Abstract:Wind tunnel tests were conducted to study the wind induced interference effect on two adjacent 200m high super large cooling towers based on full aero-elastic model. The test result indicated that interference effect significantly increased resonance response, but background response played a major role in the total displacement response. The largest average response of the downstream tower reduced due to the shielding effect caused by the upstream tower when the towers were "in tandem". However, wind-induced interference resulted in an addition on root of variance which made the maximum response basically identical to the single tower. Also, the max response magnification factor was found when the tower was in the wake of upstream tower. In addition, the interference factor defined by the max response of the tower could guarantee the max response produced by the loads equal to single tower loads multiplied by the interference factor consistent with group towers, and to the recommended interference factor which took into account the frequency of wind direction basically in accordance with the value in code.

Abstract:Some limitations and insufficiencies are found in the detection methods to check the compactness of filled subgrade，so a new method was put forward. Firstly，in view of the characteristic that the solid(soil and rock) volume does not change in the soil-rock mixture subgrade when it is loaded，a model which can describe the change of porosity in the soil-rock mixture subgrade was established，and the changing regularity of the deformation modulus of soil-rock mixture subgrade was also deduced. Then，the soil-rock mixture subgrade was regarded as a semi-infinite elastic space，and the changing regularity of its deformation modulus under the action of load was taken into account，and a method for calculating the deformation or settlement of soil-rock mixture subgrade under the vertical surface load was brought forward on the basis of Boussinesq's solution by adopting the idea of step loading. Afterwards，the relationship between the initial porosity ratio of soil-rock mixture subgrade and load-moment curves was established，and the new way to detect the compactness of soil-rock mixture subgrade was set up on the basis of static load test curves. Finally，the site test data show that the results of the new method are close to that of the common one, indicating the feasibility and validity of the new method.

Abstract:To solve the problems of low prestressed efficiency in concrete slab and local buckling of steel web in hogging moment region of prestressed steel-concrete continuous composite beams (PCB), a hybrid design method with the corrugated steel webs in hogging moment region instead of plane steel webs was proposed. The force and deformation behaviors of prestressed steel-concrete continuous composite beams with partial corrugated steel webs (PCBW) were studied by theoretical calculation and finite element analysis and were compared with PCB. The research results demonstrate that the hybrid design method can take full advantage of the low axial stiffness and excellent anti-buckling ability of corrugated steel webs, improve the prestressed efficiency and the cracking load in concrete slab. PCBW is particularly suitable for long and medium-span prestressed continuous composite beam structures.

Abstract:Taking the Weifang Kite Capital Gymnasium roof for the engineering background of suspen-dome structure, and the SRB and PCDSB as the horizontal and vertical isolation equipment for the roof respectively, the S-P three-dimensional isolation layer of the roof was designed. By using subspace iteration method, the dynamic characteristics of the isolation roof were analyzed. The non-linear time history analysis procedure X based on the Newmark step-by-step integration method and the Runge-Kutta iterative method were used to solve the seismic responses of the isolated roof programmed. The validity of the procedure X was verified with ABAQUS finite element software, and the seismic responses of the non-isolation roof and the isolation roof under Ⅷ intensity and Ⅸ intensity seismic action were contrasted and analyzed with procedure X. The results have indicated that the first four vibration modes of the isolation roof are embodied for the coupling of the horizontal vibration and vertical vibration; the responses of the isolation roof are significantly less than that of the non-isolation roof under the same intensity and the same seismic action; the responses of the isolation roof of Ⅸ intensity are greater than that of Ⅷ intensity under the same seismic action; and the isolation roof designed by this method can still hold the lower seismic responses even under low frequency pulse action.

Abstract:In order to investigate the characteristics of the radiative heat transfer for the orifice plate, a steady model was established on the basis of the basic theory of radiative heat transfer. The radiative heat transfer for diverse temperature differences between the metal plate and enclosure surface was studied, and the radiative heat transfer for the orifice plate was analyzed. Finally, a new simplified equation of the radiative heat transfer of the orifice plate was found and proved to be reasonable and reliable with an experiment.

Abstract:Based on the top-down design conception, a framework model concept was proposed. This framework model was full size driven through the EXCEL table, and on this basis, the generation of a three-dimensional mathematical model was realized. At the same time, by using the finite element analysis software secondary development technology, the improved particle swarm algorithm based on the strategy of parameter was introduced in the finite element analysis program for the united solution to advanced algorithm theory and engineering optimization problems, so that the parameterized engineering analysis of the key components of the whole machine was realized. Finally, the related procedures were highly integrated in the expert system platform. By inputting design parameters by interface, users can get the 3-d parameterized mathematical model and finite element analysis results, so as to guide practical designs. The example of bucket wheel stacker has shown that the introduction of the concept of parameterized design and engineering analysis has considerable significance and engineering application value in the serialization development of large special equipment.

