[Identifying sources of nitrate in surface water of Jiulong River Watershed].

Two representative catchments, Wuchuang catchment and Xiandu catchment, were selected from Jiulong River Watershed as study areas to trace sources of nitrate in surface water by using 15N isotope technique. In the spring of 2005, the surface water samples were twice collected from the catchments and determined for dissolved total nitrogen (DTN), nitrate nitrogen (NO3(-)-N), ammonia nitrogen (NH4+-N) and delta 15N value of nitrate. The results showed that in the samples from Xiandu catchment, the concentration ranges of DTN, NO3(-)-N and NH4+-N were 1.

[Wet deposition of atmospheric nitrogen in Jiulong River Watershed].

Spatio-temporal distributions and sources of atmospheric nitrogen (N) in precipitation were examined for Jiulong River Watershed (JRW), an agricultural-dominated watershed located in southeastern China with a drainage area of 1.47 x 10(4) km2. During 2004-2005, 847 rain samples were collected in seventeen sites and analyzed for ammonium N, nitrate N and dissolved total N (DTN) followed by filtration through 0.

[The analysis and comparison of different edge detection algorithms in ultrasound B-scan images].

In this paper, some familiar algorithms of edge detection in ultrasound B-scan images are analyzed and studied. The results show that Sobel, Prewitt and Laplacian operators are sensitive to noise, Hough transform adapts to the whole detection, while LoG algorithm's average is zero and it couldn't change the whole dynamic area. Accordingly LoG algorithm is preferable.

[Modelling pollutant loads and management alternatives in Jiulong River watershed with AnnAGNPS].

The modelling package Annualized Agricultural Nonpoint Source Model (AnnAGNPS) was used to predict pollutant loads, and simulate catchment processes and management practices in Jiulong River watershed, a medium-sized mountainous watershed in southeast of China. Four typical sub-watersheds were primarily chosen to calibrate AnnAGNPS model by data collected from storm events during the period of April to September, 2003. The model was further validated in the two biggest branches of Jiulong River watershed, i.

Heavy metals in surface sediments from Minjiang Estuary-Mazu and Xiamen-Jinmen Sea areas.

The concentrations of Cu, Pb, Zn and Cd in surface sediments from Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas of China were investigated during 1995-1996. The concentration ranges of Cu, Pb, Zn and Cd in the Minjiang Estuary-Mazu sea area were 16.4-37.