Abstract:To ensure the rationality of array design and save the cost of observation,the conventional observation array was analyzed,and a rational configuration for micro-tremors was demonstrated in this paper.The frequency-wave number spectrum (F-K spectrum) from records at arrays with different shapes and survey point numbers in a simulated sine decaying wave field was investigated,in which the circle array cross-shaped array and rhombus-shaped array were included.The acceptability of the array configuration was validated by the criterion whether there is one and only one extreme on the F-K spectrum,and whether the direction of the vector is consistent with the direction of the incident wave.The result shows that using the rhombus-shaped array can obtain more precise result with few observation points,and it is the best configuration to estimate the structure of shear wave velocity of site by the micro-tremors array observation method.

Abstract:The hybrid slip model to estimate the finite fault model is introduced first and then it is improved regarding its performance of calculating model parameter by semi-empirical relationship.In the improvement,model parameters are treated as normal random variables.The centre of normal distribution is computed by semi-empirical relationship,and the variance of normal distribution is equal to the standard deviation derived from the statistic of semi-empirical relationship.For a given magnitude,using the improved hybrid slip model could yield many different values for each model parameter,which can better describe the scatter of statistical data about the mean.Special performances for certain model parameters taken in the improvement are discussed,and a case study demonstrates the application procedure of the improved hybrid slip model.Shown in the case study,It is proved that the improved model can generate many finite fault models with different dimensions and slip distributions for one given moment magnitude,which offers references for the source estimation of a future earthquake.

Abstract:To alleviate the damage of spherical liquid-storage tank under earthquake,this paper performs seismic response analysis by building a finite element model with ANSYS for the tank,which involves fluid sloshing with the volume of 1000 m3.The effect of fluid sloshing on the seismic response is studied.The result shows that the support system is the weak link of the tank.Accordingly,this paper investigates the methods for dissipating the vibration energy by introducing the passive control technology and changing the angle of the support system.Numerical analysis result shows that the seismic response of the spherical liquid-storage tank can be effectively reduced by conducting passive control on the system of the tank,and the angle change of support system can improve the anti-seismic capacity of the tank effectively.

Abstract:This paper presents an effective stress-based numerical model for dynamic analysis of soil liquefaction considering the effect of confining pressure on of dynamic properties soil,which can be used to describe the pore pressure increment and the consequent loss of soil strength due to earthquake-induced shaking.The emendatory hyperbolic model which meets Masing rule is adopted for nonlinear analysis of soils in numerical model.The pore pressure generation is calculated using the equivalent cycle pore pressure model developed by Ishibashi and Sherif et al.To demonstrate the relability of the new method for dynamic soil liquefaction analysis,a two-dimensional numerical model is directly established to simulate shaking table test for seismic response of liquefiable ground,the parallel spring-damper connection is used to simulate the artificial boundary of computational domain and the Wilson-θ integral method is selected to solve dynamic equations of seismic response.The results obtained from the new analysis agree well with recorded accelerations and pore pressure ratio in the shaking table test,which shows the reliability and validity of the numerical model.

Abstract:The bolt-ball joint system with actual bend-bearing capacity can be used in single-layer reticulated domes.Both experimental study and sophisticated finite element analysis were carried out to obtain the bending capacity of the joint which was described by bending-rotation curves.The finite element model of a single-layer reticulated dome with bolt-ball joints was established by ANSYS,in which spring elements were used to simulate bending stiffness of the joint obtained experimentally.The stability of single-layer domes was analyzed.Results indicate that the single-layer dome with bolt-ball joints is sensible to asymmetry load distribution and its buckling is process always accompanied with bending of the joint.The critical load of a single-reticulated dome with bolt-ball joints is 32% as that of much as the rigid dome at least,and the percentage will be over 98% at most.But for a single-layer cylindrical reticulated dome,the percentage is only 10% ,indicating that the bolt-ball joint system can be used in single-layer reticulated domes,but should not be used in a single-layer cylindrical reticulated dome.

