Hierarchical Cu2O/CuO/Co3O4 core-shell nanowires: synthesis and electrochemical properties.

We prepared hierarchical Cu2O/CuO/Co3O4 core-shell nanowires (NWs) via a facile chemical deposition method followed by calcination for use as the electrode of supercapacitors. The Cu2O/CuO/Co3O4 electrode showed a specific capacitance of 318 F g(-1) at a current density of 0.5 A g(-1). 80% of the original specific capacitance was retained after 3000 cycles at a current density of 5 A g(-1). An asymmetric supercapacitor cell using Cu2O/CuO/Co3O4 NWs as the positive electrode and activated graphene as the negative electrode exhibited a maximum energy density of 12 Wh kg(-1). The electrochemical properties of the electrode were strongly related to the hierarchical nanostructure, which not only provided rich active sites but also shortened ion transport pathways.

[Subhabitat selection and differences of diet composition for Acanthogobius ommaturus in the Dongtan wetland of the Yangtze estuary, China]. / é•¿æ±Ÿå£ä¸œæ»©æ¹¿åœ°æ–‘å°¾åˆºè™¾è™Žé±¼çš„æ –æ¯äºšç”Ÿå¢ƒé€‰æ‹©å’Œé£Ÿæ€§å·®å¼‚.

We examined the temporal and spatial variation in the abundance and diet composition of Acanthogobius ommaturus at three subhabitats (mudflat, salt marsh, and creek) of the Dongtan wetland of Yangtze Estuary with monthly field samplings from July 2015 to June 2016. The results showed that the samples of A. ommaturus were mainly composed of young individuals in the period of June-November, whereas no fish was collected during the other months. Most of the samples were collected in July (71) and only three individuals was collected in November. Most of the samples were collected (93) in creek, which was 5.2 and 4.9 times of those in mudflat and salt marsh, respectively. The diet of the A. ommaturus included 10 taxa and 30 prey species, dominated by shrimps. In the taxonomic level, the dominant preys were the Exopalaemon annandalei or other Exopalaemon sp. of shrimps, the Sesarma sp. of crabs and Micromecta quadriseta of insects. Compared with other taxonomic groups, the fish prey had relatively higher mass percentage but lower abundance percentage. The prey composition of A. ommaturus differed among subhabitats. The feeding level of A. ommaturus increased gradually from July to November and reached 3.0 in late autumn. The differences in the abundances of A. ommaturus among subhabitats would be induced by prey composition.