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science china(Technological sciences) 2009年第3期52卷 584-589页

作者： XU YePeng1 & ZHOU Ding2.1 School of science, nanjing {2. of science and technology, nanjing 2.0094, china 2.college of Civil engineering, nanjing university of technology, nanjing 2.0009, china School of science Nanjing University of Science and Technology Nanjing China college of Civil engineering Nanjing University of Technology Nanjing China

This paper studies the bending of simple-supported rectangular plate on point supports, line supports and elastic foundation. On the basis of three-dimensional elasticity theory, the exact expressions of the displacement functions, which satisfy the governing differential equations and the simply supported boundary conditions at four edges of the plate, are analytically derived. The reaction forces of the in- termediate supports are regarded as the unknown external forces acting on the lower surface of the plate. The unknown coefficients are then determined by the boundary conditions on the upper and lower surfaces of the plate. Comparing the numerical results obtained from the proposed method to those obtained from Kirchhoff plate theory, Mindlin plate theory and those obtained from the commer- cial finite element software ANSYS, the high accuracy of the present method has been demonstrated.

关键词： rectangular plate point support line support elastic foundation displacement stress three-dimensional elasticity solution

Dynamic damage and stress-strain relations of ultra-high performance cementitious composites subjected to repeated impact

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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,{2. university of science and technology,{2. 2.0094,china 2.college of Materials science and engineering,Southeast university,{2. 2.1189,china Department of Materials science and engineering Nanjing University of Science and Technology Nanjing China college of Materials science and {2. 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

Dynamic Mechanical Behaviour of Ultra-high Performance Fiber Reinforced Concretes

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Journal of Wuhan university of technology(Materials {2.) 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

Resolution method for overlapping peaks based on the fractional-order differential

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science china Chemistry 2007年第6期50卷 797-805页

作者： LI YuanLu1, YU ShengLin2.& ZHENG Gang2.1 college of Information & Control, nanjing {2. of Information science & technology, nanjing 2.0044, china 2.college of Automation engineering, nanjing {2. of Aeronautics and Astronautics, nanjing 2.0016, china college of Information & Control Nanjing University of Information Science & Technology Nanjing China college of Automation engineering Nanjing University of Aeronautics and Astronautics Nanjing China

Equations between the differential order and the maximum of the fractional-order differential for the specified peak signals are developed based on the variation of the maximum of the specified peak signals at different orders. Also, equations between the differential order and the zero-crossing of the fractional-order differential of the specified peak signals are proposed according to the variation of the zero-crossing of the specified peak signals at different orders. Characteristic paramters of the Gaus- sian peak, Lorentzian peak, and Tsallis peak can be estimated using estimator I and estimator II which are obtained by the equations above. As a result, a new method is presented to resolve the overlapped peaks signal. Firstly, a fractional-order differential of the specified peak signals is obtained with the fractional-order differentiation filter. Then, characteristic paramters of the specified peak signals can be extracted using estimator I and estimator II. Finally, the Tsallis peak is used as a model to assign the overlapping peak signals correctly. Experimental results show that the proposed method is efficient and effective for the simulated overlapping peaks and detected overlapping voltammetric peak signals.

关键词： fractional-order differentiation filter, fractional-order differential, overlapping peaks, voltammetric peak

Synthesis and Lubrication of Phosphorylcholine Derivative

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Journal of Bionic engineering 2010年第3期7卷 254-258页

作者： Zhenliang Qiao~1, Dangsheng Xiong~1, Lude Lu~2. Pengju Jiang~2.1. Department of Materials science and engineering, {2. university of science and technology, {2. 2.0094, P.R. china 2. School of Chemical engineering, {2. university of science and technology, {2. 2.0094, P. R. china Department of Materials science and engineering Nanjing University of Science and Technology Nanjing P.R. China School of Chemical engineering Nanjing University of Science and Technology Nanjing P. R. China

The monomer of phosphorylcholine derivative, O-(5-（2.methacryloxy）-3, 3-dimethyl-3-azapentyl)-O’-（ω-hydroxy-octyl）-phosphatequaternary ammonium salt, was designed and synthesized successfully. It was characterized by the spectra ofHNMR and Mass spectra （ESI+）, and every signal was assigned. Then the lubricating characteristics of the phosphorylcholinederivative were investigated on the tribological setup of ball-oh-flat. The Ultra-High Molecular Weight Polyethylene（UHMWPE） flat was rotated against a stainless steel ball with 6 mm diameter. The load was 2.3 N, which corresponded to amaximal Hertz contact pressure of 2. MPa. Water, phosphorylcholine derivative, and Acrylic Acid （AA） solution were used aslubricants, respectively. Compared with AA, the phosphorylcholine derivative shows significant lubrication. It can be stronglyhydrated under water due to the charged segment in chemical structure. The thick water layers within the chains serves asboundary lubricants, and this is thought to be the molecular origins of lubricating behavior.

