Abstract:Based on the basic differential equations of a flexible pile and the C-method assumption, a power series solution of the internal forces and displacements of a flexible pile in a single homogeneous soil was obtained under inclined loads, taking the weight of the pile and its shaft resistance into account. The foundation coefficient was assumed to be parabolic to the depth of subgrade in the C-method. The flexural responses of the pile were compared with the results calculated by the traditional m-method in an engineering example. The results have indicated the internal forces and displacements of a flexural pile calculated with the power series solution are well consistent with those in practical engineering. And the maximum bending moment of the pile and the horizontal displacement of the ground based on C-method have been elevated by 10%, compared with those obtained in m-method.

Abstract:The combination of antenna array detection method of ground penetrating radar was put forward to solve the actual engineering problem that is difficult to monitor the integrity of the flexural pile composite foundation. The experiments of the lengths and defects of six tamping soil cement piles have shown that the maximum average relative error of pile lengths is 5.10% and the relative error of the pile position of defects is 5.45%. The results have indicated that there is enough reliability to determine the pile integrity by using the GPR method,which can meet the engineering needs. Furthermore, the age of cement, the ratio between soil and cement, moisture content were studied, and corresponding proposals for actual projects were presented.

Abstract:In order to prove the assumption that the corrosion rate of steel in concrete is controlled by the diffusion rate of oxygen, the effect of Icorr on the degree of the pore saturation in concrete at a given temperature was investigated by monitoring corrosion current. A comparison test of the corrosion rates of passive steel, active steel in completely water saturated concrete and active steel in atmosphere environment was conducted. The phase component of corrosion products of steel bars before and after the specimens were immersed into water was measured with the X-ray diffraction analysis technique. The research has indicated that the corrosion rate will decrease when concrete dries (the pores are more open and the pathway for oxygen is higher). After the corrosion starts, FeOOH in corrosion layer can act as depolarizer instead of oxygen, so the corrosion rate is still very high even if concrete is completely water saturated. The oxygen is one of the factors that influence the corrosion rate but is not the factor controlling the corrosion process of steel in concrete. Therefore, all predictions based on the diffusion rate of oxygen through concrete cover must be regarded as not reliable.

Abstract:This research focuses on the critical energy release rate of fly ash concrete on the basis of the dual-G criterion. The fracture properties of fly ash concrete at different ages were tested by using three-point bending beams with different initial crack-depth ratios. The experiment results have indicated that the critical energy release rate grows with time before 7 days. While after 7 days, the critical energy release rate is almost unchanged. And the initial crack-depth ratio has no clear influence on the critical energy release rate. It can be concluded from this research that, for fly ash concrete, fracture parameter can be taken as the indexes in charactering the cracking resistance properties of concrete.

Abstract:There are many problems in the engineering application of the current national standard and industrial standard of the rebound method for fired common brick, for instance, low accuracy, limitation of application and errors in citation. Based on the comparison of rebound testing method provided in 4 existing standards and on the mathematical statistical method, a general formula of the strength calculation for fired common brick in existing masonry was proposed, and the uniform provisions concerning the application of this method were made. The high accuracy of the general formula of strength calculation has been verified in the test organized by the Committee of National Standard GB 50315. The research will have reference value for site testing of masonry engineering, and will provide an important basis for the revision of the national standard GB 50315.

Abstract:The influence of the structure parameters of the lifting composite hydro-pneumatic suspension on vehicle performance was analyzed by taking the suspension frequencies under basic load, maximum load and the difference between them as the evaluation indexes. A matching and optimization of the structure parameters of the composite hydro-pneumatic suspension of a vehicle was then investigated. The optimization was carried out by taking the suspension boundaries and loading status as the constraints, the product of the quadratic sum of the suspension frequencies at basic load and maximum load and the difference between the two frequencies as the objective functions, and the structure parameters of the lifting composite hydro-pneumatic suspension as design variables. Finally, an appropriate set of structure parameters of the lifting composite hydro-pneumatic suspension was obtained, which will meet both the design constraints and the requirements of ride performance.

