[Comparative study on HPLC fingerprints between crude and processed Ligustri Lucidi Fructus].

To establish high performance liquid chromatography(HPLC) fingerprints for crude and processed Ligustri Lucidi Fructus,and to evaluate their quality through the similarity calculation and chemical pattern recognition. The separation was performed with Syncronis C_(18) column(4.6 mm × 250 mm, 5 μm), with acetonitrile(A) and 0.

Responses of soil nutrients and biological characteristics to nitrogen deposition in Hulun Buir Grassland, China.

Studies on effects of nitrogen deposition were mainly focused on temperate grasslands in Inner Mongolia of China. In addition, there are substantial differences between the present simulation methods and the natural nitrogen deposition. A three-year experiment was carried out to compare the effects of simulation methods (common urea and slow-released urea) and nitrogen deposition rates (0, 25, 50, 75, 100, 150, 200 and 300 kg N·hm·a) on soil nutrients and biological characteristics in Hulun Buir Grassland.

[Effects of carbon and nitrogen additions on soil organic C, N, P contents and their catalyzed enzyme activities in a grassland.].

Soil organic C, N, P contents and their catalyzed enzyme activities play an important role in maintaining and supplying energy and nutrient in grasslands. There is no consensus on the effects of N deposition on soil organic nutrients and enzyme activities in grassland ecosystems. It remains unclear whether C addition will retard the negative effects of N deposition.