the optimal reaction conditions, i.e., the reaction temperature of 250℃ and WHSV of 1.4 h1, the catalyst with a Pt loading of 0.4%, PW loading of 10% and a molar ratio of Ce to Pt of 15:1 shows a conversion of n-heptane of 70.3% with a high selectivity for isomerization products of 94.1%.

关键词： hydroisomerization of n-heptane bimetal catalyst heteropoly acid USY platinum

Massive Si Phase and Its Growth Mechanism in Al-Si Casting Alloy

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Journal of materials science & Technology 2004年第5期20卷 589-591页

作者： Hengcheng LIAO and Guoxiong SUNDepaxtment of materials science and engineering, southeast university, nanjing 210018, china Dept. of Mat. Sci. and Eng. Southeast Univ. Nanjing 210018 China

Optical microscope and scanning electron microscope were used to observe the microstructure of the AI-11.6%Si and AI-11.6%Si-0.4%Mg alloys and the morphology of the massive silicon particles. It is found that the massive silicon phase, observed in the unfully modified alloys with 0.010%Sr, disappears completely in the alloys fully modified with 0.020%Sr. The serrations and reentrant edges shown in the massive silicon particles with the conventional casting indicate that the TPRE mechanism plays an important role in the growth of the massive silicon phase. The ripples and steps suggest that the "lateral microscopic growth" may be another operating mechanism.

关键词： Al-Si alloy Massive silicon Microstructure Growth mechanism

Cementation of sand grains based on carbonate precipitation induced by microorganism

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science china(Technological sciences) 2010年第8期53卷 2198-2206页

作者： QIAN ChunXiang,PAN QingFeng &WANG RuiXing Jiangsu Key Laboratory of Construction materials,School of materials science&engineering,southeast university,nanjing 211189,china Jiangsu Key Laboratory of Construction materials School of Materials Science & Engineering Southeast University Nanjing China

Microbes can produce 2 3 CO32-in an environment conductive to precipitation,so the incompact sands will be *** technology is environmentally friendly not only because it gives strength to the sand body,but also it allows water to penetrate into the sand body,which is unlike silicate cement that will destroy the ecosystem of the *** comparing the activity of three kinds of bacteria,the most suitable one was chosen for the ***,the activity of this bacterium was still not high enough for the purpose,so it was purified.A suitable program for the consolidation and cementation of sands was also found in the *** compressive strength and the porosity of the cemented sand body were tested to characterize the cementation *** analysis showed that a new phase of calcite was produced between sand *** content of calcite was detected by *** study showed that the precipitation program was quite important to obtain a sound cemented sand body in addition to the activity of the bacteria.

关键词： carbonate precipitation microbe calcite sand consolidation porosity compressive strength

Hydrogen production by mixed culture of several facultative bacteria and anaerobic bacteria

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Progress in Natural science:materials International 2011年第6期21卷 506-511页

作者： Chun-xiang QIAN,Lu-yuan CHEN,Hui RONG,Xiao-ming YUAN School of materials science and engineering,southeast university,nanjing 211189,china School of materials science and engineering Southeast University Nanjing 211189 China

The characteristic of hydrogen production by facultative anaerobic bacteria,obligate anaerobic bacteria and their mixed culture was studied by the batch culture *** results showed that,due to the synergistic effect between facultative bacteria and anaerobic bacteria,the ability of hydrogen production in the mixed culture was much better than that in the pure culture. Especially,the culture Scheme No.7 mixed up with three strains(Bacterium.E:Bacterium.B:Bacterium.P = 1:1:1) not only had the best hydrogen production capacity(1.885 mol H2/mol glucose) and maximum average hydrogen production rate(212.2 mL/(L-h)), but also had stable hydrogen production under continuous culture conditions,which was 1.968 mol H2/mol glucose.

关键词： hydrogen production bacteria producing hydrogen mixed culture

Integrated intelligent control analysis on semi-active structures by using magnetorheological dampers

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science china(Technological sciences) 2008年第12期51卷 2270-2284页

作者： XU ZhaoDong1 & GUO YingQing2 1Civil engineering college, southeast university, nanjing 210096, china 2 Automation college, southeast university, nanjing 210096, china Civil engineering college Southeast University Nanjing China Automation college Southeast University Nanjing China

The control strategy is very important for semiactive control or active control systems. An integrated intelligent control strategy for building structures incorpo rated with magnetorheological (MR) dampers subjected to earthquake excitation is proposed. In this strategy, the time-delay problem is solved by a neural network and the control currents of the MR dampers are determined quickly by a fuzzy controller. Through a numerical example of a three-storey structure with one MR damper installed in the first floor, the seismic responses of the uncontrolled, the intelligently controlled, the passiveon controlled, and the passive-off controlled structures under different earthquake excitations are analyzed. Based on the numerical results, it can be found that the time domain and the frequency domain responses are reduced effectively when the MR damper is added in the structure, and the integrated intelligent control strategy has a better earthquake mitigation effect.

关键词： magnetorheological damper semi-active control intelligent