Abstract:Based on physical mechanism,a stochastic Fourier spectrum model of fluctuating wind speed with solid physical basis is proposed.In view of physical scene of atmospheric turbulence,relationship between the scales of vortex in turbulence and the subranges in energy spectrum is revealed.According to the exponential laws of Fourier spectrum in different energy ranges,a stochastic Fourier spectrum model is established.In actual physical process,the boundary wavelength lc of the two subranges corresponds to the boundary value of the scales of vortexes in energycontent range and in equilibrium range.Essentially,lcis a variable and the main physical factor which affects its value is the ratio between shearratio of the mainflow and vorticity of turbulence.It is found that the ratio is proportional to shearratio.Along with numerical calculation,the formula to calculate lc and the other parameters in Fourier spectrum model is founded.Finally,taking ground roughness length and 10 min mean wind speed as two basic variables and turbulence intensity as related variable,the distribution of lc and the normalized stochastic Fourier wavenumber spectrum with the bilinear characteristic can be obtained.The theoretical results accord with the measured results well.

Abstract:A novelmaintenanceoptimization approach under uncertainty is proposed for deteriorating reinforced concrete (RC) bridges.The component reliability is used as performance indicator and the structure performance is modeled by using lifetime function.Firstly,the lifetime function is fitted by using a group of pointintime component reliabilities evaluated by Monte Carlo simulations,associated with Latin hypercube sampling and the computer program CBDAS.Secondly,models that reflect the effects of maintenance types on the lifetime functions are presented.Finally,a novel approach for optimization of maintenance is proposed.The original optimization problem is firstly divided into a set of suboptimization problems based on possible maintenance scenarios.Then the optimal solutions of each suboptimization problem are sought in terms of genetic algorithm.Thus,the best solution with respect to any specified condition can be found out by comparing the optimal solutions of the suboptimization problems.The optimization approach is applied to a threespan RC bridge in Shanghai.

Abstract:An experiment was made to investigate the environmental effect,including environmental temperature and humidity,on concrete structural feature parameters.First,the experiment condition was introduced.Then,based on a concrete continuous supported beam model,an analysis was made of the environmental temperature effect on structural modal frequencies,especially the nonlinear effect of freezing.Finally,the environmental humidity effect on structural mass was validated by a concrete block experiment.Results show that the humidity is of an obvious timelag effect on structural mass.

Abstract:Basic mechanical behavior parameters of perfobond rib connector with transverse bar in the hole are obtained based on the state that transverse bar is located in the center of the hole.However,the position of transverse bar in the hole usually deviates from the hole center during actually construction.Nine groups,totally 27 specimens with perfobond rib connectors are designed and pushout tests are performed to investigate the influence of transverse bar position changes in the hole on mechanical behaviors of perfobond rib connectors.The test results show that transverse bar position changes have much more influence on ductility and stiffness of perfobond rib connectors rather than carrying capacity.Finally,the shear stiffness calculation expressions of perfobond rib connectors under different mechanical behavior are proposed.

Abstract:Based on the Abaqus program,a pullout test of the composite rockbolt was simulated.Considering the main failure mode of the rockbolt,i.e.interface failure,an improved cohesive element was employed to simulate the four interface materials,and an axisymmetric elastoplastical finite element model was built to analyze the pullout test.It is concluded that the axial stress and the shear stress distribute along the steel strand exponentially.The bond strength will be overcome with the increase of the load,and the peak of shear stress will move to the far end of the bolt.The peak shear stress along the bamboocomposite material interface and the bamboomortar interface will move accordingly with that of the master interface.Under the constraint of the composite material and cement mortar with higher stiffness,the peak axial stress is located on the middle of the bamboo.The shear stress along the mortarsoil interface increases from the near end to the far end due to the different boundary condition.A comparative study shows the numerical simulation agrees well with the measured data,so the numerical method is certificated to be effective.