Abstract:In order to establish a restoring-force model for concrete columns with high strength core,based on the low cyclic loading tests.112 concrete columns with high strength core were calculated and the results were regressed.The expressions for characteristic nodes of the skeleton curve were given in terms of the axial compression ratio,the area ratio of core high strength concrete and the shear-span ratio.In addition,the hysteretic rule of the restoring-force model and the expression for unloading stiffness were presented.The numerical results based on the restoring-force model given in this paper are in good agreement with experimental results,which shows that the restoring-force model presented in this paper can accurately simulate and reflect the seismic behaviors of concrete columns with high strength core.

Abstract:To study the crack resistance of reactive powder concrete beams reinforced with GFRP bars,the experiments on flexural property of 8 reactive powder concrete beams reinforced with GFRP bars were carried out and cracking loads of this kind of beams were obtained.Refering to calculation method for cross-sectional crack resistance of steel-reinforced concrete beams,combining with tensile stress-strain relationship of reactive powder concrete,the calculation model for cross-sectional crack resistance of reactive powder concrete beams reinforced with GFRP bars were established.By the calculation and analysis,formula of plastic influence coefficient of sectional resistance moment was gained which has the linear relationship with reinforcement ratio.The calculation data of cracking loads obtained by the formula and the test data of cracking loads were contrasted and the results show that they are in good agreement.Accordingly,the calculation method for cross-sectional crack resistance of reactive powder concrete beams reinforced with GFRP bars is achieved.

Abstract:Aimed at the problems that the probabilistic characteristic value of the river ice compression strength of small sample is unstable and it is difficult to obtain its distribution,the Bootstrap is applied to the determination of the characteristic value of river ice compression strength,then the stable characteristic value of the compression strength of small sample is obtained and its distribution is determined.The experimental data indicate that the probabilistic characteristic value calculated by Bootstrap is better than the results obtained by classical calculating method and Jackknife method,so Bootstrap can improve the stability of probabilistic characteristic value of the river ice compression strength of small sample.

Abstract:The back-structure is an important part of the supporting system of the FAST reflectance surface.Its performance directly affects the precision of the FAST and its costs.In this paper,a shape-keeping method for the design of sub-structures is proposed.Then several kinds of back-structures are provided,followed by optimization of the advanced back-structures such as spatial latticed,strain stressed and hybrid structures.After a comparison of their structural behaviours and manufacturing processes,it is concluded that the double-layer latticed structure in local areas has advantages of small weight,large stiffness and easy manufacturing process.

Abstract:Two thermal behavior experiments of light gauge steel-framed composite walls with slotted studs and with external thermal insulation layers were carried.The method of thermocouple temperature measurement was used.The heat transfer coefficients and the temperature of measured points of composite wall were deeply investigated and were compared with the FEA model results.Results show that web slotted studs can reduce the heat loss of light gauge steel-framed composite walls,thus weaken the thermal bridge effect of the location in stud part,then significantly improve the thermal insulation properties of composite walls.The composite wall heat transfer coefficient of the two test schemes are 0.315 W/(m2·K) and 0.250 W/(m2·K) respectively,which can meet the residential building envelope heat transfer coefficient limit value of cold areas.

Abstract:In order to study the influence of vertical loading mode on pile side resistance,the additional pile lateral stresses induced by the vertical load of pressing down and pulling up at pile top and pushing up at pile bottom were analyzed with numerical simulation method.It is shown that the additional pile lateral stress under pressing down at pile top is compressed stress,and those under pulling up at pile top and pushing up at pile bottom are tensile stresses 15 -20 m under pile top and ±2.5 m from interfaces of soil layer are the main distribution areas of additional pile lateral stress.The max reaches more than ±80% of pile lateral stress due to soil self-weight,but stress gradient along the depth is great.Influence of soil kind,pile length and pile diameter on the additional radial stress can not be ignored.According to the relation between pile lateral stress and pile side resistance,the influence of vertical loading mode on pile side resistance is discussed.It is unreasonable that the pile side resistance under pressing down at pile top multiplied a coefficient is regarded as that under pulling up at pile top and pushing up at pile bottom in spite of soil location,pile length and pile diameter.

