Advanced Materials Research Vols. 347-353

Abstract: Unsymmetrical dimethylhydrazine (UDMH) is a kind of cheap propellant for rocket luanching. But it is harmful to environment and human body. At present, the majority of UDMH eliminating agents are unsafe and inconvenient for use because of strong oxidizing property. The eliminating effects of vitamin B6, vitamin C and glacial acetic acid on UDMH are studied. 1mg vitamin B6 , 1mg vitamin C and 1mg glacial acetic acid is added into 10.00ml UDMH solution (1μg/ml) respectively, UDMH content is determined respectively in 30 minutes and 60 minutes through amino sodium ferrocyanide (TPF) spectrophotometry method at wavelength 500nm. The results show that vitamin B6 can eliminate 88% UDMH in 30 minutes. Vitamin C or acetic acid has no significant removal effect on UDMH. The chemical mechanism of vitamin B6 eliminating UDMH is that pyridoxal and pyridoxal 5 – phosphate monohydrate (PLP) can react with UDMH and generate hydrazone and water.

Abstract: Based on the measurement of the vertical velocity of ground surface vibration caused by CRH trains running on viaduct and embankment of Hu-Ning Intercity Railway, the characteristics and propagation attenuation rules of the ground surface vibration of two routes are analyzed. The result shows that the main frequency of ground surface vibration caused by the CRH trains running is less than 80Hz, which belongs to low frequency vibration. The number of carriages has little effect on ground surface vibration intensity. The effect of train speed for 153km/h to 201km/h on ground surface vibration intensity has no obvious difference. With the increased distance between the ground surface and the track, the main frequency of ground surface vibration on viaduct decreases, and the attenuation curve of peak value of ground surface vibration velocity becomes smoother. However, the main frequency of ground surface vibration on embankment is nearly unchanged and the attenuation curve of peak value of ground surface vibration velocity has several rebound regions of the vibration. Ground surface vibration intensity of viaduct is higher than that of embankment. The drainage trench built beside the embankment has vibration isolation effect on ground surface vibration.

Abstract: Lactic acid which was fermented by bean sprout was determined and the lactobacillus in bean sprout was identified by High-performance Liquid Chromatoraphy(HPLC). The optimal HPLC chromatographic conditions were determined as follows:Agilent XDB-C18 chromatography column with UV detection at 210nm.The mobile phase was Phosphate buffer solution（pH=2.3）:methanol:acetonitrile（95%:2%:3%）.The flow rate was 0.5ml/min.This method is accurate,Speedily and reproducible. This method can identify the lactobacillus, and gives a qualitative and quantitative analysis of the lactic acid which was the metabolites of Yibin bean sprout.

Abstract: Net energy (NE) output, external cost to society of emissions, total production costs, and the renewability of a fuel are four critical factors that should be taken into account while developing sustainable energy resource systems. For this purpose, a new indicator, CNERλ,(Cost of Net Energy taking into account the Renewability) is proposed in this paper. The mixture of 85% ethanol (derived from corn) and 15% gasoline by volume (E85) and conventional gasoline (CG) are selected as assessing cases for illustrating the application of the new indicator. The CNERλ of E85 is 0.885, i.e. 12.5% lower than that of CG. It is shown that E85 is a more sustainable option comparing with CG by using the novel assessment indicator.

Abstract: Based on the volume average method, gas-liquid two-phase flow CFD model is established to describe the random packing column in seawater desulfurization. The fluid velocity and porosity distribution were obtained by calculation. Based on the experimental research with three different filler, the dry and wet loss curves which describes gas flow with in each packed bed are obtained, calculations results of pressure loss and experimental results are well consistent. Analyzing the seawater velocity vector in packed columns and velocity profile of the section on the middle of the packed tower, a significant “wall flow” phenomena was found. There is an accumulation trend near the wall along the direction of the liquid flow, and the wall flow becomes much more serious. As can be seen from the chart that the porosity distribution on the radial direction near the wall is significantly higher than it is at the middle area, which is the reason for the formation of wall flow.

Abstract: A pilot-scale experimental system of filling gasoline into a tank was built to investigate gasoline vapor-air mass transfer in the tank gas space and the vapor evaporation loss from the tank in different operating conditions. The results showed that the higher the location of filling pipe exit inside the tank, the quicker the speed of the filling gasoline, and the higher the initial vapor concentration in the tank gas space, then the more severe the vapor-air convective transport and the larger the gasoline evaporation loss rates.

Abstract: A composite three-dimensional mathematical model of proton exchange membrane fuel cell is proposed, the corresponding finite element method and numerical simulation are given as well, where fluid flow, proton transport, and electrochemical reaction are addressed. Some factors that probably affect the performance of the cell are analyzed by using the model. The computational results show that the reactant concentration decreases along the flow direction, the water concentration increases in the cathode side of membrane, membrane resistance decreases, conductivity increases and proton concentration increases. The fuel cell performance is better when the porosity increases, as well as the operating pressure.

Abstract: Fracture as the main seepage channels influence the deployment of well patterns and development effects in many kinds of reservoirs because of its strong permeability anisotropy. In this paper, we describe the fracture characterization of fractured reservoir with geometry parameters and establish the analytical models of full anisotropic permeability tensor by using the parallel plate model and tensor theory. Research shows that fracture aperture and density are the mainly two factors that have big impacts on equivalent fracture permeability and its anisotropy. The changes of fracture aperture, fracture density, fracture opening or closure not only alter the magnitude of fracture permeability, but also change the directions of the principal permeability of fractures.

Abstract: A novel counter electrode has been fabricated at low temperature using nanoporous carbon (NC) with about 35 nm pore size as based catalysis materials and silver conductor paste (SCP) as connecting adhesive. The efficiency of dye-sensitized solar cells (DSCs) employing this SCP/NC electrode reaches to 5.91%, which is 15% higher than that of DSCs with NC electrode. The improved efficiency is attributed to the enhancement in the fill factor and the short circuit photocurrent density. Electrochemical impedance spectroscopy reveals that all of charge transfer resistance, ohmic serial resistance and Nernst diffusion impedance of SCP/NC electrode decrease compared with NC electrode. Especially, the efficiency of 5.91% is comparable to that of DSCs with Pt electrode.

Abstract: In this paper, the current problems existing in the water supply system are analyzed, puts forward the constant pressure water supply system based on PLC& frequency converter, Introduces the composition structure, system function, working principle and safety measures. The fact proves that the way of water supply is stable, reliable and save energy.