Advanced Materials Research Vols. 989-994

Abstract: Surface-wave dispersion analysis is widely used in civil engineering to infer a shear wave velocity model of the subsoil for a wide variety of applications. Combining with a example, multi-channel analysis of surface waves method (MASW) was discussed in this paper. The entire MASW's procedure of three steps: acquiring ground roll data in the field, processing the data to determine dispersion curve, and back calculation of the geologic parameters for different depths. Based upon all the research results by far, MASW method is an efficient methods because of its high accuracy that is achieved by both special field technique and data processing technique.

Abstract: The basic mechanical properties and penetration performance of a new type of fiber concrete reinforced by UHMWPE fiber were experimental investigated. The strengths of the cube compression, splitting tensile and beam bending of this FRC with four kinds of fiber volume fraction (FVF) was researched firstly. Then, the penetration tests for the FRC with FVF of 0.8% were then conducted. The results show that the UHMWPE fiber is of excellent effects to improve the tension strength and toughness of concrete. The penetration depth and cratering area of the FRC by bullet penetration are decreased obviously compared with plain concrete which testifies the remarkable effect of this kind of fiber on enhancing penetration resistance of concrete. Last but not least, the application prospect and field of UFRC were discussed.

Abstract: Three polyvinyl chloride (PVC) columns filled with different ratios of reactive media, ceramsite and corncob, were conducted to assess the treatment performance of simulated acid mine drainage (AMD). The results indicated that the columns could effectively remove sulfate and metal ions from AMD with the removal efficiency of 57.7% and 96.5% respectively. The removal efficiency decreased with the increasing inlet velocity and at the same sample ports the sulfate and metal ions concentrations at the velocity of 1 ml/min were lower than that at the velocity of 2ml/min and 3ml/min.

Abstract: The purpose of this paper was to predict piles’ bearing capacities and end-bearing ratios. Finite-Element-Method was derived to establish the simulation models. The studying processes were firstly to set some unified pile top settlements and then to vary pile diameters to obtain the results, thus the performance of pile could be observed. It was found that closing to ultimate state, loads under the unified settlements were approximately linear to pile diameters, and equivalent unit side-friction forces were nearly constant, and the end-bearing ratios were piecewise linear to pile diameters. Based on these findings, predictive formulas were established. Following the formulas, while piles’ bearing capacities of two certain diameters and one end-bearing ratio of them were known, the bearing capacities, side-friction forces and end resistances of other concerned diameters could be predicted.

Abstract: Mu Us sandy land is an important ecological barrier in Northern China. Artemisia ordosica is the dominant species in Mu Us sandy land, the development of biological soil crust in Artemisia ordosica community seriously impediment precipitations, which result in the deterioration of soil water within 40cm, where most of Artemisia ordosica roots distribution. That led to the recession of Artemisia ordosica in the fixed sand dunes in a long time.

Abstract: Combined the problems during the promotion of ground-coupled heat pump technology with the growing of power peak load, and considering the advantages of underground storage, this paper proposes a multi-source building air conditioning system based on heat storage capacity of the soil.On the basis of energy balance, established a mathematical model of the ground heat exchanger storaging, releasing cold and stopping running. Through simulation, analysis the effects of different types of backfill material to system operation.

Abstract: ANSYS-LS/DYNA 3D finite element software projectile penetrating concrete target three-dimensional numerical simulation , has been the target characteristics and destroy ballistic missile trajectory , velocity and acceleration and analyze penetration and the time between relationship , compared with the test results , the phenomenon is consistent with the simulation results. The results show that : the destruction process finite element software can better demonstrate concrete tests revealed the phenomenon can not be observed , estimated penetration depth and direction of the oblique penetration missile deflection .

Abstract: Based on the wind tunnel experiment for aerostatic force of section model of Jianghai direct ship channel bridge of Hongkong-zhuhai-macau great bridge in its finished stage, one calculation program considering the geometric nonlinearity and aerostatic nonlinearity is prepared by using ANSYS parametric design language in order to calculate the nonlinear aerostatic response for long-span cable-stay bridges. Then, the FEA model of Jianghai direct ship channel bridge of Hongkong-zhuhai-macau great bridge in its finished stage is established to analyze the three-dimensional nonlinear aerostatic stability. And the aerostatic response with different position of bridge is also calculated. The research result indicates that the aerostatic instability can not occur in Jianghai direct ship channel bridge of Hongkong-zhuhai-macau great bridge in its finished stage. And, the max torsion deformation, transverse and vertical displacements of finished stage occur in the mid-span of each span and decrease gradually near to both sides.

Abstract: A selective method was developed for the determination of norfloxacin lactate by Spectrophotometric method. The method was simple with high sensitivity and selectivity.It was shown that recovery of the method by standard addition method was respectively valued 102.05% for norfloxacin lactate

Abstract: Metabolic engineering of Corynebacterium glutamicum has sought to divert carbon into L-isoleucine. However, the fermentation period of this strain is long. The C. glutamicum YILW strain (Leu^L, AHV^r, SG^r, Leu-ME^r) was previously derived by repeated compound mutagenesis which could accumulate 20.2 g/L L-isoleucine in a 5-L jar fermentor. Overexpression of the threonine dehydratase gene (ilvA) from Corynebacterium glutamicum YILW and coexpression of threonine dehydratase and acetolactate synthase (ilvBN) from it were employed to divert carbon flux toward L-isoleucine. The strain E. coli TRFC with the expression of ilvA could accumulate L-isoleucine of 6.8 g/L without accumulation of any L-threonine by fed-batch fermentation in a 5-L jar fermentor. However, the production of L-isoleucine by the strain E. coli TRFC with the co-expression of ilvA and ilvBN was decreased by 19.1%, and the production of L-valine was increased by 40% compared with that of E. coli TRFC with the expression of ilvA.