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Superhydrophobic and superhydrophilic cotton fabric was successfully fabricated by immersing commercial cotton fabric in F-POSS star polymer solutions. Herein, the well-defined fluoropolymer was firstly synthesized by EY catalyzed PET-RAFT polymerization. And then, the F-POSS star polymer was prepared by thiol–ene click chemistry. The roughness increased with the concentration of F-POSS solution. When the concentration became 15 mg/ml, the water contact angle reached 152o, indicating the as-prepared cotton fabric present superhydrophobic. The oil/water separation performances were verified by selective adsorption, batch and continuous oil/water separations. Even after ten recycles, the separation efficiency and flux maintained over 96% and 65000 L/(m2·h), respectively. [ABSTRACT FROM AUTHOR]

The contamination of persistent organic pollutants (POPs), including dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), and polycyclic aromatic hydrocarbon (PAH), is the most studied environmental issue. In 2020, a total of sixty soil samples collected from ten locations in Guiyang were analyzed to assess the presence of four DDTs and HCHs and sixteen PAHs. The concentrations of total DDTs, total HCHs and Σ16PAHs in the soil were between 0.26 and 12.76, 0.23 and 51.80 μg/kg, and 10.02 and 1708.86 μg/kg, respectively. The mean and median concentrations of total DDTs, total HCHs and Σ16PAHs in the soil were 1.04 and 0.26 μg/kg, 4.32 and 0.23 μg/kg, 139.14 and 98.98 μg/kg, respectively. p,p′-DDT, p,p′-DDD and γ-HCH the dominant organochloride pollutants in the soil, while 4-ring PAHs were the dominant PAHs, occupying 41.1–53.6% of the total PAHs in the soil. The highest levels of PAHs in the soil were observed in areas of Guiyang with relatively larger population densities and more developed heave industries. Various diagnostic tools were used to identify the potential sources of the POPs in the soil. The data indicated that DDTs and HCHs were from past and recent common inputs and that mixtures of several combustion activities (biomass, coal and petroleum combustion, diesel, gasoline, and vehicular emissions) were the major sources of PAHs in the Guiyang soil. The results provide information for the assessment of the extent of POP pollution in the Guiyang soil and can help authorities establish environmental protection regulations and soil remediation techniques. [ABSTRACT FROM AUTHOR]

As a group of diversified frameworks, quinazolin derivatives displayed a broad field of biological functions, especially as anticancer. To investigate the quantitative structure-activity relationship, 3D-QSAR models were generated with 24 quinazolin scaffold molecules. The experimental and predicted pIC50 values for both training and test set compounds showed good correlation, which proved the robustness and reliability of the generated QSAR models. The most effective CoMFA and CoMSIA were obtained with correlation coefficient r2ncv of 1.00 (both) and leave-one-out coefficient q2 of 0.61 and 0.59, respectively. The predictive abilities of CoMFA and CoMSIA were quite good with the predictive correlation coefficients (r2pred) of 0.97 and 0.91. In addition, the statistic results of CoMFA and CoMSIA were used to design new quinazolin molecules. [ABSTRACT FROM AUTHOR]

To accelerate face-gear engineering application, a precision grinding method for complex surface of aero face-gear is provided in this paper. Based on the principle of face-gear drive, the principle of face-gear grinding by disc wheel is analyzed, and the tooth surface equation of the face-gear is calculated with coordinate transformations. Taking the grinding needs into account, a special machine tool is developed, and movements control method of face-gear grinding by the disc wheel on the machine tool is proposed. To ensure the correct tooth profile of the disc wheel, the method of wheel dressing is provided and the optimum design methods of CNC cutter sites and step sizes selection are provided. To verify the feasibility of the grinding method for face-gear, the simulation of face-gear grinding by disc wheel is performed based on VERICUT software according to the grinding method. The experiments of face-gear grinding and the wheel dressing are carried out finally, and the results show that it is feasible for face-gear grinding using the involute disc wheel and the special machine tool. [ABSTRACT FROM AUTHOR]