Advanced Materials Research Vols. 113-116

Abstract: On the basis of introducing the latest research status of processing methods of waste printed circuit boards, the physical mechanism of eddy current separation was explained, and the component configuration of eddy current separator was described. A series of single-factor and orthogonal experiments were carried out to prove the separation effect of multiple metals with eddy current separator. The result indicates that the separation efficiency of above 92.0% and concentrate grade of above 95.0% can be obtained in the recycling of aluminum and brass with the delivery rate of 20~40%, rotate speed of rotor of 5~15Hz and belt speed of 7~9Hz.

Abstract: In order to understand the influence mechanism of dust events on PM10 pollution, the characteristics of atmospheric boundary-layer structure and turbulent flux transport during different kinds of dust events in Lanzhou and their relation with PM10 pollution were analyzed by using the data of PM10 concentration, gradient measurements of meteorological tower and turbulent flux measurements observed at SACOL. As dust events break out, the strong inversion in the boundary layer breaks and a mixing layer develops quickly. With the rise of wind speed, PM10 concentration increases sharply. If there is obvious dust transport from upstream regions, the peak of PM10 concentration can lag behind the peak of wind speed. The vertical transport of momentum flux is very strong. The turbulent momentum downward transport, especially the downward momentum flux of meridional velocity, is the main factor which causes the dust blowing and the heavy PM10 pollution during dust events.

Abstract: We study the delayed risk model with random premium income. The premium process is not a linear function of time in contrast with the classical model, but a Poisson process which is also independent of the claim process. We shall consider the case where the discount interest process is no longer a constant in comparison with the classical expected discounted penalty function, but a stochastic interest driven by Poisson process and Wiener process. The expected discounted penalty function in the delayed renewal model is expressed in terms of the corresponding Gerber-Shiu function in the ordinary renewal model. The obtained results can be viewed as the discrete analogy of the classical Sparre-Anderson risk model.

Abstract: Magnesium oxychloride cement sawdust concrete box caused great harm to the environment. This article introduced the method to recycle the box. Magnesium oxychloride cement sawdust concrete was gradually heated, in the range of 0 ~ 800°C, and then the residue was calcined at 700 ° C. Studies showed that the 5•1•8 and sawdust in the box was decomposed into MgO in high temperature conditions. The X-ray diffraction examination results showed that the content of this MgO reached 90%. The application the MgO is very wide.

Abstract: In this paper, we apply support vector regression (SVR) for daily discharge forecasting and compare its results to other prediction methods using real daily discharge data. Since support vector machines have greater generalization ability and guarantee global minima for given training data, it is believed that support vector regression will perform well for time series analysis. Compared to other predictors, our results show that the SVR predictor can reduce significantly both relative mean errors and root mean squared errors of predicted daily discharge.

Abstract: Nonpoint source pollution, especially agriculture nonpoint source pollution is the major reason resulting in eutrophication in many receiving water bodies. At first, agriculture nonpoint source pollution and the harm pollutants bring is analyzed. Then around the questions about how the nonpoint source pollutants export from the soil and how much pollutant import into the receiving water, my study provide an overview of the progress of research on pollution forming mechanism, pollutants leaching from soil and pollutants migrating with streamflow into water body, and briefly summarizes the history of nonpoint source load estimation include model developing and application, and introduce the SWAT model which will be applied in my study. At last, I look forward to some important research direction in pollution mechanism and load estimation.

Abstract: Oil-contaminated pillars were prepared by spilling oil on soils’ surface. The weight loss of oil was determined by subtracting the pillars’ pre and post weight measured on an electronic balance. The aim of this paper was to investigate the change of oil’s volatilization mass in soils with time. The results show that the gasoline in soils volatilizes at a logarithmic rate with respect to time, and the diesel oil in soils volatilizes at a rate which can be best modelled as a linear of time. The volatilization coefficient of gasoline in grit exceeds that in loam, while the volatilization coefficient of diesel oil in loam is from 2.0 to 2.5 times higher than that in grit. Oils’ volatilization coefficients increase with the increase of oil content. Linear equation and binomial equation describe the relationships of gasoline’s and diesel oil’s volatilization coefficients with oil content respectively.

Abstract: The IFT has been investigated for an interfacially reactive immiscible system composed of oil and water. Ring tensiometry was employed to measure the IFT between the two phases. The results show that the IFT decreases at a linear rate with respect to temperature and the binomial equation can express the reducing trend of the IFT with contact time. The oil-water IFT presents a reduction at both high and low pH. The IFT of diesel engine oil-water and diesel oil-water reach lowest values under acidic and alkaline condition respectively. The IFT of diesel oil-water decreases by 19.2% and the IFT of diesel engine oil-water descends by 11.2% when the concentration of calcium chloride in aqueous solution is 0.2mol/L.

Abstract: A semi-works production method which the extraction and isolation of 7S and 11S was improved. The method of isoelectric point and cooling precipitation was developed for extraction and isolation of 7S and 11S fractions from low-temperature defatted soybean draff, based on the indices of the extraction yield which was determined by the Kjeldahl method and purity which was determined by SDS-PAGE. Compared the optimum parameters of five kinds of extraction methods that phosphate buffer’s effect is better than others, its extraction yield is 89.55%. The optimal isolation parameters of 7S are as follows: pH 4.7, sedimentation time 1h, the stirring rate of acid 40r/min, its purity and yield are 73.25% and 50.6% respectively. The optimal isolation parameters of 11S are as follows: pH 6.2, cooling precipitation 12h, temperature 4°C, the stirring rate of acid 30r/min, its purity and yield were 76.37% and 41.2% respectively. With the improvements, the extraction yield of 11S and 7S fractions were significantly increased. They may be widely used as a source of highly functional soybean protein in more food products.

Abstract: In this paper, a kind of imidazolium ionic liquid, 1-butyl-3-methyl imidazolium chloride ( [BMIM]Cl) was synthesized, and the chemical structures of the ionic liquids were characterizaed by FT-IR and NMR. The solubilities of the ionic liquid for duabanga grandiflora powder activated with different modified conditions were studied respectively. Dissolution rate of wood pretreated with about 25% NaOH solution was the best , due to the reduction of the hydrogen bond applied force. The chemical structure and crystal behavior of duabanga grandiflorar powder before and after dissolution were analyzed by FT-IR and XRD, respectively. The dissolution mechanism has also been discussed. The results showed that the ionic liquids had a good solubility for cellulose in activated duabanga grandiflorar powder. Micrographs of the original wood powder，regenerated wood powder and the residua were quite different from each others. The regenerated wood appeared some micro voids special construction.