Abstract:Based on all types of widely used prediction modes of concrete creep,the basic creep characteristics were used to build up an efficient and universal calculation method of creep.The feature of unified creep theory was simply summarized.The total variables recurrence formula and its calculation flows were deduced.In the deduction process,creep recovery theory and stress impulse function were analyzed.This method can meet the precision requirement by memorizing parts of stress history and improve the calculation efficiency greatly.It can be used for different types of creep and loading modes.

Abstract:Based on the observed concentration of eight PAHs from water of the Songhua River,generalized risk factor and four-step health risk approach were employed to address the ecological and health risk of PAHs to local aquatic ecosystem.The results show that anthracene was the most toxic compound to aquatic organisms both in low-flow period and mean-flow period.The hazard quotient indicates that the ecological risk of 8 PAHs is high in low-flow period,but low in mean-flow period.The concentration of 8 PAHs probably brings risk to human health,but the risk is in an acceptable range of 10 -6-10 -7.The main stream water of the Songhua River is with a certain carrying capacity of PAHs pollution.

Abstract:In order to increase the reaction rate of the heterogeneous Fenton-like,the catalyst FeIII /R was used to catalytically decompose H2O2 under visible light for the removal of Malachite Green (MG) in aqueous solution.The effect of initial pH,initial H2O2 concentration,initial MG concentration and t-butanol on the reaction rate was also discussed.The result shows that the visible light can enhance the degradation of MG.The experiment of t-butanol shows that the ferryl iron and hydroxyl radical coexist in the system.Repeated use of catalyst does not decrease the removal rate of MG.

Abstract:In order to increase the reaction rate of the heterogeneous Fenton-like,the catalyst FeIVF = O/R was used to catalytically decompose H2O2 for the removal of Orange IV in aqueous solution.The effect of initial pH,temperature,initial H2O2 concentration and initial Orange IV concentration on the reaction rate was discussed.It is found that the reaction rate decreases with the increase of pH.The degradation of Orange IV can be effective at pH range of 3-10.This reaction follows pseudo-first-order kinetics.The activation energy for FeIVF/R catalyzed oxidation of Orange IV is determined to be 59.94 kJ/mol.The reaction rate is positively proportional to initial H2O2 concentration and initial Orange IV concentration respectively.Repeated use of catalyst does not decrease the removal rate of Orange IV.

Abstract:The performance efficiency,stability and inner sludge distribution were investigated in the operation of the full-scale EC reactor for brewing wastewater treatment and the key factor to the formation of anaerobic granular sludge was analyzed,which provides the references for the start-up and operation of EC reactor.After operation for 95 d,the influent organic load and removal efficiency were 8.5 kg/(m3·d) and 80% respectively,and the effluent COD was lower than 400 mg/L.Meantime,the granular sludge with size of 0.5-1.0 mm was observed from the heights of 1.2 and 4 m in the EC reactor.The results demonstrate that EC anaerobic reactor using the intermittent-continuous start-up mode for treating the low COD concentration and high flow of brewing wastewater is feasible and the upflow velocity in range of 2.5-5 m/h is helpful to form granular sludge quickly.The experiment validates that the EC anaerobic reactor can start up stably and efficiently in the brewing wastewater treatment.

Abstract:In order to improve the microwave absorption properties,the compound particles of Ni-P coated barium ferrite were prepared by electroless plating.The structure,morphology,composition and microwave absorption properties of the Ni-P coated powders were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM),energy dispersive analysis of X-rays (EDS),and vector network analyzer.The results show that barium ferrite is successfully coated with Ni-P alloy and exhibits excellent microwave absorption properties.The maximum microwave absorption of the compound particles reaches-24.3 dB within 2-18 GHz.The bandwidth with the loss above-10 dB exceeds 2.8 GHz.

Abstract:In order to analyze the urban wastewater treatment efficiency in northeast China more effectively,this paper uses correlation analysis to determine the efficiency of various relevant factors,combined with second-order quadratic approximation of the investment and operation cost function to fit the actual data,based on which the efficiency of wastewater treatment is analyzed with corresponding indexes.The result shows that the analysis of urban wastewater treatment efficiency in northeast China should be concentrated on designed capacity,actual processing capacity,effluent COD concentration and sludge treatment volume.All the indices above have a positive relation with investment and operation cost,and the margin cost shows a decreasing trend,which means that the efficiency of urban wastewater treatment in northeast China is improved with increasing cost.