关键词： artificial joint articular cartilage molecular lubrication mechanism phosphorylcholine synthesis UHMWPE

Web Application Comprehension Based on Dependence Analysis

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Wuhan university Journal of Natural sciences 2004年第5期9卷 731-734页

作者： WU Jun-hua 1,2., XU Bao-wen 1 , JIANG Ji-xiang 1 1.Department of Computer science and engineering, Southeast {2., nanjing 2.0096, Jiangsu, china 2.college of Computer science and engineering, nanjing university of technology, nanjing 2.0009, Jiangsu , china Department of Computer science and engineering Southeast University Nanjing Jiangsu China college of Computer science and {2. Najing University of Technology Nanjing Jiangsu China

Many research indicate a lot of money and time are spent on maintaining and modifying program delivered. So the policies to support program comprehension are very important. Program comprehension is a crucial and difficult task. Insufficient design, illogical code structure, short documents will enhance the comprehensive difficulty. Developing Web application is usually a process with quick implementation and delivery. In addition, generally a Web application is coded by combining mark language statements with some embedded applets. Such programming mode affects comprehension of Web applications disadvantageously. This paper proposes a method to improving understanding Web by dependence analysis and slice technology. Key words Web application comprehension - program dependence - hyper graph - pogram slicing CLC number TP 311 Foundation item: Supported in part by the Young Scientist’s Fund of NSFC (60373066, 6030302.). National Grand Fundamental Research 973 Program of china (2.02.B312.00) and National Research Foundation for the Doctoral Program of Higher Education of chinaBiography: WU Jun-hua (1965-), female, Ph. D. research direction: software engineering.

关键词： Web application comprehension program dependence hyper graph pogram slicing

Cross-linked Polyethylenimine as Potential DNA Vector for Gene Delivery with High Efficiency and Low Cytotoxicity

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Acta Biochimica et Biophysica Sinica 2006年第11期38卷 780-787页

作者： Wei DONG~(1,2. Guang-Hui JIN~1 Shu-Feng LI~(1,3) Qi-Ming SUN~1 Ding-Yuan MA~1 Zi-Chun HUA~1 1 State Key Laboratory of Pharmaceutical Biotechnology,college of Life {2.,nanjing university,nanjing 2.0093,china 2.School of Chemical engineering nanjing university of {2. and technology,nanjing 2.0094,china 3 college of Basic Medical {2.,Southeast university,nanjing 2.0009,china State Key Laboratory of Pharmaceutical Biotechnology College of Life Science Nanjing UniversityNanjing 210093 China School of Chemical engineering Nanjing University of Science and TechnologyNanjing 210094 China college of Basic Medical science Southeast UniversityNanjing 210009 China

Polyethylenimine (PEI) has been known as an efficient gene carrier with the highest cationiccharge *** transfection efficiency of PEI,along with its cytotoxicity,strongly depends on itsmolecular *** enhance its gene delivery efficiency and minimize cytotoxicity,we have synthesizedsmall cross-linked PEI with biodegradable linkages and evaluated their transfection efficiencies in *** study,branched PEI with a molecular weight of 800 Da was cross-linked by small diacrylate[1,4-butanediol diacrylate or ethyleneglycol dimethacrylate (EGDMA)] for 2.6 *** efficiencies of thecross-linked PEI in in vitro transfection of plasmid DNA containing enhanced green fluorescent protein(EGFP) reporter gene were assessed in melanoma B 16F10 cell line and other cell *** cytometrywas used to quantify the cellular entry efficiency of plasmid and the transgene expression *** of the cross-linked PEI in these cells were evaluated by MTT ***-PEI 800-4h,atypical cross-linked PEI reported here,mediated a more efficient expression of reporter gene than thecommercially available 2.-kDa branched PEI control,and resulted in a 9-fold increase in gene deliveryin B16F10 cells and a 16-fold increase in 2.3T cells,while no cytotoxicity was found at the optimizedcondition for gene ***,the transfection activity of polyplexes was preserved in thepresence of serum proteins.

