Abstract:To study the lateral seismic collapse fragility of RC frame structures,multi-record incremental dynamic analysis method is utilized to get the lateral seismic collapse fragility curves of a three-bay and five-storey RC frame building,in which the FEMA-rule and computational non-convergence are taken as a rule of lateral collapse of structures.The results demonstrate that the FEMA-rule is conservative to determine lateral collapse.Under the major earthquake,the structural collapse risk is limited.

Abstract:In order to survey the vibration response of permafrost subgrade induced by train traffic along Qinghai-Tibet Railway,and provide the rational theoretical foundation for the rail transit assessment,the self-programming software of the train-track coupled dynamic system was employed to investigate the characteristics of the vertical applied force on sleeper induced by passenger trains.The researches show that,the simulation results of the self-compiling program are in accord with the field monitoring data,and the theory of the procedure is proper;the train-induced vertical acting force exerted on sleeper is in inverse proportion to the subgrade damping,and increases with the raising of the subgrade modulus and vehicle velocity,at the same time increases linearly with the rise of the rail gap;the dominant frequency bands are mainly within the action rate of shifting axle load,the vibratory energy reaches the maximum at the bogie action rate,and the sleeper vibration makes little different to the sleeper vertical applied force induced by passing trains;the effects of the freeze thawing status,rail gap width,and the train speed can not be ignored on the vertical acting force.Moreover,the function relationship of the acting force maximum value versus train velocity is given quantificationally.

Abstract:To estimate whether the concrete could complete the preconcerted service function,based on the material science rule,this paper proposes a calculation rule to estimate the service life of the concrete under the freeze-thaw action.The relationship between probability distribution function of two-parameter Weibull distribution and percentage loss of relative dynamic modulus is deduced.The applicability of the freeze-thaw damage model of concrete based on the theory of probability and damage mechanics is demonstrated.And the equivalent freeze-thaw damage model of concrete is established,which could unify the results of the freeze-thaw experiment of concrete.The results show that the freeze-thaw damage model of concrete is appropriate to estimate the service life of the concrete structure.

Abstract:To investigate out-of-plane behavior of infilled frame due to different construction measures,collapse simulation of the structure is carried out by LS-DYNA software.The influences of construction measures of infilled frame and grades of mortar are researched,respectively.The results show that the collapse prevention capacity of infill walls is effectively improved by increasing the grade of mortar and setting steel tie bars.The space of tie bars is advice to reduce when infilled structures are beyond the eighth seismic precautionary intensity.Other reasonable measures can be also adopted to protect infill walls from collapse and ensure the safety of people’s life and possessions.

Abstract:In order to establish and optimize the technology system of AFLP for Ethanoligenens harbinense’s genome,in this study several key factors influencing AFLP were studied and optimized in detail.The results showed that the effect was better when purity and concentration of template DNA(OD260/OD280) were 1.8-1.9 and 50-100 ng respectively in 25 μL reaction system.The best dosage and time of restriction enzyme digestion of(EcoRI/MseI) were EcoRI(2.0 μL)/MseI(0.7 μL) and 3 h respectively.Furthermore,agar gel electrophoresis map analysis also showed that the bands,which were amplified by 7 different primer combinations of EcoRI-A/MseI-G,EcoRI-G/MseI-A,EcoRI-G/MseI-C,EcoRI-T/MseI-A,EcoRI-T/MseI-C,EcoRI-T/MseI-G and EcoRI-T/MseI-T,were clear and stable without disturbed background and could be used to express the polymorphism distribution of DNA fingerprinting of Ethanoligenens harbinens clearly.

Abstract:Microwave-induced pyrolysis of sewage sludge was carried out to produce bio-gas and the characteristics of gaseous products were identified in this study.The analysis by GC showed that microwave pyrolysis generated gases with a high proportion(up to 56%) of CO and H2,which had relatively high overall heating values.The gases have potential applications as fuel.Moreover,the content of H2S and nitrogen-containing gases were also investigated to evaluate the safety of this method.

Abstract:Low temperature anaerobic digestion,that is how to convert biomass waste into biogas effectually in low temperature,is the key technique which restricts biogas application in northern rural.This paper mainly states the current biogas application technique and existing problem,and suggests some new research theory and technology.Additionally,microbial molecular ecology and proteomics are used to ensure process of biogas production stabilization and the research development in the future are discussed.

