Abstract:A parametric analysis of constructional details for diagonal unbonded steel plate brace encased in reinforced concrete panel(Panel BRB) has been carried out to examine the effects of the width and yield strength of the brace,the brace thickness,the panel thickness,the width to thickness ratio of the steel plate brace,as well as the friction and clearance between the panel and the brace,on the working behavior of the diagonal Panel BRBs.When the appropriate clearance is provided,the regression formula to determine the smallest thickness ratio of panel to brace to prevent the panel from flexural cracking until 1/50 lateral drift is provided.The analysis reveals that,to prevent the brace from earlier local buckling,to reduce the number of buckling waves of the brace,and to decrease the frictional action and the punching shear force applied to the panel by the brace,an appropriate clearance and an appropriate ratio of width to thickness of the plate brace,which should not be larger than 5 but smaller than 19,should be adopted.

Abstract:To research the load-bearing capacity,deflection and effective prestress in steel wire of prestressed concrete(PC) slabs after elevated temperature,experiments on mechanical performance of thirteen unbonded and one bonded PC simply-supported slab after elevated temperature were completed.The section of the slab was divided into strips along its depth according to the distribution of temperature field,and the strain-stress relationship of concrete and steel after elevated temperature were introduced,and then the moment-curve of the PC slab was obtained based on equilibrium equations of force and moment on slab section,therefore,the deflection of slab could be obtained by curve integral of section.The experimental results show that: the prestress losses in stress wire in the PC slab after elevated temperature increases with the rise of the effective prestress at ambient temperature and the heating time.The rate of load-bearing capacity degradation of the PC slab increases with the rise of heating time and load level and the decrease of concrete cover.The rate of load-bearing capacity degradation of bonded PC slab after elevated temperature is larger than that of the unbonded PC slab in the same condition.The residual stress and ultimate stress in unbonded stress wire in the PC slab were obtained by fitting curve of experimental data,and the calculation method for normal section load-bearing capacity of the PC slab was established.

Abstract:Direct displacement-based seismic design is a more rational approach to performance-based seismic design,which was used to design steel frame structures.In this method,the yield displacement depends on the initial structures and the ductility factors are calculated according to objective displacement.Then equivalent viscous damping or strength discount factors are ensured,then high damping elastic displacement response spectra or elastic-plastic response displacement spectra are established.Based on structural bilinear model,effective period corresponding to objective displacement are ascertained on displacement response spectra,the structural stiffness and base shear force are confirmed.Component sections are modified to make the structural displacement approach to original displacement,then the structural design are accomplished.Seismic performance objectives of steel frame structures are implemented by the method.Compared to elastic response spectra,the application of elastic-plastic response spectra makes the design results more accurate.Base on elastic-plastic response spectra,performance-based seismic design of steel frame can be implemented by direct displacement-based design method.

Abstract:The efficiency and mechanism of ozonation of dichlorvos(DDV) had been studied,and experimental result showed that ozone could effectively decompose DDV in the water,and the removal efficiency of DDV could be increased under basic condition.More than 90% of the DDV was removed within the initial 5 min.During the DDV ozonation degradation process,organic chlorine was almost completely converted into chloride.In the initial reaction stage,most of the TOC decomposition was finished during the first 5 min.The TOC removal rate increased with the increasing of ozone concentration.The analysis of GSMS showed that the main intermediate products were trimethyl phosphate,dichloroacetic acid(DCAA) and dichloro acetaldehyde.The quantitative analysis of DCAA showed that pH and reaction time had no obvious influence on the formation of DCAA.During the DDV ozonation process,there were three reaction modes: hydrolysis,direct ozone molecular oxidation and free radical reaction.The double bond of ethylene in the DDV molecule was first attacked by hydroxyl radical(·OH) to form dimethyl phosphate and dichloroethylene radical,which were further oxidized to other kinds of product or mineralized to phosphoric acid,carbondioxide and chloride.

Abstract:To study the influences of dissolved oxygen(DO) on denitrification ability of biofilm-electrode,a system consisting of electrolysis reactor and biofilm-electrode reactor was fabricated.The effects of electrolysis current of electrolysis reactor system on the DO content in influents and the DO grads in biofilm-electrode reactor were investigated.Results implied that both microbe respiration and electrochemistry had effects on DO consumption in biofilm-electrode reactor system.The DO,the removal of nitrate-N and the nitrite-N in the biofilm-electrode system were measured when the current in the electrolysis reactor was applied in continuous and batch changes.Although the DO in cathodes area had a little increasing with the increasing of DO in influent,the DO values were all below 2 mg/L.No evidence proves the influences of DO on nitrate removal but the negative influences might be obtained on nitrite accumulation.Some changes on microbial species of bio-film electrode were found at different DO concentrations by transmission electron microscopy micrographs.