Abstract:An experiment of diesel-butanol combined injection combustion, combining direct injection of diesel with port injection of butanol, was carried out on a research diesel engine. The effects of the butanol ratio on the emission characteristics were investigated at 1 400 and 1 900 r/min, and IMEP (indicated mean effective pressure), 0.5 and 1.0 MPa, respectively. The results have shown that butanol ratio is a key parameter for controlling diesel-butanol combined injection combustion. With the increase of butanol ratio, soot emissions are reduced, with a slight increase in NO-x- emission, but HC and CO emissions are increased markedly. When compared with the direct injection combustion of diesel-butanol blend-fuel, the diesel-butanol combined injection combustion is a major issue related to lower indicated thermal efficiency and higher HC emission. Therefore, future research is required for an improved manifold injection strategy.

Abstract:To reduce the gearbox volume and the impact of running while improving bearing capacity, pin and pin hole profile parameters and material parameters were quoted to establish the mathematical model of normal contact force on the basis of Hertz contact theory. Five reducer dimensions were selected as the design variables to construct eight nonlinear constraint equations, and a multi-objective optimization model of optimizing contact force and reducer volume was established. Evaluation function method and penalty function method were used to verify the optimization model. A comparison of the results before and after the optimization showed that the reducer volume and the normal contact force obtained an optimization rate of 13.1% and 24% respectively. ADAMS was applied for the dynamic simulation of the normal contact force, and the simulation diagrams of time domain and frequency domain were obtained. The results showed that its average optimization rate reached 29.4% and coincided with the theoretical results.

Abstract:The two dimensional Meshless local Petrov-Galerkin method (MLPG) was expanded to three dimensional theory, and its codes were programmed in Fortran. Then, two classical numerical examples, the cube under uniform tension and the 3D cantilever beam, were calculated, and the results of MLPG3D were compared with the results of analytic theory and three dimensional finite element method (FEM). The results have shown the feasibility and effectiveness of MLPG for solving three dimensional elasto-static problems, and the precision of the results is better than those of FEM.

Abstract:Grid-connected inverter plays an important role in new energy power generation system. In the development, debugging and building of a grid-connected inverter, the switching devices in the main circuit tend to be damaged due to the improper control algorithm, improper protection circuit design or improper debugging method, thus leading to economic losses and affecting the development progress of inverter. An analog switch and op-amp analog circuit based equivalent model for grid-connected inverter was derived and established, and a semi-object hardware simulation system based on this equivalent model was then designed to emulate the real single-phase grid-connected inverter. The feasibility of the equivalent model was verified through active current disturbing method of islanding detection. The proposal presented can effectively simplify hardware design and reduce debugging cost. The feasibility and effectiveness of the inverter equivalent model were verified with simulation and experiment results.

Abstract:A new global optimization algorithm (Powell-DE algorithm) was introduced. Powell algorithm with strong local search ability was integrated into the differential evolution algorithm to overcome shortcomings such as slow convergence and the tendency to fall into local optimum. Meanwhile, typical test function simulation was used to test and compare Powell-DE algorithm and to verify the effectiveness of the algorithm and reflect the superiority of the new algorithm. Then, Powell-DE algorithm was used to soft measure the NK concentration on the basis of LSSVM model in the evaporation process, and was compared with the other two methods. The new model shows better track performance and high accuracy, and can be applied to the online prediction of the NK concentration of the feed solution.

Abstract:Chitosan-g-PEI-g-PEG-OH is a new cationic copolymer. The influencing factors of Chitosan-g-PEI-g-PEG-OH gene delivery efficiency were studied, and these properties demonstrated that this copolymer could be used as the gene carrier. The surface topography and sizes of self-assembly complexes of the Chitosan-g-PEI-g-PEG-OH and DNA were observed through DSL and TEM, and the main size of the Chitosan-g-PEI-g-PEG-OH／DNA complex was approximately 160～210 nm spherical particles. The particles with the size were suitable for entry into cells. Cytotoxicity of Chitosan-g-PEI-g-PEG-OH was evaluated in MTT method and compared with Cytotoxicity of PEI and PEI-g-PEG-OH. Chitosan-g-PEI-g-PEG-OH／pEGFP complexes were transfected into Hela, and the effects of the transfection conditions were evaluated with FACS. Chitosan-g-PEI-g-PEG-OH copolymer presented a lower cytotoxicity and higher transfection efficiency than PEI．The results show that the copolymer is quite promising as an efficient carrier for gene delivery.

Abstract:Manganese oxide octahedral molecular sieve (K-OMS-2) was prepared in the hydrothermal method. The K-OMS-2 was characterized with XRD, FT-IR, N2-adsorption and SEM, and was also employed as the catalyst for the vapor phase oxidation of toluene to benzaldehyde. It was shown that the K-OMS-2 prepared in the hydrothermal method had a morphology of nano-fiber with an average diameter of ca. 30 nm and length of above 1 μm. Compared with those prepared in the solid phase method and refluxing method, the K-OMS-2 prepared in the hydrothermal method exhibited a larger yield of benzaldehyde with obviously higher selectivity.