Abstract:To effectively protect drinking water resources,a scientific assessment on site selection of River drinking water resources was carried out.Twenty-eight key factors including law,environmental quality,water resources assurance and environmental risk were selected,and based on analytic hierarchy process(AHP),a mathematical model of assessment system was established.The weight of factors was defined by the method of document data and expert questionnaire,and these weights were synthesized under single criterion.These influence factors were classified and quantized with laws,technical standards and statistical data.According to the calculation of factor scores and weights,the recommendations of site selection can be given.

Abstract:To improve traditional L-aspartic acid polymerization in organic liquids,Polyaspartic acid(PASP) was synthesized in the medium of AlCl3-Et3NHCl ionic liquids by polymerization using L-aspartic acid as a raw material.The influence of composition of ionic liquids and reaction conditions on PASP weight average molecular weight and inhibiting effect on calcium carbonate were studied.The characteristics of the infrared spectrum of the product were analyzed.The results show that the obtained product in the medium of AlCl3-Et3NHCl ionic liquids is PASP,the molecular weight of PASP is between 1 000-5 000,and the optimal conditions of polymeric reaction are that the molar ratio of anhydrous aluminum chloride and triethylamine hydrochloride is 2.2∶1,reaction temperature is 220 ℃,concentration of L-aspartic is 0.2 g/mL and reaction time is 2.0 h.Under the above conditions,its molecular weight is 4 750,the scale inhibition rate to calcium carbonate reaches to 93.8% and it is increased by 5% compared with the traditional liquid-phase polymerization process.The PASP can be synthesized in ionic liquids.

Abstract:The excess activated sludge was pretreated by six-methods(acid,alkaline,heat,aeration,chloroform and 2-bromoethanesulfonate(BES),respectively) in batch tests to evaluate and compare their suitability in the enrichment of hydrogen-producing bacteria.The experimental results showed that,at 35 ℃ and initial pH 7.0,the hydrogen yields of the pretreated sludge(except BES) were higher in comparison with the control test during the fermentative hydrogen production.In all tests,for fermentative hydrogen production from glucose,the sludge pretreated by acid and alkaline could obtain the maximal hydrogen production potential,using glucose as the substrate,and the hydrogen yield from glucose and specific hydrogen yield in terms of mixed liquor volatile suspend solid(MLVSS) reached 1.51 mol/mol and 27.29 mol/gMLVSS,respectively.It was concluded that the pretreatment methods led to different fermentation types.Butyric-acid type fermentation was achieved by acid and alkaline pretreatments,an ethanol-type fermentation was observed using aeration,BES pretreatments and the control,while mixed-acid type fermentation was achieved by heat and CHCl3pretreatments.

Abstract:To investigate the effect of COD,NO3--N and post-aerobic on denitrifying dephosphorization process,a lab experiment was carried out by using an anaerobic/anoxic sequencing batch reactor(A2SBR) for a long time.The results show that when the influent COD is between 200 to 250 mg/L and PO43--P is between 4 mg/L to 6 mg/L,the removal efficiency of anaerobic COD,anoxic PO43--P is 80% and 92%,respectively,and when the influent of NO3--N is 35 mg/L,the effluent PO43--P concentration is lowest(0.34 mg/L) and the removal efficiency of PO43--P is 98.4%.Post-aeration can effectively remove the residual phosphate and the removal efficiency of PO43--P is up to 99%,meanwhile,post-aeration can significantly improve the sludge settling characteristics.

Abstract:Using phase change material of phase-change temperature 6 ℃,a triple-sleeve energy storage exchanger was proposed,in which the exchanger,air source and solar heat pump were integrated.Cool storage characteristics of the triple-sleeve energy storage exchangers with direct evaporative was simulated by a mathematical model.Comparing with the traditional ice storage,the average evaporation temperature of high-temperature phase change cold storage was 10 ℃ higher than that of the ice storage.The COP values of high-temperature phase change cold storage were increased by nearly 25 percent than that of the ice-storage.The power saving rate of the phase change cold storage achieved 36% at the same cooling capacity.