Abstract:As for the problem of pile vibration,the properties of the soils surrounding the pile are always nonlinear,that is,the dynamic module and damping of the soil are associated with the displacements of the pile shaft.In present methods,only constant properties of the soil are adopted,but the nonlinearities are neglected.Based on the achievements of the research on vertical dynamic response of partially embedded pile groups,nonlinearities are taken into consideration through the method of calculating pile shaft displacements and soil properties by iterative method according to the interrelationships between them,and iterative convergence is also analyzed.Taking 3×3 pile group for example,the effect of soil nonlinearities are analyzed,and the relationships between it and the load value are observed.Finally this method is used to predict the dynamic response of the pile group foundation of an offshore wind turbine generator,gaining its impedances and displacement response curves.

Abstract:The deformation and strength behaviour of Shanghai fine sand is studied through a series of plane strain compression (PSC) tests with different stress paths.The result from the PSC tests shows that the shear strain,volumetric strain,plastic shear strain,plastic volumetric strain and plastic work are all influenced by stress path for Shanghai fine sand.Therefore,none of the above quantities can be used as appropriate hardening parameter for Shanghai fine sand.Based on the experimental results from the PSC tests for Shanghai fine sand,a modified plastic work parameter and the related function are proposed.The proposed parameter and function are independent of stress path,which can be used as the shear hardening state parameter and hardening function in the constitutive modelling for Shanghai fine sand. Key words： Shanghai fine sand; plane strain compression tests; stresspath; hardening parameter; hardening function

Abstract:In the research background of the three dimensional elasticity problem,the idea of the threedimensional fast multipole virtual boundary element collocation method is proposed,in other words,the generalized minimal residual (GMRES) algorithm and the basic idea of fast multipole method (FMM) are jointly employed to solve the equations related to virtual boundary element collocation method (VBEM).The fundamental solutions of threedimensional problem of elasticity are derived as the numerical scheme to be suitable for the FMM of virtual boundary element method.After the evolution of numerical format,the amount of the computational elapsed time and the memory volume of the storage problems with the calculation of demand are linearly proportional to the number of degrees of freedom of the problem to be solved.Then the numerical simulation largescale degrees of freedom question might be achieved by the method.The numerical examples have proved the feasibility,efficiency and calculating precision of the method.Moreover,the idea of the proposed method has the generality and the extension in the engineering applications.

Abstract:A two dimensional tidal flow numerical model is developed based on models like UnTrim type.The model takes the two dimensional shallow water equations as governing equations and uses unstructured triangular mesh on horizontal plane to enhance the efficiency and accuracy of computation.Then the simulation of tidal flow and the wetting and drying is verified by several channel tests.The results show that the model is effective and stable.Then the model is applied to the simulation of the hydrodynamic process in the Yangtze Estuary,and the model is calibrated and validated through the observed field data.The result shows a good agreement between the simulation and computation.

Abstract:An insitu research was made to investigate the building material consumption and source of three steelconstruction residential buildings with different volumes.Then a comparative study was made of the life cycle energy consumption and environmental emissions of building structures and envelops with the BESLCI software.Results show that the steel component,concrete and cement consume more than 60% of the total life cycle energy;the life cycle energy consumption of steel construction residential building during construction stage is only 50% of that of conventional structure.The building volumes have little impact on inventory analysis results per building area unit.The results are different from the former research results because of the accuracy of inventory data,rationality of research boundary partition and the shortage of inventory analysis data base.

Abstract:Through constructing virtual node and transfer lines,the complex traffic system including car network,public transportation network and rail transit network was transferred into the super network,and the evaluation model of traffic system capacity of composite super network was built.The upper model was maximum flow problem,and reflected the maximum services flow of compound traffic system; the lower was the combination model of the trip distribution and equilibrium assignment,and reflected the bicycler using route choice,mode and transfer nodes choice simultaneously.By taking traffic network system capacity calculation in Wuhu city as an example,the results show that network capacity agrees well with the urban development strategy to south and to east,which proves the correctness and effectiveness of the model and algorithm.