Abstract:An anaerobic microbial community cultured in vitro with efficient and stable ability of cellulose degradation was obtained from rumen residue by the techniques of restricted cultivation,which was named as FYG-2.The characteristics of FYG-2 for cellulose degradation were investigated by taking enzymic activity,gravimetry and glucose concentration as parameter.FYG-2 can hydrolyze 1.00 g filter paper completely within 5 d at the condition of 38.5 ℃ and pH6.4-6.8,and degrade both non-sterilized and sterilized substrate and its degradation ability keeps stable after 30 generations.It can degrade natural lignocellulosic materials more easily than pretreated one.The highest enzyme activity(159.7 IU) was obtained with 15 percents initial seed ratio and after 3 d cultivation.Seven pure cultures were separated from FYG-2,however,all their enzymic activities were far lower than FYG-2.This phenomenon demonstrated that strong synergy probably existed in the cellulose-degrading microorganisms and non-cellulose-degrading microorganisms or in the cultured microorganisms and uncultured microorganisms.

Abstract:To investigate the mechanism of denitrifying phosphorus removal and provide functional strains for nitrogen and phosphorus removal,denitrifying phosphorus removal bacteria(DPB) were enriched and isolated from A2SBR.This study made use of controlling the inflow water operation mode of A2SBR for DPB enrichment and screening.The isolated DPB were complex formulated for construction of nitrogen and phosphorus removal functional bacteria.Two-stage inflow water operating mode and high inflow water rate enabled DPB to become rapidly dominant in the reactor.Five DPB strains were isolated and identified by the microbial identification system with fatty acids.The DPB strain and phosphorus accumulating organisms or denitrobactcria were complex formulated,the results showed that the best combination was b204 and 16.Its phosphorus removal rate was 85.78% and its denitrification efficiency was 75.02%,better than the single strains removal rate.Experimental results also showed that DPB could become dominant populations quickly with optimum cultivation conditions and appropriate influent.

Abstract:To further promote the water pollution control of Northeast China,to ensure the water environmental safety of Songhua river and Liaohe river,and to accelerate the harmonious development of economy,society and environment in Northeast China,the performances of 32 typical municipal wastewater treatment plants(MWWTPs) located in 13 key cities of Liaoning,Jilin and Heilongjiang were investigated and analyzed.General problems generated in the operation and management of these MWWTPs were found out,and the corresponding strategies for their stable performances were proposed.These provide guidance from the perspective of water pollution control for the sustainable development and benign circulation of the economy in Northeast China.

Abstract:In order to investigate the optimal C/N ratio for simultaneous nitrogen and carbon removal by a gas-water alternate membrane bioreactor(AMBR)treating wastewater,an AMBR in which two hydrophilic polypropylene hollow-fiber membrane modules was used for aeration and filtration alternately was constructed,and the effect of C/N ratio on simultaneous removal of nitrogen and carbon by AMBR treating synthetic wastewater was studied during the 150 days’ continuous operation.The results showed that under the condition that DO in the mixed liquor was 0.5 mg/L around,the influent COD and NH4+-N was(100-350)mg/L and 34 mg/L,and C/N ratio was in the range of 3-10,increase of C/N ratio had no influence on COD and NH4+-N removal.During the 150 days’ operation,COD and NH4+-N in effluent maintained 20 mg/L and 2 mg/L around,respectively.However,increase of C/N ratio was beneficial to TN removal by AMBR.When C/N ratio was more than 5,TN removal efficiency was more than 66%,and the effluent TN was lower than 15 mg/L,which met the First A-level requirement of national GB 18918—2002.