Abstract:To evaluate the effect of urban planning on urban thermal climate quantitatively,an urban region thermal climate prediction model based on the calculation of heat transfer,heat storage and evaporation rate from various kinds of underlying surfaces is presented and a new evaluating index named as urban district local temperature rising is introduced.Taking a certain eco-city planning project in Beijing as a case study,its temperature variation between pre-and post-urban planning is studied by the model and index.By comparing with normal urban planning,the results show that under the conditions of high temperature and huge solar radiation in midsummer,effective urban planning strategies(such as the increase of lawn and tree ratio,reduction of building energy consumption and building heat release,and so on) can alleviate the negative effect of urbanization on thermal climate.

Abstract:At present,yeast is the main microorganism involved in ethanol production using xylose as carbon source.The filamentous fungi have been less studied compared to yeast.Duchenne tube and ethanol yield assay methods were applied to screen different microbes for xylose fermentation.The microorganism producing the highest amount of ethanol was identified by microscopy and 18s rRNA amplification and analysis.Fermentation assays of this microorganism were studied by the Potassium dichromate method.The screening results showed that the organism code named cs-28 was Fusarium oxysporum.It was found that this fungus could ferment xylose,glucose,sucrose and corn stalk to produce ethanol.The optimal nitrogen source was yeast extract.The ethanol production rate was highest at initial pH 6.0 and 30 ℃,when initial xylose concentration was 20 g·L-1.Thus,cs-28 can be used as a new strain for transformation of cellulose materials to ethanol.Moreover,characterization of cs-28 on xylose fermentation can be applied in technological advancement.

Abstract:In order to maintain the harmony and stability of ecosystems,in this paper,the stability of Nicholson’s blowflies model with time delay was investigated.The distribution of the characteristic roots,the stability of the equilibrium,the existence of Hopf bifurcation and its conditions were discussed.Meanwhile,some simulations were carried out,which supported the theoretical results obtained previously and the global existence of Hopf bifurcation near the positive equilibrium point was got.At last,the reasons of circulating ecosystems were explained by the bifurcation theory.

Abstract:To improve the control performance of vehicle in automated highway systems,we studied the longitudinal control for vehicle following using front and back information in the presence of parametric uncertainty.Based on the longitudinal dynamical model of vehicle,with constant spacing safety policy in a platoon,the longitudinal directed adaptive sliding mode control laws for each vehicle in a platoon was designed depending on the information from the immediate predecessor,the immediate follower and the platoon leader available for feedback.By using vector Lyapunov function and the properties of M-matrix,the asymptotic stability domain of the controller parameters of string of vehicle was established.The simulation results show that,when the speed of the lead vehicle changes,the convergence rate of spacing errors of the vehicle with parametric uncertainty is fast.

Abstract:To improve the precision of estimated rotor angle for the interior permanent magnet synchronous motor(IPMSM),this paper presents a novel model based on the linear flux.The rotor position and speed is estimated by the sliding mode observer(SMO) via the current error between the actual current and the estimated current.The effect of stator resistor and inductance on the estimated rotor angle is analyzed quantitatively,and to reduce the effect,Lyapunov function is established to identify stator resistor and inductance.The experimental result shows the validity and reliability of this algorithm.

Abstract:For the purpose of the degradation assessment of concrete bridges in life-cycle,a finite element-based methodology for the degradation process of concrete bridges is proposed.This is done by:(a) the computation formulas of the three critical times;and(b) the simulation methods of several special mechanics problems in the degradation process.Based on the theoretical analysis,a program named CBDAS is written in FORTRAN 95.The research on the variation of structural performance in given service life with chloride penetration is carried out by means of a reinforced concrete continuous girder bridge.The results show that: the initiation time of reinforcement corrosion is early and the corrosion rate is fast with chloride penetration.In 80 years after structure completion,bending capacities are smaller than the relative envelope moments at two critical sections for the ultimate limit state.As a result,as for the reinforced concrete bridges,the ultimate limit states are more likely to have durability defects.