Abstract:To develop an approach to evaluate the capacity reliability of road network based on ice and snowfall conditions,the capacity reliability was studied on the basis of travel time reliability and capacity of links.The concept of network capacity reliability was proposed.Through the introduction of free travel time and capacity correction functions for Bureau of Public Roads (BPR) model,an Ice and Snowfall Based-Bureau of Public Roads (ISB-BPR) function was proposed.Then the bi-level programming model of road network capacity reliability was developed.The travel time reliability and link capacity as restrictions were proposed in the upper programming model.To follow the characteristics of route choice under ice and snowfall conditions,the elastic demand user equilibrium (EDUE) was set up in the lower programming model.An assessment methodology integrating sensitivity analysis of EDUE and Monte Carlo simulation was proposed to evaluate the capacity reliability.A numerical case was also given to demonstrate the practicality of the given model.The results show that the ice and snowfall intensity,traffic supply and demand all have great influence on the capacity reliability.The methodology is useful and applicable.It may provide a basis for network planning,design and maintenance.

Abstract:The image distortion caused by lens reduces the quality of images and the processing of image correction is complex.A new effective matching algorithm of distorted images is proposed in this paper,which has two steps of the initial matching and the relaxation optimization matching.The circular projection method is applied in the initial matching step and the algorithm with characteristics of anti-rotation and anti-scale of rotating angle of vectors is applied as the optimization criterion of matching pairs.The value difference of the rotating angle of vectors should be calculated at first,and then the optimal matching pairs can be selected by using of the support function and the rules of rejection.Experimental results with a large number of images prove that the algorithm is still effective in the condition of large nonlinear distortion error of images.

Abstract:The physiochemical properties of non-crystalline maize starch made by ball milling were studied in this paper.The granular morphology and physicochemical properties of it were further characterized using scanning electron microscopy,X-ray diffractometry,differential scanning calorimetry,rapid visco analyser and specific surface area analyzer.The results show that non-crystalline maize starch granules lose smoothness on surface and become rough,the Maltese crosses of non-crystalline maize starch disappear and its relative crystallinity is decreased from 23.4% to 1.91% ,the gelatinization temperature and enthalpy of non-crystalline maize starch decrease and the phase transition peaks disappear gradually during gelatinization.The crystal structure of non-crystalline maize starch is changed from polycrystalline to amorphous.Compared with native starch,except turbidity,all other property factors of non-crystalline maize starch,such as specific surface area,specific pore volume,particle size,size distribution,the solubility,swelling power and water binding capacity are significantly increased.For non-crystalline maize starch,its turbidity and viscosity are lowered,while its hot paste stability and mechanical stability are better than those of native maize starch.

Abstract:This paper proposed a realization method of BIST technique of digital circuits based on improved Tent chaotic sequence to address the problem of testing digital circuits.Random sequence of"0 -1"with white noise characteristics which generated by improved tent chaotic logistic map model hardware implementation is used as automatic test pattern generation (ATPG) of digital circuits.Test response signatures of chaotic sequence are obtained from CRC analysis of output response.It is shown that the method presented in this paper is easy for realization of BIST and has superior performance of higher rate of fault detection and fault isolation than that of M sequence.It is suitable for large-scale FPGA and automatic testing of other programmable logic circuits.

Abstract:A total of four specimens have been tested with different edge distances and spacings in order to study the failure of chemical anchor bolt anchorage group subjected to shearing strength.The influence of different edge distances and spacings on the failure form,shearing strength and ultimate displacement is taken into account by the whole variety test of failure load and the results of finite element.The results indicate that the edge distance has impact on the failure form and displacement of chemical anchor bolt anchorage group under load.Brittle fracture may occur under the condition of small edge distance while ductile fracture may occur under the condition of large edge distance.In addition,the spacing has impact on the interaction of chemical anchor bolts.The test indicates that the stress generated by the interaction of anchors with small spacing will result in the propagation of crack along the depth of anchor.When the stress generated with the row of anchor bolts is independent of each other under the condition of large spacing,cracks form two separate concrete wedges.Comparison of the test data with finite element analysis result shows that the equation provided by the related code is reliable in shearing strength.

