Advanced Materials Research Vols. 518-523

Abstract: X-ray Fluorescence was used to determine the content of 25 inorganic elements in Chengdu dust in this article, and enrichment factor was used to analyze its distribution characteristics and source apportionment. The results showed that Cr was the extremely severe pollutant, with its average concentration of 64.57μg/g, the average enrichment factor coefficient of 477.79, which was more than 10 times higher than background value, suggested it was significantly contributed by the anthropogenic sources. Ca was the heavily polluted element, with its concentration of 7.71μg/g in average, and the average enrichment factor coefficient being 12.26, which was more than 10 times of the background value, showed it was also affected by the anthropogenic sources. The enrichment factor coefficient of Na, As, Co, Cu, Mn, Ni, Pb, Se, V, Zn, K, Mg, Br, Cs was about 1 in average, illustrated that they were not obviously affected by the man-made pollution.

Abstract: Aquaculture can bring excess phosphorus to lakes which causing eutrophication. Figuring out the amount of phosphorus is meaningful to water pollution control. This study aims to clarify how much phosphorus is produced by aquaculture in Baiyangdian Lake each year. A phosphorus balance equation which is based on conservation of matter is established and used to calculate the input and output phosphorus carefully of an experimental field during a breeding cycle. Six parameters which are little fish, adult fish, feed, plants, sediment deposition and release are included in the equation. By the equation, the document gets a model: Q(x)＝0.033x, which shows that breeding every 1kg grass carp, there will be 0.033kg phosphorus into the water. As a result, the phosphorous pollution load of aquaculture in Baiyangdian Lake is 302.6 t/a.

Abstract: In order to have a comparative investigation of the pollution and speciation characteristics of heavy metals between the gold and iron mine tailings of the upstream areas of Miyun Reservoir, the tailing samples from the typical gold and iron mines were analyzed. The total metal concentration is determined by acid digestion and the chemical fractionation of metal by the Tessier sequential extraction method. It is found that compared to background values of Beijing, the heavy metal in both gold and iron mine tailings is higher, while the heavy metal in gold mine tailings is higher than that of iron mine tailings, with Mn as an exception. Mercury is the most serious pollution element in gold mine tailings. Results of the sequential extraction suggest that the exchangeable of Cd exhibits the highest percentage of total metal in gold and iron mine tailings（15% and 6.5% of the total metal, respectively) among Cd, Mn, Zn, Cu, Pb, Cr. In the majority of iron mine tailing samples collected, large amounts of Cu were mainly associated with the organic form. The percentage of the bioavailable metals in both gold and iron mine tailing samples follows the order: Cd>Mn>Zn>Cu>Pb>Cr.

Abstract: Illegal logging is a pervasive problem due to lack of effective monitoring methods. A novel wireless method for illegal logging is proposed which leverage the RSSI ranging and communication of WSN and GPRS. The node displacement incurred by tree’s falling down can be detected in time. Furthermore, failure of target node can be judged with its neighbor cooperation. The effectiveness and efficiency of this system was verified in our test-bed. Thus this solution has several characteristics such as lower power, remote, lower cost, real-time and non-intrusive，which are very appropriate to protect rare trees continuously.

Abstract: Based on the scheme of Empirical Mode Decomposition(EMD), different low pass filtering algorithms were derived from Intrinsic Mode Function (IMF), then the rules to select superior filtering algorithms were established by minimum noise energy principles and filtering flatness indicators. The superior filtering algorithms proved to be theoretically effective and reasonable. The study finally revealed the filtering algorithm without the first four IMFs was the best. Utilizing the internal waves flow field data observed in the South China Sea, the filtering effect on the waves’ velocity propagating eastward was analyzed. The results obtained using the superior filtering algorithms could depict internal solitary waves phenomenon more clearly as compared with other algorithms. It was proved that the results were practical, and filtering algorithms and effects were appropriate.

Abstract: Field runoff pools were used to collect the surface runoff samples of wheat-rice rotation in Nansi Lake region, and different forms of nitrogen (N) and phosphorus (P) data were analyzed. The average runoff concentrations, losses, and characteristic ratios of N and P were studied. The average runoff concentrations of TN and TP in wheat–rice rotation were 0.87–7.94 and 0.08–0.81, respectively. The characteristic ratios of N and P were also observed. And the characteristic ratios of NO3--N, NH4+-N, DP, and PO43--P were 45.03%, 17.55%, 71.43%, and 54.01% in wheat–rice rotation, respectively.

Abstract: Ulanbuh Desert located in the ecological environment fragile areas of the monsoon margin, which is extremely sensitive to climate change. With the support of the temperature and precipitation data of the four meteorological stations in the distribution of Ulanbuh Desert margin over the nearly 60 years data, and by using the Mann-Kendall and the Mann-Whitney test, the mutation changes has analyzed. The results show that the temperature of the study area after its significant change in 1990 has been through a obvious warming process, and the average temperature from 1990 to 2010 was more than 1 °C higher than in 1955-1989. While there was a slight increase trend in the precipitation after its significant change in 1992, and the climate condition is generally warm and dry, so temporarily the conclusion that the climate condition will change to warm and wet is impossible.

Abstract: Leak detection and calibration of pipe internal roughness in a water distribution network are significant issue for environment pollution around the world. In recent years the problem of leak detection in pipelines, tanks, and process vessels has been the focus of many man-hours of effort. Acquisition the acoustic signal around the leakage to determine the location and size of leaks is emerging as an important tool. A double acoustic data acquisition and signal processing system based on the TI digital signal processor TMS320VC5410 and analog to digital converter TLC320AD50C is presented in this paper. The system design is introduced, with emphasis on the digital signal processor minimal system and TMS320VC5410 interface circuit which consists of two chips of A/D TLC320AD50C. The software development of the data acquisition and signal analysis is introduced. The system can be used in the application of real-time acoustic signal acquisition and leak location.

Abstract: Based on the forecast products of Community Multiscale Air Quality Model (CMAQ), observational data of air pollutants and the conventional meteorological observation data of surface from January 2007 to June 2010 in Fuzhou City, Fujian Province, China, the weather systems influencing on Fuzhou City are divided into 7 weather patterns, including continental high, subtropical high, shear, warm sectors convergence, upper trough, typhoon and tropical convergence. According to the forecast method of combination of dynamic and statistic, using multiple linear stepwise regression method, the forecasting models of daily pollutant concentration under different weather systems are established. The confidence level of the equations achieves 0.000 and so the models are statistically significant. Using the models, the prediction effect of the concentration of different air pollutants in Fuzhou City from July to December, 2010 is tested by back substitution. The forecasting accuracy on contamination index level of PM10 reaches to 71.3%, and the forecasting accuracy on SO2和NO2 both reaches to 100%. The comprehensive score of air quality daily forecast in the city comes to 88.8 points on average.

Abstract: The correlative and partial correlative analysis as well as plural factors analysis of variance among Hg, Fe, Mn and organic matter in sediments of the Songhua River were conducted. Results of correlative analysis showed that Hg was positively related to Fe, Mn and organic matter. When eliminated Fe and Mn, Fe and organic matter, Mn and organic matter, respectively, results of the partial correlative analysis showed that Hg was still positively related to Fe. However, the correlations of Hg and other components disappeared. The results of variance analysis showed high contribution ratio (85.1%) of Fe to squared deviation of Hg. Therefore, Fe was the dominant factor affected Hg and its distribution.