Abstract:To consider dynamic load while equivalent standard axle load conversion is carried out,two degree of freedom vehicle model is built to calculate power spectral density of dynamic load coefficient,and then distribution of dynamic load coefficient is calculated.Increasing degree of equivalent standard axles is calculated in theory while dynamic load is considered.The results of examples show that equivalent standard axle load shall be increased when dynamic load is considered for various kind of pavement: for asphalt pavement,while design deflection and tensile stress at the bottom of asphalt pavement is taken as index,1%-2% shall be increased for expressway and first class highway,2%-5% shall be increased for other classes highway;while tensile stress at the bottom of semi-rigid base is taken as checking index,3%-6% shall be increased for expressway and first class highway,7%-17% shall be increased for other classes highway;for cement concrete pavements,15%-25% shall be increased for expressway and first class highway,35%-80% shall be increased for other classes highway.

Abstract:To intensively study the responses of single piles under combined vertical and lateral loads,the common form of the coefficient of subgrade reaction was introduced.The semi-analytical solutions were obtained by dividing the pile shaft under ground into many small segments and supposing the axial force of the pile and the coefficient of subgrade reaction corresponding to each segment to be constants.Together with the pre-existing power series solutions for the pile shaft above ground,the relevant computer program was developed by Fortran programming.The calculation results indicate that the maximum lateral displacement and bending moment increase significantly with the increase of lateral loads.The vertical load can cause the instability of the pile.The soil resistance at the ground surface and the distribution of the coefficient of subgrade reaction along depth play important roles in pile responses.The computed results obtained using solutions corresponding to a special case agree well with those obtained using pre-existing solutions,meaning that the presented solutions are dependable.

Abstract:A FEA program using 8-node degenerated solid shell element was developed to analyze the spatial stress of long span prestressed concrete box girder bridges for the purpose of researching the relationship between cracking damage and the spatial stress state.The influences of dead load,box girder stiffness,effective prestress and temperature on the principal stress were researched,the reasonable magnification factors of live load stress were discussed and a two-axis strength criterion was proposed to control the concrete cracking of box girder.An analysis of real bridge shows that the FEA program is helpful to control the cracking damage of long span prestressed concrete box girder bridges.

Abstract:Based on the crack seepage theory for simulating the water infiltration in pavement,a mathematical model for calculating infiltration rate of pavement with cracks has been established and the theoretical calculation formula of infiltration rate has been deduced.The formula can be applied to evaluate the infiltration,optimize the drainage design and improve the efficiency of drainage system.Further,the map cracks distributed in pavement are also considered and included in another mathematical model for calculating the infiltration rate in pavement with map cracks.The experimental results for the infiltration rate and flow quantity of damaged pavement show that cracks and map cracks give a great contribution to the water quantity infiltrating into the pavement.It is suggested that the design of infiltration rate should take the cracks and map cracks into consideration reasonably.By calculating and analyzing the two models established in this paper,it shows that the evaluation of infiltration rate should be conducted according to the damage degree of pavement,such as crack length,crack width,crack density and the distribution of map cracks throughout pavement.Additionally,if the thickness of surface course of pavement is determined,the thickness of permeable base not only depends on the permeability coefficient of the material of permeable base but also the strength of pavement structure.

Abstract:This study provided quantitative analyses from several aspects of signal timing related to bandwidth optimization,including: the influence of signal phasing sequence,the impact of intersection spacing,and the impact of number of signals in a system.A large number of arterial scenarios were randomly generated to simulate 90 000 traffic signal systems that likely exist in the real world.After comparing the effectiveness of four phasing sequences,it was concluded that lead-lag or lag-lead phasing sequence was used 5% more than leading or lagging.The impact of intersection spacing was analyzed by comparing uniformly and randomly spaced signal systems.Uniformly spaced signal systems did not provide better progression bandwidth than non-uniformly spaced systems.The study also found that the number of signals had a significant impact on bandwidth attainability.When the number of intersections exceeded 16,there were practically no two-way bandwidth solutions,suggesting that bandwidth based signal timing approach may not be feasible.

Abstract:To study vertical steel storage tank isolation design and analysis methods,three-stage design method is used as the optimal design of base isolated for the vertical steel storage tank.In the first stage,from rigidity theory,the wave height amplification effect caused by the base isolated is considered firstly,and the wave amplification is limited to the boundaries of isolation design to adjust the frequency.In the second stage,from elasticity theory,the base shear of isolation is analyzed,and the damping effect of the base isolated is studied.In the third stage,the square and square root results of the base shear obtained by the rigid theory and the theory of elasticity are used as a design basis.In theory,the only guarantee the effect of the two effects,but also for engineering design and analysis provides a easy to understand method of analysis.The results showed that this approach to design can not only achieve the right base shear reduction,but also be capable of controlling the amplification effect of wave height.

