Advanced Materials Research Vols. 347-353

Abstract: The Time Series method and Statistical Process Control strategy is applied to predict failures of wind turbine gearboxes. First, based on the real-time temperature data of gearboxes measured by temperature sensors, the temperature prediction model under normal operating conditions is established by ARIMA model. The analysis of the predicted values and the actual values of gearbox temperature is done, and proves that its residuals are normally distributed; then combined with statistical process control (SPC) methods, the big number of temperature data is used to calculate the standard deviation(σ) of residuals, and the gearbox failure threshold will be identified; Finally, the temperature data are analyzed both in normal operating condition and the failure condition to determine the operation status of the gearbox, statistical analysis and residual charts are carried out for gearbox failure prediction, verifying the feasibility and effectiveness of the proposed method.

Abstract: The domestic and foreign evaluations of ecosystem service value are difficult to draw on results accepted by the public and academia. This reflects the research methods are still not mature, need to continue to be improved. In this paper, an attempt has been made to give urban unit value of ecosystem services and set up the values per unit area in southwestern Guizhou of China, in accordance with unit value of global ecosystem services developed by Costanza, et al., Chinese one by Xie, et al. and the actual situation of karst region. The analysis revealed that in the study area, the total ecosystem service value is $1.876×109 in 2006, equivalent to 104.3% of 2006 GDP (Gross Domestic Product), $1.799×109（1US$=7.8136，2006）. If the rocks change into forest in the study area, ecosystem service value will add $0.221×109, equivalent to 12.28% of GDP in 2006. Therefore, we conclude that the ecosystem services value is higher, compared to the local economy. In addition, the rocky desertification area is larger, and has already seriously influenced ecosystem service function. The tasks of ecological environment protection, propaganda and education in this region are of great significance.

Abstract: In this paper, the effects of operating parameters such as UV light wavelength, initial pH, reaction temperature and hydrogen peroxide concentration on decolorization of metal complex dyes (Neutral Bordeaux GRL, Neutral Pink BL and Neutral Blue BNL) by UV/H₂O₂ process were studied in detail. The results showed that the decolorization rate constants were obviously enhanced with the increase of UV intensity. In UV (254nm)/H₂O₂ system, 94.4% decolorization of Neutral Bordeaux GRL, 99.2% decolorization of Neutral Pink BL and 65.4% decolorization of Neutral Blue BNL were achieved after 60 min reaction. The results also indicated that both suitable amount of H₂O₂ and initial pH were needed for effective decolorization of different metal complex dyes. The reaction activation energy of Neutral Bordeaux GRL, Neutral Pink BL and Neutral Blue BNL were 3.43, 14.4 and 23.39 KJ mol^-1, respectively.

Abstract: A kind of novel airfoil sail is proposed in this paper based on the research of traditional arc wing sails. The aerodynamic characteristic- the lift coefficient and drag coefficient is numerically calculated with FLUENT 6.0 and the results are verified by wind tunnel test. It is proved that the aerodynamic characteristic of the novel sail is much better than the arc wing sail.

Abstract: The dissipation dynamics and final residues of fluopyram in cucumber and soil were studied. Cucumber and soil samples were extracted with acetonitrile, cleaned up by PSA, determined by gas chromatography with electron capture detection. The LOQ of this method was found 0.003 mg/kg. The results of residual dynamics experiment showed that the half-lives of fluopyram in cucumber and soil were 3.7-4.3 days and 5.8-6.2 days, respectively. Residues of fluopyram in cucumber were all below 0.5mg/kg at both recommended high dosage and 1.5 times of recommended high dosage.

Abstract: Load fluctuation of wind turbine under tower shadow was researched，introducing individual pitch control. First，establish the linear time-varying model of the rotor，make it into the linear time invariant model through Coleman transformation. Then，based on this model，achieving the design of individual pitch system with PID controller. Comparing the loads of wind turbine under tower shadow between individual pitch control and collective pitch control and analysing the fatigue damage of wind turbine through rainflow cycle counting.The result shows that load fluctuation of wind turbine using the individual pitch control under tower shadow has better effect and reduces the effect of tower shadow，extend the working life of wind turbine.

Abstract: The research treats the lakes of the Guangzhou Higher Education Mega Center(HEMC) as the main research objects. According to the relationship of the lakes and university city drainage system,lakes are the accepter of rain and sewage.In fact, the lakes of HEMC can be divided into five categories,our researches choose the natural pond,ornamental pond , the oxidation pond as the main bodies of researches，which have a great impact on environment and people. The lakes of HEMC are not a source of drinking water. We select the phosphorus, nitrogen, COD, Fe, Mn, and ctc. as the main indexs of water quality assessment. The results of the typical sampling points are under the surface water environment quality standard for level Ⅴ. The main pollutants are TN and TP. According to the situation of the lakes, putting forward views to improve the water quality.

Abstract: With the intermittent and randomness of wind power,the power system needs to arrange certain spinning reserve capacity in response to wind power fluctuations,so the optimal allocation of spinning reserve problem is the key point. This paper first analyzes the potential problems of optimal allocation of spinning reserve by the principle of equal proportion in wind power system; then calculate the optimal power flow which aims to minimize the network loss with the original dual interior point method, of which all thermal power’s active power outputs are optimized objects. You can watch the total network loss and the thermal power’s spinning reserve in the optimal power flow calculation results.Finally the IEEE39 system example and the comparison of two methods demonstrate that the principle of equal proportion exists potential problems and it is necessary to calculate the optimal power flow.

Abstract: As the influenced factors on the maximum power injection plays an important role in synchronization of wind power, this paper is based on MATLAB/Simulink what used it to constructed a model,then it analyse the influence factors of the power injection of the synchronization of wind power and adopt corresponding measures to improve efficiencies.

Abstract: CO₂ storage in coal seam is the important way of reducing CO₂ emission into atmosphere and enhancing coal-bed methane (CBM) recovery. This paper based upon the results of CO₂ storage in coal seam in theoretical research and demonstration project, analyzed the mechanism of CO₂ storage in coal seam, and recognized that the process is a complex process from a single physical process to physical, chemical, and microbial effect process. The paper also summarized the fluid-solid coupling actions between H₂O-CO₂ and minerals in coal seam and its effect on coal reservoir characteristics. It is considered that after H₂O-CO₂ action, the components of coal petrography changed. At the same time, there has been marked change in coal physical properties: the porosity enhanced, mechanics property reduced, and the changed of adsorptivity and permeability need further researches. This paper can guide the prediction storage ability and assessment the safety of CO₂ in coal seam.