a b s t r a c tSeasonal coagulation objectives for a typical North-China water treatment plant with micro-polluted and high alkalinity source waters are proposed in this paper. These are based on a yearlong data collection period where raw water characteristics, trihalomethanes formation potential (THMFP) and coagulation features were investigated using a jar test procedure, resin absorption and ultrafiltration fractionations. Three approaches beyond simply increasing the coagulant dose were used to achieve optimized coagulation. One is coagulation by adjusting the pH of the raw water when metal salt coagulants (FeCl 3 and AlCl 3 ) are used. At pH levels of about 5.0 for FeCl 3 and about 5.8 for AlCl 3 , the highest removal of natural organic matter (NOM) was obtained, which is twice that without pH control. The second is enhanced coagulation through coagulant optimization based on raw water characteristics. A high efficient composite polyaluminum chloride (HPAC) coagulant was developed for the water taking the advantages of polyaluminum chloride (PACl) and other additives. HPAC exhibited 30% more efficiency than AlCl 3 , FeCl 3 and polyaluminum chloride (PACl) in dissolved organic carbon (DOC) removal and was also very effective in turbidity removal. The third is enhanced softening with coagulant addition. Higher removal of NOM is achieved by enhanced softening with coagulant addition conditions as compared with conventional coagulation at natural pH. Especially with PACl addition, it can enhance the formation of Mg(OH) 2 precipitate and remove NOM efficiently at a relatively lower pH range (pH < 10). By this approach, the pH for enhanced softening can be decreased significantly into a practical operation pH range for high-hardness water at a treatment plant.

There is some research showing that social anxiety is related with attentional bias to threat. However, others fail to find this relationship and propose that gender differences may play a role. The aim of this study was to investigate the gender differences in the subcomponents of attentional bias to threat (hypervigilance and difficulty in disengaging) among children and adolescents with social anxiety. Overall, 181 youngsters aged between 10 and 14 participated in the current study. Images of disgusted faces were used as threat stimuli in an Exogenous Cueing Task was used to measure the subcomponents of attentional bias. Additionally, the Social Anxiety Scale for Children was used to measure social anxiety. The repeated measures ANOVA showed that male participants with high social anxiety showed difficulty in disengaging from threat, but this was not the case for female participants. Our results indicated that social anxiety is more related with attentional bias to threat among male children and adolescents than females. These findings suggested that developing gender-specific treatments for social anxiety may improve treatment effects.

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Developing a mild and efficient method for highly selective amination of alcohols to amines as important versatile compounds is very interesting in the organic synthesis field. In this work, we have developed a simple and efficient approach for high-yield preparation of cyclohexylamine from the vapor-phase catalytic amination of cyclohexanol with ammonia under atmospheric pressure. The results indicated that the hydrotalcite-derived NiCu/MgAlO alloy catalyst exhibited excellent catalytic performance and stability, and 98% cyclohexanol conversion with 95% selectivity toward cyclohexylamine had still been maintained after running for over 300 h at 170 °C. The super high activity and stability of the NiCu/MgAlO catalyst are attributed to the active Ni–Cu alloy nanoparticles with high dispersion and uniform particle size (about 4 nm). DFT calculation results indicated the Ni site of the NiCu alloy (111) facet as the main catalytic active site. The energy profiles for the potential comparative free energy of cyclohexanol to cyclohexylamine on the NiCu alloy (111) facet were calculated. This approach employing a highly dispersed and stable Ni–Cu bimetallic alloy catalyst for efficient amination of cyclohexanol to cyclohexylamine in the vapor phase is promising and has potential industrial application prospects. Especially, the designed Ni–Cu alloy catalyst can also be applied in the amination of other alcohols with ammonia to prepare the corresponding organic amines.

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