Abstract:The idea of traffic microcirculation was proposed,and the bilevel programming model were constructed for the traffic microcirculation network design.The upperlevel problem was to minimize the total cost and adverse influence on environment and to maximize traffic efficiency under the constraints of saturation and reconstruction space of road links; the lowlevel problem adopted the user equilibrium traffic assignment to describe drivers’ route choice behaviors.With the efficacy coefficient method,an evaluation function of the multiobjective programming was found and the genetic algorithm for this model was proposed.A numerical example shows that the structure of the traffic microcirculation network and the capacity of each of the selected branch road can both be determined by solving the bilevel programming model.

Abstract:The object is to develop a simulationbased dynamic traffic assignment model to analyze the impact of various emergency situations and response countermeasures.The analysis was conducted from three perspectives:network,route,and link levels.The effectiveness of route guidance system (RGS) was also assessed.Simulation results reveal that incident duration is the most significant factor for network performance.For traffic crashes,clearance time and quick response are highly recommended.Lane closure has a relatively slight impact due to the low demand.Incidents occurring in the middle of the bridge have more influence on the traffic condition than the upstream.RGS has great potential to alleviate the traffic congestion due to incidents.However,the effectiveness is not consistent with the market penetration of equipped vehicles.

Abstract:In order to put eye states indices such as the frequency of blink,how long all blinks have taken,the average time of blink into practice to monitor drive fatigue,an experiment with 173 samples was set out.On the basis of classifying samples by age and sexuality,the threshold values of these three indices were calculated with the reference to EGG index.The three indices were investigated from two aspects,namely,significance of difference and stability,and then the average of blink time is regarded as the most appropriate index.Classifying people by the age is more reasonable.In the light of the data,the threshold values of this index of every crowd with different ages were figured out,and their practicality in realtime monitoring was verified in realtime monitoring through an outofdoor experiment.

Abstract:Comparison with base asphalt,an evaluation was made of the performance of warm asphalt modified by the surfactant based warmmix additives in asphalt properties,mixture performance and asphalt durability after hot storage.The technical indicators (including viscosity) of this warm asphalt were on the same level with base asphalt.But the warm asphalt could improve mixture workability,reduce compaction temperature.And the performance of its warm mix asphalt (WMA) was not less than the hot mix asphalt (HMA) technology requirements.At the production site,the warm asphalt after a longterm storage at high temperature could still reduce compaction temperature,so it had good thermal storage durability.According to such evaluation results,the WMA technology using the warm asphalt directly is feasible.

Abstract:The performance of 2,4,6trichlorophenol (2,4,6TCP) adsorption by powdered activated carbon (PAC) was investigated in aqueous solutions to evaluate the effects of PAC species,PAC dosage and temperature on the adsorption of 2,4,6TCP by PAC.The adsorption kinetics,thermodynamics and isothermal models were established.The removal efficiencies of 2,4,6TCP by the combination of PAC adsorption and preoxidation were figured out.The results indicate that the effects of all the three factors on adsorption of 2,4,6TCP are significant and follow the order of PAC dosage> PAC species> temperature.The PAC adsorption is an effective method to remove 2,4,6TCP.The adsorption rate of 2,4,6TCP by PAC is rapid and more than 80% adsorption capacity of PAC can be reached within the initial 20 min.The adsorption behaviors can be well described by pseudo second order adsorption kinetic model and Freundlich adsorption isotherm model.The adsorption of 2,4,6TCP by PAC is spontaneous,exothermic and entropy decreasing.The combination of PAC adsorption and preoxidation can enhance the removal of 2,4,6TCP.