Abstract:In order to achieve an optimum DO for simultaneous carbon and nitrogen removal by the Membrane Aerated Bioreactor(MABR)treating wastewater,a MABR in which the hydrophilic polypropylene hollow-fiber membrane module was used was constructed,and the effect of DO on simultaneous removal of carbon and nitrogen by MABR treating synthetic wastewater was investigated during the 80 days’ continuous operation.The results show that under the relative stable condition that hydraulic retention time(HRT)was 8 h,and the membrane surface loading rate was 3.7 g·m-2·h-1(COD)or 0.36 g·m-2·h-1(TN),MABR realized preferable simultaneous removal of carbon and nitrogen when DO was 0.5 mg/L around.The removal rate of COD,NH4+-N and TN was 80%,86.4% and 66.5%,respectively.When DO was 4 mg/L or 2 mg/L around,both COD and NH4+-N removal rate rose to more than 88%,but denitrification was limited,which resulted in a poor TN removal,with the former TN removal rate being 10% and the latter 24%.When DO dropped to 0.1 mg/L around,COD and NH4+-N removal rate decreased to 60% and 57.4%,respectively,and TN removal rate also decreased to 46.8%.It was suggested that DO in the mixed liquor of MABR should be controlled at 0.5 mg/L around for an effective simultaneous carbon and nitrogen removal.

Abstract:Summarizes the research achievements of different technological methods of dealing with sulfide malodor in sewage plant,and discusses the mechanism of deodorization method,which indicates that the selected and domesticated high-efficient deodorizing bacteria can be used according to their sulfide group differences to form two or more levels of drop filter or filtration system to deodorize sulfide malodor.Nanometer desulfurizer with high precision and capability of desulfuration under room temperature could be obtained by adding nanometer ZnO with REE,which meets the requirement of desulfuration of low concentration sulfurous gas under room temperature in sewage plant.Study shows that the nanometer ZnO with smaller particle diameter and more oxygen vacancy plays a key role in the process of desulfuration under room temperature.Using sewage sludge from sewage plant as raw material,adding metal activator and relevant accessories and using traditional carbonization or microwave carbonization method,we could produce sewage sludge deodorization adsorbent with high efficiency and adaptability.

Abstract:To improve cellulase activity and obtain strong degradating strains,the Trichoderma viride(T.viride) was treated by compound mutagenic way of ethyl sulfate and ultraviolet radiation,and high producing cellulase strains were screened by plates of Congo red dying,which then were transfered to PDA culture-medium cultured for 10 generation successively and further screened by liquid fermentation.Liquid fermentation condition was optimized using straw as only carbon source.The results showed that: six T.viride mutant strains with high producing cellulase were breeded,and CMCase,FPase and β-Gase enzyme activity of h157 were increased by 72.53%,42.18% and 69.29% respectively compared with wild strain.The highest level of cellulase activity for h157 was obtained by the compound carbon sources of rice stalk and maize straw,and their optimal ration was 6∶ 1.The optimal organic and inorganic nitrogen source were bean cake powders and ammonium sulfate,and their optimal ration was 1∶ 1.The optimal ratio of C∶ N was 7∶ 1,and the optimal mass concentration was 3.3%.The optimal conditions for producing enzyme were pH 5.2,28 ℃ and 4 d.

Abstract:A reliable and rapid method for genomic DNA extraction was constructed here to accelerate the identification of important genes in yak.In this method,the yak milk was first centrifuged,and then somatic cells were obtained for DNA extraction.The influences of different methods of protein removal,DNA precipitants,and storage conditions of yak milk on DNA quality were discussed.The quality of DNA was detected using PCR.Experimental results indicated that both the salting-out and phenol-chloroform method were effective for the removal of proteins,however the salting-out method was more simple and rapid.The precipitants isopropyl alcohol and ethanol were similar to precipitate DNA,but the glycol ether was the worst precipitant in this study.The storage conditions of yak milk have remarkable influence on the quality of DNA,and when the yak milk was stored at 4 ℃ for short term,or-20 ℃ for long term,the desired DNA can be got.The DNA extracted from yak milk using the salting-out method can be used in the later genetic research.

Abstract:The lithium metal electrode was pretreated to be soaked in 1,3-dioxolane,1,4-dioxane and tetrahydrofuran separately,then Li metal cell was assembled with LiCoO2cathode.It is found that the cycling and discharge performance are improved greatly when lithium electrode was pretreated with 1,3-dioxolane and 1,4-dioxane.But lithium electrode properties treated with tetrahydrofuran can’t be improved.Comparatively,the cell has better performance when treated with 1,4-dioxane,but its discharge property was depressed after 50 cycles.Further measurements show that the performance of lithium electrode can be improved greatly if it is pretreated in the following project: 1,4-dioxane(70%)+electrolyte(30%)+LiPF6(saturated concentration).The cycling life increases about 20%,and the discharge plateau at 80th cycle increases about 200 mV.