关键词： polyethylenimine gene delivery cytotoxicity B16F10 2.3T cell line

MMSE relay precoding schemes based on quantization error compensation for multi-relay system

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science china(Information sciences) 2010年第12期53卷 2548-2556页

作者： LI Ting 1,2.& YANG LuXi 2.1 college of Communication and Information engineering,{2. university of Posts and Telecommunications,{2. 2.0003,china 2.School of Information science and engineering,Southeast university,{2. 2.0096,china college of Communication and Information engineering Nanjing University of Posts and Telecommunications Nanjing China School of Information science and engineering Southeast University Nanjing China

In order to deal with the performance degradation resulting from the quantization error,this paper introduces the statistics of Grassmannian codebook's quantization error into relay precoding design for multirelay *** on the two-step MMSE optimization algorithm for relay precoding and receiver equalizing with full feedback under QoS requirements,we first propose a limited feedback two-step MMSE optimization scheme for relay precoding and receiver equalizing with quantization error compensation,and then we propose a limited feedback joint MMSE optimization scheme for relay precoding and receiver equalizing with quantization error compensation subject to a global power constraint at the output of *** results show that the proposed joint MMSE optimization scheme with quantization error compensation has a much lower bit-error rate than the two-step MMSE optimization scheme with quantization error compensation and the joint MMSE optimization scheme without quantization error compensation.

关键词： multi-relay precoding limited feedback minimum mean square error

Stability of a linear oscillator with damping force of the fractional-order derivative

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science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 345-352页

作者： WANG ZaiHua1,2.& HU HaiYan1 1 Institute of Vibration engineering Research,nanjing {2. of Aeronautics and Astronautics,nanjing 2.0016,china 2.Institute of science,PLA {2. of science and technology,nanjing 2.1101,china Institute of Vibration engineering Research Nanjing University of Aeronautics and Astronautics Nanjing China Institute of science PLA University of Science and Technology Nanjing China

It begins with the study of damping representation of a linear vibration system of single degree of freedom (SDOF),from the view point of fractional calculus. By using the idea of stability switch,it shows that the linear term involving the fractional-order derivative of an order between 0 and 2.always acts as a damping force,so that the unique equilibrium is asymp-totically stable. Further,based on the idea of stability switch again,the paper proposes a scheme for determining the stable gain region of a linear vibration system under a fractional-order control. It shows that unlike the classical velocity feedback which can adjust the damping force only,a fractional-order feedback can adjust not only the damping force,but also the elastic re-storing force,and in addition,a fractional-order PDα control can either enlarge the stable gain region or narrow the stable gain region. For the dynamic systems described by integer-order derivatives,the asymptotical stability of an equilibrium is guaranteed if all characteristic roots stay in the open left half-plane,while for the systems with fractional-order derivatives,the asymptotical stability of an equilibrium is guaranteed if all characteristic roots stay within a sector in the complex plane. Analysis shows that the proposed method,based on the idea of stability switch,works effectively in the stability analysis of dynamical systems with fractional-order derivatives.

关键词： vibration system fractional-order derivative asymptotical stability stability switch

Delayed Hopf bifurcation in time-delayed slow-fast systems

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science china(Technological sciences) 2010年第3期53卷 656-663页

作者： ZHENG YuanGuang1 & WANG ZaiHua1,2.1 Institute of Vibration engineering Research,nanjing {2. of Aeronautics and Astronautics,nanjing 2.0016,china 2.Institute of science,PLA {2. of science and technology,nanjing 2.1101,china Institute of Vibration engineering Research Nanjing University of Aeronautics and Astronautics Nanjing China Institute of science PLA University of Science and Technology Nanjing China

This paper presents an investigation on the phenomenon of delayed bifurcation in time-delayed slow-fast differential *** the two delayed's have different *** delayed bifurcation means that the bifurcation does not happen immediately at the bifurcation point as the bifurcation parameter passes through some bifurcation point,but at some other point which is above the bifurcation point by an obvious *** a time-delayed system,the evolution of the system depends not only on the present state but also on past *** this paper,the time-delayed slow-fast system is firstly simplified to a slow-fast system without time delay by means of the center manifold reduction,and then the so-called entry-exit function is defined to characterize the delayed bifurcation on the basis of Neishtadt's *** shows that delayed Hopf bifurcation exists in time-delayed slow-fast systems,and the theoretical prediction on the exit-point is in good agreement with the numerical calculation,as illustrated in the two illustrative examples.

关键词： time delay delayed bifurcation Hopf bifurcation slow-fast systems exit-point entry-exit function