Abstract:Three dimesional excitationemission matrix fluroscence spectroscopy (3DEEMs) was used to analyze natural organic matters in raw water from Huangpu River.The 3DEEMs of raw water contain two proteinlike peaks (T)and one humiclike peak(A).The relative high intensity of peak T indicates a heavy pollution.The variation of peak A along with the treatment processes is similar with traditional indexes,such as CODMn,UV254 and total organic carbon (TOC).All measures,which enhanced chlorination such as increasing chlorination reaction time,replacing monochloramine with free chlorine and increasing chlorine dosage,decreased fluorescence characteristic values and consequently increased HAAs amount.By adding bromide ions,oxidation capacity lowered as free chlorine concentration decreased,but halogenation capacity increased because free bromine concentration increased,which led to a buildup of fluorescence characteristic values,as well as a first going up followed by a decline of HAAs amount.3DEEMs is a promising supplement index to better characterize the variation of dissolved organic matters in water.

Abstract:Total phosphorus (TP),inorganicphosphorus (IP),organicphosphorus (OP),Fe/Al bound phosphorus (Fe/AlP) and Ca bound phosphorus (CaP) in surface sediments and sediment cores of urban rivers in Chaohu City of Anhui Province were measured based on the modified standard measurement and test (SMT) procedure of phosphorus forms in the freshwater sediments.The correlations between phosphorus forms and organic matter content were also analyzed.The results show that the TP content in surface sediments varies from 832.09 to 2 572.41 mg?kg-1.Fe/AlP is the major phosphorus species,and accounts for 42.0%～62.3% of TP.With the increase of depth,the trends of all phosphorus forms first increase and then decrease,and different sampling sites have different peak depths,which can well indicate surrounding environment status and changes in pollution load into the river.For the sediments of different depths,there are significant (P<0.01) positive correlations between all phosphorus forms,and the correlations between organic matter contents and different phosphorus forms are also significant.

Abstract:The intelligent solar protection materials can be made out by using soluble polymer and inorganic salts.The switching temperatures,transmittance,sensitivity and hysteresis of these materials can be changed by adjusting the proportion of soluble polymer and inorganic salts.Based on this,the optimal compositions were optimized.The results of daytime insolation indicate that the maximum temperature difference of the insolation device reaches 30 ℃ when the intelligent solar protection material is transparent.However,when the material changes to opaque,the maximum temperature difference is 10 ℃ lower than that of the transparent state,which can make the overhot phenomenon above the switching temperature diminished.No problems are recognized in 1 000 cycles of tests from -10 ℃ to 50 ℃.The freezing point of these materials are lower than -10 ℃.Besides,these materials can keep 5 years light durability and keep steady white and opaque state for longer than 1 year above the switching temperature.

Abstract:Three kinds of carbon nanotubes,carboxylated carbon nanotubes (MWCNTsCOOH),diamino biphenyl methane modified carbon nanotubes (MWCNTsDDM) and boric acid modified carbon nanotubes (MWCNTsBorate),are prepared by covalent grafting method.The modified MWCNTs with phenolic resin (BPR) are composed by insitu polymerization.These modified carbon nanotubes (mMWCNTs) are added into the phenolic resinbased friction materials.The results show that the stability of the friction coefficient of friction material is improved,wear rate is reduced and thermal recession is improved after adding the mMWCNTs.1wt% of the MWCNTsBorate brings the largest improvement,wear rate is decreased by 43.2%,decline rate of the friction coefficient and wear rate are only 10.3% and 28.6%,also,the friction surface remains intact.

Abstract:The torque interruption is the inherent flaw due to the topological structure of automated mechanical transmission(AMT).First,a brief introduction is made to the cause and the influence of the vehicle drivability of the torque interruption,and then the research on torque interruption based on fixedaxle transmission is reviewed and the solutions are discussed.The concepts of powered torque gap filler and unpowered torque gap filler are presented.At last,the future development trends of AMT is concluded.

Abstract:Chemical adsorption performance is one of the key parameters in cathode air filter design for fuel cell engine.The paper focuses on the simulation of chemical adsorption in air filter with chemical experiments.The SO2 adsorption action of adsorbent in filter was studied by experiments,a threedimension mathematic model between inlet property and adsorption property was built based on experimental data.user define function was compiled according to 3D model,which was used in FLUENT software as restraint joint.The chemical simulation of air filter was studied based on Fluent,which was applied to the air filter structure design for a 5kW fuel cell stack system successfully.The SO2 chemical adsorption was simulated in air filter and the deadline of filter calculated was about 1 203 h.