Abstract:In order to solve the problem of high aerodynamic drag for truck, a study of applying a passive drag reduction technology to the van was carried out. A simplified truck model〖CD2〗Ahmed model was used. And a two-equation model, SST k-ω model, was adopted as the turbulence model in the CFD simulation, then the effect of attack angle of the bottom tail plate of the Ahmed body on the flow field and aerodynamics drag was investigated, including the drag coefficient, surface pressure distribution and the tail vortex structures. The results show that the angle of the bottom plate of the van can reduce the strength of the tail vortex and thus recover the surface pressures of the tail, which in return decreases the drag. It is found that the drag coefficient reaches its minimum value when the attack angle is 10 degree and a reduction of drag about 6% is obtained.

Abstract:This paper propose a new method to predict fatigue life based on the virtual load spectrum technology. Taking the bevel gear deceleration system as the object, the contact model of bevel gears was calculated with finite element analysis for stress and points cloud data about gear drive. According to the analysis results, the estimated fatigue life of bevel gear drive based on Miner and Corten-Dolan criteria was compared with the results of simulation cloud life.The application case demonstrates higher accuracy and reliability of fatigue life analysis results based on the virtual load spectrum calculation under the engineering application background.

Abstract:Automotive antiskid control system schedulability analysis is a difficult issue in the design stage. In this paper, the Structural Analysis and Design Language AADL techniques were used for ABS and ASR control system modelling. According to real time system, task scheduling with thread, computation time and the relationship between processor performance, and by selecting different performance processors without change in the task number, and by using tools OSATE to analyze the system model，a method to solve the problem effectively was demonstrated. This modelling method provides a new approach for the system schedulability analysis and optimal design in the area.

Abstract:In order to better solve large-scale flexible shop scheduling problems and improve the searching performance of flexible shop scheduling algorithms, a hybrid particle swarm optimization(HPSO) algorithm based on entropy was proposed, which combines the particle swarm optimization, genetic algorithm with simulated annealing algorithm, and the inertia factor and mutation probability were adjusted adaptively according to population entropy in order to enhance the searching ability of the algorithm and overcome the premature convergence of the algorithm. Simulation results on benchmark instances have shown that the proposed algorithm can solve flexible shop scheduling problems, and has obvious advantages in the accuracy of optimization over traditional optimization algorithms.

Abstract:A new soft-switching power supply for ozone generator was studied, in which soft-switchings for all IGBTs could be achieved with the assistance of two DC-busline switches and a resonant capacitor. The timing control conditions for all IGBTs to achieve soft-switching were developed on the basis of the analysis of working modes during half cycle of the circuit. Using IPM module as the power switches and TMS320F28335 as the controller, an ozone generator switch with an ozone production of 160 g/h was designed. In the generator, a phase-shift PWM controller was used to adjust the discharge power, a PI algorithm of the ozone tube voltage and a DPLL switch finish frequency automatic tracking of load curren were used to guarantee the power supply working in series resonant. Simulation and experimental results were provided to verify the effectiveness of the proposed system.

Abstract:The coding region of FoxA1，amplified by PCR, was cloned to construct the lentivirus vector plv-rFoxA1-IRES-EGFP. The recombinant plasmid was transfected transiently into 293T cells and the expressions of GFP and FoxA1 were confirmed by fluorescent microscopy and Western blot. The plv-rFoxA1-IRES-EGFP was cotransfected with the packaging plasmids △8.91, pVSV-G to 293T cells to produce the lentivirus. The results show that lentiviral vector that expresses rat FoxA1 was successfully constructed, and infection ability of the recombinant lentivirus was confirmed by the effective expression of FoxA1 protein in cells. These results provided an important material to study the FoxA1 functions in the future.

Abstract:Strains R4-1, R4-2, R4-3, R4-5, H4-3 were obtained by separation and purification experiment from poly-containing wastewater, Sodium Alginate-PVA as embedding medium, immobilized experiment research of mixed bacteria group were studied by Embedding fixed method . The volume ratio of wet bacterium to embedding medium, the mass fraction of calcium chloride, the mass fraction of boric acid and the immobilized time on degrading poly-containing wastewater were investigated by experiment of single factor and orthogonal experiment. The optimum process conditions of degrading poly-containing wastewater by immobilize microorganism are as follows: the mass fraction of sodium alginate is 4%; the mass fraction of PVA is 4%; the volume ratio of wet bacterium to embedding medium is 1∶1; the mass fraction of calcium chloride is 2%; the mass fraction of boric acid is 3%; the immobilize time is 4 h immobilization in calcium chloride solution and then 20 h immobilization in boric acid solution. The main factor affecting microbial immobilization was volume ratio of wet bacterium to embedding medium. Experiment subjoined by optimum process. Degradation rate of immobilization grains degrading poly-containing wastewater is 83.1%.