Abstract:To investigate the leak detection strategy of heating network,a math model of failure hydraulic regime on spatial network is described by graph theory,and by which the pressure changes of all nodes of the network can be obtained for both node leak and pipe leak regime.On this basis,the leakage diagnosis system based on two-stage BP neural network is established,which can predict the leakage location and rate by collecting the real time data of pressure changes of the monitoring points,and its usefulness is proved by an example.The results show that the prediction of the first stage BP neural network for leakage pipe can reach to 100%,and the average relative error of the second stage prediction for leakage location and rate are both 0.03%,which are satisfactory.

Abstract:To investigate the heat pump performances at the condition of four-way reversing valve leakage,a test-rig was built by which tests were conducted,and experimental data such as pressure and temperature of compressor suction and discharge,air temperature difference through the indoor coil,and compressor power consumed were measured.The experimental results show that the leakage makes the pressures of compressor suction and discharge declined,the temperatures of compressor suction and discharged increased,the air temperature difference of indoor coil lowered to 0.9 ℃,and the compressor input power to be only 58.6% of that without leakage,which means the performance of heat pump has been seriously affected by the leakage of four-way reversing valve.The results are helpful to the fault detection of four-way reversing valve and the performance diagnosis of heat pumps.

Abstract:To determine the calculation formula for subcritical flow big leakage,its character was analyzed in gas pipelines.Based on the small hole model and the pipeline breaking model,a big nozzle model was build and a calculation formula was given for the leakage intensity.Tests were carried out to measure the leakage intensity under different pressure and aperture and to verify the accuracy and applicability of the calculation formula.It is shown that the calculated result agrees well with the measuring one when the nozzle size is small.

Abstract:This research uses basic principle of the rheological theory to realize the formation process of the accidents in the building construction process;analyzes the developing process of the single and multi rheological model of the building construction safety accidents;provides the variation of the these two models.This paper also presents the conception of safety accidents rheological strength;gives the calculation method of the rheological strength by using the theory of fault tree analysis;discusses the structure and probability sensitivity of the rheological strength under the model of multi rheological.

Abstract:To describe the characteristics of travelers’ route choice and estimate capacity reliability of road network with ice and snowfall,the function of generalized travel cost was defined by using the weighted sum of travel time,travel time reliability and safety,and the safety coefficient of driving on ramp was introduced to quantify the safety cost index of driving under ice and snowfall conditions,so that a stochastic user equilibrium(SUE) assignment model was formulated on the assumption of minimization of generalized travel cost in choosing path.The capacity reliability was defined based on the viewpoint of links and its model of road network was set up.Moreover,an assessment method integrated Monte Carlo simulation and solution of traffic plan models was developed.The simulation results show that the weighted coefficients have conspicuous impacts on reliabilities of links and road network,and the adventure travelers’ attitude decreases the road network reliability.

Abstract:First,oscillatory differential equation with wrinkle membrane is established based on Lagrange equation and analysis flow of membrane dynamic characteristics is set up by FE program,and then post-buckling dynamic characteristics of rectangle shear membrane are studied.Results indicate that the post-buckling vibration modal of rectangle shear membrane has great correlation with wrinkle configuration.The position of vibration pitch line gets along with the position of wrinkle wave crest.With the increasing of mode number,the number of vibration pitch line is reduced sequentially,and more wrinkle waves crest at the state of vibration.At high order mode,local vibration is presented at the edge of membrane.As shear distance increased,the amplitude of membrane wrinkle is enlarged,and oscillatory variety takes place in natural frequency.The natural frequency is obviously reduced after buckling.

Abstract:The torque ripple and the torque jumping exist in the electromagnetic torque of reaction wheel.The mechanisms of these two kinds of non-ideal electromagnetic torque are analyzed.The simulation model of micro-satellite attitude control system controlled by reaction wheel is constructed.Then the effect of the torque ripple coefficient,the torque ripple frequency,the torque jumping amplitude,and the duration of jumping torque on micro-satellite attitude are analyzed.Finally the methods to eliminate the non-ideal electromagnetic torque are proposed.The results show that the effect of non-ideal electromagnetic torque cannot be neglected in case that the required controlling precision of satellite attitude is higher.The ripple torque and the jumping torque make satellite attitude generate identical frequency ripple and bias error,respectively,and the effect of these two kinds of torque on micro-satellite attitude is maximum under zero-crossing rotate speed of reaction wheel.The methods,such as preventing zero-crossing rotate speed of reaction wheel,improving the torque ripple frequency,lowering the torque ripple coefficient,and decreasing the torque jumping amplitude and duration,can reduce the effect of non-ideal electromagnetic torque on satellite attitude effectively.