Abstract:The compositions of ZL101 were optimized with an orthogonal test, and the effects of the alloying elements on the mechanical properties of Al-Si alloy were analyzed. The heat treatment process of the as-modified alloy was investigated. The optimal parameter obtained was 500 ℃×5.5 h+180 ℃×5 h. The results showed that the mechanical properties of as-modified alloy were -σ-b=244.57 MPa,- δ-=5.95%, HB=75.1 under the F treatment and -σ-b=397.92 MPa,- δ-=4.68%, HB=141.2 under the T6 treatment, respectively. Compared with conventional casting aluminum silicon alloy for engine cylinder head, the as-modified alloy shows excellent mechanical properties.

Abstract:The effects of Ce and Zn addition on the microstructures and mechanical properties of Mg-1.3Mn-based alloys were studied. The Ce and Zn addition refined both the as-cast and the heat treatment grain structure of the Mg-1.3Mn alloy. Moreover, the tensile strength and Brinell-Hardness were enhanced. The fracture mechanism of Mg-1.3Mn-1.0Ce-xZn alloys changed with the increase of Zn addition.

Abstract:Nanoscale zero-valent iron supported on activated carbon (nZVI/AC) was synthesized in liquid phase reduction method. The nZVI/AC was characterized through X-ray diffraction (XRD), scanning electron microscope(SEM) and transmission electron microscope (TEM). The removal of BrO-3 with nZVI/AC under different conditions and the removal mechanisms were assessed. The results showed that nZVI/AC displayed high reactivity to BrO-3, which should be attributed to the synergetic adsorption and reduction ability of AC and nZVI. The removal efficiency of bromate increased as initial pH decreased. NO-3 and SO2-4 had little effect on BrO-3 removal, but could decrease the removal rate. The BrO-3 removal mechanism indicated that bromate in aqueous solution was adsorbed onto nZVI/MAC, which led to the increase of local bromate concentration in the vicinity of iron nanoparticles, and subsequently reduced to innocuous bromide rapidly with nZVI.

Abstract:The effects of Triton X-100 on the removal of aqueous phenol catalyzed by laccase were studied. 155 μM was the optimal concentration of Triton X-100 to improve phenol removal when the concentrations of phenol and laccase were 50 mg/L and 0.05 mg/mL, respectively. Laccase activity was increased with Triton X-100 at concentrations from 31 to 930 μM and the highest increase was about 17% by 930 μM Triton X-100. The removal efficiencies of phenol with 155 μM Triton X-100 were 1.2, 1.6, 3.4, 4.5 and 5.7 times of those of the control after 6 h when the initial concentrations of phenol was 50, 100, 200, 400 and 600 mg/L, respectively. The reaction of phenol removal was also characterized by using UV spectra. The results indicated that Triton X-100 had application potential for the enhancement of phenol removal catalyzed by laccase in water treatment or remediation.

Abstract:The residual correlation assumption of the CPV model was adjusted, and then, the stress scenarios generation model and the risk conduction model can be handled separately. Therefore, the partial least square method can be used to estimate the parameters of credit risk conduction model , avoiding the problem that macroeconomic factors could not be contained in the stress testing system for multicollinearity. The parameters of stress scenarios generation model were estimated through seemly unrelated regression, and Monte Carlo simulation method was used for stress scenarios generation when there exist lagged terms of macroeconomic factor in credit risk conduction model . Case analysis results show that the proposed stress testing method can be effectively applied to banking reverse cycle management.

Abstract:Based on remote sensing images and GIS data, we applied spatial expansion method and geographically weighted logistic regression (GWLR) model to explore the driving forces of urban expansion in Jiangning District of Nanjing from 1999 to 2010. Special attention was paid to spatial heterogeneity of key factors behind urban growth. The results show that 1) the spatial expansion method and GWLR model explained 57%, 64% of the urban land change of the area under study over the period from 1999 to 2010. The two methods both enhanced explanatory power in comparison with the global regression model (51%) and confirmed the spatially non-stationary process of urban growth; 2) compared with spatial expansion method, GWLR model is more effective in characterizing the spatial variations of the underlying factors of urban growth and therefore, it can be well applied to explore the mechanisms of urban expansion and policy making, as evidenced in this research; and 3) among various explanatory factors, DIS2INDU, DIS2ORD (proximity variables), DIS2CENT (neighborhood variables) and DENURBAN (policy variables) are the key driving factors of urban expansion in the area under investigation.

Abstract:In order to reduce the error in solving the effectiveness of DEA decision making units (DMU's) and to simplify the computation concerned, this paper applied the linear programming of traditional DEA models as the basis, and eliminated the non-Archimedean infinitesimal in the linear programming of traditional DEA models, which was converted into a linear programming without non-Archimedean infinitesimal, and then, further converted into a simple linear programming by introducing Poset set. At last, a numerical example was given and calculated with this new algorithm. The result reveals that this new algorithm eliminates the non-Archimedean infinitesimal and is able to reduce calculation errors. Meanwhile, the introduction of the Poset set reduces the operations of DEA models.