Abstract:According to the filed frost damage investigation,frost heaving test and moisture migration simulation test,this paper describes results from filed and experimental data that investigated the reason and factors affecting freeway subgrade frost damage in seasonally frozen ground region.The results of field observation and the test series are compared to discuss the relationship of frost damage and water content,the origin of water on frost damage,the characteristic of water translocation and the road frost boiling caused by the lime-ash-soil deterioration of the subbase.Furthermore,by virtue of comprehensive study of this project,the distribution data of capillary water along the height by standpipe method are combined with the change law of frost heaving radio and water content,then the effective frost damage height can be obtained.Experimental results show that the values in specification are lower than those in test in some cases,which is unfavorable for the design of the subgrade prevention frostbite and anti-freeze.These results are significant for the design of the least height of road embankment and the depth of prevention frostbite at the site of excavation.

Abstract:A series of double-skin facades of cylindrical building was designed and multi-parameter comparison wind tunnel tests were conducted.The space distribution characteristic and mechanics of internal pressure acted on the corridor were studied,then the theoretical method for estimating the mean internal pressure coefficient was introduced emphatically,and the theoretical results were compared with the test ones.It is found that when the arc double-skin facade is in leeward side,the distribution of internal pressure acted on the corridor is even,and it is little influenced by the wind velocity,the opening ratio of the external skin facade and the spacing of corridor.When the arc double-skin facade is in windward side or crosswind side,the distribution of internal pressure acted on the corridor is uneven,and it will become more and more uneven by the decreased spacing of corridor and the increased wind velocity and opening ratio.

Abstract:In order to describe the shape of soil arch behind anti-slide piles,numerical simulations were carried out based on plane stain FEA models.Maximum principal compressive stress traces were investigated based on the calculated results and arch axis equations were set up by fitting analysis.The influences of major factors such as pile space,soil and pile-soil interface parameters,load magnitude on the arch shape were analyzed,and the equation with consideration of aforementioned factors was finally obtained.The results show that pile space and the magnitude of pressure on piles are the most notable factors affecting the arch shape.Ratio of span to rise of arch has a quadratic correlation with pile space.Arch effect will bring soil strength into full use as the pile space is 4.46 times of diameter.Arch rise drops as a steep dropping logarithmic function curve with the increase of pressure,which reflects the evolutionary process of arch effect from formation to development and destruction.

Abstract:The ground motion of an scalene triangular dike impacted by SH waves is discussed.The methods of complex function and moving coordinate system as well as a simple mathematic model are used here.The model is divided into two parts,a wave function which satisfies the condition of stress free at the triangular wedges is constructed in one part,and a scattered wave function which satisfies the condition of stress free at the horizontal surface is constructed in the other part.Then the moving coordinate system is used to transform the solution of this problem into a"conjunction"problem.Finally,the solution of the problem is reduced to a series of algebraic equations and can be solved numerically.Numerical examples show that the influence of incident SH wave characters on the ground motion is great,and the influence of structure on incident SH wave is significant.Compared with stiff structures,the values of ground motion and the points where they happen for soft structures are different greatly because of their good capability of energy absorption.

Abstract:Based on the seismic isolation study of the storage tanks,starting with sloshing,rigid motion and fluid-structure coupling motion of the tanks,the dynamic response theory of hydrodynamic pressure,sloshing wave,base shear and overturning moment of the storage tanks was studied.Rational potential function was selected according to the velocity potential and boundary conditions that the structure of storage tanks satisfied.The equivalent mass and the relative height of mass center were given by using the same base shear and overturning moment of the liquid tank system and equivalent mechanical model when subjected to the same ground motion,and a three centralized particles mechanics analysis model was established.The simplified expressions of sloshing wave,base shear and overturning moment were given as well.The motion equation of the seismic system was established according to Harmilton principle.The earthquake responses of 2 × 104 m3and 15 × 104 m3 isolated and non-isolated tanks were analyzed by adopting the time history method.The numerical result shows that the base isolation seismic system exhibits good performance of seismic isolation.

