Alnus cremastogyne, a broad-leaved tree endemic to south-western China, has both commercial and restoration importance. However, little is known of its morphological, physiological and biochemical responses to drought and phosphorous (P) application. A randomized experimental design was used to investigate how drought affected A. cremastogyne seedlings, and the role that P applications play in these responses. Drought had significant negative effects on A. cremastogyne growth and metabolism, as revealed by reduced biomass (leaf, shoot and root), leaf area, stem diameter, plant height, photosynthetic rate, leaf relative water content, and photosynthetic pigments, and a weakened antioxidative defence mechanism and high lipid peroxidation level. However, the reduced leaf area and enhanced osmolyte (proline and soluble sugars) accumulation suggests drought avoidance and tolerance strategies in this tree. Applying P significantly improved the leaf relative water content and photosynthetic rate of drought-stressed seedlings, which may reflect increased anti-oxidative enzyme (superoxide dismutase, catalase and peroxidase) activities, osmolyte accumulation, soluble proteins, and decreased lipid peroxidation levels. However, P had only a slight or negligible effect on the well-watered plants. A. cremastogyne is sensitive to drought stress, but P facilitates and improves its metabolism primarily via biochemical and physiological rather than morphological adjustments, regardless of water availability.

A combined amphiphilic catalyst of octadecyltrimethylammonium bromide (STAB) and phosphotungstic acid was formed directly in a reaction system. Deep desulfurization of dibenzothiophene (DBT) with high selectivity was achieved using the combined amphiphilic catalyst with hydrogen peroxide (H2O2) as the oxidant at 50 °C under atmospheric pressure. The optimum molar ratio between STAB and phosphotungstic acid in DBT oxidation has been determined, and the highest reaction rate was obtained when the molar ratio between STAB and phosphotungstic acid approached 1, not 3 as has been reported in some literature, whereas superfluous STAB beyond this ratio caused resistance for mass transfer of products and reagents at the interface. The influence of reaction temperature, catalyst concentration, H2O2/DBT ratio, and mixing conditions on the oxidation of DBT was examined in detail. An increase in the reaction temperature from 40 °C to 70 °C led to a remarkable increase in the reaction rate. A complete DBT conversion with a DBT concentration of 3000 ppm could be shortened to 10 min as the temperature was elevated to 70 °C. The reaction rate of DBT was improved when the H2O2/DBT ratio was increased. Complete sulfur removal from a 3000 ppm dibenzothiophene mixture was achieved within 20 min at 50 °C. This oxidation process showed high selectivity toward DBT, and the enhancement of DBT oxidation was illustrated when investigated in the presence of 2-methylnaphthalene.