Abstract:To explore control method of multiphase fluid path,experiments of two-phase fluid path driving were carried out,during which when applying AC electric signal on the electrodes subjected on the microchannel,the fluid with higher conductivity would occupy the microchannel,and when the signals disappeared,the fluid path restored.A 2D analytical geometry model of the experimental system was proposed to deduce the net charges and Coulomb force at the interface and to analyze the system itself.By the charge conversation equation,convection-diffusion equation and Navier-Stokes equation,a numerical analysis has been done and the results show that the control of two-phase microfluid path can be achieved efficiently based on the logical conductivity gradient and electric field,which provides a theory basis for the integrated functions on lab-on-a-chip system.

Abstract:In order to research the stability performance of cooling tower with gas flue in Xuzhou power plant,the rigid model and aero-elastic model ofsome super large cooling tower in Tongji TJ-3 wind tunnel are carried out,the parameters taken to calculate the wind-induced stability performance are gained in the test,with the numerical simulation and the post processor the local and whole stability are analysed.It is found that the local stability safety factor is lower than the norm value,so the reinforcement scheme must be adopted;the whole stability critical wind speed is higher than the designed wind velocity,the critical wind speed would reduce 30% when considering the internal suction;the critical wind speed is gradually small with the increase of the moulding board,the value is 119.41 m/s when the moulding board is 100,which is much higher than the maximum wind speed.

Abstract:In order to study application of waveform fitting method of high strain dynamic testing methods in testing vertical bearing capacity of single-egress analysising of the data of pile shaft resistance and corresponding pile-soil relative displacement.The analysis indicates that hyperbola can fit the relation of pile shaft resistance and the corresponding pile-soil relative displacement well.So a new method to gaining quake limit for stratified soil is designed.Applying the method to actual engineering,and achieved more reasonable results.

Abstract:In order to study the partial safety coefficient concerned the effect of human error in construction.The contaminated distribution model was employed to obtain the realistic mean value and standard variance of variable X of structural parameters which coexisted with random error and human error.The reasonable partial safety coefficient can be calculated based on the realistic value of structural parameters concerned the effects of random error and gross error.The results show that the current studies of partial safety factors do not consider human error in construction for structural reliability.It is not comply with the real situation.Partial safety factors must be evaluated precisely for the given target β to ensure the certain level of structural reliability due to uncertain factors.

Abstract:To understand the effects of anti-slip techniques between main cable and saddle of a three-tower suspension bridge with a rigid middle tower,five structural schemes are proposed,which are adding a central buckle,changing the rise-span-ratio,installing a buckling cable between tower and main cable,setting a steel structure on the top of tower and fabricating an assistant cable near the saddle.The calculated results by finite element method and analytical method show that the central buckling scheme and buckling cable scheme have little anti-slip effect,but the other three schemes are very effective.Based on these some design recommendations are given.

Abstract:In the modern bridge construction control,the application of artificial neural network BP algorithm is practically used to solve the calculation of temperature field,with the On-site temperature test data.Based on the measured temperature data of the HU LU WAN Bridge,and by using mature BP network model and MATLAB,the mapping relationship between input and output is established.Some key factors on temperature field are analyzed and a method with less number of input nodes and high calculating speed is studied.The calculated temperature field is significant for the temperature field simulation of the whole bridge and its construction.

Abstract:To get the volume forecasting method which can reflect the mechanism of regional transportation demand characteristics,and considering the limited data of regional transportation volume and the stochastic and uncontrollable of the inducing factors,a rolling forecasting model of regional transportation volume was developed based on the Support Vector Machine and the analysis of the characteristics of regional transportation demand and the defects of existing forecasting methods.Through continuous interaction between predictive value and statistical value to update the training samples,the model realized the rolling forecasts of the regional transportation volume,and avoided the process of establishment and calculation of the nonlinear function.Taking the transportation volume of Beijing-Tianjin-Hebei area for instance,the rationality of the model has been validated and the results indicate that the model enhances the forecasting accuracy of regional volume,and has better prospects.

Abstract:In order to improve the efficiency of traffic incident detection algorithm in urban expressway and reduce the impact of incidents,basing on proposing the definition of lengthways time series of traffic parameters and defining abnormal traffic statuses clearly,the relation between abnormal traffic statuses and traffic incident is analyzed,the traffic status variability index is constructed using gain amplification principle,then automated detection algorithms for the traffic incident is designed.This method can not only detect the location of traffic incident but also the incidence of traffic incident,the result show that detection effect and robustness of this algorithms is better than classical algorithms.