Abstract:In the investigation of real loading capacities in concrete bridge deck slabs,the study of this type of structure was carried out with consideration of compressive membrane action.A series of experimental test of steel-concrete bridge structures was developed with the analysis of influences from the varying of structural parameters on loading capacities,including reinforcement percentages,supporting beam sizes and concrete compressive strength.Through the study of the experimental results,it was found that the real structural loading capacities are larger than those predicted by current design methods.Therefore,based on the previous research,a prediction method for loading capacities of concrete bridge deck slabs was established with consideration of CMA,which was built based on the plastic ultimate analysis.In this method,the lateral restraint stiffness subjected by concrete bridge deck slabs was provided.The proposed theoretical model is capable of predicting the loading capacities of this type of structure accurately with comparison of results from several bridge deck experimental tests.

Abstract:In order to investigate the inhibitory effect of antibiotic on anaerobic digestion of piggery wastewater methane production was measured in batch experiment with aureomycin as inhibitor.Results showed that the maximum methane production rate of simulative wastewater was 19.6 mL/(L·h).In the presence of 10 mg/ L of aureomycin,the maximum methane production rate was reduced by 47.4% .The hydrolysis and hydrogen-producing were more inhibited than methane producing process in this experiment,which was supposed to be the sensitive step in anaerobic degradation of piggery wastewater treatment.As aureomycin in piggery wastewater is inhibitory to anaerobic,digestion measures should be taken to strengthen the hydrolysis and hydrogen producing process.

Abstract:To improve the security of long and steep downgrade in mountain highway,we establish a temperature model of truck brake speed on long and steep downgrade with the theory of energy conservation.Some parameters of the model have been modified through field tests and mathematical statistics.The critical gradient Ⅰ and Ⅱ concept of long and steep downgrade is proposed,and the security risk rating index of long and steep downgrade is proposed.The results show that the critical gradient based on the brake temperature is the control gradient of the smooth transition section design in the long and steep downgrade section of freeway in mountain areas.Brake temperature model for truck owners is as an effective means of rapid assessment of road safety.It can quantify the security risk rating of long and steep downgrade,which is helpful for p the selection of hedge lane location and the implementation of other security support measures.

Abstract:In order to improve the accuracy of extracted contours and raise calculation speed,this paper presents an improved method based on level set for underwater objects contours extraction.Object evolution subregion,which is determined by the underwater objects detection results,is proposed to dwindle the search region.At the same time,the centers coordinates of initial closed curves of each object evolution sub-region are determined by the location of object-highlight and shadow regions.The contours of object-highlight and shadow regions are extracted by the four-phase piecewise constant Vese-Chan level set evolution functions.Experimental results and analysis of different kinds of real sonar images demonstrate that the method proposed here is highly adaptable and the calculation speed is faster,moreover,it can more accurately extract object-highlight and shadow contours.

Abstract:In order to study the characteristics of blast in geotechnical materials,the material behavior of power-hardening solid was investigated by the elliptic-equation yield criteria and self-similar hypothesis with a Hopkins three region model.First,by studying elastic region,the stress distribution and the continuous conditions in the intersection of plastic and elastic areas were given.Then the nonlinear differential equations to solve the problem of dynamic expansion in the plastic zone were deduced.At last,numerical solutions of the non-linear differential equations which meet with the given boundary conditions were obtained by shooting method,the effects of material parameters on the stress-strain fields were also discussed.Result shows that the elliptic-equation yield criteria can discribe the dynamic expansion of spherical cavity in pressure-sensitive medium.

Abstract:To enhance the thermal property of diglycidyl ether of bisphenyl A (DGEBA),(polyhydroxyl) POSS (SP2-POSS) modifier was prepared using a reaction of (γ-aminopropyl)POSS (A-POSS) and phenyl glycidyl ether (PGE).Different fractions of SP2-POSS (8% ,15% ,30% ,45% ,60% and 75% ) were added into diglycidyl ether of bisphenyl A (DGEBA) to modify the network and enhance the thermal property.The results show that the crosslinking-network density,curing heats and glass transition temperature are enhanced due to the existance of the polyhydroxyls.The network containing 75% SP2-POSS possesses the best thermal properties.