Abstract:To examine the fluid flow and heat transfer characteristics in a microchannel with fan-shaped reentrant cavities,the numerical investigations were conducted,and the results were compared with the conventional rectangular microchannel data.The SIMPLEX method was used for the computation.The effects of volumetric flow rate,heat flux on the pressure drop and thermal resistance were investigated in detail.The numerical simulation results indicate that a microchannel with fan-shaped reentrant cavities can improve heat transfer performance with an acceptable pressure drop when the Reynolds numbers are larger,and the fluid flow and heat transfer mechanism can be attributed to the interaction of the redeveloping of hydraulic and thermal boundary layers,the effect of jet and throttling and the stagnation zone of laminar flow.

Abstract:To investigate strength reduction factor R and dynamic magnification factor β,dynamic response of single degree of freedom(SDOF) elastic-perfectly plastic(EPP) hysteretic system are analysed.The influence of site types,natural vibration periods,displacement ductilities,damping ratios and P-Δ effect coefficients are taken into account.The characteristic periods Tga and TgR are used to normalize the R spectra and β spectra.Results indicate that ductility,damping ratio and P-Δ effect coefficient all have obvious effect on R and β.β produces more ideal effect than R on elastic-plastic seismic force calculation.

Abstract:For the purpose of effectually utilizing untreated sewage heat pump for heating and air conditioning,it needs to know the effect of untreated sewage source heat pump on biochemical sewage treatment.The temperature of untreated sewage and the increased electricity consumption of sewage treatment plants for lowering the sewage temperature were investigated,and the relation between sewage temperature and effects of biochemical sewage treatment and the extent of the temperature lowered by pump system were analyzed.The electricity consumption of sewage treatment plants was calculated through an engineering example.The results showed that,when sewage temperature is too low,it was good to use cold-adapted microorganisms for biochemical sewage treatment,and a small quantity of electricity consumption(0.003～0.007 5)kWh/(℃·t)is used.About 0.01 kWh/t quantity of electricity consumption would be used when heat pump system was exploited,which was only 0.6% of the quantity of electricity consumption of pump system.The effect of untreated sewage source heat pump on biochemical sewage treatment is very small.

Abstract:To obtain more effective prediction effects,based on study of LMS algorithm,affine projection algorithm is proposed in this paper which is apply to estimating AR model parameters.The adaptive AR predicted model is built by using measured dynamic data combining with AIC criterion and the model is applied in the ship motion prediction.After comparative analysis of the simulation results,the predicted model based on Affine projection algorithm can get more precise prediction and the prediction time is more longer.The convergence rate of adaptive estimation of parameters about AR model is faster compared with LMS algorithm,LMS-Newton algorithm and NLMS algorithm.So the method provides theoretical basis for real time on-line prediction of ship motion.

Abstract:To set up inherent immune response of the adjustable fuzzy matching negative selection immune algorithm,based on fuzzy idea,the vaccine theory is used to pick up the vaccine during abnormal monitoring,and the algorithm performance influenced by vaccine operator and positive selection operator is studied.The simulation results show that the antibody storeroom memory function is increased by the vaccine operator and the second response period is shorten obviously,while the positive selection operator is the executant.The improved adjustable fuzzy matching negative selection algorithm has better self-study function,it has self-adaptation for the inherent immune response.

Abstract:To improve chitosan’s solubility in water,citric-chitosan was successfully synthesized for the first time in the mild condition with chitosan and citric acid as raw material and ethanol as reaction medium,and the process parameters were optimized: the molar ratio of citric acid to chitosan is 2∶1,the reaction temperature is 20 ℃ and the reaction time is 0.5 h.IR analysis result shows that the carboxylation reaction has occurred between citric acid and chitosan and citric acid has been successfully grafted on chitosan.In addition,the result of solubility in water shows that the citric chitosan’s solubility in water has increased a lot compared with that of the former chitosan.