Two nonlinear optical (NLO) crystals based on the 3-phenyl-5-isoxazolone moiety, (Z)-4-(4-(dimethylamino)benzylidene)-3-phenylisoxazol-5(4H)-one (C₁₈H₁₆N₂O₂, DLS) and (Z)-4-(4-methoxybenzylidene)-3-phenylisoxazol-5(4H)-one (C₁₇H₁₃NO₃, MLS), have been successfully grown by a slow evaporation method. The powder second-harmonic generation intensities of DLS and MLS are strong, about 2.8 and 1.5 times that of OH1, respectively. Such a large SHG effect is further elucidated by structure analyses and theoretical calculations. The optical and thermal properties of DLS and MLS have been characterized by UV-vis absorption spectroscopy, IR spectroscopy, thermal gravimetric analysis and differential scanning calorimetry.

Triclosan has been widely used as addition ingredient in personal care and medical antibacterial products, and the increasing amounts of triclosan discharged in aquatic environments pose a potential risk to aquatic ecological systems. In this study, we investigated the effects of exposure to varying triclosan concentrations on the growth, chlorophyll fluorescence and antioxidant enzyme activity of Chlorella vulgaris. The results showed that low-concentration triclosan (<0.75 mg/L) can stimulate the growth of Chlorella vulgaris, whereas 1.05 mg/L triclosan exhibited significant inhibition. Low-concentration triclosan (<0.75 mg/L) could improve the tolerance and utilization ability of Chlorella vulgaris in relation to strong light. We observed a significant increase in the malondialdehyde content of Chlorella vulgaris exposed to 1.05 mg/L triclosan. The intracellular superoxide dismutase and catalase (CAT) activities of Chlorella vulgaris exposed to triclosan were higher than the control groups, and the increase in this activity was positively correlated with the concentration of triclosan. The results also showed that excessive H₂O₂ may in turn damage the CAT structure and eventually inactivate CAT activity when Chlorella vulgaris is exposed to 1.05 mg/L triclosan. This study provided a theoretical basis which can be used to evaluate the ecological risk of triclosan in the aquatic environment.