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A two-year field experiment using maize hybrid Yidan 629 with nitrogen (N) application and film mulching was conducted in Wuxue, Hubei Province, during 2012-2013 growing season to study the characteristics of yield performance parameters and N use efficiency of spring maize in the Middle Reaches of Yangtze River. The results showed that film mulching could make an earlier seed germination times of 7-8 d, N application and film mulching could promote the vegetative growth of spring maize, the tasseling stage and silking stage were advanced 8-12 d and 6-11 d, respectively, the maturity stage advanced 2-7 d and the physilogical maturity stage advanced 3-6 d. Compared with the control, the yield performance parameters of spring maize such asmean leaf area index (MLAI), mean net assimilation rate (MNAR), harvest index (HI), grain number per ear (GN) and 1000-kernels weight (GW) increased by 81.18%-112.38%, 19.20%-25.82%, 72.61%-95.30%, and 13.09%-21.26% in N application treatment, and increase 11.12%-17.12%, 0.80%-10.66%, 0.44%-6.50%, 7.02%-16.07%, and 5.64%-7.93% in film mulching treatment. With the super compensative effect of yield performance parameters, the grain yield of spring maize increased by 6.80%-24.66% and 7.16%-22.19%, respectively, resulting from N application and film mulching. The N use efficiency was significantly reduced with increasing N application, the partial factor productivity (PFPN) and nitrogen agronomic efficiency (ANUE) were decreased 31.34%-51.20% and 30.39%-42.12%. Film mulching enhanced N absorbing ability of spring maize, and increased PFPN and ANUE 18.30%-31.67% and 25.83%-56.80%, respectively. Comprehensive considering the super compensative effect of yield performance parameters and the characteristics of N use efficiency, achieving high yield of 8995-9220 kg ha -1 in spring maize needs the N application of 202.5-270 kg ha -1 with film mulching in the Middle Reaches of Yangtze River.

Aromatic amines (AAs) are common chemical pollutants and banned ingredients in cosmetics. In this study, a rapid, simple and stable method for the detection of nine AAs in cosmetics was established based on the optimization of cation exchange solid-phase extraction and liquid chromatography tandem mass spectrometry. The method displayed good linearity within a range of 2-1,000 µg/kg, with limits of quantitation at the level of µg/kg for cosmetic samples. The recoveries obtained for all analyzed amines ranged between 83.6 and 97.8%, and the repeatability (r) and reproducibility (R) values indicated that all nine AAs showed good precision (r ≤ 4.5% and R ≤ 7.7%). The method was applied for the detection of 36 cosmetic samples. It was found that the primary pollutants of AAs were 3, 3'-dichlorobenzidine and 4-aminoazobenzene. The total amine concentration in cosmetic samples ranged from 880 to 5,200 µg/kg. The proposed method is applicable for the analysis of most cosmetic samples.

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