Advanced Materials Research Vols. 356-360

Abstract: A simulation based on Brownian dynamic for perikinetic flocculation of fine sediment under the ionization is presented. The Langevin equation is used as dynamical equation for tracking each particle making up a floc. Monte Carlo method was used for simulate random variation in particle movement. An initial condition and periodic boundary condition which conformed to reality well is used for calculation. In each cell 1000 particles of 10𝝁 m, 15𝝁m, 20𝝁m, 25𝝁m, 30𝝁m in diameter were served as primary particles. Floc growth is based on the thermal force and the electrostatic force. The electrostatic force on a particle in the simulation cell is considered as a sum of the electrostatic force from other particles in the original cell. The particles are supposed to be motion with uncharged and charged state in dispersion system. A comparison of the initial flocculent time and smashing time in sludge density 1010kg/m³, 1025 kg/m³, 1050 kg/m³, 1075 kg/m³, 1100 kg/m³ were present to show the effect of it on floc growth. The increase of sludge density deferred the flocculation rate. To study morphological shape of floc, the radius of gyration was revealed under different situations. On one hand the radius of gyration presented random variation with uncharged particle, On the other hand, the radius of gyration increases gradually with the increase of polar electrical charges on primal particle. Moreover, the morphological shape for the charged floc was more open than that of unchanged state. Finally, a series of experimental results are present, which is coincide with model well.

Abstract: This paper is concerned with a mathematical model for numerical simulation of 2D flood waves due to partial dam-break. The governing water equations are solved by an implicit bidiagonal numerical scheme, based on the MacCormack’s predictor-corrector technique. The mathematical model is used to compute 2D flood waves due to partial instantaneous symmetrical dam-break in a rectangular open channel with a rectangular cylinder barrier downstream. Results, in terms of water velocity vectors and contours of water depth, water surface, following dam-break phenomena, are investigated in the two-dimensional problems.

Abstract: Hydraulic system is the core driving power of hydraulic support, and its performance directly affects the use of hydraulic support. The content of chloride ion in hydraulic transmission medium is one of the important reasons for the working failure of hydraulic support. Nowadays our country mainly uses the simply treated mine water as fluid in the hydraulic support system. In order to ensure hydraulic support can work safely and reliably underground, this study selected two representative kinds of mine fields in Huainan coal mine area, focusing on the analysis of the various factors which influence the introduction of chloride ion in the transmission medium of hydraulic support, and exploring the solution. The experimental results showed that different crude mine water and different water treatment processes were the main factors of introducing chloride ion. The study has important guiding significance of safely using Electro-hydraulic Control System in hydraulic support and achieving high productivity and high efficiency of the fully mechanized working face.

Abstract: The annual runoff forecasting of set pair analysis (SPA) based on SPA principle that describe error distribution of prediction model from identical, discrepancy and contrary, and to describe the precision by correlation degree, Therefore the prediction model was built. According to the nonlinear and the multi-time scale character of hydrological sequence, the establishment of hydrological forecast model is not high precision, Here we apply wavelet de-noising characteristics, and use 1959-1989 years of data of Fenhe reservoir baxia station to establish wavelet de-nosing SPA model. Through contrast between the single prediction model and the synthetic prediction model of hydrological forecasting and measured series. The results show that the synthetic prediction model is superior to the single prediction model.

Abstract: A typical arid area in China is the province of Xinjiang. The objective of this paper is to present a description of a method based on the energy balance and evaporative fraction, which is obtained by broadband albedo and land surface temperature, to estimate evapotranspiration (ET) in Arid Areas. In Arid areas, the ET always fluctuates from 0 to 2mm in the most part of region in 2005, especially the Tarim, Junggar and Turpan basins. In the mountain especially Tian-shan mountain and crop land of oasis, ET values rises 6mm.

Abstract: The Fukang Station of Desert Ecology is the desert grassland ecosystem. The objective of this paper is to based on the character of latent heat flux in one day measured by eddy covariance tower site during the growing season, the fitting equations of monthly average latent heat flux of grass are obtained in the desert ecology system and the mean R2 is 0.93. It is important to the time scale extended of ET in arid areas and semi-arid areas.

Abstract: Aiming at the problem of joint optimal operation at the five hydropower plants of Three Gorges and Qing River cascades, the paper adopts three-class structure to decompose and coordinate the optimal problem, which takes the maximum system power benefit as the optimization criterion under considering the flow propagation and the variable price factor. This paper derives the iterative formula of decomposition coordination method and identifies the convergence conditions of problem. The study case of Three Gorges and Qing River cascades in different conditions shows that total output of joint optimal operation is bigger than that of cascade single operation. Three Gorges and Shuibuya with large capacity of regulation, have larger output in power systems correspondingly when inflow is the same. In addition, this method is also effective in reducing the resolving time of giant hydropower stations optimal operation and improving the operational efficiency.

Abstract: The groundwater table depths from 1982 to 1986 of 58 unconfined wells in North China Plain(NCP) were analyzed using principal component analysis method. Results showed there were mainly three hydrograph patterns over the area: increasing trend with steady moderate seasonal fluctuations in Taihang Mountain piedmont area; decreasing trend with large seasonal fluctuation magnitudes in central plain of NCP; increasing-decreasing trend with large variance of fluctuation magnitude in piedmont of Yan Mountain piedmont.The distribution of precipitation, irrigating abstraction, and water table depths were the main factors determining the hydrograph patterns and their distribution.

Abstract: The aqueous environment quality plays an important role in controlling the circulation track of ecological environment. Environmental isotopes widely exist in various kinds of water and can be extensively applied in water environment. Isotopes as natural tracers can be used to trace the transportation process of water in hydrologic cycle and the variations of isotopic value can also provide the information about the transference of contamination. The dynamical process of the movement and mix of waters can be studied by applying the composition characteristics of stable isotopes contained in natural waters, thus the main processes of water resources formation and aqueous environment evolution as well as their driving forces mechanism can be revealed. In this paper, the development history of the application of stable isotopes in the water circulation is reviewed, the application theory and analytical method of the environmental stable isotopes, and the new progress of the applied study on water resources formation and aqueous environment evolution are mainly discussed.

Abstract: Water source heat pump system(WSHPS) is a new energy saving and environmentally air conditioning system, its degree of influence to groundwater related to the feasibility of construction of WSHPS and development & protection of regional groundwater. After introducing WSHPS, this paper analyzed the influence of WSHPS to groundwater, brought up the protection method to reduce influence. At last, a case study of new campus of Taiyuan university was carried out. The results showed that running of WSHPS won’t bring up disadvantage to groundwater environment.