Abstract:In order to improve the fusion quality of the multispectral images and panchromatic images,a new fusion algorithm based on the generalized IHS transformation and supervised classification is proposed.Taking into account the spectral response of the multipectral and panchromatic sensors,the generalized HIS fusion can be improved in two parts:the construction of intensity component and injection method of detail information.In the proposed method,the images are classified into different parts,and then the Gaussian probability density function is used to do the weighted fusions to the images after the classification.These works reduce significantly the spectral distortion and all the multispectral bands can be fused at the same time.IKONOS images is taken as an example to evaluate the performance and efficiency of the proposed method.The result shows that the proposed algorithm can provide high spatial resolution images,as well as the spectral features based on original multispectral images.This algorithm proves to be prospective in the application for image fusion.

Abstract:A study was made of the navigation calculation model in local frame and detailed steps for strapdown inertial navigation system(SINS).Then the error characteristics of SINS was analyzed through navigation calculation with the measured data.Finally,GPS/SINS loose coupling was implemented by using Kalman filter and Kalman smooth.The results show that,coordinate error of SINS grows as parabola function,in a short time it can provide accurate navigation parameters,with coordinate error less than 2 meters within one minute.SINS/GPS integrated navigation system,which combines advantages of the two systems,gains more reliability and integrity respect to each subsystem.

Abstract:This paper describes a fast and efficient 3D method to emulate trees with parametric Lsystem.The emulation was performed in three stages.First,parametric Lsystem was employed to construct the initial skeleton of tree by analyzing the tree abstract model,and the tree skeleton was optimized by Hermite curve fitting.The second stage was 3D emulation of the tree.A 3D mesh model of the tree was reconstructed with the help of Frenet frame and the associated 3D geometric theory under the constraints of the optimized skeleton and branch radii generated by Parametric Lsystem.Finally the 3D model was completed in combination with the simplified model of leaves.Experimental results show that the proposed emulation method for 3D trees not only reduce the amount of tree model data effectively,but also can limberly emulate many kinds of trees models.

Abstract:It is studied how to get solution to global optimization of the concave function problem.The relationship equal in value between the global optimization of concave function problem and the corresponding optimal control problem is established.The result shows that,with Krotov’s extension method,the solution to a kind of global optimization of concave function problem can be obtained by constructing auxiliary functions.Furthermore,the method is applied to other concave objective functions.Some examples are given to illustrate the method.

Abstract:Let H be a complex Hilbert space,AH the standard C*algebra on H,and AH+ the set of all positive elements in AH.In 1977,Cuntz introduced a comparison in the set of all positive elements in a C*algebra.Let A be a C*algebra.For A,B∈A+,we write A≤B if there exists an element X∈A such that A=XBX*.In this paper,we characterize all weakly continuous semilinear surjective maps on AH+ which preserves the positive elements comparison in both directions.

Abstract:With the development and application of video license plate recognition system which represented the automatic vehicle identification (AVI) technologies in China,a novel high resolution OD estimation method was proposed based on AVI detector information.4 detected categories (Ox+Dy,Ox/Dy+(s),Ox/Dy、P(s)) were divided at the first step.Then the initial OD matrix was updated by using the Ox+Dy sample information considering the AVI detector errors.Referenced by particle filter,the linkpath relationship data were revised by using the last 3 categories information based on Bayesian inference and the possible trajectory and OD were determined with the Monte Carlo random process.Then the OD was corrected through reserve operation based on AVI path flow information at last.Finally,according to the current application of video detector in Shanghai,the NorthSouth expressway was selected as the test bed which including 17 OD pairs and 9 AVI detectors.The results show that the calculated average relative error is 11.09% under the constraints that the simulation error is under 15%,the detector error is about 10% and the AVI facility coverage is 27.2%.This method is highly efficient and can make full use of the partial vehicle trajectory which can be satisfied with the dynamic traffic management application in reality.