A two-year field experiment was conducted to illustrate the effects of sowing date on cottonseed properties at different fruiting-branch positions (FBPs).  Two cotton cultivars (Kemian 1 and Sumian 15) were sowed on 25 April, 25 May, and 10 June in 2010 and 2011, respectively.  The boll maturation period increased with the delaying of sowing date.  Normal sowing treatment (25 April) had higher seed weight, embryo weight, embryo oil content and protein content than late sowing treatments (25 May and 10 June).  The flowering date, seed weight, embryo weight, embryo oil and protein contents, and the dynamic changes of embryo oil and protein contents were altered by different FBPs.  A significant interaction of sowing date×FBP was observed on embryo weight, embryo oil content, embryo protein content and the dynamic changes of embryo oil and protein contents, but was not observed on seed weight.  Seed weight, embryo weight, embryo oil and protein content had significant positive correlations with the mean daily temperature (MDT), mean daily maximum temperature (MDT_max), mean daily minimum temperature (MDT_min), and mean daily solar radiation (MDSR), indicating that temperature and light resources were the main reasons for different sowing dates affecting the cottonseed properties at different FBPs.  Moreover, the difference in MDT was the main difference in climatic factors among different sowing dates.

    A fluorescent competitive assay for melamine was first developed utilizing dummy molecularly imprinted polymers (DMIPs) as artificial antibodies. This method is based on the competition between fluorescent substances and the unlabeled analyte for binding sites in synthesized DMIPs and the decreased binding of fluorescent substances to DMIPs due to increased concentrations of melamine in the solutions. DMIPs for melamine were synthesized under a hot water bath in the presence of the initiator azobisisobutyronitrile (AIBN) using 2,4-diamino-6-methyl-1,3,5-triazine (DAMT) as a dummy template, methacrylic acid (MAA) as a functional monomer, and ethylene glycol dimethacrylate (EGDMA) as a crosslinking agent. The adsorption capacity and selectivity of DMIPs for melamine were evaluated by the isothermal adsorption curve and Scatchard analysis. The evaluation results showed that the synthesized DMIPs had specific recognition sites for melamine and the maximum adsorption amount was 1 066.33 μg g^–1. Later, 5-(4,6-dichlorotriazinyl) amino fluorescein (DTAF) with a triazine ring, which slightly resembles melamine, was selected as the fluorescent substance. The fluorescent competitive assay using DMIPs as the antibody mimics was finally established by selecting and optimizing the reaction solvents, DMIPs amount, DTAF concentration, and incubation time. The optimal detection system showed a linear response within range of 0.05–40 mg L^–1 and the limit of detection (LOD) was 1.23 μg L^–1. It was successfully applied to the detection of melamine in spiked milk samples with satisfactory recoveries (71.9 to 86.3%). According to the comparative analysis, the result of optimized fluorescent competitive assay revealed excellent agreement with the HPLC-MS/MS result for melamine.