Abstract:The pyrolysis and combustion of sewage sludge particles (d≤0.25 mm, 0.25 mm＜d ≤0.83 mm and d＞0.83 mm) were analyzed with the thermogravimetric analyzer (TGA, STA 409 model, NETZSCH, Germany) at the heating rate of 20 ℃/min. To determine the chemical characteristics of sewage sludge, elemental and proximate analysis was carried out, and the metal content of the dry sewage sludge was determined. Meanwhile, a new method was developed to calculate pyrolysis kinetic parameters with surface fitting tool in software MATLAB7.11.0 (R2010b). The results have shown that sewage sludge pyrolysis process are divided into three stages: water evaporation (100～180 ℃), volatile matter pyrolysis (205～550 ℃) and inorganic salt decompose (550～900 ℃). Sewage sludge combustion process are divided into four stages: water evaporation (100～180 ℃), volatile matter combustion (180～475 ℃), carbon combustion (475～595 ℃) and inorganic salt decompose (595～900℃). The pyrolysis kinetic parameters of the second stage are as follows: the reaction orders are in the range of 1.5~1.8 and the activation energy is about 48 kJ/mol. The combustion kinetic parameters of the second stage and the third stage are as follows: the reaction orders are in the range of 1.2～1.3 and 1.1～1.2, and the activation energy is about 48 kJ/mol and 176 kJ/mol respectively.

Abstract:The water temperature and quality of Yangtze River in Chongqing section were analyzed，and the performance of water source heat pump units in different sediment concentrations, turbidity and algae material conditions were tested experimentally. Water quality standards in particular surface water conditions in the Yangtze River region that adapt to energy-efficient heat pump were proposed .The experiment results have showed that the coefficient of performance heat pump fell by 3.73% to the greatest extent, the fouling resistance of cooling water in heat exchanger increased by up to 25.6% in different water conditions. When the sediment concentration was less than or equal to 100 g/m3 and the turbidity of the river water was less than or equal to 50 NTU, the performance of heat pump was better, which could be used as the suitable river water quality standards for river water source heat pump.

Abstract:For digital video in complex scene, a multi-scale technique was fused into the conventional gradient detection, and a two-stage coarse-to-fine text detection algorithm was proposed. The features of weighted averaging gradient energy and motion energy were exploited to coarsely detect sample frame and obtain the candidate text regions. The false detected candidate text regions were filtered by connected-component analysis. The statistical characteristics of gradient direction were further utilized to obtain the fine detection results. Experimental results have shown that the proposed approach is robust for digital video with complex backgrounds.

Abstract:The reliability of a Grid resource site will affect the execution performance of tasks on the site, which will bring effect on the queuing time of other tasks on this site. Repairable queuing system was used to describe the reliability of Grid resource sites, and the queuing time of each site in steady-state could be obtained by solving this model. A queuing time aware dynamic Grid workflow scheduling (QTADGWS) algorithm was proposed,and the corresponding dynamic Grid workflow scheduling system was designed. A lot of simulation experiments in different scenarios with different parameter setups have been done based on GridSim. The experimental results indicated that QTADGWS could achieve better performance on makespan and average waiting time than HEFT and CPOP algorithms.

Abstract:Resource-saving agriculture and environment-friendly agriculture is a complex organism involving production, economy, society and ecology. Its development process is influenced by various factors, such as producers, nature, society, etc, and so is agricultural production efficiency. In order to overcome the measurement error of traditional data envelopment analysis caused by ignoring random factors, this paper employed the three-stage data envelopment analysis model to remove environmental factors and random effects. On the basis of this model, it estimated the resource-saving agriculture and environment-friendly agriculture comprehensive production efficiency of 31 provinces and cities in China, and brought forth corresponding policy proposals to promote agricultural development.